Efficacy of first-line therapy in elderly patients with prostate cancer in real clinical practice

Objective: to evaluate the efficacy of first-line systemic therapy administered in real clinical practice to patients >75 years old with prostate cancer (PCa).Material: the retrospective study included data from 315 patients >75 years old (median age — 84 (75-99) years) with hormone-sensitive PCa (HSPCa) who received antitumor therapy. Non-metastatic HSPCa (nmHSPCa) was observed in 223 (70,8%) patients, while metastatic HSPCa (mHSPCa) — in 92 (29,2%) patients. In 8 (3,6%) cases of nmHSPCa, bicalutamide monotherapy was prescribed, while androgen deprivation therapy (ADT) was administered in 215 (96,4%) cases (intermittently — 164 (73,5%)). All 92 patients with mHSPC received ADT, including in combinations corresponding to current clinical recommendations — in 38 (41,3 %) cases (with docetaxel — 17 (18,4 %), abiraterone acetate — 7 (7,6 %), enzalutamide — 10 (10,9 %), apalutamide — 1 (1,1 %)). The median follow-up time for patients with nmHSPC was 64,2 (2,1-275,7) months, for patients with mHSPC — 48,6 (1,0-234,3) months.Results: the median duration of the 1st line of therapy for nmHSPC was 40,6 (1,0-243,8) months. In nmHPRPC, PSA reduction by>90% during the first line of therapy was seen in 67,3 % of patients. Five-year survival of patients with nmHPRPC without PSA progression (PFPS) reached 70,8%, progression-free survival (PFS) — 70,8%, metastasis-free survival (MFS) — 85,0%, specific survival (SS) — 97,3% and overall (OS) — 91,5%. Continuous ADT in lowand intermediate-risk nmHPRPC reduced PFS compared to intermittent therapy (p = 0.014), but did not affect MFS, SS and OS. The median duration of the first line of therapy for mHPRPC was 14,3 (1,1-137,7) months. In mHSPC, the frequency of PSA decrease by>90% during the first line of therapy was 38,0%. In patients with mHSPC, the 4-year PFSSA was 50,1%, DFS — 50,1%, DFS — 83,5% and OS — 77,2%. In mHSPC, ADT compared with combination therapy reduced DFS (p = 0.018), DFS (p = 0.053) and OS (odds ratio 3.675 (95% confidence intervals: 1.001-13.489); p = 0.008). No significant effect of the combination drug on the survival of patients with mHSPC was found.Conclusions: in elderly patients with nmHSPC, intermittent ADT is not inferior to continuous ADT in terms of OS. In patients > 75 years old, combination therapy based on ADT with docetaxel or androgen signal inhibitors provides an increased OS compared to ADT alone.