Temporal changes in the efficacy of chemotherapy for recurrent or metastatic squamous cell carcinoma of the head and neck: a systematic review and meta-analysis.

Cytotoxic chemotherapy remains a standard treatment option for patients with recurrent or metastatic squamous cell carcinoma of the head and neck (RMSCCHN), but its effectiveness is debatable. We hypothesized palliative chemotherapy efficacy has decreased due to intensification of primary treatment, and investigated this by examining time trends of objective response rates (ORRs) in published reports of randomized trials (RCTs).