Accumulating Evidence and Research Organization graph stratified by biomarker ensemble, as defined by assay, tissue type, reagents, prespecified cutoff value, and drug regimen. Square nodes are retrospective analyses, and circular nodes are prospective trials. Numbers within nodes represent the sample size. Green nodes are studies that showed a statistically significant association between low excision repair cross‐complement group 1 (ERCC1) expression on both objective response rate and overall survival. Yellow nodes are studies that showed statistical significance for one outcome but not for the other. Red nodes showed no statistically significant associations. The gray node showed an opposite association—that is, high ERCC1 expression was associated with better response and survival. Red shading indicates investigations that fell below a quality score of 3. Pragmatic regimen is patient population treated with more than two regimens.

Abbreviations: car, carboplatin; cis, cisplatin; doc, docetaxel; gem, gemcitabine; ifo, ifosfamide; iri, irinotecan; NS, not stated; pac, paclitaxel; pem, pemetrexed; Prim./Meta., primary/metastatic.