Docetaxel use in castrate resistant prostate cancer, how timing of treatment and age of patients affect outcome Single Centre Audit Research

Abstract

Background: New therapeutic strategies have resulted in some uncertainty over the optimum scheduling of treatments in metastatic prostate cancer (MPC) and with the aging population, it is important to assess outcomes in this age group.

Methods: Patients diagnosed with MPC and treated with docetaxel from 2006 to 2016 were identified and their records retrospectively reviewed via electronic clinical and prescribing systems. Number of treatments received pre and post docetaxel, prostate specific antigen (PSA) response, number of cycles and dosing of docetaxel and castrate resistant overall survival (OS) were analysed.

Results: 209 consecutive patients with MPC receiving docetaxel were categorised according to age; younger than 75 years old (n=150), 75-79 years (n=40) and 80 years or over (n=19). Excluding early docetaxel, mean survival times younger to older were 1001, 1045 and 1294 days and PSA response rates were 39%, 38% and 42%. The oldest group received fewer docetaxel cycles (3.8, p=0.006) and less dose (226mg/m2, p=0.004) compared with less than 75 years (5.8 cycles, 409mg/m2) and 75-79 years (5.1 cycles, 341mg/m2). 168 consecutive patients received second line and beyond docetaxel. 48 patients (29%) received docetaxel after 1 or 2 treatments, 105 (63%) after 3 or 4 treatments and 15 (9%) after 5 or 6. PSA response rates were superior in the earliest treated group (61%, p=0.003), compared with 30% and 31% respectively. Median OS was 29 months, 35 months and 42 months earlier to later, not significantly different (p=0.1).

Conclusions: In these MPC patients in routine clinical practice, the 80 years plus age group received fewer cycles of docetaxel and less dose, but achieved similar PSA responses. In patients who do not receive initial docetaxel, PSA response rates were significantly improved with subsequent earlier use. OS was not significantly different according to age, nor between early and later docetaxel treated patients.