5‐iodo‐2‐deoxyuridine as cytotoxic chemotherapy and as a possible radiosensitizer in a mouse ovarian ascites tumor model

Abstract

SUMMARY The mouse ovarian ascites tumor model was used to evaluate the intraperitoneal (IP) administration of 5-iodo-2-deoxyuridine (IUDR) as a radiosensitizer and tumor cytotoxic agent. A 7 day continuous infusion of IUDR starting on the day of tumor cell implantation (1 x lo6 tumor cells) was extremely effective in prolonging survival compared to no treatment or radiation alone. Infusions starting on day 7 after implantation of tumor cells were less effective. Whole abdominal irradiation (either 500 cGy x 2 or 750 cGy x 2) on days 5 and 7 from tumor cell implantation had very little beneficial effect (P = 0.15 and 0.10, respectively). The combination of radiation and IUDR as used in these experiments did not show any benefit over IUDR alone. As yet, an optimum combination of radiation and IUDR which would be superior to IUDR alone has not been demonstrated for this tumor model. However, these results suggest that the IP administration of IUDR alone or possibly with radiotherapy might be beneficial for malignancies such as ovarian cancer which tend to disseminate IP.