Budding as a useful determinant of the optimal treatment for T1 rectal carcinomas

If a locally excised specimen has poorly differentiated or undifferentiated histology, positive vascular invasion, or massive invasion to the cut end or a positive margin, additional surgery is recommended for the treatment of T1 rectal carcinoma. However, positive predictive values of these histological criteria are low. This study was undertaken to clarify more reliable risk factor(s) for lymph node metastasis in T1 rectal carcinomas.

In 58 patients with T1 rectal carcinoma undergoing local excision or radical surgery, the associations between lymph node metastasis or intrapelvic recurrence and clinicopathological features were studied using multiple regression analysis with special reference to tumor budding at the invasive front.

Lymph node metastasis was observed in 1 of 9 patients undergoing additional bowel resection after local excision, and in 2 of 24 patients undergoing radical surgery alone. Intrapelvic extrarectal recurrence was observed in 3 of 25 patients undergoing local excision alone. Logistic regression analysis revealed that budding at the invasive front alone was significantly associated with lymph node metastasis or intrapelvic recurrence (p = 0.0484).

Additional bowel resection with lymph node dissection should be recommended for locally excised T1 rectal carcinoma with budding at the invasive front.