Prognostic significance of immunoglobulin M overexpression in laryngeal squamous cell carcinoma

Conclusions: Immunoglobulin (Ig) M is overexpressed in laryngeal squamous cell carcinoma (LSCC), and its expression has an independent protective impact on disease-free survival in LSCC. Objective: A number of studies have reported on the ectopic expression of Ig in cancer cells, yet there has been a lack of understanding of its clinical and prognostic significance. This study aimed to investigate the expression of IgM in resected specimens of LSCC and to evaluate its clinical significance and prognostic value. Methods: Immunohistochemistry (IHC) and Western blotting were used to detect the expression of IgM in LSCC and normal laryngeal tissues. The serum level of IgM was also analyzed by immunoturbidimetric assay. Results: IHC and Western blot studies demonstrated that IgM was overexpressed in LSCC specimens (p < 0.001), while the serum level of IgM in patients with LSCC was not different from healthy controls. Chi-squared analysis revealed that the expression level of IgM was negatively correlated with regional lymph node metastasis and tumor stage (p = 0.011 and 0.025, respectively). Univariate analysis showed that IgM expression was significantly correlated with enhanced disease-free survival (DFS) (p = 0.004). In multivariate analysis, IgM retained its independent prognostic value for DFS (p = 0.048, HR = 0.506, 95% CI = 0.257-0.995).