Objectives/hypothesis: The posterior commissure is an uncommon site of glottic carcinoma. The aim of the study was to compare the clinical and prognostic characteristics of glottic carcinoma of the posterior commissure and the vocal cords.
Study design: Retrospective case control study.
Methods: The study group consisted of 40 patients aged 32 to 84 years (mean, 62.7 +/- 10.7) diagnosed with T1 glottic carcinoma involving the posterior commissure from 1960 to 2008. Data on clinical features and outcome were collected from the medical files and compared with the data for 42 patients aged 30 to 87 years (mean, 64.4 +/- 11.8) with T1 vocal cord carcinoma.
Results: : There were no significant differences in clinical characteristics between the groups except for the higher rate of smokers among the patients with vocal cord carcinoma (95% vs. 65%, P = .01). All patients were treated primarily with radiotherapy. Disease-free survival in the posterior commissure carcinoma group was 76.1% after 5 years and 72.3% after 10 years, and in the vocal cord carcinoma group, 95% after 5 and 10 years (P = .012). The risk of recurrence was higher when the tumor involved the posterior commissure (hazard ratio, 8.78; 95% CI, 1.12-68.5, P = .038).
Conclusions: T1 glottic carcinoma involving the posterior commissure has a more aggressive biological behavior and a worse prognosis than T1 glottic carcinoma of the vocal cords. Smoking, which is an important pathogenetic factor in vocal cord carcinoma, plays a lesser role in posterior commissure carcinoma. Laryngoscope, 2009.