Influence of pT3 subgroups on outcome of R0-resected colorectal tumors.

OBJECTIVE

Evaluate whether depth of infiltration within T3 colorectal tumors influences long-term oncologic outcome.

PATIENTS AND METHODS

Patients with stage pT3 colon and rectal tumors were divided into four subgroups according to the depth of infiltration. The influence on overall and disease-free survival was tested for each subgroup and compared in univariate and multivariate analyses.

RESULTS

A total of 368 patients were evaluated, with a median follow-up time of 92.5 months. In 181 patients with colon cancer 5- and 10-year overall survival rates were 82.7% and 65.0%, respectively, and 5- and 10-year disease-free survival rates were 80.9% and 64.4%, respectively. For 187 patients, rectal cancer 5- and 10-year overall survival rates were 69.0% and 50.5%, respectively, and disease-free survival rates were 61.3% and 47.5%, respectively. In either colon or rectal cancer, different pT3 categories showed neither a statistically significant influence on survival nor the occurrence of local or distant recurrence in univariate and multivariate analyses; however, higher pT3 subgroups had a significant influence on lymph node involvement and vessel invasion in patients with rectal cancer.

CONCLUSIONS

Subdivision of pT3 tumors in colon cancer based on depth of infiltration does not provide additional information about prognosis. In rectal cancer, T3 substages were associated with lymph node involvement; however, we could not demonstrate an impact on recurrence or survival.