Predicting the risk for distant metastasis in hypopharyngeal squamous cell carcinoma and assessing the survival benefit of induction therapy

Hypopharyngeal squamous cell carcinoma (HPSCC) has a poor prognosis due, in large part, to distant metastasis (DM). Although induction therapy (IT) can reduce DM rates, its translation to an overall survival (OS) benefit remains unclear, highlighting the need for tools to identify patients who would benefit most from IT. This study developed a nomogram to predict the risk for DM in patients with HPSCC, and assessed the survival benefit of IT across risk groups. Data from patients obtained from the Surveillance, Epidemiology, and End Results (i.e., "SEER") database (2004-2015) were randomly assigned to 1 of 2 groups at a ratio of 7:3: training; and internal validation. The external validation set comprised patients from 2 medical centers in China. Risk factors were identified using multivariate logistic regression analysis. Male sex, T classification ≥ 2, N classification ≥ 1, and poorer histological grade were independent risk factors for DM. The nomogram demonstrated good discriminative ability, with areas under the receiver operating characteristic curve of 0.702 (95% confidence interval [CI]: 0.669-0.735) in the training set, 0.704 (95% CI: 0.648-0.759) in the internal validation set, and 0.863 (95% CI: 0.804-0.923) in the external validation set. Based on the optimal cut-off value, patients were stratified into high- and low-risk groups. In the high-risk group, patients who received IT exhibited significantly improved OS (hazard ratio [HR] 0.364; 95% CI: 0.165-0.805; P = 0.040) and progression-free survival (PFS; HR 0.420; 95% CI: 0.190-0.928; P = 0.042) compared with those who did not receive IT. There was no significant survival benefit from IT in the low-risk group (OS: HR 0.881; 95% CI: 0.414-1.875, P = 0.095; PFS: HR 0.544 95% CI: 0.182-1.626, P = 0.250). This study constructed and preliminarily validated a nomogram for predicting DM in patients with HPSCC, and may serve as an exploratory tool for screening high-risk patients who are likely to benefit from IT, thereby providing a reference for the design of future prospective intervention trials.