Researchers affiliated with the RTOG 94-08 clinical trial have reported that short-term androgen deprivation therapy (ADT) delivered before and during moderate-dose radiation therapy improves survival and reduces risk of recurrence compared with radiation alone in men with intermediate-risk, early-stage prostate cancer. The results of this Phase III study were presented at the 2010 Genitourinary Cancers Symposium in San Francisco on March 5-7.1

There are several randomized trials documenting the benefit of neoadjuvant and/or adjuvant ADT plus radiotherapy in men with locally advanced or high-risk prostate cancer. However, there are little data documenting the effects of neoadjuvant and/or adjuvant ADT in men with low-risk or intermediate-risk localized prostate cancer. One report from the Dana Farber Cancer Center has reported that the use of neoadjuvant and adjuvant ADT with radiation therapy improves survival of patients with localized Stage T1-T2b prostate cancer compared with radiation therapy alone.

The Phase III Radiation Therapy Oncology Group (RTOG) study involved 1,979 men with early-stage prostate cancer who had a PSA of 20 or less; 987 men received four months ADT, starting two months prior to radiation therapy, and 992 men received the standard treatment of radiation therapy alone.

After a median follow-up of 8.4 years in the ADT group and 8.1 years in the radiation-only group, 51% of patients who received ADT were still alive at 12 years compared with 46% of those who received radiation alone. The survival benefit appeared to be greatest for men with intermediate-risk disease; men with low-risk disease did not benefit from the addition of ADT. Furthermore, two years following treatment, 843 men underwent prostate biopsies. Seventy-eight percent of biopsies in the ADT group showed no cancer compared with 60% in the radiation-only group. The hormone therapy was well tolerated.

Comments: These researchers concluded that men with intermediate-risk, early-stage prostate cancer may benefit from the addition of a short course of neoadjuvant and adjuvant ADT in addition to radiation therapy. Research will be ongoing to evaluate the risks and benefits of this treatment strategy.

Reference:

1 McGowan D, Hunt D, Jones C, et al. Effect of short-term endocrine therapy prior to and during radiation therapy on overall survival in patients with T1b-T2b adenocarcinoma of the prostate and PSA equal to or less than 20: Initial results of RTOG 94-08. Presented at the 2010 Genitourinary Cancers Symposium in San Francisco March 5-7, 2010. Abstract #6.