The effect of malignant and inflammatory fixation of rectal carcinoma on prognosis after rectal excision.

Fixity of colorectal carcinoma at operation seems an important prognostic indicator, perhaps equally as significant as lymph node invasion. A proportion of tumours are, however, tethered by inflammatory adhesions only and, although patients with these tumours should fare better than those with tumours fixed by extramural malignant spread, available data is contradictory. With the recent interest in pre-operative radiotherapy for patients with fixed rectal tumours an in order to clarify the above points we studied 625 patients who had undergone rectal excision a minimum of 10 years previously. Excluding those with disseminated disease, 169 (27 per cent) were fixed, 124 (20 per cent) by direct malignant spread, 45 (7 per cent) by inflammatory tissue. Survival and recurrence rates in these patients were compared with an equivalent number who had mobile lesions. The groups were matched for age, sex and Dukes' stage. The degree of differentiation and height of the lesion above the anal margin were similar. Corrected 5 year survival rates were 28.5 per cent in patients with malignant fixation, 68.9 per cent (P less than 0.01) in those with mobile tumours and 64.6 per cent (P less than 0.01) where the lesion was tethered by inflammation. The incidence of local recurrence in the three groups was 41.3, 15.1 and 20.0 per cent respectively. Five year survival rate in patients with fixed Dukes' B lesions was 43.5 per cent and in patients with mobile C lesions was 62.9 per cent (P less than 0.01). Thus, patients with fixed carcinomas of the rectum have a poor prognosis but only if contiguous spread of the tumour has occurred. These findings have important implications for patients in whom fixity is used as an indication for adjuvant therapy.