Description:
Study Type – Therapy (case series)Level of Evidence 4What's known on the subject? and What does the study add?Docetaxel rechallenge has shown preserved anti‐tumour activity and has therefore been proposed as an option for further treatment in patients with metastatic castration‐resistant prostate cancer, who have shown a good response to first‐line chemotherapy with docetaxel.The present study provides evidence of docetaxel activity in patients who were treated with full‐dose (75 mg/m2) 3‐weekly docetaxel at first‐line chemotherapy and rechallenge. It shows that PSA response to first‐line chemotherapy may provide a rational indication for docetaxel rechallenge.OBJECTIVETo determine whether prostate‐specific antigen (PSA) response at first‐line chemotherapy with docetaxel correlates with PSA response and survival at docetaxel rechallenge in patients with metastatic castration‐resistant prostate cancer (mCRPC).PATIENTS AND METHODSWe retrospectively evaluated the oncological outcomes of patients with mCRPC, who were treated with full‐dose (75 mg/m2), 3‐weekly docetaxel plus prednisone/prednisolone at first‐line chemotherapy and rechallenge, between 1999 and 2011, at our institution.The endpoints were PSA‐progression‐free survival (PSA‐PFS) and overall survival (OS) at docetaxel rechallenge.Statistical analyses included Kaplan–Meier curves and log‐rank tests to evaluate the effect of PSA response at first‐line chemotherapy on PSA‐PFS and OS at rechallenge.RESULTSFourty‐four patients were included in the analysis.At a median (range) follow‐up of 26.4 (9.8–89.8) months after the first administration of docetaxel, 24 (55%) patients had died. At first‐line chemotherapy, 36 (82%) patients achieved a reduction in PSA level of ≥50%. At rechallenge, 10 (28%) patients responded with a reduction of ≥50% for a second time.The median (95% confidence interval [CI]) PSA‐PFS was 5.9 (95% CI 3.5–6.8) months and the median OS was 21.8 (95% CI 19.9–23.7) months at docetaxel rechallenge.Of the PSA response variables evaluated, only a PSA level reduction of ≥50% at first‐line chemotherapy correlated significantly with prolonged PSA‐PFS (5.8 vs. 4.5 months; P= 0.01) and OS (22.1 vs. 7.2 months; P= 0.03) at rechallenge.CONCLUSIONIn the present single‐institution study, a reduction in PSA level of ≥50% at first‐line chemotherapy with docetaxel correlated with superior PSA‐PFS and OS in the rechallenge setting and might, therefore, present a rational indication for docetaxel rechallenge.