Nursing management of the patient with colon and rectal cancer

Nursing

Management of the Patient With Colon and Rectal Cancer Diane M. Otte

OLOREETAL cancer is an increasingly significant health problem. It is the second most common cause of cancer-related deaths in men and the third most common causein women.’ The American Cancer Society estimates 147,000 new casesin 1988 with 61,500 people dying from the disease.*Unfortunately, colorectal cancer survival figures decline if the diseaseis not found and treated in an early, localized stage.233

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ETIOLOGY

The etiology of colorectal cancer is most likely multifactorial and follows the initiation and promotion model.4 In studies of migrant populations, environmental agentshave beenimplicated most in the development of colorectal cancer.’ In these studies, migrants from low-incidence areas have been observed to exhibit increasedincidence similar to those found in the population of the new area.3 Individuals working in factories producing synthetic fibers, those with cumulative occupational exposure to organic solvents, dyes, or abrasives, and those with more sedentaryactivity at the workplace may also be at increasedrisk.5 Many studies have suggesteda positive correlation between dietary intake of fats and meat and an inverse correlation with fiber consumption. It appearsthat high-fat diets elicit increaseddelivery of bile acids into the colon, and that bacteria convert bile acids and other materials into carcinogensand cocarcinogens.5A diet high in fiber may protect the epithelium. Mutagens/carcinogensthat result from cooking meats and other products are also being studied.3 McMichael and Potter found that the correlation of dietary componentswith the incidence of colon carcinoma might be influenced by age, sex, and anatomic location of the malignancy.6 Careful consideration of the patient’s previous and current dietary history may be important in assessingrisk. Adenomatous intestinal polyps may be precursors of colorectal cancer. Thesepolyps, which occur in 2% to 15% of the adult US population, are usually found in the rectum and the sigmoid colon.3,537Prophylactic removal of thesepolyps in asymptomatic patients greatly decreasesthe exSeminars in Oncology Nursing,

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petted frequency of cancer.839The likelihood of malignant progression of adenomatouspolyps to carcinoma is associatedwith size, growth pattern, and the degreeof dysplasia. Adenomaslarger than 2 cm are considered high-risk, as are those classified as villous and having evidence of severe dysplasia.5s’0 Nonspecific injury may act as a promoter in colorectal carcinogenesis.Conditions that result in chronic injury to colonic mucosa, such as ulcerative colitis, suture lines, or foreign bodies can predispose to colon cancer.435*11 The mechanism involved is thought to be mucosal hyperplasia. Recent studies suggest that hereditary factors, when combined with environmental factors, may actually accountfor a larger percentageof colorectal cancersthan previously thought. i* Whereasinherited syndromes such as familial polyposis, Gardner’s syndrome, and cancer family syndrome accountfor <5% of the total casesof colon cancer, patients who have a neoplastic polyp, an adenoma, or a carcinoma in the colon and rectum are at risk for subsequentdevelopmentof carcinomas.5 These carcinomas, which tend to be synchronous or metachronous,do not necessarily arise in the area of the previous polyps. 5,‘3 For this reason, the entire colon should be routinely examined once polyps have been detected. EPIDEMIOLOGY

Colorectal cancersexhibit a distinctive epidemiological pattern varying acrossgeographical locations and populations. The highest incidence occurs in the Western cultures, believed to be due to the high-fat, low-fiber diet of Westemers.14There has been a nearly 50% increasein incidence in US blacks.l5 Third world countries exhibit the lowest incidence of colorectal cancers.

From the GynecologylOncology Department. University of Iowa Hospitals and Clinics, Iowa City. Address reprint requests to Diane M. Otte, RN, MS, CETN, Nurse Clinician II, GynecologylOncology, University of Iowa Hospitals and Clinics, Iowa City, IA 52242, 0 1988 by Grune & Stratton, Inc. 0749-2081/88/0404-wO6$05.00i0

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Age is strongly associatedwith the development of colorectal cancer. Incidence begins to climb at age 40, doubles at age 50, and at each subsequent decade until the age of 80, when the incidence stabilizes.4*157’6The influence of gender remains an area of active study. In the United States, men are more likely to have colorectal cancer than women.’ DETECTION

Controversy exists about appropriate screening modalities for colorectal carcinoma. The World Health Organization suggeststhat a screeningprogram for colorectal cancer be affordable, easily available, and acceptableto patients.I7 The American Cancer Society (ACS) recommends the following three routine screening tests: annual digital rectal exams beginning at age 40, annual fecal guaiac screeningbeginning at age 50, and sigmoidoscopy every 3 to 5 years after two initial negative testsat least 1 year apart, beginning at age 50.2,18The fecal occult blood test continues to be safe, noninvasive, and a convenient way to detect colonic lesions in asymptomaticpeople. The sensitivity of present modalities for fecal guaiac screening is estimatedto be approximately 80%. l5 Immunochemical stool screening is currently under investigation and should provide greater sensitivity, specificity, and enhanced patient compliance.I9 Attempts are being made to find biochemical markers for colon cancer. One study demonstratedthat a high percentageof human colon, cecal, and rectal tumors contained retinoic acid-binding proteins (RABP) .3 The use of sigmoidoscopy for screening purposesis somewhatcontroversial since the predominant distribution of colorectal lesions has shifted from the left colon to the right colon,‘8-21 where lesions lie beyond the reach of the sigmoidoscope.l5 Thorson et al believe that the incidence of synchronous neoplasmsin colorectal cancer patients necessitatesa thorough evaluation of the entire colon and that colonoscopy in the preoperative period is the procedure of choice.22 Isler agrees and further statesthat the use of colonoscopy may potentially improve long-term survival rates.20The double contrast enema(DCE) is often presentedas an alternative to complete colonoscopy, but comparisons of the two examination procedures have led to the conclusion that colonoscopy should re-

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main the key procedure.23,24Of the controversies associatedwith screeningfor colorectal cancer, patient compliance and cost effectivenessare the two major unresolved issues.25 Signs and symptomsof colorectal cancerdepend largely on the location and function of the portion of the intestine involved with tumor. Most cancers occur in the rectosigmoid and rectum (see Fig 1). The major symptoms of colorectal carcinoma are (1) blood in the stool, (2) abdominal cramping or pain, (3) weight loss, and (4) a change in bowel habits such as constipation, increased frequency, or diarrhea.5 Many times people will be asymptomatic or will attribute symptoms to other conditions. Generally, symptoms of motor dysfunction and visible bleeding are associatedwith left-sided and distal lesions while symptomsfrom right-sided lesions may be characterized only by vague abdominal pain and anemia.5926Acute symptoms may include obstruction and perforation.5 Patients with poorly differentiated tumors tend to seek medical attention earlier than patients with tumors of better grade. Studies have found that patient delay in seeking medical attention is associated with increased local, lymphatic, or distant spread of tumor and with a poorer outlook for survival.27 DIAGNOSIS

A number of tests may be used to diagnose colorectal cancer including digital rectal exam, sigmoidoscopy, colonoscopy, and barium enema. Laboratory evaluation may include a complete blood cell count (CBC) to detect anemia and a Transverse Hepatic Flexure

Ascending COlOll

Cecum

plenic Flexure

Descending COl0l-l

Sigmoid Colon

Fig 1. Cancer Incidence. Two thirds of all colorectal cancer occurs in the rectosigmoid and the rectum. Many of these cancers are within reach of the examining finger and 604/o ere within the reach of a sigmoidoscope.

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CANCER

carcinoembryonic antigen assay(CEA), a biologic marker that may indicate the presenceof colorectal cancer. The CEA assay, which is not conclusive for the initial diagnosis of cancer, may be useful as an early indication of recurrencein some patients. Other tumor and organ-associatedantigens, such as colon-specific antigens (CSAs) and colonspecific antigen proteins (CSAPs), are being studied.3 Liver function tests, chest x-ray, and liver scan may be performed to detect metastases. Computed tomography (CT) scans and endoluminal ultrasonography (ELU) are used to detect the extent of invasion of rectal lesions.5,28 Colorectal cancer is stagedby direct observation of the tumor during surgery as well as by pathological staging. Three classification systems are available: Dukes, the Gastrointestinal Tumor Study Group (GITSG), and the postsurgical TNM system.5 The Dukes classification system is the most widely used. Dukes “A” indicates growth is confined to the mucosawith no nodal involvement; Dukes “B” indicates growth spreadto the muscularis but no nodal involvement; Dukes “C” indicates metastasis to regional lymph nodes; and Dukes “D” indicates distant metastasis.4’26 BIOLOGIC BEHAVIOR

The bowel wall is composedof four layers: the mucosa, submucosa,muscularis, and serosa.The dividing line between the mucosal layer and the submucosallayer is the muscularis mucosa.29The crypts of Lieberkiihn located in the mucosal layer are the location for cellular reproduction in the colon. New undifferentiated cells are constantly produced in the lower two thirds of the crypts; these cells then migrate to the upper portion where they differentiate (mature) and then migrate out of the crypt to the mucosal surface where they are shed. The mucosausually remains in a steadystate of cellular production, migration, and 10~s.~’ Carcinogenic exposure affects the reproducing cells in the crypt. If there are many transformed cells or repeated exposure to carcinogens, the crypts may become populated with error-prone DNA repair cells. The transformed cells which may differentiate partially, defectively, or not at all may form early neoplastic lesions3’ Neoplasms grow in different directions and at different rates, with the downward growth, or invasive behavior, distinguishing between benign

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and malignant neoplasms.3’ In addition, gradual changes in the cytological features of the cells occur.3oTumor DNA content and distribution may prove to be sensitive predictors of biologic behavior of colorectal carcinomas. Macroscopically, fungating exophytic lesions and flat infiltrative lesions are the two major types seen. The fungating exophytic lesion is most often seen in the right colon and the flat infiltrative lesion in the left colon.4 Microscopically, largebowel carcinomas usually exhibit a glandular arrangement of cells, a tubular pattern of growth, and mucus secretion.5Adenocarcinomasof the tubular type constitute 85% of colorectal cancers, with the majority of them being at least moderately well-differentiated. Mutinous adenocarcinoma is seen 10%to 1.5%of the time and is associatedwith a poorer prognosis.4,5 Signet ring carcinomas make up <2% of colorectal carcinomas.’ Primary colorectal neoplasmshave highly variable growth rates. The size of the tumor does not correlate clearly with its malignant or invasive potential. Direct, lymphatic, and venous invasion are the three pathways by which a malignant lesion spreads.3oWithin the bowel wall tumor may grow radially, longitudinally, or circumferentially. Radial extension is strongly associatedwith the risk of lymphatic and venous metastasis.Lymph node metastasis increases from 15% to 50% or 60% when the tumor has extended beyond the bowel wall.’ The extensive lymphatic network in the pelvis contributes to extension of tumor outside the bowel wall. Location of the tumor in the bowel determines the direction of nodal metastasis.5 Lymph drains from the epicolic nodes (on bowel wall), to the pericolic nodes (adjacent to bowel wall), to the intermediate nodes (in midportion of mesentery), to the central nodes (at junction of aorta and mesenteric artery). Lymphatic spread is not always orderly and nodes may be “skipped” with progression directly to the central nodes.’ There is evidence that lymphatic vessels could form within abdominal adhesions, and thus these adhesions may provide the routes of spread to nearby structures. Venous circulation is the major mechanism for metastatic spread. Metastatic sites include the liver, lung, and to a lesser extent, the lumbar vertebral bodies.4ss Adenocarcinomas of the large bowel metastasizeto the ovary with a 6% frequency. which prompts some to recommend that

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an oophorectorny be performed in postmenopausal women at the time of primary resection.32 Factors significant in determining prognosis include the extent of local invasion, lymph node metastases, distant metastases,and tumor type and grade.4 The incidence of local and distant recurrences of colon carcinoma is related to depth of mural invasion and involvement of lymph nodesin the primary tumor. In general, patients with nodal disease have a greater likelihood of relapse (approaching 50%) 4 to 5 years following resection.5 Five-year survival of 80% to 90% may be expected by patients with disease confined to the bowel wall without evidence of distant or nodal metastasis,while those with diseaseextending beyond the bowel wall without tumor in nodes or distant sites, may expect a long-term survival rate of 50% to 60%. Those with disease involving nodes but no distant sites may have long-term survival rates of 30% to 40%.5 SURGICAL THERAPY AND NURSING MANAGEMENT

Surgical excision remains the most effective modality for treating colon cancer,33whether performed as a curative treatment or a palliative measure. Improved surgical techniques using stapling devices and colonoscopy have reduced the incidence of ostomy surgery, fear of which causesdelay in seeking attention for symptoms.33’34The type of surgery performed may dependon the surgeon’s expertise and personal preference; the tumor site, size, and histological grading; whether or not perforation or obstruction is present; evidence of spread or resectability; the goal of cure or palliation; bowel preparation before surgery; and the sex, age, and health status of the patient.33 The standard treatment for colorectal cancer is surgical excision of the tumor, lymph nodes, and surrounding tissue with end-to-end anastomosis (EEA) when possible. Controversy still exists regarding the extent of bowel to be excised. Most surgeonsremove the lymph nodesdraining the primary tumor because there is a >50% chance of lymph node involvement.33 The “no-touch” technique advocatedby Tumbull and associates, involving isolation of the blood supply prior to handling the tumor-bearing segmentof the bowel, is thought by someto min-

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imize the chanceof disseminating the cancer cells via the blood supply during surgical removal.33 The EEA stapling device has provided a secure anastomosisat a lower level than was technically possible with manual sewing.33 Primary resection is the operative choice for cure in treating right- and left-sided lesions of the colon. A right hemicolectomy is performed for a right-colon lesion. Excision of lesions in the proximal, midtransverse, and distal transverse colon may involve a right hemicolectomy, transverse colectomy, or left partial colectomy.33Left hemicolectomy is performed for lesions in the descending colon, and segmentalresection for sigmoid lesions. The surgical managementof rectal cancer is related to tumor location. The distance of the tumor from the anal verge determines the options available to the surgeon. Abdominoperineal resection (APR) is the usual operation for low rectal cancer while resection with anastomosisis appropriate for tumors in the upper third of the rectum. Sphinctersaving techniquessuch aspull-through procedures, abdominotranssacraloperation, transanal anastomosis, and stapledEEA are used for midrectal and high rectal lesions, but they still generate controversy.26733Techniques for excision of lesions in the middle third of the rectum remain controversial and may involve either low anterior resection or APR. Temporary or permanent colostomies may be createdat the time of surgery. A temporary colostomy may be made if there is concern for the integrity of the anastomosisand the long-term goal is reestablishing bowel continuity. Permanentcolostomies cannot be reversed and include the end, single-barreled, and double-barreled colostomies. Excellent descriptions of these surgical procedures, as well as specific nursing managementfor these patients, can be found in Broadwell and Jackson35and Smith and Johnson.36 Infection is a major perioperative concern. Septic complications after elective surgery occur approximately 40% of the time if prophylactic measures to reduce infection have not been implemented. Administration of broad-spectrum, poorly absorbedantibiotics (neomycin and erythromycin) along with mechanical cleansing of the bowel before surgery, reduces bacterial counts in the bowel lumen and reduces septic complications

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to < 10%.37Whether parenteral administration of antibiotics prior to surgery provides prophylaxis as effective as that accomplished with mechanical bowel preparations is not clear.5 Nutritional assessmentas well as supplementation is another perioperative issue. Studies suggest that total parenteral nutrition (TPN), administered for seven days before surgery and through the perioperative period, reduces postoperative complications and possibly mortality. Patients with a poor prognosis who may benefit from nutritional supplementation include those with a serum albumin level ~3.5 g/dL, anergic skin tests, and weight loss of at least 5% to 1O%.38Enteral alimentation may be equally beneficial and less expensive, and it is associated with fewer complications.5 In particular, elderly patients might benefit from preoperative nutritional intervention since they have been shown to have lower hematocrits and serum albumin values.39 Obstruction and perforation are two serious complications of colorectal carcinoma. Recent trials4’ have shown that factors associatedwith obstruction worsen the long-term outcome for the patient, especially when the tumor is located on the right side. Mortality rates following surgery for perforated colon cancersmay be as high as 30%.5 Nursing management of patients undergoing colorectal cancer surgery includes extensive preparation of the patient and family preoperatively, ideally beginning in the physician’s office. An understanding of the surgical plan is essential. If a resection and reanastomosisis planned, preoperative care may include standardpreoperative teaching and bowel preparation. If the creation of a temporary or permanent colostomy is anticipated, consultation with an enterostomaltherapist (ET) is highly recommended. The ET nurse can be very helpful in reviewing the anticipated procedurewith patients as well as marking the stoma site prior to surgery. It is necessary to describe the normal stomacharacteristicssince patients frequently have misconceptions about its appearance.Seeing the variety of pouches available often helps diminish the surprise after surgery. Patients and significant others need opportunities to discuss their sexual concernsand options since sexual dysfunction may occur with certain surgical procedures.The United Ostomy Association (UOA) offers an ostomy rehabilitation program whereby persons with colos-

tomies make visits to patients and families preoperatively and postoperatively.41,42 Postoperative care will be determined by the surgical procedure performed. Learning the outcome of the surgical procedure and the results of pathology tests and making decisions regarding future treatment all require support the nurse can provide.41 The patient w’tth an ostomy will have even more concerns to deal with: peristomal skin care, pouch care, body image, and preventing obstruction of output. A number of sources provide extensive discussion of postoperative care.35.36.41.42 RADIATION THERAPY AND NURSING MANAGEMENT

Radiation therapy is becoming increasingly important in the treatment of colon and rectal cancer. Adjuvant radiotherapy, in conjunction with surgical resection of all known disease,has shown improved local control in patients with high risk of local recurrence.43 Controversy exists about whether radiotherapy should be administered preoperatively or postoperatively. Advantages of preoperative radiation include a decreasein the number of cancer cells that may spread locally or to distant sites at the time of surgery,43’44the avoidance of irradiating segmentsof small bowel fixed by adhesions,and reduction of tumor size.5 A disadvantageis the possibility of inaccuratepathological staging.43,ti The major advantageof postoperative irradiation is the ability to better select an appropriate candidate. The “sandwich” technique, or using both preoperative and postoperative irradiation has also been evaluated.44 Rectal cancer patients stagedB2 through C3 by the Astler-Coller system may benefit from adjuvant postoperative radiotherapy. Postoperativeradiotherapy is initiated 3 to 6 weeks after surgery, allowing adequatehealing and recovery time.43,44 Patients receive external beam radiotherapy using a three- or four-field technique and a total dose of 4,500 to 5,000 rads fractionated over 5 to 6Y2 weeks. The field includes the tumor bed and the interior iliac and presacralnodes.43,45 The skin and reproductive organs also may be affected. Patients with limited disease of the rectum (stageA) may be candidatesfor intracavitary radiation, a conservative technique to preserve anal

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sphincter control. These patients avoid the problems associated with an APR (permanent colostomy and impotence). Hassey& presentsan excellent discussion of usual doses and possible side effects. Intraoperative radiation therapy (IORT) is being used for patients with locally advancedrectal cancer or recurrent disease.Higher dosesof radiation can be delivered to the area at greatest risk for recurrence with reduced risk to normal tissues in the pelvis.44 Radiotherapy may also be used for palliative purposes to provide pain relief for patients with nonresectable primary tumors and to treat metastasesor malignant effusions.26 Patients and families have fears and anxieties about radiation and its complications. Skilled nursing care and patient education will help reduce these fears.43344 Witt46 has developed a patient education booklet that can be reproduced, which addresses questions on colon and rectum radiation therapy. Possible side effects of radiotherapy are skin changes(dry to wet desquamation), fistula formation, and nutritional deficits resulting from diarrhea, nausea, and anorexia. An important role for the nurse is to instruct the patient about strategies to improve nutritional status, skin care, and the need for frequent blood monitoring. Promoting comfort involves teaching patients how to deal with the fatigue reported by almost 75% of persons receiving external beam radiation.47 Assuring the patient that fatigue is a normal responsethat will gradually disappearfollowing completion of treatments may help dispel someof the associatedguilt and anxiety. 43 A discussion about contraception and the potential for infertility is critical. Women should know that intercourse may be uncomfortable because of dryness of the vaginal mucosa. Sexual performance in men may be affected, with some men experiencing impotence. Counseling about expressionsof love and sexuality may assist partnersto expressfeelings and thus alleviate guilt, fear, or frustration.43 The possibility of long-term effects on fertility exists. Bowel adhesionsand fibrosis may occur. Becausepatients are at risk for local recurrences, second malignancies, and chronic irradiation enteritis, follow-up is essential. 43 For an extensive discussion of side effects and nursing care seeHassey’s article.44

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Chemotherapy has three potential uses for patients with colorectal cancer: treating nonresectable local or metastaticdisease,treating occult metastases (adjuvant chemotherapy), and treating recurrent cancer.48,49Since chemotherapy is most effective when the tumor burden is small, it is advantageousto give the treatment at the time of surgery or shortly thereafter.5o Intravenous administration of chemotherapeutic agents 4 to 6 weeks after resection continues to receive the most attention. Although a number of studies have been conducted, none have directly demonstratedthat patients with colon cancer may benefit from adjuvant chemotherapy.50It is hoped that the results of the National Surgical Adjuvant Breast and Bowel Project (NSABP) trials using 5fluorouracil (5FU), semustine, and vincristine may help clarify inconsistencies.50Other treatment strategies have involved intraluminal administration of 5-FU or immediate postoperative infusion of chemotherapy into the portal circulation of patient undergoing curative resection4’ 5-FU is also being used as a radiosensitizer. Potential problems for patients receiving chemotherapy for colorectal cancer include: diarrhea and stomatitis (5-FU); delayed myelosuppression (semustine); GI symptoms(floxuridine, or FUDR) including nausea, epigastric burning, abdominal pain, cramping and lack of appetite; peripheral neuropathies (vincristine) and nephrotoxicity and ototoxicity (cisplatin). Monitoring the patient’s hematologic status, administering antiemetics, reviewing dietary changes to control side effects, and providing good oral hygiene are only a few of the appropriate nursing interventions.26 MAJOR PATIENT CARE ISSUES

A major issue in the area of colorectal cancer is the controversy regarding screening. Who should be screened, how often, what is the most appropriate and cost-effective method, and who should do the screening are all important questions yet to be answered satisfactorily. The nurse is in a key position to seethe patient in an asymptomaticstage and to initiate appropriate care. Someauthors have suggestedthat sigmoidoscopesshould be usedroutinely by trained nurses.”

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In an ACS study performed in 1983it was found that there was a strong perception by the public that colon cancer equateswith colostomy and that this serves as a major deterrent to interest in early detection of colorectal cancer.33 Nurses can design and implement researchstudies to examine both the relationship of lifestyles and environmental factors to the development of colorectal cancer and also the psychological barriers to compliance.’ 5 Nurse specialists in the areasof sexuality, radiation therapy, surgery, enterostomaltherapy, chemotherapy, and home care need to addresspatient and family concerns to provide optimum care to the patient. With patients returning to their homes “quicker and sicker,” follow-up instruction and care must be coordinated for the patient who has undergone a major surgical procedure and who is anticipating further adjuvant therapy. Many prob-

lems experienced by patients and families cannot be anticipated or dealt with during the patient’s short hospital stay. The continuum of care in the home will be fostered by a well-coordinated care process. It is hoped that earlier detection and more effective treatment modalities will improve colorectal survival rates. Optimal care of the person with colorectal cancer will require a coordinated and multidisciplinary approach. Providing the patient and family with the necessaryinformation to make an informed decision about the appropriate choice of treatment is essential. ACKNOWLEDGMENT The author would like to gratefully acknowledge the assistance of Gail Ardery, RN, PhD, and Beverly Folkedahl. RN, BSN, ET, for their review of the manuscript and Kevin Pitzer, BA, for his assistance with preparation of the manuscript.

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14. Burkitt D: Etiology and prevention of colorectal cancer. Hosp Pratt 2161-77, 1984 15. Messner RL, Gardner SS, Webb DD: Early detectionThe priority in colorectal cancer. Cancer Nurs 9:8-14. 1986 16. Young JL, et al: Cancer incidence and mortality m the United States, 1973-1977. NC1 Monogr 57:1-49, 1981 17. Khan AH: Colorectal carcinoma: Risk factors. screening, early detection. Geriatrics 39:42-47, 1984 18. Sherlock P, Winawer SJ: Colorectal Cancer. Professional Education. New York. American Cancer Society, 1984 19. Anonymous: A screen for early colorectal cancer. Transition:33-37, November 1983 20. lsler JT, Brown PC, Lewis FG, et al: The role of preoperative colonoscopy in colorectal cancer. Dis Colon Rectum 30:435-439, 1987 21. Mamazza J, Gordon PH: The changing distribution of large intestinal cancer. Dis Colon Rectum 25:558-562, 1982 22. Thorson AG, Christensen MA, Davis SJ: The role of colonoscopy in the assessment of patients with colorectal cancer. Dis Colon Rectum 29:306-311, 1986 23. Bader JP: Screening of colorectal cancer. Dig Dis Sci 31:43S56S, 1986 (suppl) 24. Tedesco FJ, Gottfried EB, Corless JK, et al: Prospective evaluation of hospitalized patients with nonactive lower intestinal bleeding-Timing and role of barium enema and colonoscopy. Gastrointest Endosc 30:281-283, 1984 25. Winawer SJ: Introduction to position papers from the Third International Symposium on Colorectal Cancer. CA 34:130-133, 1984 26. Lind J: Colorectal cancer, in Ziegfeld CR ted): Core Curriculum for Oncology Nursing. Philadelphia, Saunders, 1987, pp 163-171 27. McDermott FT. Hughes ESR, et al: Prognosis in relation

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to symptom duration in colon cancer. Br J Surg 68846-849, 1981 28. Saitoh N, Okui K, Sarashina H, et al: Evaluation of echographic diagnosis of rectal cancer using intrarectal ultrasonic examination. Dis Colon Rectum 29:234-242, 1986 29. Sordelett S: Gastrointestinal system, in Broadwell DC, JacksonBS (eds): Principles of Ostomy Care. St Louis, Mosby, 1982, pp 23-43 30. Chang W: Histogenesisof colon cancer in experimental animals. Stand J Gastroenterol 104:27-43, 1984 (suppl) 3 1. ShamsuddinA: Comparative pathology-Human large intestinal cancer and animal models, in Autrup H, Williams G (eds): Experimental Colon Carcinogenesis. Boca Raton, FL, CRC, 1983, pp 125-138 32. Bin&rant A, SampsonJ, SugarbakerPH: Ovarian metastasisfrom colorectal cancer. Dis Colon Rectum 29:767-771, 1986 33. Wicks LJ: Treatment modalities for colorectal cancer. Semin Oncol Nurs 2:242-248, 1986 34. Cancer of the colon and rectum: Summary of a public attitude survey. CA 33:359-365, 1983 35. Broadwell DC, JacksonBS (eds): Principles of Ostomy Care. St Louis, Mosby, 1982 36. Smith DB, Johnson DE (eds): Ostomy Care and the Cancer Patient-Surgical and Clinical Considerations. Orlando, &me & Stratton, 1986 37. Condon RE: Antibiotic coverage for bowel surgery. Int Adv Surg Oncol 7:1-31, 1984 38. Chwals WJ, Blackbum GL: Perioperative nutritional support in the cancer patient. Surg Clin North Am 66:11371165, 1986

39. Bader TF: Colorectal cancer in patients older than 75 years of age. Dis Colon Rectum 29:728-732, 1986 40. Wolmark N, NSABP Investigators: The prognostic significance of tumor location and bowel obstruction in Dukes B and C colorectal cancer. Ann Surg 198:743-750, 1983 41. Dobkin KA, Broadwell DC: Nursing considerationsfor the patient undergoing colostomy surgery. Semin Oncol Nurs 2:249-255, 1986 42. Alterescu KB: Colostomy. Nurs Clin North Am 22:281289, 1987 43. Witt ME, McDonald-Lynch A, Grimmer D: Adjuvant radiotherapy to the colorectum: Nursing implications. Oncol Nurs Forum 14:17-21, 1987 44. Hassey KM: Radiation therapy for rectal cancer and the implications for nursing. Cancer Nurs lo:31 1-318, 1987 45. Sugarbaker PH, GundersonLL, Wittes RE: Colorectal cancer, in DeVita VT Jr, Hellman S, Rosenberg SA (eds): Cancer: Principles and Practice of Oncology (ed 2). Philadelphia, Lippincott, 1985, pp 795-884 46. Witt ME: Questionson colon and rectum radiation therapy. Oncol Nurs Forum 14:79-82, 1987 47. King KB, Nail LM, Kreamer K, et al: Patients’ descriptions of the experience of receiving radiation therapy. Oncol Nurs Forum 12:55-61, 1985 48. O’Connell MJ: Chemotherapyfor colorectal carcinoma. CA 36:360-366, 1986 49. Schabel FM: Rationale for perioperative anticancer treatment. Recent Results Cancer Res 98:1-10, 1985 50. Wolmark N: Adjuvant chemotherapy in colorectal cancer. Can J Surg 28:416-419, 1985 51. Rosevelt J, Frank1 H: Colorectal cancer screening by nurse practitioner using 60 cm flexible fiberoptic sigmoidoscope. Dig Dis Sci 29:161-163, 1984