Tumor nodules are occasionally found in adjacent mesentery of colorectal cancer specimens and are felt to reflect a worse prognosis. The clinical significance of mesenteric tumor nodules was investigated.

A review of 786 patients with stage III colorectal cancer referred between 1995 and 1999 was undertaken. TNM staging was standardized by considering mesenteric nodules separately and not assigning them to T or N categories. Survival analyses were performed.

Mesenteric tumor nodules were found in 116 (14.8%) patients: 48 (41.4%) with colon cancer and 68 (58.6%) rectal cancer. Mean age at surgery was 63 years. Adjuvant chemotherapy was given to 84.8% of colon cancer patients. Two (2.9%) rectal cancer patients received neoadjuvant chemoradiation, and 63 (92.6%) received adjuvant therapy (chemotherapy and/or radiation). In the cohort with mesenteric nodules, the median time to progression was 23.1 months, the median 5-year disease-free survival was 35%, and the median overall survival (OS) was 47.9 months, with 44% OS at 5 years. In the 19 (16.4%) patients with mesenteric nodules and no lymph nodes the 5-year OS was 60% (SEER stage II 5-year survival 82.5%), whereas in 97 patients who were lymph node-positive the 5-year OS was 40% (SEER 5-year survival stage IIIc 44.3%; stage IV 8.1%).

In comparison to SEER survival data, the presence of mesenteric nodules appears to worsen the prognosis of any T/N0 disease to that of overall stage III disease. Mesenteric nodules with any T/N+ disease had prognosis similar to that of stage IIIC disease, but the prognosis was better than M1 disease. .