Predictive factors for tolerance to taxane based chemotherapy in older adults affected by metastatic prostate cancer (ANCHISES-NCT05471427): A prospective observational trial including patients with metastatic hormone sensitive and castrate resistant prostate cancer treated with taxane chemotherapy

Introduction: Taxane-based chemotherapy is one of the main cornerstones for treatment of metastatic prostate cancer (mPCa). In aged and well-fit patients, an indication for taxane chemotherapy should remain similar to the general population. Aiming to explore predictive factors of fitness to taxane chemotherapy in older adult patients, a prospective observational study was carried out in our institution. Materials and methods: We collected data from a prospective mono-centric database of patients aged ≥70 years old that were treated in our department. All patients underwent taxane treatment (either docetaxel or cabazitaxel, the latter only in second line setting) starting with standard treatment schedules (75 mg/m2 or 25 mg/m2 every three weeks, respectively). Data about G8 score post treatment decreases were collected and reported. We explored associations between baseline age, G8 score, and Charlson Comorbidity Index (CCI) with taxane dose reduction (DR), treatment temporary suspension (TS), or definitive interruption (TDI). Logistic regression analysis was performed to explore potential predictive factors for tolerability in patients treated with docetaxel. Results: One hundred-eighteen patients underwent taxane chemotherapy between 2011 and 2022, the majority of cases in metastatic castrate resistant prostate cancer (mCRPC) setting (85.6%). In the overall population, DR was performed in 40.7% of cases, and TS and TDI were deemed necessary in 28% and 22.9% of patients, respectively. Forty-seven percent of patients reported a significant deterioration in terms of G8 score (from > to ≤14). Sixty-two percent of the overall population were deemed fit for further treatment after taxane chemotherapy. Rate of DR, TS, and TDI was 29.4%, 11.8% and 9.2% in the docetaxel subgroup, vs 48%, 60% and 12% of patients treated with cabazitaxel, respectively. Lower baseline G8 was reported as a continuous variable and the only independent predictive factor for TDI in docetaxel subgroup (odds ratio [OR] 0.41, 95% confidence interval [CI] 0.25-0.68, p = 0.0008). Discussion: Our data suggest that tolerability of taxane regimens in a pre-treated population of older patients with prostate cancer is acceptable, despite a non-negligible rate of TDI. Taxane chemotherapy should not be denied a priori in order to avoid undertreatment of older adult patients.