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Current trends for the use of androgen deprivation therapy in conjunction with radiotherapy for patients with unfavorable intermediate-risk, high-risk, localized, and locally advanced prostate cancer

Androgen deprivation therapy (ADT) is now a well-established standard of care in combination with definitive radiotherapy for patients with unfavorable intermediate-risk to high-risk locally advanced prostate cancer. It is also well established that combination modality treatment with ADT and radiotherapy is superior to either of these modalities alone for the treatment of patients with high-risk locally advanced disease. Current treatment guidelines for prostate cancer in the United States are based on the estimated risk of recurrence and death. This review examines the clinical evidence underpinning the use of ADT and radiotherapy among patients with high-risk localized and locally advanced disease in the United States. This review also considers the rationale for moving from traditional luteinizing hormone-releasing hormone agonists to more recently developed gonadotrophin-releasing hormone antagonists.

Short- vs long-term androgen suppression plus external beam radiation therapy and survival in men of advanced age with node-negative high-risk adenocarcinoma of the prostate

BACKGROUND

The study evaluated whether the use of 3 years as compared with 6 months of androgen suppression therapy (AST) combined with external beam radiation therapy (RT) in the treatment of high-risk prostate cancer was associated with prolonged survival in advanced age men.

METHODS

A pooled analysis of 311 men enrolled in 3 prospective randomized trials between 1987 and 2000 who received 6 months or 3 years of AST and RT for locally advanced or high-grade localized adenocarcinoma of the prostate comprised the study cohort. Cox regression multivariable analysis was performed adjusting for known prognostic factors to determine whether the treatment received was associated with time to death after randomization. The median age and follow-up was 70 and 5.9 years, respectively, during which 82 (26%) deaths occurred.

RESULTS

Treatment received was not significantly associated with survival time after randomization (adjusted hazard ratio [AHR]: 1.1; 95% confidence interval [CI]: 0.7, 1.8; P = .70), whereas age at randomization (AHR: 1.05; 95% CI: 1.01, 1.09; P = .02) was. The presence of Gleason score 8 to 10 cancers approached significance (AHR: 1.6; 95% CI: 0.9, 2.6; P = .09).

CONCLUSIONS

After adjusting for known prognostic factors, the treatment of node-negative, high-risk prostate cancer using 3 years as compared with 6 months of AST with RT was not associated with prolonged survival in men of advanced age. The European Organization for Research and Treatment of Cancer randomized trial will help answer whether unknown confounding factors affected the results of the study.

Duration of testosterone suppression and the risk of death from prostate cancer in men treated using radiation and 6 months of hormone therapy

BACKGROUND

The authors evaluated whether the duration of androgen suppression (AS) after the completion of hormone therapy (HT) was associated with the risk of prostate cancer-specific mortality (PCSM) and all-cause mortality (ACM).

METHODS

The study cohort was comprised of 220 men who received radiation therapy (RT) and 6 months of HT for prostate cancer between 1996 and 2005. The duration of AS was defined as the time to return to the baseline testosterone level after the completion of HT. Grays and Cox regression analyses were used to evaluate whether the duration of AS after the completion of HT was associated with the time to PCSM and ACM, respectively, after adjusting for known prognostic factors.

RESULTS

An increasing duration of AS was associated with a decreased risk of PCSM (adjusted hazards ratio [HR], 0.89; P = .003) and ACM (HR, 0.94; P = .007). Men who had prostate cancer with Gleason scores from 8 to 10 had significantly lower cumulative incidence estimates of PCSM (P = .04) if the duration of AS plus the length of HT administration was >/=2 years compared with <2 years. After a median follow-up of 6.1 years, the respective 5-year estimates were 0% and 38%.

CONCLUSIONS

The duration of AS after 6 months of HT was associated with the risk of PCSM and ACM. This duration could be used to identify men who have prostate cancer with Gleason scores from 8 to 10 in whom 6 months of HT produces long-term testosterone suppression, which may provide the cancer-specific survival benefit observed with long-term HT.