Protocol digest of a single-arm confirmatory trial for less intensive postoperative surveillance in low-risk colorectal cancer patients: JCOG1915 (less study).

The Japanese Society for Cancer of the Colon and Rectum guidelines recommend intensive surveillance for curatively resected pathological stage I-III colorectal cancer. However, there is still no global consensus on the optimal method, duration, or frequency of surveillance, and no clinical trials have demonstrated the usefulness of surveillance. We are conducting a clinical trial to confirm the efficacy of less-intensive surveillance after R0 resection with lymph node dissection for stage I or low-risk stage II colorectal cancer in patients without risk factors for recurrence. If this less intensive surveillance method proves effective, medical costs will be considerably reduced. The primary endpoint is overall survival. A total of 680 patients will be enrolled from 59 institutions over 2 years. This trial has been registered at the Japan Registry of Clinical Trials (jRCT) as study number jRCT1030220350.