Characteristics of recurrence after curative resection for T1 colorectal cancer: Japanese multicenter study

Because the rate of recurrence after curative resection for T1 colorectal cancer is low, the characteristics of recurrence remain obscure. This multicenter study attempted to clarify the characteristics of recurrence after curative resection for T1 colorectal cancer. We analyzed the associations between recurrence and various clinicopathological features in 798 patients who had undergone curative resection alone for T1 colorectal cancer at 14 hospitals between 1991 and 1996. The rate of lymph node metastasis (LNM) in patients with T1 colorectal cancer was 10.5% (84/798), and 18 (2.3%) of the 798 patients developed recurrence during the median follow-up of 7.8 years. The recurrence rates in patients with colon cancer with and without LNM were 3.6 and 1.3%, respectively (p = 0.19). These rates in patients with cancer of the rectum were 25.0 and 1.1% (p < 0.0001). Among various parameters, histological grade (p < 0.0001), location (p = 0.025), LNM (p < 0.0001), and venous invasion (p = 0.0013) were risk factors for recurrence. Among them, LNM (p = 0.0008) and histological grade (p = 0.041) were independent risk factors for recurrence after curative resection for T1 colorectal cancer. Time to recurrence was more likely to be shorter for patients with, than without nodal involvement. In patients with an unfavorable histological grade, all recurrences developed within 1 year. The recurrence rate after curative resection for node-negative T1 colorectal cancer was very low. The effectiveness of surveillance to detect recurrence after curative resection for T1 colorectal cancer should be validated in further studies.