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JACS CME Featured Articles, Volume 217, July 2013
CONTINUING MEDICAL EDUCATION PROGRAM
JACS CME Featured Articles, Volume 217, July 2013 Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC J Am Coll Surg 2013;217:7e16 Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A J Am Coll Surg 2013;217:153e161 Additional Articles for July 2013 Online at: http://jacscme.facs.org Current use and surgical efficacy of laparoscopic colectomy in colon cancer Sticca RP, Alberts SR, Mahoney MR, et al J Am Coll Surg 2013;217:56e63 Outcomes with split liver transplantation are equivalent to those with whole organ transplantation Doyle M, Maynard E, Lin Y, et al J Am Coll Surg 2013;217:102e114
Objectives: After reading the featured articles published in this issue of the Journal of the American College of Surgeons (JACS) participants in this journal-based CME activity should be able to demonstrate increased understanding of the material specific to the article featured and be able to apply relevant information to clinical practice. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. The American College
of Surgeons designates this journal-based CME activity for 1 AMA PRA Category 1 Credit per completed article, and a score of 75% is required to receive CME credit. The JACS Editor-in-Chief does not assign a manuscript for review to any person who discloses a conflict of interest with the content of the manuscript. Two articles are available each month in the print version, more may be available at jacscme.facs.org. Physicians should claim only credit commensurate with the extent of their participation in the activity.
ARTICLE 1
Learning Objectives: After careful review of this manuscript, surgeons should be able to reiterate the inclusion criteria and results of the American College of Surgeons Oncology Group (ACOSOG) Z0011 study, define the intent and limitations of axillary ultrasound (US) with US-directed fine needle aspiration (FNA), and describe the results of this study that warrant avoidance of frozen section of sentinel lymph nodes in patients who meet the ACOSOG Z0011 inclusion criteria and have negative axillary US.
(Please consider how the content of this article may be applied to your practice.)
Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC J Am Coll Surg 2013;217:7e16
ª 2013 by the American College of Surgeons Published by Elsevier Inc.
176
ISSN 1072-7515/13/$36.00 http://dx.doi.org/10.1016/j.jamcollsurg.2013.04.013
Vol. 217, No. 1, July 2013
Question 1 The basis for our study was the ACOSOG Z0011 study, which found which of the following to be true: a) The addition of an axillary radiation field was necessary for the Z0011 favorable results. b) Only breast conservation patients were included in the Z0011 study. c) Additional systemic therapy beyond surgical treatment was not allowed. d) Patients randomized in the Z0011 study could have tumors of ductal carcinoma in situ or T1- 3, and up to 4 metastatically involved lymph nodes. e) Patients undergoing neoadjuvant chemotherapy with clinically negative axillary lymph nodes were acceptable candidates for the Z0011 study. Critique: Results of the ACOSOG Z0011 study applied to patients with T1-2 cancers, without preoperative palpable lymphadenopathy, treated with breast conservation surgery (BCS) followed by usual breast radiotherapy and standard adjuvant medication. There was no benefit of completion axillary lymph node dissection beyond sentinel lymph node (SLN) biopsy alone for patients with 1 or 2 positive sentinel lymph nodes with respect to disease-free or overall survival, or local recurrence. Question 2 This study determined which of the following to be true: a) Axillary US with or without US-directed FNA can replace axillary SLN biopsy or dissection. b) Axillary US allowed inclusion of patients undergoing neoadjuvant (preoperative) chemotherapy to fall within the ACOSOG Z0011 guidelines for treatment. c) Axillary US would fail to detect fewer than 5% of breast cancer patients with either 3 metastatically involved lymph nodes or lymph node metastasis measuring >7 mm in largest diameter. d) A breast cancer patient with a negative preoperative axillary US but a single SLN containing a 3-mm focus of metastatic disease requires a completion lymphadenectomy. e) All breast cancer patients managed with USdirected FNA of axillary lymph nodes were excluded from this study. Critique: Applying the same inclusion criteria of the ACOSOG Z0011 study to our institutional breast cancer patients who either underwent BCS or were
Continuing Medical Education Program
177
candidates for BCS but chose mastectomy, preoperative axillary US (with use of FNA as indicated) proved highly sensitive, failing to detect only a small percentage of potentially higher risk axillary lymph node macrometastasis or more than 2 metastatically involved lymph nodes. Question 3 This study concluded that frozen section of axillary sentinel lymph nodes can be omitted in which patients? a) Clinically negative axillary lymph nodes in patients undergoing mastectomy. b) Patients whose preoperative US-directed needle biopsy of a suspicious lymph node proved positive for metastatic breast cancer. c) Patients undergoing BCS who meet the ACOSOG Z0011 criteria, whose axillary US is negative (using US-FNA as indicated) for metastatic lymph nodes. d) In patients undergoing BCS with preoperative negative axillary ultrasound, permanent section histology with addition of immunohistochemistry is indicated instead of frozen section. e) Patients whose postoperative management is already known to include axillary radiation. Critique: In patients undergoing BCS with anticipated usual postoperative breast radiation and adjuvant therapy, with the addition in this study of negative preoperative axillary US ( FNA as indicated), frozen section of SLNs could be avoided because those SLNs that were found to contain metastatic deposits (thereby false negative axillary US) were judged small enough and few enough not to require completion axillary dissection (commensurate with the Z0011 study findings). Question 4 In this study, patients whose preoperative US-directed FNA of an axillary lymph node that proved positive for metastasis were: a) Excluded from the study. b) Included if preoperative chemotherapy restored the nodes to radiologically normal. c) Randomized between adjuvant chemotherapy with or without axillary radiation. d) More correlated with estrogen receptor negative and higher nuclear grade tumors. e) Were included if the size of nodal metastasis was smaller than 2 mm.
178
J Am Coll Surg
Continuing Medical Education Program
Critique: We used preoperative axillary US as an “extension of the physical examination,” and, therefore, if metastatic disease was identified by US-FNA, we judged these patients to have clinically positive lymph nodes, so they were not eligible for our study analysis. Clinical palpation was the only axillary lymph node screening technique used in the Z0011 study, and because US is certainly more sensitive than clinical palpation, one might expect the Z0011 study to have more advanced, lymph node positive disease than our study. Actually, they were roughly equivalent. This likely reflects some degree of preselection of the patients entered into the Z0011 study.
ARTICLE 2
a variety of topics. It contains clinical and resource use information included in a typical discharge abstract. Critique: NSQIP has the goal of assisting hospitals in tracking surgical complications in an effort to improve quality of care delivered to surgical patients. A trained surgical clinical reviewer at each participating hospital collects data included in NSQIP directly from patient charts. NSQIP measures are both risk-adjusted and case-mix adjusted to account for patient severity of illness and complexity of operations performed. NSQIP includes 30-day outcomes for patients rather than outcomes to hospital discharge.
(Please consider how the content of this article may be applied to your practice.)
Question 2 When a sample size is limited, which of the following is the preferred method for validation of a statistical model?
Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A J Am Coll Surg 2013;217:153e161
a) b) c) d) e)
Learning Objectives: After study of this article, surgeons should be able to identify key predictors of mortality in patients who present with necrotizing soft tissue infection (NSTI). This NSQIP-based model of risk from NSTI can help to inform discussions between surgeons, patients, and families.
Critique: Split-sample validation and bootstrapping are both techniques that are used for validation of a statistical model with a limited sample size. Splitsample reduces an already limited dataset by using half of the data for model development and the other for model validation. Bootstrapping permits use of the entire dataset for model development and validation. Bootstrapping outperforms split sample validation in many studies. The c-statistic, or concordance statistic, is used specifically to measure discrimination of a model. Multivariable logistic regression is used for model development. The probability of mortality formula is generated by multivariable logistic regression and accounts for the impact of statistically significant independent variables on the outcome of interest (in this case, mortality).
Question 1 Which of the following statement best describes NSQIP? a) NSQIP does not account for complexity of operations performed. b) NSQIP is a network with the goal of pursuing welldesigned collaborative quality improvement projects in surgical care. c) NSQIP is a multicenter, prospective database that collects data on 136 variables, including pre-, intraand postoperative variables and 30-day mortality and morbidity outcomes for patients undergoing surgical procedures. d) NSQIP is a retrospective database that collects data from claims or administrative data and is not reviewed by trained auditors. e) NSQIP is a uniform, multistate database that promotes comparative studies of health care services and will support health care policy research on
Bootstrapping c-statistic Multivariable logistic regression Probability of mortality formula Split-sample validation
Question 3 Laboratory data collected in the NSQIP Participant Use Data File (PUF) and included in this analysis include which of the following? a) b) c) d) e)
Serum albumin Serum bilirubin Serum glucose Microbial identification Platelet count
Vol. 217, No. 1, July 2013
Critique: Serum albumin and serum bilirubin are both collected in the NSQIP PUF but were excluded from this analysis because they did not achieve statistical significance during exploratory univariate analysis. Serum glucose is not included in the NSQIP PUF, nor is microbial identification. Platelet count is part of the PUF and independently predicted mortality in a multivariate model when <150,000 at admission. Question 4 Which patient described below has the highest mortality risk based on the calculator for patients with NSTI? a) Age 65, dialysis-dependent, required assistance with many activities of daily living, American Association of Anesthesiologists (ASA) class 4, septic shock at presentation, thrombocytopenic at presentation. b) Age 65, female, glomerular filtration rate of 25, partially dependent with activities of daily living,
Continuing Medical Education Program
179
ASA class 3, systemic inflammatory response syndrome at presentation, platelet count of 100K at presentation c) Age 45, diabetic, smoker, bed-bound, ASA class 3, required intraoperative blood transfusion, and was on the ventilator for 72 hours postoperatively. d) Female, alcoholic, and diabetic, bed-bound, ASA class 5, in septic shock at time of presentation, had leukocytosis at presentation. e) Male, dialysis-dependent, required assistance with many activities of daily living, ASA class 4, developed acute lung injury postoperatively, had anemia on presentation. Critique: Independent risk factors for mortality associated with NSTI identified from analysis of NSQIP were age >60 y, partially or totally dependent functional status, requiring dialysis before presentation, ASA class 4 or greater, emergent surgery, septic shock at presentation, and thrombocytopenia (<150K) at presentation.
180
Continuing Medical Education Program
J Am Coll Surg
To complete CME please go to http://jacscme.facs.org Log in with your ACS Member ID# and last name. The JACS CME website has additional articles available for credit (maximum 4 per issue)
Issues are available for the past 24 months. You can print your certificate immediately. For those who are unable to access the internet, fax this page ONLY to 312-202-5027 Your certificate will be faxed or emailed to you; incomplete submissions will not be processed. No mail submissions will be accepted.
JACS CME Featured Articles, Volume 217, July 2013 Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC. J Am Coll Surg 2013;217:7e16 Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A. J Am Coll Surg 2013;217:153e161
JACS CME Featured Articles, Volume 217, July 2013 Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC J Am Coll Surg 2013;217:7e16 Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A J Am Coll Surg 2013;217:153e161 Additional Articles for July 2013 Online at: http://jacscme.facs.org Current use and surgical efficacy of laparoscopic colectomy in colon cancer Sticca RP, Alberts SR, Mahoney MR, et al J Am Coll Surg 2013;217:56e63 Outcomes with split liver transplantation are equivalent to those with whole organ transplantation Doyle M, Maynard E, Lin Y, et al J Am Coll Surg 2013;217:102e114
Objectives: After reading the featured articles published in this issue of the Journal of the American College of Surgeons (JACS) participants in this journal-based CME activity should be able to demonstrate increased understanding of the material specific to the article featured and be able to apply relevant information to clinical practice. The American College of Surgeons is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to sponsor continuing medical education for physicians. The American College
of Surgeons designates this journal-based CME activity for 1 AMA PRA Category 1 Credit per completed article, and a score of 75% is required to receive CME credit. The JACS Editor-in-Chief does not assign a manuscript for review to any person who discloses a conflict of interest with the content of the manuscript. Two articles are available each month in the print version, more may be available at jacscme.facs.org. Physicians should claim only credit commensurate with the extent of their participation in the activity.
ARTICLE 1
Learning Objectives: After careful review of this manuscript, surgeons should be able to reiterate the inclusion criteria and results of the American College of Surgeons Oncology Group (ACOSOG) Z0011 study, define the intent and limitations of axillary ultrasound (US) with US-directed fine needle aspiration (FNA), and describe the results of this study that warrant avoidance of frozen section of sentinel lymph nodes in patients who meet the ACOSOG Z0011 inclusion criteria and have negative axillary US.
(Please consider how the content of this article may be applied to your practice.)
Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC J Am Coll Surg 2013;217:7e16
ª 2013 by the American College of Surgeons Published by Elsevier Inc.
176
ISSN 1072-7515/13/$36.00 http://dx.doi.org/10.1016/j.jamcollsurg.2013.04.013
Vol. 217, No. 1, July 2013
Question 1 The basis for our study was the ACOSOG Z0011 study, which found which of the following to be true: a) The addition of an axillary radiation field was necessary for the Z0011 favorable results. b) Only breast conservation patients were included in the Z0011 study. c) Additional systemic therapy beyond surgical treatment was not allowed. d) Patients randomized in the Z0011 study could have tumors of ductal carcinoma in situ or T1- 3, and up to 4 metastatically involved lymph nodes. e) Patients undergoing neoadjuvant chemotherapy with clinically negative axillary lymph nodes were acceptable candidates for the Z0011 study. Critique: Results of the ACOSOG Z0011 study applied to patients with T1-2 cancers, without preoperative palpable lymphadenopathy, treated with breast conservation surgery (BCS) followed by usual breast radiotherapy and standard adjuvant medication. There was no benefit of completion axillary lymph node dissection beyond sentinel lymph node (SLN) biopsy alone for patients with 1 or 2 positive sentinel lymph nodes with respect to disease-free or overall survival, or local recurrence. Question 2 This study determined which of the following to be true: a) Axillary US with or without US-directed FNA can replace axillary SLN biopsy or dissection. b) Axillary US allowed inclusion of patients undergoing neoadjuvant (preoperative) chemotherapy to fall within the ACOSOG Z0011 guidelines for treatment. c) Axillary US would fail to detect fewer than 5% of breast cancer patients with either 3 metastatically involved lymph nodes or lymph node metastasis measuring >7 mm in largest diameter. d) A breast cancer patient with a negative preoperative axillary US but a single SLN containing a 3-mm focus of metastatic disease requires a completion lymphadenectomy. e) All breast cancer patients managed with USdirected FNA of axillary lymph nodes were excluded from this study. Critique: Applying the same inclusion criteria of the ACOSOG Z0011 study to our institutional breast cancer patients who either underwent BCS or were
Continuing Medical Education Program
177
candidates for BCS but chose mastectomy, preoperative axillary US (with use of FNA as indicated) proved highly sensitive, failing to detect only a small percentage of potentially higher risk axillary lymph node macrometastasis or more than 2 metastatically involved lymph nodes. Question 3 This study concluded that frozen section of axillary sentinel lymph nodes can be omitted in which patients? a) Clinically negative axillary lymph nodes in patients undergoing mastectomy. b) Patients whose preoperative US-directed needle biopsy of a suspicious lymph node proved positive for metastatic breast cancer. c) Patients undergoing BCS who meet the ACOSOG Z0011 criteria, whose axillary US is negative (using US-FNA as indicated) for metastatic lymph nodes. d) In patients undergoing BCS with preoperative negative axillary ultrasound, permanent section histology with addition of immunohistochemistry is indicated instead of frozen section. e) Patients whose postoperative management is already known to include axillary radiation. Critique: In patients undergoing BCS with anticipated usual postoperative breast radiation and adjuvant therapy, with the addition in this study of negative preoperative axillary US ( FNA as indicated), frozen section of SLNs could be avoided because those SLNs that were found to contain metastatic deposits (thereby false negative axillary US) were judged small enough and few enough not to require completion axillary dissection (commensurate with the Z0011 study findings). Question 4 In this study, patients whose preoperative US-directed FNA of an axillary lymph node that proved positive for metastasis were: a) Excluded from the study. b) Included if preoperative chemotherapy restored the nodes to radiologically normal. c) Randomized between adjuvant chemotherapy with or without axillary radiation. d) More correlated with estrogen receptor negative and higher nuclear grade tumors. e) Were included if the size of nodal metastasis was smaller than 2 mm.
178
J Am Coll Surg
Continuing Medical Education Program
Critique: We used preoperative axillary US as an “extension of the physical examination,” and, therefore, if metastatic disease was identified by US-FNA, we judged these patients to have clinically positive lymph nodes, so they were not eligible for our study analysis. Clinical palpation was the only axillary lymph node screening technique used in the Z0011 study, and because US is certainly more sensitive than clinical palpation, one might expect the Z0011 study to have more advanced, lymph node positive disease than our study. Actually, they were roughly equivalent. This likely reflects some degree of preselection of the patients entered into the Z0011 study.
ARTICLE 2
a variety of topics. It contains clinical and resource use information included in a typical discharge abstract. Critique: NSQIP has the goal of assisting hospitals in tracking surgical complications in an effort to improve quality of care delivered to surgical patients. A trained surgical clinical reviewer at each participating hospital collects data included in NSQIP directly from patient charts. NSQIP measures are both risk-adjusted and case-mix adjusted to account for patient severity of illness and complexity of operations performed. NSQIP includes 30-day outcomes for patients rather than outcomes to hospital discharge.
(Please consider how the content of this article may be applied to your practice.)
Question 2 When a sample size is limited, which of the following is the preferred method for validation of a statistical model?
Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A J Am Coll Surg 2013;217:153e161
a) b) c) d) e)
Learning Objectives: After study of this article, surgeons should be able to identify key predictors of mortality in patients who present with necrotizing soft tissue infection (NSTI). This NSQIP-based model of risk from NSTI can help to inform discussions between surgeons, patients, and families.
Critique: Split-sample validation and bootstrapping are both techniques that are used for validation of a statistical model with a limited sample size. Splitsample reduces an already limited dataset by using half of the data for model development and the other for model validation. Bootstrapping permits use of the entire dataset for model development and validation. Bootstrapping outperforms split sample validation in many studies. The c-statistic, or concordance statistic, is used specifically to measure discrimination of a model. Multivariable logistic regression is used for model development. The probability of mortality formula is generated by multivariable logistic regression and accounts for the impact of statistically significant independent variables on the outcome of interest (in this case, mortality).
Question 1 Which of the following statement best describes NSQIP? a) NSQIP does not account for complexity of operations performed. b) NSQIP is a network with the goal of pursuing welldesigned collaborative quality improvement projects in surgical care. c) NSQIP is a multicenter, prospective database that collects data on 136 variables, including pre-, intraand postoperative variables and 30-day mortality and morbidity outcomes for patients undergoing surgical procedures. d) NSQIP is a retrospective database that collects data from claims or administrative data and is not reviewed by trained auditors. e) NSQIP is a uniform, multistate database that promotes comparative studies of health care services and will support health care policy research on
Bootstrapping c-statistic Multivariable logistic regression Probability of mortality formula Split-sample validation
Question 3 Laboratory data collected in the NSQIP Participant Use Data File (PUF) and included in this analysis include which of the following? a) b) c) d) e)
Serum albumin Serum bilirubin Serum glucose Microbial identification Platelet count
Vol. 217, No. 1, July 2013
Critique: Serum albumin and serum bilirubin are both collected in the NSQIP PUF but were excluded from this analysis because they did not achieve statistical significance during exploratory univariate analysis. Serum glucose is not included in the NSQIP PUF, nor is microbial identification. Platelet count is part of the PUF and independently predicted mortality in a multivariate model when <150,000 at admission. Question 4 Which patient described below has the highest mortality risk based on the calculator for patients with NSTI? a) Age 65, dialysis-dependent, required assistance with many activities of daily living, American Association of Anesthesiologists (ASA) class 4, septic shock at presentation, thrombocytopenic at presentation. b) Age 65, female, glomerular filtration rate of 25, partially dependent with activities of daily living,
Continuing Medical Education Program
179
ASA class 3, systemic inflammatory response syndrome at presentation, platelet count of 100K at presentation c) Age 45, diabetic, smoker, bed-bound, ASA class 3, required intraoperative blood transfusion, and was on the ventilator for 72 hours postoperatively. d) Female, alcoholic, and diabetic, bed-bound, ASA class 5, in septic shock at time of presentation, had leukocytosis at presentation. e) Male, dialysis-dependent, required assistance with many activities of daily living, ASA class 4, developed acute lung injury postoperatively, had anemia on presentation. Critique: Independent risk factors for mortality associated with NSTI identified from analysis of NSQIP were age >60 y, partially or totally dependent functional status, requiring dialysis before presentation, ASA class 4 or greater, emergent surgery, septic shock at presentation, and thrombocytopenia (<150K) at presentation.
180
Continuing Medical Education Program
J Am Coll Surg
To complete CME please go to http://jacscme.facs.org Log in with your ACS Member ID# and last name. The JACS CME website has additional articles available for credit (maximum 4 per issue)
Issues are available for the past 24 months. You can print your certificate immediately. For those who are unable to access the internet, fax this page ONLY to 312-202-5027 Your certificate will be faxed or emailed to you; incomplete submissions will not be processed. No mail submissions will be accepted.
JACS CME Featured Articles, Volume 217, July 2013 Preoperative axillary ultrasound in breast cancer: safely avoiding frozen section of sentinel lymph nodes in breast-conserving surgery Ibrahim-Zada I, Grant CS, Glazebrook KN, Boughey JC. J Am Coll Surg 2013;217:7e16 Development and validation of a necrotizing soft-tissue infection mortality risk calculator using NSQIP Faraklas I, Stoddard GJ, Neumayer LA, Cochran A. J Am Coll Surg 2013;217:153e161