Optimal waiting time to surgery after radiation therapy in rectal cancer

This study investigated the optimal waiting time between radiation therapy and surgery in rectal cancer patients. Researchers suggested that a prolonged waiting time is associated with tumor shrinkage. 

Surgery is the only curative treatment for rectal cancer. Chemotherapy and radiation therapy is the recommended treatment before rectal surgery, since they have been found to improve tumor shrinkage and survival. There are two applied schedules, radiation therapy followed by a long or short waiting time before surgery. Prior studies have not found a difference between both schedules with respect to overall survival and recurrences (when the cancer comes back). However, the patients in these studies are not the same as seen in daily practice, as patients in clinical trials are carefully chosen.

The objective of this study was to investigate the effects of a short and prolonged waiting time after radiation therapy in usual daily practice in a group of rectal cancer patients. This study included information on 113 patients who underwent surgery. These patients were divided into 3 groups. 22 patients underwent surgery without being treated with radiation therapy, 71 where treated with short course schedule and 20 with the long course schedule.

No difference was observed in cause of death, cancer recurrence and time to recurrence between the 3 different groups. There was also no significant difference in overall 5-year survival between the 3 groups. However, a prolonged waiting time between radiation and surgery was associated with improvements in tumor shrinkage.

This study determined that a longer waiting period after radiation therapy results in increased tumor shrinkage.