KDR and small cell lung carcinoma: We used a combination of Medical Subject Headings [MeSH] phrases to build our search strategy, including "Nintedanib OR BIBF 1120 OR VEGFR inhibitor," and "chemotherapy OR antineoplastic agents," and "Lung neoplasms OR non-small cell lung cancer OR small cell lung cancer." As part of our rigorous approach, we manually searched the reference lists of studies that fulfilled our initial criteria to ensure that no potentially suitable papers were missed during our search process.