T1 Glottic Cancer: Does Anterior Commissure Involvement Worsen Prognosis?

Radiotherapy (RT) and transoral laser microsurgery (TLM) represent the main treatment modalities for early glottic carcinoma. Local failure is notoriously more frequent in T1b glottic cancer in comparison to T1a and T2 tumors. In this scenario, the role of anterior commissure (AC) involvement is still controversial. The aim of the present study was therefore to determine its potential prognostic power in worsening patients' survival and outcomes. We categorized different tumor glottic fold locations with respect to the involvement of one (T1a) or both vocal cords, with or without AC involvement. We analyzed a retrospective cohort of 74 patients affected by Stage I glottic cancer, treated between 2011 and 2018 by TLM or RT at a single academic institution. There were 22 T1a (30%) and 52 T1b (70%) cases. The median follow-up period was 30 months (mean, 32.09 ± 18.738 months; range, 12-79). Three-year overall survival (OS), disease-specific survival (DSS), recurrence-free survival (RFS), and laryngectomy-free survival (LFS) were compared according to tumor location, extension, and cT category. According to both uni- and multivariate analyses, an increased risk for recurrence in T1b with AC involvement and T1a tumors was 7.31 and 9.45 times, respectively (p-values of 0.054 and 0.030, respectively). Among the 17 recurrences, T1b with AC involvement experienced 15 tumor relapses (88.2%), thus significantly affecting both the RFS and LFS in comparison to the other two tumor subcategories (T1a, p = 0.028 and T1b without AC involvement, p = 0.043). The deteriorating prognosis in the presence of AC involvement likely reflects the need to power the hazard consistency and discrimination of the T1b category when associated with such a risk factor, thus deserving an independent T category.