Introduction Radiotherapy and chemotherapy are the most common treatments for advanced or recurrent cervical cancer, but the prognosis is poor. We have investigated viral therapy with triple mutant herpes simplex virus (T-01) in a mouse model of cervical cancer as a novel therapeutic approach. However, its antitumor effect is not sufficiently effective. In this study, we examined whether the combination of viral therapy and anticancer agents could enhance the antitumor effect.

Methods A mouse-derived immortalized cell line TC-1 with HPV16 E6/E7 as tumor antigen was inoculated subcutaneously into the back of C57BL/6 mice to generate cervical cancer model mice. cisplatin (CDDP), etoposide (ETP), fluorouracil (5-FU) from in vitro results, irinotecan (CPT-11), and cyclophosphamide (CPA) were administered to model mice, and anticancer agents that showed antitumor effects were combined with T-01. The combination therapy was evaluated as enhancing the antitumor effect when it exceeded the antitumor effect of viral therapy and chemotherapy.

Results The CPT-11, ETP, and 5-FU combination with T-01 groups showed no enhancement of antitumor effect. In contrast, the CDDP and CPA combination with T-01 group showed significant tumor growth inhibition compared to the chemotherapy and T-01 groups. Although there was no significant difference in survival rates between the chemotherapy and T-01 groups, no mice died during the observation period in either treatment group.

Conclusion/Implications The combination of CDDP or CPA and viral therapy exceeded the tumor growth inhibitory effect of viral therapy and chemotherapy, and we concluded that the combination of the two therapies enhanced the anti-tumor effect.