Utility of lymphocyte-to-monocyte ratio and pretreatment tooth extraction in intra-arterial chemoradiotherapy for oral cancer to prevent osteoradionecrosis of the jaw

The objective of this study was to evaluate the utility of inflammation-based prognostic scores (IBPS) in predicting ORN among patients undergoing superselective intra-arterial chemoradiotherapy (SSIACRT). This retrospective cohort study examined the medical records of 54 patients with advanced oral cancer (stage 3 or 4) treated with SSIACRT. The predictor variable was IBPS. The main outcome variable was onset of ORN. Covariates comprised sex, median age, tooth status, tumor size, and pretreatment tooth extraction with professional oral care (pretreatment tooth extraction). For each factor, cumulative incidence and univariate and multivariate analyses of ORN incidence were performed. The cumulative incidence of ORN in patients with pre-treatment lymphocyte-to-monocyte ratio (LMR < 4.95vs LMR ≥4.95, P = 0.01) and pretreatment tooth extraction (no vs. yes, P = 0.03) was significantly different. Univariate and multivariate analyses identified pre-treatment LMR cutoff values < 4.95 and pre-treatment tooth extraction as significantly associated with the development of ORN. Pretreatment tooth extraction reduced the incidence of ORN in low LMR group (P = 0.04). LMR is a useful biomarker to predict ORN in SSIACRT. Pretreatment tooth extraction was a useful treatment to prevent ORN. Pretreatment extraction with LMR may be important for the prevention of ORN in SSIACRT.