The relations between age and androgen deprivation therapy use among men receiving radiation therapy for prostate cancer in the Medicare population.

Abstract

e15150 Background: For older men with prostate cancer who are undergoing radiotherapy, the benefit of neoadjuvant and concurrent androgen deprivation therapy (ncADT) varies according to tumor characteristics and life expectancy (LE). National Comprehensive Cancer Network (NCCN) guidelines recommend ncADT for men with high-risk cancer characteristics, but not for men with low-risk cancer, or for men with LE < 5 years. Although older patients with shorter LE have the lowest likelihood of benefit, it is unclear whether ncADT is used less frequently in this group. Methods: We used the Surveillance, Epidemiology, and End Results-Medicare database to assess patterns of ncADT use among men diagnosed with prostate cancer during 2004 through 2007 who received external beam radiation. Men were stratified according to NCCN guidelines into low- (T1-T2a/N0/M0 and Gleason 2-6 and PSA< 10 ng/mL), intermediate- (T2b-T2c or Gleason 7 or PSA 10-20 ng/mL), and high- (Gleason >7 or PSA> 20 ng/mL) risk groups. Men were further stratified according to LE, which was calculated based on age and comorbid illness. We used logistic regression to identify patient and clinical factors associated with ncADT use within each risk group. Results: There were 11,080 men in the sample (mean age= 74.2 years; 83.5% white). The use of ncADT was highest in the high-risk group (80.7%). However, a considerable number of men in the intermediate- (54.1%) and low-risk (27.8%) groups also received ncADT. Compared to men with longer LE, men with LE < 5 years had higher rates of ncADT use in all risk groups. For instance, in the low-risk group 32.7% men with LE < 5 years received ncADT compared to 26.5% men with LE ≥ 10 years. Similarly, within each risk group, advancing age was associated with a higher likelihood of receiving ncADT (OR for men aged 80-84 compared to 67-69 = 1.93(95% CI 1.37-2.70); 1.51(95% CI 1.22-1.87); and 1.71, (95% CI 1.14-2.57) for high-, intermediate-, and low-risk groups, respectively). Conclusions: The use of ncADT in actual practice is not consistent with guideline recommendations and is used more frequently among men who are older, have a shorter LE, and are less likely to benefit from therapy.