According to results recently presented at the 47th annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO), radiation following surgery reduces cancer recurrences in men with early prostate cancer.
The prostate is a gland of the male reproductive system. It produces some of the fluid that transports sperm during ejaculation. After skin cancer, prostate cancer is the most common form of cancer diagnosed in men.
Localized or early prostate cancer refers to cancer that has not spread from the prostate and surrounding tissues. One common treatment for early prostate cancer is the surgical removal of the prostate (prostatectomy). However, some undetectable cancer cells may remain in the tissues near the prostate; these cells are responsible for the cancer recurrences that some patients will experience. This has prompted researchers to evaluate whether radiation to the area of the prostate will kill the undetectable cancer cells and thus reduce the risk of a recurrence.
Researchers affiliated with the Southwest Oncology Group (SWOG) recently conducted a clinical trial to directly compare a prostatectomy alone to a prostatectomy plus radiation therapy in patients with early-stage prostate cancer. This trial included 473 men who were all treated with a prostatectomy; approximately half then received radiation therapy to the area around the prostate.
Radiation following surgery improved outcomes for these patients compared to surgery alone:
- At both five and 10 years, the rate of cancer recurrences was reduced by 25% in the group of patients who received radiation therapy.
- Survival was improved in the group of patients who received radiation therapy.
- At both five and 10 years, cancer-free survival was improved in the group of patients treated with radiation therapy.
- In patients not cured by either treatment, subsequent treatment for prostate cancer was delayed by four years in the group treated with radiation therapy.
The researchers concluded that radiation therapy following surgery significantly reduces the risk of developing cancer recurrences in men with early prostate cancer. This has translated to improved cancer-free and overall survival at five and 10 years for these patients. Longer follow-up may reveal even greater survival differences. Patients diagnosed with early prostate cancer who are to undergo a prostatectomy may wish to speak with their physician regarding the risks and benefits of additional radiation therapy.
Reference: Swanson GP, Thompson IM, Tangen C, et al. Phase III randomized study of adjuvant radiation therapy versus observation in patients with pathologic T3 prostate cancer (SWOG 8794). Proceedings of the 47th annual meeting of the American Society of Radiation Oncology 2005;abstract 1, page S1.