H Mulcahy

Identifying stage B colorectal cancer patients at high risk of tumor recurrence and death.

PURPOSE: This study was designed to determine clinical and pathologic variables associated with poor outcome following resection of Stage B colorectal cancer. METHODS: This was a retrospective study of 117 patients with Stage B cancer who underwent curative surgery and survived the postoperative period. Fourteen clinical and pathologic features were studied. Clinical data were extracted from a prospective colorectal cancer database, and histologic slides were retreived and examined by a pathologist blinded as to clinical details and outcome. RESULTS: After a median follow-up period of 8.2 years, bowel obstruction was significantly related to a poor prognosis (log-rank test; P=0.03). Extensive necrosis (P=0.01) and perineural invasion (P= 0.03) were also associated with decreased survival. Vascular invasion was associated with poor long-term outcome in the subgroup of patients with rectal (P=0.07) but not colonic (P=0.57) cancer. Multivariate regression analysis identified both tumor necrosis (P=0.01) and perineural invasion (P=0.03) as independently related to outcome. CONCLUSION: Further study of prognostic indicators might result in an algorithm to distinguish Stage B cases at high risk of tumor recurrence and death. Such patients could be included in future trials of adjuvant therapies.

Duration of colorectal cancer symptoms and survival: the effect of confounding clinical and pathological variables

The relationship between symptom duration and long-term survival following colorectal cancer is complex, and a number of factors may influence the length of time from onset of symptoms of cancer diagnosis. We prospectively studied 777 consecutive colorectal cancer patients to determine the association between symptom duration and survival independent of other clinical and pathological features. We used survival curves, the logrank test and Coxs proportional hazards model to assess possible changes in relative risk of death with increasing symptom duration, without making any a priori assumptions. We found that symptom duration shortened with advanced tumour stage (P < 0.0006) and was also shorter for patients presenting with bowel obstruction (P < 0.0001). Univariate survival analysis showed that long-term survival increased consistently with symptom duration (P < 0.001). However, when the effect of tumour stage and bowel obstruction were accounted for in a multivariate analysis, no decrease in the relative risk of death was seen as symptom duration increased. The addition of other variables to the proportional hazards model such as age, sex or tumour site did not further influence the risk function form of symptom duration. Our results suggest that early diagnosis of colorectal cancer should remain our goal when assessing patients with suggestive gastrointestinal symptoms.

Colonoscopic surveillance after curative resection for colorectal cancer

Colonoscopic surveillance after resection for colorectal cancer has been advocated to improve detection of anastomotic recurrence, and of synchronous and metachronous tumours. The benefit provided by colonoscopy remains unproven, and the best timing of examination is unclear. To determine the value of colonoscopy after curative resection for large bowel cancer, the efficacy of an endoscopic surveillance programme in the early detection of intraluminal bowel recurrence in a series of patients admitted with colorectal cancer was examined. Between April 1983 and December 1988, 132 patients underwent colonoscopy. Eight (6.1 per cent) were found to have intraluminal recurrence without evidence of extraluminal spread. Six of these recurrences were at the site of anastomosis and two represented metachronous tumour development. All of these patients were symptomatic at the time of diagnosis. In 15 patients (11.4 per cent), adenomatous polyps were discovered during the initial endoscopic examination. These results indicate that colonoscopic surveillance will rarely allow early detection of asymptomatic intraluminal bowel recurrence, but is valuable in the detection of synchronous lesions. Frequent surveillance is not justified in the early postoperative years and colonoscopy should probably be confined to a single procedure to exclude synchronous lesions.