Effect of treatment modality on the long-term survival of patients with early glottic squamous cancer: a retrospective cohort study based on the SEER database.

ABSTRACT

Background: The optimal treatment strategy for patients with early glottic (T1-2N0M0) squamous cancer remains unclear. Methods: A retrospective population-based analysis was performed using the Surveillance, Epidemiology, and End Results (SEER) database. Propensity score matching (PSM) was used to balance treatment arms, and Cox regression analysis was used to determine prognostic factors for survival. Kaplan-Meier analysis, log-rank tests, and competing risk analysis were used to compare survival outcomes between treatment modalities (surgery vs. radiotherapy). Results: Among the 3,994 eligible patients in this study, surgery was associated with improved cancer-specific survival (CSS) and overall survival (OS) compared with radiotherapy (log-rank test, P<0.05). This survival trend favoring surgery was consistent in the T1a, well/moderately differentiated grade, male, and all age subgroups. However, after the baseline characteristics were balanced with PSM, the survival outcomes (CSS and OS) did not differ significantly between the surgery and radiotherapy groups. Interestingly, surgery was associated with a 39% reduced risk of cancer-related death compared with radiotherapy in patients aged ≥70 years (hazard ratio 0.61; 95% CI 0.43-0.87; P=0.006). However, this survival trend favoring surgery was not observed in younger patients (age <70 years), T stage subgroups, male or female subgroups, or in any of the pathological grade subgroups. Conclusions: In patients with early glottic squamous cell carcinoma undergoing surgery or radiotherapy, there is no sufficient evidence favoring one method over another in terms of survival. However, surgery is recommended in patients aged ≥70 years because, in this group, it was associated with improved survival outcomes compared with radiotherapy.