Histological grade predicts survival time associated with recurrence after resection for colorectal cancer.

BACKGROUND/AIMS: This study analyzed the patients who died of recurrent colorectal cancer and determined the clinicopathologic indicators that were associated with the survival time.

METHODOLOGY

The study included 282 patients who died of recurrent colorectal cancer after resection. The clinicopathologic findings were compared between 162 patients who died within 3 years after resection (the short-term survival group) and 120 patients who died more than 3 years after resection (the long-term survival group). Multivariate analysis was performed to determine the independent factors correlated with the timing of death.

RESULTS

When compared with the long-term survival group, the short-term survival group was characterized by a tumor size >5 cm (51.2% in the short-term survival group vs. 39.2% in the long-term survival group), poorly differentiated tumor (13.3% vs. 0.9%), invasion through the muscularis propria (98.8% vs. 88.3%), positive lymphatic invasion (43.2% vs. 20.8%), positive vascular invasion (34.0% vs. 16.7%), positive perineural invasion (17.9% vs. 8.3%), extended lymph node metastasis and Dukes' stage C disease (80.9% vs. 60.8%). The mean survival time was significantly influenced by the histologic grade, the depth of wall invasion, the presence of lymphatic or vascular invasion, the level of lymph node metastasis and the Dukes' stage. On multivariate analysis, however, histologic grade was the only independent factor associated with the survival time.

CONCLUSIONS

The histological grade was the only significant factor influencing the survival time after resection of colorectal cancer. The patients with poorly differentiated adenocarcinoma frequently died of recurrence within 3 years after colorectal resection.