Abstract

PURPOSE AND METHODS: Patients with nodal negative colorectal cancer (CRC) suffer recurrent or metastatic disease in 40% of cases after surgical resection. To investigate a potential prognostic impact of vascular tumor infiltration, we retrospectively analyzed 185 nodal negative stage I and II CRC specimens for the presence of intra- and/or extramural venous invasion (V1(IM)/V1(EM)) using elastic stains of all tumor sections and correlated our findings with the clinical follow-up. RESULTS: Venous invasion was observed in 43 (23.2%) patients by elastic stains compared with six (3.2%) using HE only (p < 0.05). Venous invasion was more common in stage II than in stage I tumors (28.1% versus 5.1%; p < 0.05). However, survival analyses showed no significant differences in 5-year survival rates comparing patients with and without venous invasion (68% and 71%, p = 0.543) or patients with V1(IM) and V1(EM) (62% vs. 74%, p = 0.473), respectively. CONCLUSIONS: Our data emphasize the need for standardized criteria, including elastic stains, to reliably detect vascular invasion in CRC. Doing so, however, the prognostic impact of venous invasion in stage I and II CRC may be lower as previously anticipated.