Meta-analysis of impaired vocal cord mobility as a prognostic factor in T2 glottic carcinoma

To pool and meta-analyze the reported outcomes in patients receiving radiotherapy for T2 glottic carcinoma with impaired vocal cord mobility.

A MEDLINE search and manual search were conducted to identify all studies published between January 1, 1950 and September 30, 2007, in English on the treatment of T2 glottic carcinoma. Search terms included laryngeal neoplasm, glottis, and glottic carcinoma.

All studies of primary radiotherapy for T2 glottic carcinoma with explicit reporting of outcomes with regard to the presence or absence of vocal cord immobility were included in the meta-analysis. Studies with data reported elsewhere were excluded.

A meta-analysis using a fixed-effects model was conducted for outcome measures of local disease control, ultimate survival after salvage surgery, absolute survival, and disease-specific survival. Odds ratios (ORs), 95% confidence intervals (CIs), and tests for heterogeneity were reported.

Thirty-five studies were identified, of which 21 met criteria for meta-analysis. All studies were retrospective. Comparison of 5-year local control of disease for lesions with impaired vocal cord mobility (T2b) vs those with normal vocal cord mobility (T2a) showed a statistically significant difference (OR, 1.83; 95% CI, 1.52-2.20; P < .001). Ultimate control after salvage surgery was reported in 7 studies, which also showed significantly better outcomes for T2a lesions over T2b lesions (OR, 1.90; 95% CI, 1.23-2.92; P = .005).

This meta-analysis indicates that impaired vocal cord mobility has a negative impact on local disease control and ultimate disease control in patients receiving primary radiotherapy for the treatment of T2 glottic carcinoma. We recommend that the subdivision of glottic cancer to T2a and T2b be reviewed and considered by the American Joint Committee on Cancer for inclusion in the Cancer Staging Manual.