Colorectal Cancer

Recurrence after colorectal cancer surgery

Advances in surgery and adjuvant therapy have reduced local recurrence of rectal cancer, but it still occurs in some patients. Such recurrences are often difficult to resect or require major surgery. Most colorectal cancers are adenocarcinomas, and recurrent tumors contain many hypoxic cells and are often radioresistant; if the pelvis has already received X-ray therapy, repeat X-ray therapy is difficult. Carbon ion therapy is included in Japan’s colorectal cancer treatment guidelines.