INFLUENCE OF LOCAL PERITONEAL INVOLVEMENT ON PELVIC RECURRENCE AND PROGNOSIS IN RECTAL-CANCER

Aims-To evaluate the influence of involvement of the peritoneal surfac e by carcinoma of the rectum on local recurrence and prognosis. Method s-Prospective analysis of pathological prognostic factors in 209 resec tions for rectal carcinoma between 1988 and 1993 with meticulous patho logical technique particularly to assess the relation of tumour to the peritoneal surface. Comprehensive clinical follow up with cause of de ath established from all available sources of information (hospital an d general practitioner data) with necropsies where necessary. Local re currence was determined by accepted clinical, radiological and patholo gical criteria. Results-Local peritoneal involvement was detected in 2 5.8% (54/209) of cases. It was more common in women and was associated with tumour differentiation, size and site, and lymph node involvemen t. Local peritoneal involvement showed considerable prognostic disadva ntage in all cases and in curative cases alone. Multivariate analysis demonstrated independent prognostic disadvantage for all cases althoug h this was lost in the curative group. With a 30 month median follow u p time, comprehensive clinical surveillance detected 25 (12.0%) local recurrences. Thirteen (52%) palliative cases had Shown spread to invol ve the mesorectal (deep, circumferential) resection margin. Of the 12 curative cases, six were upper rectal cancers with local peritoneal in volvement suggesting that tumour seeding into the pelvic peritoneal ca vity was the cause of local recurrence. Local recurrence of the six ot her rectal tumours was probably because of intraluminal seeding in two , involvement of the distal margin in one, extensive extramural venous involvement in two, and tumour spread to the bladder in one. Conclusi ons-Comprehensive pathological analysis of a resection specimen can id entify cases with a high probability of local recurrence which may ben efit from early adjuvant therapy. Involvement of the peritoneal surfac e is a common event in rectal cancer, has adverse prognostic influence and may be an important factor in local recurrence of upper rectal ca rcinoma.