Prognosis in synchronous colorectal carcinomas.

The prognosis of synchronous colorectal carcinomas is a matter of controversy. 5-year survival rates are reported to be either better or worse in comparison with single carcinomas. In this study 736 cases with histologically proven malignancies oft the large intestine were reviewed. 22 patients (3 per cent) showed multiple primary tumors. Patients with multiple tumors had associated adenomas in 72 per cent vs 14 per cent of the patients with single cancers (P < 0.01). 77 per cent of the synchronous tumors were located in the left colon. Only in 5 patients (23 per cent) two different lymphatic drainage areas were involved. 15 patients (68 per cent) presented without lymph node or distant metastases. A radical procedure was performed in 82 per cent. The overall 5-year survival rate was 54.5 per cent for multiple and 44.5 per cent for single carcinomas. The better survival rate seems to be due to the higher rate of early detection because of rectal bleeding in patients with synchronous tumors.