Evaluation of outcomes after discontinuing androgen suppression therapy in a series of elderly patients with advanced prostate cancer and in prolonged clinical and biochemical response

Abstract

20504 Background: To describe and discuss the outcomes following the suspension of androgen suppression therapy (AST) in a series of elderly patients in advanced stage of prostate cancer and in established clinical and biochemical response after an extended period of treatment. Methods: A retrospective review of 371 consecutive patients with stage T3–4 NX- 1M0–1 prostate cancer and treated with single or combined androgen suppression therapy revealed 44 older patients who, after at least 36 months of treatment, showed the following findings of stable response (SR): absence of noteworthy dysuria, normal prostate findings on digital rectal examination (DRE), and prostate specific antigen (PSA) value lower than 0.50 ng/ml. Treatment was suspended in these patients, but was to be re-scheduled in one of the following cases: onset of important dysuria, evidence of palpable lesion on DRE, rise in PSA above 10 ng/ml or above pre-treatment values if these were below 10. Progression disease was defined as follows: PSA level increase at two subsequent measurements, and/or appearance of new lesions, and/or evidence of progression disease on DRE. Results: After a median follow-up of 93.9 months from the start of AST and 57.5 months from its suspension, 27 (61.4%) patients resumed therapy. Median age of patients at the moment of therapy suspension was 78.5 years (95% CI, 76 - 81). Fourteen (31.8%) showed progression disease, but only seven (15.9%) of these died. In seven (15.9%) patients serum testosterone level did not exceed 0.5 ng/ml, indicating an absence of gonadal activity. The median time to progression was 138.2 (95% CI, 14.3% - 66.1%) months, and the median cumulative survival from the start and from the suspension of AST was 105.5 (95% CI, 30.6% - 64.5%) months and 64.1 (95% CI, 31.4% - 65.1%) months, respectively. The savings in drug costs amounted to 772,267 euros. Conclusions: We can conclude that, taking in consideration these outcomes of survival and of savings in drug costs, in these selected elderly patients, this option of treatment could be of interest. No significant financial relationships to disclose.