Pretreatment Systemic Immune-Inflammation Index Predict Needs for Teeth Extractions for Locally Advanced Head and Neck Cancer Patients Undergoing Concurrent Chemoradiotherapy

BACKGROUND: To evaluate the utility of pretreatment systemic immune-inflammation index (SII) in predicting the teeth caries and need for tooth extraction after concurrent chemoradiotherapy (C-CRT) for locally advanced squamous-cell head and neck cancer (LA-SCHNC) patients. METHODS: The records of LA-SCHNC patients who underwent formal dental evaluations at pre- and post-C-CRT periods were retrospectively analyzed. The pretreatment SII values were calculated using the platelet, neutrophil, and lymphocyte measures acquired on the first day of C-CRT: SII=Platelets×neutrophils/lymphocytes. Receiver operating characteristic (ROC) curve analysis was employed to identify the ideal pre-C-CRT SII cutoff that may predict the teeth caries and the need for tooth extraction after the C-CRT. The primary endpoint was the link between the pre-C-CRT SII and the need for tooth extraction during the follow-up period. RESULTS: A sum of 126 patients were included. Median follow-up was 4.9 years (range: 2.7–7.8). Nasopharyngeal and laryngeal cancers comprised the majority (75.4%) study cohort. Post-treatment teeth extractions were reported in 62.7% patients. The optimal cutoff was 558 [Area under the curve (AUC): %76.8 sensitivity: 72.3%; and specificity: 70.9%] that grouped the patients into two subgroups with significantly different post-C-CRT tooth extraction rates: Group 1: SII≤558 (n = 70) and SII>558 (n = 56), respectively. Correlation analysis revealed a significant relationship between the pretreatment SII and the tooth extraction rates after the C-CRT (r(s):0.89: P = 0.001). The comparative analysis displayed that the teeth extractions rates were significantly higher in the SII>558 group (77.1% versus 51.4% for SII≤558; Hazard ratio: 1.68; P = 0.001). Further analyses showed that the pre-C-CRT SII>558 was the unique factor associated with meaningfully higher necessities for post-C-CRT teeth extractions. CONCLUSION: The present outcomes intimated that high pretreatment SII levels were linked to significantly increased post-treatment teeth extractions in LA-SCHNC patients undergoing definitive C-CRT.