Data collection
non-squamous cell carcinoma, SCC
SQUAMOUS CELL CARCINOMA, SECONDARY
Data were extracted from publications and reported in an electronic database. These included first author, digital object identifier (DOI), name of the trial, journal, date of publication, and class of therapy investigated (chemotherapy, immunotherapy, or target therapy). Data were analyzed by two independent investigators. Discrepancies were resolved by consensus.The following data were also extracted from trials: histological subtype (squamous cell carcinoma (SCC), non-squamous cell carcinoma (NSCC), “non-specified histology”); if required, mandatory mutations for patients enrolment (“Assessment of QoL in RCTs was investigated by examining the methods sections of the articles or study protocols. When protocols were not available as supplementary material of publications, they were searched on the For trials not reporting QoL results in primary publication, we assessed their disclosure in secondary manuscripts. Secondary articles were searched among the list of articles obtained with our research strategy (Additional file For RCTs with non-available or immature OS data at the time of primary publication, we evaluated the final OS results reported in secondary publications.