Patients whose tumors shrink in response to radiation therapy before surgery for rectal cancer have both improved overall survival and improved disease-free survival. However, even patients who responded to presurgical radiation did not reach survival rates for stage I rectal cancer patients treated with surgery alone.
Within the Surveillance,Epidemiology, and End Results (SEER) registry using data from January1, 1994, through December 31,2003, researchers studied nearly 11,000 people with rectal cancer — 3,760 who were treated with radiotherapy and 7,200 who had stage I cancer and received only surgery.
- For patients who responded to presurgical radiotherapy, 94 percent were alive without cancer five years later compared to 78 percent of those who didn’t respond with tumor shrinkage.
- Overall survival at five years was 82 percent in responders, 60 percent in those with no tumor downstaging.
- For stage I patients with surgery only, disease-free survival at 5 years was 97 percent, overall survival 79 percent.
Eric T. Castaldo, MD, MPH and his colleagues at Vanderbilt University Medical Center in Nashville concluded,
Patients with rectal adenocarcinoma downstaged after neoadjuvant radiotherapy have improved survival compared with nonresponders. While disease-free survival is excellent for responders to neoadjuvant radiotherapy, it did not equal the disease-free survival of patients with stage I disease undergoing resection alone.
SOURCE: Castaldo et al., Archives of Surgery, Volume 144, Number 2, February 2009.