The influence of antibiotic administration on the outcomes of head-and-neck squamous cell carcinoma patients undergoing definitive (chemo)radiation

Abstract

Purpose Effects of antibiotic administration on patients’ microbiome may negatively influence cancer outcomes, and adverse prognoses after antibiotic application have been demonstrated for cancer patients receiving immune checkpoint inhibitors. While the microbiome may play an important role also in head-and-neck squamous cell carcinoma (HNSCC), the prognostic value of antibiotic treatment here is largely unknown. We therefore analyzed whether antibiotic prescription is associated with impaired oncological outcomes of HNSCC patients undergoing definitive (chemo)radiation. Methods A cohort of 220 HNSCC patients undergoing definitive (chemo)radiation between 2010 and 2019 was analyzed. The influence of antibiotic administration on locoregional control, progression-free survival (PFS) and overall survival (OS) was determined using Kaplan–Meier and Cox analyses. Results A total of 154 patients were treated with antibiotics within 30 days before (chemo)radiation (pretherapeutic) or during (chemo)radiation (peritherapeutic). While antibiotic prescription was not associated with age, ECOG, tumor localization or radiotherapy characteristics, patients treated with antibiotics had significantly higher tumor stages. Peritherapeutic antibiotic administration diminished PFS (HR = 1.397, p < 0.05, log-rank test) and OS (HR = 1.407, p < 0.05), whereas pretherapeutic administration did not. Antibiotic application was an independent prognosticator for OS (HR = 1.703, p < 0.05) and PFS (HR = 1.550, p < 0.05) in the multivariate Cox analysis within the subgroup of patients aged < 75 years. Conclusion Peritherapeutic antibiotic usage was associated with impaired oncological outcomes in HNSCC patients undergoing (chemo)radiation. Further studies including microbiome analyses are required to elucidate underlying mechanisms.

Authors’ response to the Letter to the Editor by Efsun Somay and Erkan Topkan regarding our study “The influence of antibiotic administration on the outcomes of head-and-neck squamous cell carcinoma patients undergoing definitive (chemo)radiation”

“…We thank Dr. Somay and Dr. Topkan for the interest in our study about the association between antibiotic application and oncological outcomes in head-and-neck squamous cell carcinoma (HNSCC) patients undergoing (chemo)radiation [1]. We would like to shortly respond to their letter, in which they addressed the unequal distribution in the treatment type and cancer stage in our cohort, two aspects that are closely linked [2].…”

Authors’ response to the letter to the editor by Busra Yilmaz and Ugur Selek regarding our study “The influence of antibiotic administration on the outcomes of head-and-neck squamous cell carcinoma patients undergoing definitive (chemo)radiation”

“…We very much appreciate the interest in our study and the valuable issues raised by Dr. Yilmaz and Dr. Selek in their Letter to the Editor regarding our analysis about the association between antibiotic application and oncological outcomes in head-and-neck squamous cell carcinoma (HNSCC) patients undergoing (chemo)radiation [1,2].…”