Use of docetaxel in low- and high-burden metastatic hormone-sensitive prostate cancer: A systematic review and assessment of subgroup analyses.

Abstract

Use of docetaxel in low- and high-burden metastatic hormone-sensitive prostate cancer presents considerable controversy. There is literature suggesting lack of benefit for low-volume of metastases. The study aims to develop a systematic review and methodological assessment of subset analysis about use of docetaxel in metastatic hormone-sensitive prostate cancer regarding volume of metastatic disease. A systematic review in the Pubmed® database was conducted up to 25 September 2020. A reference tracking was also developed. Randomised clinical trials with subgroup analysis according volume of metastatic disease for overall survival were selected. Two methodologies were used. One of them considered statistical interaction of subsets (p(i) < 0.1), pre-specification, biological plausibility and consistency among subset results of similar randomised clinical trials. The second methodology was a two-part validated tool: preliminary questions to discard subset analysis without minimal relevance and a checklist The checklist provides recommendations for applicability of subgroup analysis in clinical practice. A total of 31 results were found in systematic reviews in the Pubmed® database. One result was identified in the reference tracking. Of the total of 32 results, four randomised clinical trials were included in the study. About first methodology, statistical interaction among subgroups was obtained in one randomised clinical trial. Subgroup analysis was pre-specified in two randomised clinical trials. Biological plausibility was reasonable. No external consistency among results of subgroup analyses in randomised clinical trials was observed. Preliminary questions of second methodology rejected applicability of subgroup analysis in three randomised clinical trials. A 'null' recommendation for applicability of subset results was obtained in the remaining randomised clinical trial. Patients with low- and high-burden metastatic hormone-sensitive prostate cancer would benefit from docetaxel therapy. No consistent differences for overall survival were observed in subgroup analyses regarding volume of metastatic disease.