Outcomes of resection and non-resection strategies in management of patients with advanced colorectal cancer.

BACKGROUND: The management of patients with surgically incurable bowel cancer at presentation is controversial. The aims of treatment are to optimise quality of life and prolong survival. It has been believed that the most effective palliation is achieved by resection of the primary cancer in order to pre-empt future complications. This study reviews and compares the outcomes of patients with incurable bowel cancer managed by resection and non-resection strategies over a 7-year period in a single District General Hospital. PATIENTS AND METHODS: All patients with surgically incurable bowel cancer at presentation were identified from the prospectively collected local ACPGBI database. Survival, using Kaplan-Meier method and log-rank test, was compared between patients managed by resection of the primary, non-resectional intervention (surgery, stent & oncological treatments) and those managed with supportive care only. The primary endpoint of the study was survival on an intention to treat basis, compared using Kaplan-Meier and log-rank tests. RESULTS: Of 646 consecutive newly diagnosed bowel cancer patients over a 7 year period 154 cases (24%) were deemed surgically incurable at presentation. Of these surgical resection was carried out in 45 patients (29%), non-resectional intervention was followed in 52 patients (34%) and supportive treatment alone in 57 patients (37%). Median survival of each group was as follows: resected patients 11 months (I.Q range 3-18 months), non-resectional intervention 7 months (I.Q range 2-15 months) and supportive care alone 2 months (I.Q range 1-8 months). Only one patient (2%) managed by non-resectional intervention required later surgery to treat primary tumour related complications. Survival was not significantly different between resection and non-resection treatments. The overall operative mortality for the resection group was 16% (7/45 cases), with an elective mortality of 14% (4/28 cases) and emergency mortality 18% (3/17 cases). CONCLUSION: In an unselected bowel cancer population surgical resection of the primary tumour in patients presenting with incurable disease does not improve survival and is associated with a high risk of post-operative mortality.

A national study on lymph node retrieval in resectional surgery for colorectal cancer.

PURPOSE: This study was designed to develop a mathematical model for predicting the number of lymph nodes harvested in bowel cancer resection specimens based on the current clinical practice in the United Kingdom. METHODS: Prospective clinical data were collected from 8,409 newly diagnosed bowel cancer patients presenting to 79 hospitals in Great Britain and Ireland during a variable 12-month period from 2000 to 2002. A two-level hierarchical regression model was used to identify predictors for lymph node harvest. The model was internally validated by comparing observed and model predicted lymph node harvest for patient subgroups. RESULTS: Inclusion criteria were satisfied by 5,164 patients. The average lymph node harvest was 11.7 nodes with significant between-center variability in lymph node harvest (range, 5.5-21.3 nodes). Increasing age, American Society of Anesthesiology grade, and preoperative radiotherapy were associated with a reduction of lymph node harvest (P < 0.001). Abdominoperineal resection of the rectum and transverse colectomy were the lowest yield procedures for lymph node harvest. Independent predictors of lymph node harvest were age, American Society of Anesthesiology grade, Dukes stage, operative urgency, type of resection, and preoperative radiotherapy. When tested, the model was found to accurately predict lymph node harvest for group statistics (comparison of observed and model predicted lymph node harvest F(1,5154) = 0.63; P = 0.427). CONCLUSIONS: The results of the study suggest that the minimum number of lymph nodes harvested in colorectal cancer surgery cannot be set at a fixed value. The lymph node harvest model provides a simple tool to the frontline clinician for comparing standards between multidisciplinary bowel cancer teams.

Prediction of postoperative mortality in elderly patients with colorectal cancer.

PURPOSE: This study was designed to develop a model for predicting postoperative mortality in elderly patients undergoing surgery for colorectal cancer. METHODS: This multicenter study was conducted by using routinely collected clinical data, assessing patients older than aged 80 years, with 30-day operative mortality as the primary end point. Data were collected from The Association of Coloproctology of Great Britain and Ireland database, encompassing 8,077 newly diagnosed colorectal cancer patients undergoing resectional surgery in 79 hospitals between April 2000 to March 2002, The Association of Coloproctology Malignant Bowel Obstruction Study, encompassing 1,046 patients with malignant bowel obstruction in 148 hospitals, between April 1998 to March 1999, and The Wales-Trent audit, encompassing 3,522 newly diagnosed colorectal cancer patients, between July 1992 to June 1993. A multilevel logistic regression model was developed to adjust for case-mix and to accommodate the variability of outcomes between the three study populations. The model was internally validated using a Bayesian resampling technique and tested using measures of discrimination, calibration, and subgroup analysis. RESULTS: A total of 2,533 patients satisfied the inclusion criteria, with a 30-day mortality of 15.6 percent. Multivariate analysis identified the following independent risk factors: age (odds ratio for 85-90, 90-95, >95 vs. 80-85 = 1.1, 1.8, 2.9), American Society of Anesthesiology grade (odds ratio for Grade III, IV vs. I-II = 2.7, 6.1), operative urgency (odds ratio for emergency vs. elective = 1.9), no cancer excision vs. resection (odds ratio = 1.2), and metastatic disease (odds ratio for metastases vs. no metastases = 1.9). The model offered adequate discrimination (area under receiver operator curve = 0.732) and excellent agreement between observed and predicted outcomes during eight colorectal procedures (P = 0.885). CONCLUSIONS: The elderly colorectal cancer model can accurately estimate 30-day mortality in patients older than aged 80 years undergoing surgery for colorectal cancer. Because the mortality can be considerable, this may have important implications when determining management for this group of patients.

Evaluating operative risk in colorectal cancer surgery: ASA and POSSUM-based predictive models.

OBJECTIVE: To review two predictive models, based on the American Society of Anaesthesiologists (ASA) and the Physiological and Operative Severity Score for the enumeration of Mortality and morbidity (POSSUM)-used for estimating postoperative mortality in patients, undergoing surgery for colorectal disease, in the UK. METHODS: Data was derived from three multicentre, UK-based studies involving a total of 16,006 patients with malignant or non-malignant bowel pathologies. Data sources were: The Colorectal-POSSUM (CR-POSSUM) Study population, comprising 6883 patients undergoing colorectal surgery in 15 UK hospitals between 1993 and 2001; The Association of Coloproctology of Great Britain and Ireland (ACPGBI) Colorectal Cancer (CRC) Database, encompassing 8077 newly diagnosed CRC patients, undergoing surgical resections in 79 hospitals, between April 2000 and March 2002; The ACPGBI Malignant Bowel Obstruction (MBO) Study, encompassing 1046 patients with MBO in 148 hospitals, treated between April 1998 and March 1999. Multifactorial logistic regression analyses were used to adjust for case-mix, identify risk factors for in-hospital/30-day operative mortality and to accommodate the variability of outcomes between hospitals. RESULTS: In the ACPGBI CRC study, 7374 patients had surgery, 6622(89.8%) a major bowel resection and 1465(19.9%) emergency surgery. Nine hundred and eighty-nine (94.6%) patients with MBO had surgery and 854(86.3%) underwent bowel resection. In the CR-POSSUM study, of the 6790(98.6%) patients undergoing surgery, 3451(50.8%) had a major colorectal resection, including 2107(31.0%) as an emergency. The operative mortality was 7.5% for the ACPGBI CRC study, 15.7% for patients with MBO and 5.7% for patients in the CR-POSSUM study. When tested, the predictive models showed good discrimination, with an area under the receiver-operator characteristic curve of 77.5% for the ACPGBI CRC, 80.1% for the MBO and 89.8% for the CR-POSSUM. CONCLUSIONS: Prediction of postoperative death can be made by the clinician using simple, numerical, tables derived from the ACPGBI CRC, MBO and CR-POSSUM models. The models can be used in everyday practice for pre-operative counselling of patients and their carers, as a part of the process of informed consent. They may also be used to compare the outcomes between multidisciplinary CRC teams.

The Association of Coloproctology of Great Britain and Ireland study of large bowel obstruction caused by colorectal cancer.

BACKGROUND: This study was designed to investigate the early outcomes after surgical treatment of malignant large bowel obstruction (MBO) and to identify risk factors affecting operative mortality. METHODS: Data were prospectively collected from 1046 patients with MBO by 294 surgeons in 148 UK hospitals during a 12-month period from April 1998. A predictive model of in-hospital mortality was developed using a 3-level Bayesian logistic regression analysis. RESULTS: The median age of patients was 73 years (interquartile range 64-80). Of the 989 patients having surgery, 91.7% underwent bowel resection with an overall mortality of 15.7%. The multilevel model used the following independent risk factors to predict mortality: age (odds ratio [OR] 1.85 per 10 year increase), American Society of Anesthesiologists grade (OR for American Society of Anesthesiologists grade I versus II,III,IV-V = 3.3,11.7,22.2), Dukes' staging (OR for Dukes' A versus B,C,D = 2.0, 2.1, 6.0), and mode of surgery (OR for scheduled versus urgent, emergency = 1.6, 2.3). A significant interhospital variability in operative mortality was evident with increasing age (variance = 0.004, SE = 0.001, P < 0.001). No detectable caseload effect was demonstrated between specialist colorectal and other general surgeons. CONCLUSIONS: Using prognostic models, it was possible to develop a risk-stratification index that accurately predicted survival in patients presenting with malignant large bowel obstruction. The methodology and model for risk adjusted survival can set the reference point for more accurate and reliable comparative analysis and be used as an adjunct to the process of informed consent.

Operative mortality in colorectal cancer: prospective national study.

OBJECTIVE: To develop a mathematical model that will predict the probability of death after surgery for colorectal cancer. DESIGN: Descriptive study using routinely collected clinical data. DATA SOURCE: The database of the Association of Coloproctology of Great Britain and Ireland (ACPGBI), encompassing 8077 patients with a new diagnosis of colorectal cancer in 73 hospitals during a 12 month period. STATISTICAL ANALYSIS: A three level hierarchical logistic regression model was used to identify independent predictors of operative mortality. The model was developed on 60% of the patient population and its validity tested on the remaining 40%. RESULTS: Overall postoperative mortality was 7.5% (95% confidence interval 6.9% to 8.1%). Independent predictors of death were age, American Society of Anesthesiology (ASA) grade, Dukes's stage, urgency of the operation, and cancer excision. When tested the predictive model showed good discrimination (area under the receiver operating characteristic curve = (0.775) and calibration (comparison of observed with expected mortality across different procedures; Hosmer-Lemeshow statistic = 6.34, 8 df, P = 0.610). CONCLUSIONS: Clinicians can predict postoperative death by using a simple numerical table derived from the statistical model of the ACPGBI. The model can be used in everyday practice for preoperative counselling of patients and their carers as a part of multidisciplinary care. It may also be used to compare the outcomes between multidisciplinary teams for colorectal cancer.