Serum lactate dehydrogenase is a predictive biomarker in patients with oropharyngeal cancer undergoing radiotherapy: Retrospective study on predictive factors

BACKGROUND: The present study aimed to evaluate the prognostic factors in human papillomavirus (HPV)‐positive and HPV‐negative oropharyngeal cancer (OPC) treated with definitive radiotherapy. METHODS: We retrospectively evaluated 101 patients with OPC who underwent definitive radiotherapy between 2008 and 2018. RESULTS: The median follow‐up period of the surviving patients was 68 months (range, 8–164 months). The 5‐year overall survival rate was 69.8%. Univariate analyses revealed that poor survival was associated with male sex, smoking ≥30 pack‐years, Eastern Cooperative Oncology Group performance status ≥1, tumor‐node‐metastasis (TNM) stage III‐IV (8th edition), HPV‐negativity, serum lactate dehydrogenase (LDH) ≥202, C‐reactive protein/albumin ratio ≥0.15, and lymphocyte‐to‐monocyte ratio <2.90. In multivariate analyses, poor survival was independently correlated with smoking ≥30 pack‐years (p < 0.01) and LDH ≥202 (p = 0.02). CONCLUSIONS: The present study suggested that high LDH levels predicted poor survival after definitive radiotherapy for patients with both HPV‐positive and HPV‐negative OPC.