- Email: [email protected]
Can We Predict the Outcomes of National Colorectal Cancer Screening and Can Predictions Help Us Plan?
GASTROENTEROLOGY 2005;129:1339 –1347
EDITORIALS Can We Predict the Outcomes of National Colorectal Cancer Screening and Can Predictions Help Us Plan? See article on page 1151.
he importance of colorectal cancer screening is becoming more widely recognized by the public and by medical and public health communities. Screening rates are beginning to increase,1,2 and a growing number of organizations, including local medical communities, state health departments, and federal agencies are in various stages of planning for organized and widespread colorectal cancer screening programs. The ability to anticipate the clinical and economic outcomes of widespread screening, as well as its consequences for health care delivery, would greatly benefit those involved in the planning such programs. In particular, issues of cost and capacity are critical to many planning efforts. In this issue of GASTROENTEROLOGY, Ladabaum and Song3 provide information that might be used in such a planning process. Using a natural history colorectal cancer model, with various screening scenarios superimposed over the model, they predicted a wide range of outcomes that might result from widespread colorectal cancer screening of the US population. They used model outcomes to try to answer some overarching questions: How will widespread screening affect colorectal cancer incidence and mortality rates? How will it affect overall national colorectal cancer-related health care costs? Will currently estimated numbers of endoscopic procedures performed be enough to meet the demand generated by sustained widespread screening? The authors began with a previously described4 –7 model of the natural history of colorectal cancer that predicts the progression through colorectal cancer health states in the absence of screening over a 50-year period (from age 50 to 100 or death). They then superimposed screening over this natural history model, for persons 50 – 80, with different screening strategies, using “conventional” screening tests–annual fecal occult blood testing (FOBT), sigmoidoscopy every 5 years, FOBT and sigmoidoscopy combined, and colonoscopy every 10 years—and “emerging strategies”—fecal DNA every 5 years and CT-colonography (virtual colonoscopy) every 10 years. Follow-up and surveillance colonoscopies were accounted for in the model. They assumed a cost for each
T
of the screening tests, an average cost for colonoscopy complications, and took a societal perspective. Where test costs for the newer tests were unknown, they referred to the literature.3,8 Model outcomes included the number of colorectal cancers detected by stage, death by cause, discounted, and undiscounted average life-years, the cost per person, and the number and type of tests performed in each screening test strategy. They assumed a compliance rate of 75% for each screening strategy and a steady state for the population growth and age distribution. They compared numbers of needed tests predicted to recently estimated endoscopic procedural utilization rates9 to explore whether supply could meet demand in the steady state. Clinical and cost outcomes from the model, in both a natural history setting and in various screening settings, were projected and compared. Disease projections showed a decrease in colorectal cancer incidence and mortality similar to what has been shown in published case control and randomized trials.10 –15 Cost projections, with assumed screening take-up rate of 75%, showed that for any of the screening tests used, total colorectal cancer-related expenditures for the screened population were higher than those expenditures for the unscreened population, because any savings in colorectal cancer treatment costs for the screened population caused by early detection were offset by screening costs. Numbers of tests needed in each screening scenario were estimated and compared with numbers of tests being performed nationally as recently reported,9,16 to try to estimate the endoscopic capacity to sustain screening over the life of the model. Results showed that the current colonoscopic capacity would be able to sustain population screening over time. The authors’ stated goal was to provide information for use regionally and nationally to help guide policy regarding colorectal cancer screening. Colorectal cancer screening is an extremely dynamic area, and it may therefore be particularly difficult to make projections regarding colorectal cancer screening outcomes based solely on modeling efforts. Issues like which of the currently recommended screening tests, if any, will become most commonly recommended; how well the newer screening tests will be received by the public and
1340
EDITORIALS
health care providers; test costs; and reimbursement rates are all still in flux. Additionally, there are inherent limitations in using any model to predict outcomes and guide public health planning since a model relies completely on the assumptions on which it is designed; if those assumptions are inaccurate, the model conclusions may not be robust. Despite these general modeling limitations, this study asks the relevant questions being considered by public health planners, clinicians, and policy makers, in particular regarding the overall costs and endoscopic capacity to provide widespread screening. However, full answers may not yet be available, in part because of the effect of model assumptions on results, and in part because these issues are still too uncertain. The handling of cost and capacity in this model, and their potential to guide planning, deserve particular attention. In terms of cost, a key conclusion is that nationally, colorectal cancer screening is unlikely to be cost-savings, and treatment costs are estimated in this study to be between $3.6 –$8.0 billion, roughly in line with other analyses, when adjusted for inflation.17 However, since some cost projections were based on assumed test costs and may have been overestimates when compared with national reimbursement rates (particularly FOBT costs18,19), the model may have projected lower cost savings than could be realized. FOBT-based programs remain appealing in many settings because of the low cost of FOBT, as well as ready test availability and the strength of evidence that supports its effectiveness; FOBT is 1 of 4 screening tests currently recommended by national organizations.20 –22 Another assumption that may have influenced cost outcomes is that this model assumed a steady population growth and age distribution. In fact, the US population ⬎50 is growing rapidly. From 1990 to 2000, the population in this age group grew at nearly twice the rate of the population under age 50 years (20.6% versus 10.6%),23 a trend expected to continue as the population ages and life expectancies increase.24 Using a static population growth rate and age distribution, and a high screening take-up rate of 75%, the analysis may have underestimated colorectal cancer disease burden and cost. If higher numbers of cancers were detected than predicted in this model, subsequent treatment costs might then increase. Ladabaum and Song3 showed that widespread colorectal cancer screening may not be cost-saving to society as a whole, but from a planning perspective, it might be useful to consider this issue by health care sector, since there is an unequal cost impact to different sectors. Costs to private and other pre-Medicare payers may increase
GASTROENTEROLOGY Vol. 129, No. 4
with widespread screening and early detection, while Medicare may save money if 50 – 64 year olds are screened and treated before becoming eligible for Medicare. As local communities continue to partner with these different health care sectors and plan for how they will allocate costs for colorectal cancer screening and project long-term expenditures, they may consider this unequal cost burden by the different sectors as they seek ways to more widely cover screening. The conclusion that current colonoscopic capacity may be sufficient to support widespread screening also needs to be examined. In contrast, a recent study, which did not look at screening in a steady state, suggested that endoscopy resources would be limited in providing for immediate screening of the unscreened US population.9,16 The CDC is in the process of trying to describe the national capacity to screen for colorectal cancer, given that we are not yet in a “steady state” but rather are trying to provide “catch-up screening” to a large segment of the population that has not received any screening. As a first step in trying to understand capacity, we estimated numbers of endoscopic tests being performed for colorectal cancer screening in a single year,16 and then used a static forecasting model to estimate the number of unscreened persons at a single point in time.16 We compared currently available volumes to test need under a series of scenarios, to measure the capacity to provide “catch-up” screening to the unscreened. There was sufficient immediate endoscopic capacity if widespread screening was conducted with FOBT, using colonoscopy only for follow-up of positive FOBTs, but insufficient capacity to provide screening colonoscopy to all unscreened within a year. In order to provide primary endoscopic screening with resources immediately available, screening services would need to be provided over an extended period of time, between 5–10 years. This amount of time may well be acceptable, but each planning organization would need to decide individually, based in part on local resources. This was only the initial step in describing the national capacity picture. Our next step is assessing the capacity to sustain screening over a 10-year period of time. Addressing dynamic features such as the rate and distribution of growth of the population 50 years and older, compliance with colorectal cancer screening and uptake, the number of follow-up diagnostic tests and re-screens needed over time should provide a better estimate of screening capacity over time. While it is possible that this kind of analysis may show that colonoscopy capacity will be sufficient to sustain screening over time, we do not yet know this. Repeat estimates of
October 2005
endoscopic utilization will provide the ability to estimate how utilization will continue to compare with need. One critical unknown addressed by Ladabaum and Song3 is how newer screening tests will fold into the mix of screening test options. That remains a question that will have to unfold over time, and will depend on further evidence about their effectiveness, patient acceptance, and cost. The issue of capacity to sustain widespread screening over time necessarily cannot be fully understood until these issues have evolved over time. Ultimately, as the authors suggest, real-world data is needed to truly understand the clinical cost and health delivery outcomes of widespread screening. Such data are beginning to accumulate, as opportunistic screening continues and as more examples of organized screening programs appear.25,26 CDC has just funded 5 demonstration colorectal cancer screening programs to begin organized colorectal cancer screening in spring 2005.27 These community-based screening programs were given flexibility in program design and choice of test, including those recommended by United States Preventive Services Task Force,20 as well as fecal immunochemical testing, and among the various sites, chose to use a combination of screening tests to reach their populations. Clinical, cost, and programmatic outcomes will be closely followed and evaluated. With this variety in test choice and in health care setting, we will be able to observe and measure compliance rates and variation in test costs in a variety of settings and using a variety of tests, and we will be able to observe how measured capacity relates to the ability to sustain widespread screening. Each of the outcomes estimated in the modeling effort by Ladabaum will be measured throughout these demonstration screening programs, adding real world data to projections being generated through models. As organized screening continues to build, many of the issues raised in the model will need to be watched closely. Capacity will need to be built over time, and in some regions more than others. Costs will influence test choice, as will patient and physician preference and safety. With careful planning, measurement of the capacity and attention to test costs, it should be possible to design widespread cost-effective colorectal cancer screening programs that reduce colorectal cancer disease burden. LAURA C. SEEFF FLORENCE K. L. TANGKA Division of Cancer Prevention and Control Centers for Disease Control and Prevention Atlanta, Georgia
EDITORIALS
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References 1. Centers for Disease Control and Prevention. Colorectal cancer test use among persons aged ⱖ50 years–United States, 2001. MMWR Morb Mortal Wkly Rep 2003;52:193–196. 2. Seeff LC, Nadel MR, Klabunde C, Thompson T, Shapiro JA, Vernon SW, Coates RJ. Patterns and predictors of colorectal cancer test use in the adult US population. Cancer 2004;100: 2093–2103. 3. Ladabaum U, Song K. Projected national impact of colorectal cancer screening on clinical and economic outcomes and health services demand. Gastroenterology 2005;129:1151-1163. 4. Song K, Fendrick AM, Ladabaum U. Fecal DNA testing compared to conventional colorectal cancer screening methods: a decision analysis. Gastroenterology 2004;126:1270 –1279. 5. Ladabaum U, Song K, Fendrick AM. Colorectal neoplasia screening with virtual colonoscopy: when, at what cost, and with what national impact? Clin Gastroenterol Hepatol 2004;2:554 –563. 6. Ladabaum U, Chopra CL, Huang G, Scheiman JM, Chernew ME, Fendrick AM. Aspirin as an adjunct to screening for prevention of sporadic colorectal cancer. A cost-effectiveness analysis. Ann Intern Med 2001;135:769 –781. 7. Ladabaum U, Scheiman JM, Fendrick AM. Potential effect of cyclooxgenase-2-specific inhibitors on the prevention of colorectal cancer: a cost effectiveness analysis. Am J Med 2003;114: 546 –554. 8. Syngal S, Chung D, Willet C, Schoetz D, Schroy P, Stoffel E, Jagadeesh D, Morel K, Ross M. The loss of stool DNA mutation abnormalities in colorectal neoplasia after treatment. Gastroenterology 2003;124:A5. 9. Seeff LC, Richards TB, Shapiro JA, Nadel MR, Manninen DL, Given LS, Dong FB, Winges LD, McKenna MT. How many endoscopies are performed for colorectal cancer screening? Results from CDC’s survey of endoscopic capacity. Gastroenterology 2004;127:1670 –1677. 10. Mandel JS, Church TR, Bond JH, Ederer F, Geisser MS, Mongin SJ, Snover DC, Schuman LM. The effect of fecal occult-blood screening on the incidence of colorectal cancer. N Engl J Med 2000;343:1603–1607. 11. Mandel JS, Bond JH, Church TR, et al. Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. N Engl J Med 1993;328:1365– 1371. 12. Selby JV, Friedman GD, Quesenberry CP Jr, Weiss NS. A casecontrol study of screening sigmoidoscopy and mortality from colorectal cancer. N Engl J Med 1992;326:653– 657. 13. Newcomb PA, Norfleet RG, Storer BE, Surawicz TS, Marcus PM. Screening sigmoidoscopy and colorectal cancer mortality. J Natl Cancer Inst 1992;84:1572–1575. 14. Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar SS, Balfour TW, James PD, Mangham CM. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet 1996;348:1472–1477. 15. Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecaloccult-blood test. Lancet 1996;348:1467–1471. 16. Seeff LC, Manninen D, Dong F, Chattapodhyay SK, Nadel MR, Tangka F, Molinari N. Is there endoscopic capacity to provide colorectal cancer screening to the unscreened population in the United States? Gastroenterology 2004;127:1661–1669. 17. Schrag D, Weeks J. Costs and cost-effectiveness of colorectal cancer prevention and therapy. Semin Oncol 1999;26:561–568. 18. Centers for Medicare & Medicaid Services. HCPC: Step 1. Available at: http://www.cms.hhs.gov/physicians/mpfsapp/step1. asp. Accessed August 18, 2005 19. Centers for Medicare and Medicaid Services. CMS files for download for Medicare payment systems. Available at: http://www.
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20.
21.
22.
23.
24.
EDITORIALS
cms.hhs.gov/providers/pufdownload/default.asp#labfee. Accessed August 18, 2005 U.S. Preventive Services Task Force. Screening for Colorectal Cancer: Recommendations and Rationale. July 2002. Agency for Healthcare Research and Quality, Rockville, MD. Available at: http://www.ahrq.gov/clinic/3rduspstf/colorectal/colorr.htm. Accessed August 24, 2005. Winawer SJ, Fletcher RH, Rex D, et al. Colorectal cancer screening and surveillance: clinical guidelines and rationale— updated based on new evidence. Gastroenterology 2003;124:544 –560. Smith RA, von Eschenbach AC, Wender R, et al. American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. CA Cancer J Clin 2001;51:38 –75. U.S. Census Bureau. Census 2000 summary file 1; 1990 census population, general population characteristics, United States (1990 CP-1-1), a trend expected to continue as the population ages and life expectancies increase. Day J. Population Projections of the United States by Age, Sex, Race, and Hispanic Origin: 1995 to 2050, U.S. Bureau of the Census, Current Population Reports, P25-1130. Washington, DC: U.S. Government Printing Office; 1996.
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25. New York State Department of Health. New York State cancer services. Available at: http://www.health.state.ny.us/nysdoh/ cancer/center/cancer_services.htm. Accessed August 19, 2005. 26. Palitz AM, Selby JV, Grossman S, Finkler LJ, Bevc M, Kehr C, Conell CA. The Colon Cancer Prevention Program (CoCaP): rationale, implementation, and preliminary results. HMO Pract 1997; 11:5–12. 27. U.S. Government Printing Office (GPO Access). Federal Register: http://frwebgate.access.gpo.gov/cgi-bin/multidb.cgi. Accessed August 25, 2005.
Address reprint requests to: Laura C. Seeff, MD, Centers for Disease Control and Prevention, DCPC, 4770 Buford Highway, NE, Mailstop K-55, Atlanta, Georgia 30341-3717. e-mail: [email protected]; fax: (770) 488-4639. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. © 2005 by the American Gastroenterological Association 0016-5085/05/$30.00 doi:10.1053/j.gastro.2005.08.048
The Tipping Point: Balancing the Risks and Benefits of Screening in the Elderly See article on page 1163.
andomized controlled trials show the mortality benefits of colorectal cancer screening for adults ages 50 –70,1–3 and practice guidelines recommend regular screening for all adults at average risk.4 Although the guidelines are nearly unanimous in recommending screening starting at age 50, there are no clear guidelines about when to stop screening. As the population ages, and as interest in colon cancer screening increases, clinicians will increasingly face decisions about whether elderly individuals are candidates for screening. The article by Ko and Sonnenberg5 in this issue of GASTROENTEROLOGY provides some guidance. Although colorectal cancer is more common after age 70, the potential benefits from colorectal cancer screening in adults over age 70 are less certain. Few trials have included adequate numbers of adults over age 70 so the potential benefits must be extrapolated from evidence in younger populations.6,7 These data indicate that older adults are not equally likely to realize a net mortality benefit from screening. The benefits do not accrue until 5 or more years after screening, and competing causes of mortality may be an issue for the elderly. Furthermore, adults over age 70 who are in poor health may have more screening complications than those who are younger.8 Therefore, age, health status, and life expectancy are all
R
important factors in determining who is likely to benefit.7,9,10 Accordingly, clinical practice guidelines state that it is reasonable to consider discontinuing colon cancer screening in the elderly. The United States Preventive Services Task Force states that it is reasonable to discontinue screening in those patients whose age and comorbid conditions limit life expectancy.4 The American Cancer Society states that discontinuing screening is reasonable in persons with significant comorbidity that would preclude treatment.11 The American Geriatrics Society recommends against screening elderly who are too frail to undergo colonoscopy and in persons with short life expectancy (3–5 years).12 These guidelines support individualized decision making for colon cancer screening in the elderly and put the onus on physicians to determine who is likely to benefit from screening and who is not. For physicians to make these determinations, information about the risks and benefits of screening is needed for patients with different life expectancies. Recently, Mandleblatt et al13 published a cost effectiveness analyses for breast cancer screening in elderly women that addresses cancer screening in the elderly from the societal perspective. The article by Ko and Sonneberg5 in this issue of GASTROENTEROLOGY addresses colorectal cancer screening in patients ages 70 and older but with the intent of providing information to be used clinically to aid decision making at the patient level.
EDITORIALS Can We Predict the Outcomes of National Colorectal Cancer Screening and Can Predictions Help Us Plan? See article on page 1151.
he importance of colorectal cancer screening is becoming more widely recognized by the public and by medical and public health communities. Screening rates are beginning to increase,1,2 and a growing number of organizations, including local medical communities, state health departments, and federal agencies are in various stages of planning for organized and widespread colorectal cancer screening programs. The ability to anticipate the clinical and economic outcomes of widespread screening, as well as its consequences for health care delivery, would greatly benefit those involved in the planning such programs. In particular, issues of cost and capacity are critical to many planning efforts. In this issue of GASTROENTEROLOGY, Ladabaum and Song3 provide information that might be used in such a planning process. Using a natural history colorectal cancer model, with various screening scenarios superimposed over the model, they predicted a wide range of outcomes that might result from widespread colorectal cancer screening of the US population. They used model outcomes to try to answer some overarching questions: How will widespread screening affect colorectal cancer incidence and mortality rates? How will it affect overall national colorectal cancer-related health care costs? Will currently estimated numbers of endoscopic procedures performed be enough to meet the demand generated by sustained widespread screening? The authors began with a previously described4 –7 model of the natural history of colorectal cancer that predicts the progression through colorectal cancer health states in the absence of screening over a 50-year period (from age 50 to 100 or death). They then superimposed screening over this natural history model, for persons 50 – 80, with different screening strategies, using “conventional” screening tests–annual fecal occult blood testing (FOBT), sigmoidoscopy every 5 years, FOBT and sigmoidoscopy combined, and colonoscopy every 10 years—and “emerging strategies”—fecal DNA every 5 years and CT-colonography (virtual colonoscopy) every 10 years. Follow-up and surveillance colonoscopies were accounted for in the model. They assumed a cost for each
T
of the screening tests, an average cost for colonoscopy complications, and took a societal perspective. Where test costs for the newer tests were unknown, they referred to the literature.3,8 Model outcomes included the number of colorectal cancers detected by stage, death by cause, discounted, and undiscounted average life-years, the cost per person, and the number and type of tests performed in each screening test strategy. They assumed a compliance rate of 75% for each screening strategy and a steady state for the population growth and age distribution. They compared numbers of needed tests predicted to recently estimated endoscopic procedural utilization rates9 to explore whether supply could meet demand in the steady state. Clinical and cost outcomes from the model, in both a natural history setting and in various screening settings, were projected and compared. Disease projections showed a decrease in colorectal cancer incidence and mortality similar to what has been shown in published case control and randomized trials.10 –15 Cost projections, with assumed screening take-up rate of 75%, showed that for any of the screening tests used, total colorectal cancer-related expenditures for the screened population were higher than those expenditures for the unscreened population, because any savings in colorectal cancer treatment costs for the screened population caused by early detection were offset by screening costs. Numbers of tests needed in each screening scenario were estimated and compared with numbers of tests being performed nationally as recently reported,9,16 to try to estimate the endoscopic capacity to sustain screening over the life of the model. Results showed that the current colonoscopic capacity would be able to sustain population screening over time. The authors’ stated goal was to provide information for use regionally and nationally to help guide policy regarding colorectal cancer screening. Colorectal cancer screening is an extremely dynamic area, and it may therefore be particularly difficult to make projections regarding colorectal cancer screening outcomes based solely on modeling efforts. Issues like which of the currently recommended screening tests, if any, will become most commonly recommended; how well the newer screening tests will be received by the public and
1340
EDITORIALS
health care providers; test costs; and reimbursement rates are all still in flux. Additionally, there are inherent limitations in using any model to predict outcomes and guide public health planning since a model relies completely on the assumptions on which it is designed; if those assumptions are inaccurate, the model conclusions may not be robust. Despite these general modeling limitations, this study asks the relevant questions being considered by public health planners, clinicians, and policy makers, in particular regarding the overall costs and endoscopic capacity to provide widespread screening. However, full answers may not yet be available, in part because of the effect of model assumptions on results, and in part because these issues are still too uncertain. The handling of cost and capacity in this model, and their potential to guide planning, deserve particular attention. In terms of cost, a key conclusion is that nationally, colorectal cancer screening is unlikely to be cost-savings, and treatment costs are estimated in this study to be between $3.6 –$8.0 billion, roughly in line with other analyses, when adjusted for inflation.17 However, since some cost projections were based on assumed test costs and may have been overestimates when compared with national reimbursement rates (particularly FOBT costs18,19), the model may have projected lower cost savings than could be realized. FOBT-based programs remain appealing in many settings because of the low cost of FOBT, as well as ready test availability and the strength of evidence that supports its effectiveness; FOBT is 1 of 4 screening tests currently recommended by national organizations.20 –22 Another assumption that may have influenced cost outcomes is that this model assumed a steady population growth and age distribution. In fact, the US population ⬎50 is growing rapidly. From 1990 to 2000, the population in this age group grew at nearly twice the rate of the population under age 50 years (20.6% versus 10.6%),23 a trend expected to continue as the population ages and life expectancies increase.24 Using a static population growth rate and age distribution, and a high screening take-up rate of 75%, the analysis may have underestimated colorectal cancer disease burden and cost. If higher numbers of cancers were detected than predicted in this model, subsequent treatment costs might then increase. Ladabaum and Song3 showed that widespread colorectal cancer screening may not be cost-saving to society as a whole, but from a planning perspective, it might be useful to consider this issue by health care sector, since there is an unequal cost impact to different sectors. Costs to private and other pre-Medicare payers may increase
GASTROENTEROLOGY Vol. 129, No. 4
with widespread screening and early detection, while Medicare may save money if 50 – 64 year olds are screened and treated before becoming eligible for Medicare. As local communities continue to partner with these different health care sectors and plan for how they will allocate costs for colorectal cancer screening and project long-term expenditures, they may consider this unequal cost burden by the different sectors as they seek ways to more widely cover screening. The conclusion that current colonoscopic capacity may be sufficient to support widespread screening also needs to be examined. In contrast, a recent study, which did not look at screening in a steady state, suggested that endoscopy resources would be limited in providing for immediate screening of the unscreened US population.9,16 The CDC is in the process of trying to describe the national capacity to screen for colorectal cancer, given that we are not yet in a “steady state” but rather are trying to provide “catch-up screening” to a large segment of the population that has not received any screening. As a first step in trying to understand capacity, we estimated numbers of endoscopic tests being performed for colorectal cancer screening in a single year,16 and then used a static forecasting model to estimate the number of unscreened persons at a single point in time.16 We compared currently available volumes to test need under a series of scenarios, to measure the capacity to provide “catch-up” screening to the unscreened. There was sufficient immediate endoscopic capacity if widespread screening was conducted with FOBT, using colonoscopy only for follow-up of positive FOBTs, but insufficient capacity to provide screening colonoscopy to all unscreened within a year. In order to provide primary endoscopic screening with resources immediately available, screening services would need to be provided over an extended period of time, between 5–10 years. This amount of time may well be acceptable, but each planning organization would need to decide individually, based in part on local resources. This was only the initial step in describing the national capacity picture. Our next step is assessing the capacity to sustain screening over a 10-year period of time. Addressing dynamic features such as the rate and distribution of growth of the population 50 years and older, compliance with colorectal cancer screening and uptake, the number of follow-up diagnostic tests and re-screens needed over time should provide a better estimate of screening capacity over time. While it is possible that this kind of analysis may show that colonoscopy capacity will be sufficient to sustain screening over time, we do not yet know this. Repeat estimates of
October 2005
endoscopic utilization will provide the ability to estimate how utilization will continue to compare with need. One critical unknown addressed by Ladabaum and Song3 is how newer screening tests will fold into the mix of screening test options. That remains a question that will have to unfold over time, and will depend on further evidence about their effectiveness, patient acceptance, and cost. The issue of capacity to sustain widespread screening over time necessarily cannot be fully understood until these issues have evolved over time. Ultimately, as the authors suggest, real-world data is needed to truly understand the clinical cost and health delivery outcomes of widespread screening. Such data are beginning to accumulate, as opportunistic screening continues and as more examples of organized screening programs appear.25,26 CDC has just funded 5 demonstration colorectal cancer screening programs to begin organized colorectal cancer screening in spring 2005.27 These community-based screening programs were given flexibility in program design and choice of test, including those recommended by United States Preventive Services Task Force,20 as well as fecal immunochemical testing, and among the various sites, chose to use a combination of screening tests to reach their populations. Clinical, cost, and programmatic outcomes will be closely followed and evaluated. With this variety in test choice and in health care setting, we will be able to observe and measure compliance rates and variation in test costs in a variety of settings and using a variety of tests, and we will be able to observe how measured capacity relates to the ability to sustain widespread screening. Each of the outcomes estimated in the modeling effort by Ladabaum will be measured throughout these demonstration screening programs, adding real world data to projections being generated through models. As organized screening continues to build, many of the issues raised in the model will need to be watched closely. Capacity will need to be built over time, and in some regions more than others. Costs will influence test choice, as will patient and physician preference and safety. With careful planning, measurement of the capacity and attention to test costs, it should be possible to design widespread cost-effective colorectal cancer screening programs that reduce colorectal cancer disease burden. LAURA C. SEEFF FLORENCE K. L. TANGKA Division of Cancer Prevention and Control Centers for Disease Control and Prevention Atlanta, Georgia
EDITORIALS
1341
References 1. Centers for Disease Control and Prevention. Colorectal cancer test use among persons aged ⱖ50 years–United States, 2001. MMWR Morb Mortal Wkly Rep 2003;52:193–196. 2. Seeff LC, Nadel MR, Klabunde C, Thompson T, Shapiro JA, Vernon SW, Coates RJ. Patterns and predictors of colorectal cancer test use in the adult US population. Cancer 2004;100: 2093–2103. 3. Ladabaum U, Song K. Projected national impact of colorectal cancer screening on clinical and economic outcomes and health services demand. Gastroenterology 2005;129:1151-1163. 4. Song K, Fendrick AM, Ladabaum U. Fecal DNA testing compared to conventional colorectal cancer screening methods: a decision analysis. Gastroenterology 2004;126:1270 –1279. 5. Ladabaum U, Song K, Fendrick AM. Colorectal neoplasia screening with virtual colonoscopy: when, at what cost, and with what national impact? Clin Gastroenterol Hepatol 2004;2:554 –563. 6. Ladabaum U, Chopra CL, Huang G, Scheiman JM, Chernew ME, Fendrick AM. Aspirin as an adjunct to screening for prevention of sporadic colorectal cancer. A cost-effectiveness analysis. Ann Intern Med 2001;135:769 –781. 7. Ladabaum U, Scheiman JM, Fendrick AM. Potential effect of cyclooxgenase-2-specific inhibitors on the prevention of colorectal cancer: a cost effectiveness analysis. Am J Med 2003;114: 546 –554. 8. Syngal S, Chung D, Willet C, Schoetz D, Schroy P, Stoffel E, Jagadeesh D, Morel K, Ross M. The loss of stool DNA mutation abnormalities in colorectal neoplasia after treatment. Gastroenterology 2003;124:A5. 9. Seeff LC, Richards TB, Shapiro JA, Nadel MR, Manninen DL, Given LS, Dong FB, Winges LD, McKenna MT. How many endoscopies are performed for colorectal cancer screening? Results from CDC’s survey of endoscopic capacity. Gastroenterology 2004;127:1670 –1677. 10. Mandel JS, Church TR, Bond JH, Ederer F, Geisser MS, Mongin SJ, Snover DC, Schuman LM. The effect of fecal occult-blood screening on the incidence of colorectal cancer. N Engl J Med 2000;343:1603–1607. 11. Mandel JS, Bond JH, Church TR, et al. Reducing mortality from colorectal cancer by screening for fecal occult blood. Minnesota Colon Cancer Control Study. N Engl J Med 1993;328:1365– 1371. 12. Selby JV, Friedman GD, Quesenberry CP Jr, Weiss NS. A casecontrol study of screening sigmoidoscopy and mortality from colorectal cancer. N Engl J Med 1992;326:653– 657. 13. Newcomb PA, Norfleet RG, Storer BE, Surawicz TS, Marcus PM. Screening sigmoidoscopy and colorectal cancer mortality. J Natl Cancer Inst 1992;84:1572–1575. 14. Hardcastle JD, Chamberlain JO, Robinson MH, Moss SM, Amar SS, Balfour TW, James PD, Mangham CM. Randomised controlled trial of faecal-occult-blood screening for colorectal cancer. Lancet 1996;348:1472–1477. 15. Kronborg O, Fenger C, Olsen J, Jorgensen OD, Sondergaard O. Randomised study of screening for colorectal cancer with faecaloccult-blood test. Lancet 1996;348:1467–1471. 16. Seeff LC, Manninen D, Dong F, Chattapodhyay SK, Nadel MR, Tangka F, Molinari N. Is there endoscopic capacity to provide colorectal cancer screening to the unscreened population in the United States? Gastroenterology 2004;127:1661–1669. 17. Schrag D, Weeks J. Costs and cost-effectiveness of colorectal cancer prevention and therapy. Semin Oncol 1999;26:561–568. 18. Centers for Medicare & Medicaid Services. HCPC: Step 1. Available at: http://www.cms.hhs.gov/physicians/mpfsapp/step1. asp. Accessed August 18, 2005 19. Centers for Medicare and Medicaid Services. CMS files for download for Medicare payment systems. Available at: http://www.
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20.
21.
22.
23.
24.
EDITORIALS
cms.hhs.gov/providers/pufdownload/default.asp#labfee. Accessed August 18, 2005 U.S. Preventive Services Task Force. Screening for Colorectal Cancer: Recommendations and Rationale. July 2002. Agency for Healthcare Research and Quality, Rockville, MD. Available at: http://www.ahrq.gov/clinic/3rduspstf/colorectal/colorr.htm. Accessed August 24, 2005. Winawer SJ, Fletcher RH, Rex D, et al. Colorectal cancer screening and surveillance: clinical guidelines and rationale— updated based on new evidence. Gastroenterology 2003;124:544 –560. Smith RA, von Eschenbach AC, Wender R, et al. American Cancer Society guidelines for the early detection of cancer: update of early detection guidelines for prostate, colorectal, and endometrial cancers. CA Cancer J Clin 2001;51:38 –75. U.S. Census Bureau. Census 2000 summary file 1; 1990 census population, general population characteristics, United States (1990 CP-1-1), a trend expected to continue as the population ages and life expectancies increase. Day J. Population Projections of the United States by Age, Sex, Race, and Hispanic Origin: 1995 to 2050, U.S. Bureau of the Census, Current Population Reports, P25-1130. Washington, DC: U.S. Government Printing Office; 1996.
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25. New York State Department of Health. New York State cancer services. Available at: http://www.health.state.ny.us/nysdoh/ cancer/center/cancer_services.htm. Accessed August 19, 2005. 26. Palitz AM, Selby JV, Grossman S, Finkler LJ, Bevc M, Kehr C, Conell CA. The Colon Cancer Prevention Program (CoCaP): rationale, implementation, and preliminary results. HMO Pract 1997; 11:5–12. 27. U.S. Government Printing Office (GPO Access). Federal Register: http://frwebgate.access.gpo.gov/cgi-bin/multidb.cgi. Accessed August 25, 2005.
Address reprint requests to: Laura C. Seeff, MD, Centers for Disease Control and Prevention, DCPC, 4770 Buford Highway, NE, Mailstop K-55, Atlanta, Georgia 30341-3717. e-mail: [email protected]; fax: (770) 488-4639. The findings and conclusions in this report are those of the authors and do not necessarily represent the views of the Centers for Disease Control and Prevention. © 2005 by the American Gastroenterological Association 0016-5085/05/$30.00 doi:10.1053/j.gastro.2005.08.048
The Tipping Point: Balancing the Risks and Benefits of Screening in the Elderly See article on page 1163.
andomized controlled trials show the mortality benefits of colorectal cancer screening for adults ages 50 –70,1–3 and practice guidelines recommend regular screening for all adults at average risk.4 Although the guidelines are nearly unanimous in recommending screening starting at age 50, there are no clear guidelines about when to stop screening. As the population ages, and as interest in colon cancer screening increases, clinicians will increasingly face decisions about whether elderly individuals are candidates for screening. The article by Ko and Sonnenberg5 in this issue of GASTROENTEROLOGY provides some guidance. Although colorectal cancer is more common after age 70, the potential benefits from colorectal cancer screening in adults over age 70 are less certain. Few trials have included adequate numbers of adults over age 70 so the potential benefits must be extrapolated from evidence in younger populations.6,7 These data indicate that older adults are not equally likely to realize a net mortality benefit from screening. The benefits do not accrue until 5 or more years after screening, and competing causes of mortality may be an issue for the elderly. Furthermore, adults over age 70 who are in poor health may have more screening complications than those who are younger.8 Therefore, age, health status, and life expectancy are all
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important factors in determining who is likely to benefit.7,9,10 Accordingly, clinical practice guidelines state that it is reasonable to consider discontinuing colon cancer screening in the elderly. The United States Preventive Services Task Force states that it is reasonable to discontinue screening in those patients whose age and comorbid conditions limit life expectancy.4 The American Cancer Society states that discontinuing screening is reasonable in persons with significant comorbidity that would preclude treatment.11 The American Geriatrics Society recommends against screening elderly who are too frail to undergo colonoscopy and in persons with short life expectancy (3–5 years).12 These guidelines support individualized decision making for colon cancer screening in the elderly and put the onus on physicians to determine who is likely to benefit from screening and who is not. For physicians to make these determinations, information about the risks and benefits of screening is needed for patients with different life expectancies. Recently, Mandleblatt et al13 published a cost effectiveness analyses for breast cancer screening in elderly women that addresses cancer screening in the elderly from the societal perspective. The article by Ko and Sonneberg5 in this issue of GASTROENTEROLOGY addresses colorectal cancer screening in patients ages 70 and older but with the intent of providing information to be used clinically to aid decision making at the patient level.