%0 Journal Article %A KAZUYUKI HAMADA %A KIYOSHI YOSHIMURA %A YUYA HIRASAWA %A MASAHIRO HOSONUMA %A MASAKAZU MURAYAMA %A YOICHIRO NARIKAWA %A HIROTSUGU ARIIZUMI %A RYOTARO OHKUMA %A MIDORI SHIDA %A YUTARO KUBOTA %A SATOSHI MATSUKUMA %A TOMOYUKI ISHIGURO %A TAKEHIKO SAMBE %A ATSUSHI HORIIKE %A ATSUO KURAMASU %A SATOSHI WADA %A JUNJI TSURUTANI %A EISUKE INOUE %A NAOKI UCHIDA %A YUJI KIUCHI %A SHINICHI KOBAYASHI %A ROBERT M. HOFFMAN %A TAKUYA TSUNODA %T Antibiotic Usage Reduced Overall Survival by over 70% in Non-small Cell Lung Cancer Patients on Anti-PD-1 Immunotherapy %D 2021 %R 10.21873/anticanres.15312 %J Anticancer Research %P 4985-4993 %V 41 %N 10 %X Background/Aim: There is an increasing use of immunotherapy for non-small cell lung cancer (NSCLC) patients. The present study analysed the effect of antibiotic use on the outcome of NSCLC patients undergoing treatment with anti-programmed cell death-1 (anti-PD-1) immunotherapy. Patients and Methods: This was a retrospective study of 69 NSCLC patients. Eighteen out of 69 patients received antibiotics within 21 days before or within 21 days after start of anti-PD-1 therapy. Results: Patients treated with anti-PD-1 antibodies receiving antibiotics had greatly decreased objective response rate (ORR), overall survival (OS) and progression-free survival (PFS) compared to those who did not use antibiotics. Multivariate analysis showed that antibiotic treatment of patients on anti-PD-1 antibody therapy was an independent negative predictive factor of PFS; however, it was not a significant independent predictive factor of OS. Conclusion: Use of antibiotics within 21 days before and after anti-PD-1 treatment initiation in patients with NSCLC strongly reduced OS and PFS, suggesting the two treatments should not be combined. %U https://ar.iiarjournals.org/content/anticanres/41/10/4985.full.pdf