Evaluation of cisplatin in combination with a biologic response modifier in a murine mammary carcinoma model

The purpose of this study was to determine the efficacy of intracavitary cisplatin against local regrowth and metastasis after resection of a murine mammary carcinoma and the ability of a biologic response modifier (Virulizin) to enhance chemotherapy. C3H-HeJ mice were injected with Gollin-B tumor cells. Once growth reached 8 mm, tumors underwent marginal resection and the mice were assigned randomly to intraperitoneal (i.p.) cisplatin, Virulizin, a controlled release cisplatin-impregnated sponge (OPLA-Pt), a combination of treatments or no treatment and were evaluated for local regrowth, metastasis, and toxicity at 14 or 60 days after surgery. A possible beneficial interaction was seen between OPLA-Pt and Virulizin at 14 days. All cisplatin groups had significant advantages over controls in all variables measured with OPLA-Pt displaying significant advantages over i.p. cisplatin in local recurrence rate, tumor score, survival time, and delay in regrowth at 60 days. No toxicity related to either cisplatin or Virulizin was observed.