Purpose: The features of T1 colorectal adenocarcinoma and the risk determination of lymph node metastasis were reviewed. Prognostic factors were assessed to verify whether the risk of lymph node metastasis would influence the long-term prognosis.
Methods: Patients undergoing curative resection of T1 colorectal adenocarcinoma at the Taipei Veterans General Hospital from December 1969 to August 2002 were retrospectively studied. Patients with synchronous colorectal cancer, distant metastasis, familiar adenomatous polyposis, or inflammatory bowel disease were excluded. The associations between lymph node metastasis and clinicopathologic variables were evaluated univariately using chi-squared test, Fisher's exact test, or Student's t -test, and multivariately using logistic regression. Univariate analysis by the log-rank test and multivariate analysis by Cox regression hazards model determined the factors influencing the overall survival.
Results: A total of 159 patients were included. Sixteen patients (10.1 percent) had lymph node metastasis. The risk of lymph node metastasis included histologic grade (P = 0.005), lymphatic vessel invasion (P = 0.023), inflammation around cancer (P = 0.049), and budding at the invasive front of tumor (P = 0.022). Age (P = 0.001) and number of total sampling lymph nodes (P < 0.0001) were found to be the factors influencing the overall survival.
Conclusions: Variables that predict lymph node metastasis in surgically resected T1 colorectal carcinoma may not impact the long-term prognosis.