M. R. Thompson

Operative mortality in colorectal cancer: prospective national study

Abstract 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, Dukess 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.

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.

Evidence of the effect of 'specialization' on the management, surgical outcome and survival from colorectal cancer in Wessex.

A prospective audit of the management of colorectal cancer was established to investigate factors associated with variation in survival observed within the former Wessex region (population three million).

A National Study on Lymph Node Retrieval in Resectional Surgery for Colorectal Cancer

PurposeThis 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.MethodsProspective 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.ResultsInclusion 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 F1,5154 = 0.63; P = 0.427).ConclusionsThe 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.

Comparison of circumferential margin involvement between restorative and nonrestorative resections for rectal cancer

Objective  To study circumferential margin involvement (CMI) in patients undergoing restorative, compared with nonrestorative, surgery for rectal cancer.

Prediction of Postoperative Mortality in Elderly Patients With Colorectal Cancer

PurposeThis study was designed to develop a model for predicting postoperative mortality in elderly patients undergoing surgery for colorectal cancer.MethodsThis 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.ResultsA 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).ConclusionsThe 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.

Disease stage and psychosocial outcomes in colorectal cancer.

Objective  Disease stage is a strong predictor of cancer survival and is therefore assumed to influence psychosocial outcomes. However, existing findings are inconsistent, perhaps reflecting limited sample sizes, especially among patients with advanced disease. There has also been an emphasis on breast cancer, resulting in a focus on outcomes among women. The present study investigated associations between disease stage and psychosocial wellbeing in 128 patients (52% male, 48% female) diagnosed with colorectal cancer.

Predictive value of common symptom combinations in diagnosing colorectal cancer

This study compared the diagnostic values of age and single symptoms of colorectal cancer with those of age and symptom combinations.

Identifying and managing patients at low risk of bowel cancer in general practice

All NHS patients who are suspected to have bowel cancer by their general practitioner should now be seen by a specialist within two weeks. The government introduced this policy in July 2000 in response to concerns that some patients had to wait too long for an outpatient appointment. However, this new policy could distort referral patterns either by increasing the referral of patients with transient symptoms or by increasing the delay for cancer patients presenting with non-typical symptoms. Unless general practitioners act as efficient gatekeepers, specialist services could become overloaded. We explain the basis for the governments guidelines for referral and discuss how to manage patients at low risk of cancer. The Department of Health has developed guidelines to help general practitioners decide which patients require fast track referral and which can safely be treated and monitored in general practice (table).1 2 View this table: Department of Health criteria for high and low risk of bowel cancer The guidelines were based on data from relevant studies, which were assigned levels of evidence by established methods.3 The grading system for the higher risk symptoms was similar to that used to grade recommendations for hypertension, thrombosis, and diabetes.4–6 The high prevalence of rectal bleeding,7 8 changes in bowel habit,9 and abdominal pain10 in the community relative to the incidence of bowel cancer means that most patients with these symptoms are at very low risk of cancer. Many of these symptoms are transient or cause no alarm, and over 80% of patients do not seek medical advice.7–11 Of those who do, only 40-50% are referred to hospital.7 8 The risk of cancer in patients with rectal bleeding, for example, varies from 1:700 in the community8 to 1:30 in primary care,12 and 1:16 …

Social deprivation and outcomes in colorectal cancer

The aim of this study was to examine the influence of social deprivation on postoperative mortality and length of stay in patients having surgery for colorectal cancer.