Prognostic and Treatment Differences Between T1a and T1b Glottic Cancer.

OBJECTIVES: This study was designed to evaluate significant differences in treatment and survival outcomes between patients with T1a and T1b glottic cancer. METHODS: Patients within the SEER Research Plus, 18 Registries dataset who were diagnosed with Stage I T1a or T1b cancer of the glottis between 2004 and 2015 were included in this study. Data prior to 2004 could not be included, as the SEER database did not distinguish between T1a and T1b glottic cancer until that year. RESULTS: The 5-year disease-specific survival for T1a patients was significantly better than that of patients diagnosed with T1b glottic cancer. Age and year of diagnosis were also independent factors that impacted mortality. More patients who were diagnosed with T1b glottic cancer underwent external beam radiation than those diagnosed with T1a glottic cancer. CONCLUSION: Our data shows that there are several independent factors effecting mortality including T classification, age at time of diagnosis, and year of diagnosis. T1a glottic cancers also show a significantly better prognosis compared with T1b. T1b glottic cancers are much more likely to be treated with primary radiotherapy compared with surgery. LEVEL OF EVIDENCE: 4 Laryngoscope, 132:2187-2193, 2022.