Among rectal cancer patients treated with chemotherapy and radiation therapy prior to surgery, providing a higher dose of radiation therapy (50 Gy rather than 45 Gy) may reduce the risk of cancer recurrence. These results were presented at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO).
Each year in the United States, close to 40,000 people are diagnosed with rectal cancer. Thanks to advances in early detection and treatment, however, individuals with rectal cancer are living longer. It is estimated that there are more than 200,000 rectal cancer survivors in the U.S. today.
The primary treatment for rectal cancer is surgery. Some patients may be treated with radiation therapy and/or chemotherapy prior to surgery in order to reduce the risk of cancer recurrence and help to shrink the cancer prior to surgery. The optimal approach to delivering preoperative chemotherapy and radiation therapy continues to be explored.
To explore two different chemotherapy regimens and two different doses of radiation therapy, researchers in France conducted a Phase III clinical trial among close to 600 patients with locally advanced rectal cancer. Half the patients received preoperative Xeloda® (capecitabine) and 45 Gy of radiation therapy, and half the patients received preoperative Xeloda and Eloxatin® (oxaliplatin) and 50 Gy of radiation therapy.
Patients have now been followed for three years. The researchers used the results of this trial as well as the results of three other Phase III trials to draw conclusions about the safety and efficacy of the different chemotherapy regimens and radiation doses.
- Compared with Xeloda, chemotherapy with the combination of Xeloda and Eloxatin increased side effects and did not improve treatment effectiveness.
- 50 Gy of radiation therapy was well tolerated and reduced the risk of cancer recurrence compared with 45 Gy of radiation therapy.
These results suggest that a fairly modest increase in radiation dose may improve outcomes among patients with rectal cancer treated with radiation and chemotherapy prior to surgery.
Reference: Gerard J, Gourgou-Bourgade S, Azria D et al. Accord12/0405-prodige 2 phase III trial neoadjuvant treatment in rectal cancer. Results after 3 years of follow-up. Presented at the 53rd Annual Meeting of the American Society for Radiation Oncology (ASTRO). Miami Beach, FL, October 2-6, 2011. Abstract 3.