2.2. Data sources and literature search strategy

A systematic literature search was performed using MEDLINE (through PubMed) and a comprehensive query ( Figure 1 ) in order to retrieve all relevant studies published until September 15, 2022 and reporting data on the associations between ABX use and the clinical outcomes of cancer in patients treated with anti-PD-(L)1-based treatments. In order to include the largest possible patient population, no filters for language (although the query was submitted in English) or year of publication were applied. Besides, proceedings of major oncology conferences held between 2017 and 2022 were also screened to identify unpublished studies that could be included, thus minimizing publication bias, using the following keywords: antibiotic, antibiotics, antimicrobial, antimicrobials, anti-infective, anti-infectives. Such conferences were the European Lung Cancer Congress (ELCC) and the World Conference on Lung Cancer (WCLC), as well as annual meetings from the American Association for Cancer Research (AACR), the American Society of Clinical Oncology (ASCO), the European Society for Medical Oncology (ESMO), the International Association for the Study of Lung Cancer (IASLC) and the Society for Immunotherapy of Cancer (SITC). Any relevant article references were also screened for additional studies.

Literature query used on PubMed.