Effect of intratumor dendritic cell vaccination with and without chemoradiation in induced oral squamous cell carcinoma of hamsters.

OBJECTIVES: Oral squamous cell carcinoma represents an important health problem since its increasing incidence and persistent high mortality rates. The traditional therapies remain surgery and chemoradiation which have shown limited success in treating recurrent and metastatic cancers with multiple complications. Immunotherapy using dendritic cell vaccination is a rather novel approach that, yet, showed limited therapeutic efficacy in eradicating oral squamous cell carcinoma since the latter is known for its immunosuppressive microenvironment. Hence, there is pressing demand for adopting new multimodality approaches that would augment the antitumor effect of dendritic cell vaccine with lesser side effects and no relapse. DESIGN: Chemically induced oral squamous cell carcinoma model of hamster buccal pouch using 7,12-Dimethylbenz[a]anthracene was established. The clinically evident tumor masses were then 75 % surgically debulked. Resected tumors were manipulated to prepare dendritic cell vaccine. Animals were divided into 3 groups and subsequently subjected to different treatment approaches. RESULTS: The combination therapy of debulking surgery, chemoradiation, and intratumor dendritic cell vaccination significantly delayed tumor growth with complete regression of induced tumors. Moreover, this modality was associated with the highest survival rate (89 %) with establishment of immunological memory. CONCLUSIONS: Our findings emphasize the importance of modifying post-surgical environment, via co-administration of adjuvant chemoradiation, in generating robust anti-tumor immunologic activity. Chemoradiation and dendritic cell vaccines are available for clinical use/trial which endows this approach the merit of potential clinical application.