beta-glucan therapy converts the inhibition of myeloid-derived suppressor cells in oral cancer patients

Objectives The myeloid-derived suppressor cells (MDSCs) frequently have a high expansion in cancer patients. This research explored whether administration of beta-glucan could increase anti-tumor immunity in oral squamous cell carcinoma (OSCC) patients. Materials and Methods This study evaluated the MDSC level of circulating blood as CD33(+)/CD11b(+)/HLA-DR-/low by flow cytometry in 30 healthy donors (HDs, group I), in 48 oral squamous cell carcinoma (OSCC) patients before and after 14-day preoperative administration of beta-glucan (group II), and in 52 OSCC patients without taking beta-glucan (group III). Results A significantly higher mean MDSC level was observed in 100 OSCC patients than in 30 HDs (p < .001). There was a significant reduction of the mean MDSC level in group II patients after taking beta-glucan (p < .001). Moreover, we discovered a significantly higher recurrence-free survival (RFS) in group II than in group III patients (p = .026). Finally, the multivariate Cox regression further identified the MDSC level <= 1% and administration of beta-glucan as more favorable prognostic factors for OSCC patients. Conclusion Preoperative administration of beta-glucan can augment anti-tumor immunity and increase RFS rate via subversion of suppressive function of MDSC in OSCC patients.