In order to develop a new method of administration for CDDP, in vitro models of malignant
tumors in the field of gynecology were prepared using two cell lines maintained by the authors, and fundamental experiments on the topical injection of CDDP were carried out. In experimental topical injection of CDDP in
tumor-bearing nude mice, the test
drug demonstrated an excellent
tumor regression effect and an inhibitory effect on
tumor growth. In the histopathologic examinations, specific
necrosis of
tumor cells was observed. It was confirmed that this is a highly safe method, as tissue separation, ulceration, or hemorrhagic lesions attributable to the local administration of CDDP were not observed. In the present study, treatment with oral
medroxyprogesterone acetate was also used. At the doses used in this study, however, no inhibitory effect on
tumor growth or synergism between
medroxyprogesterone acetate and CDDP was observed. Topical injection is an excellent pharmacodynamic method that permits the injection of free platin into the
tumor itself or in the boundary area between the
tumor and normal tissues, with no loss of the
drug, and it is considered a safe and effective mode of local administration.
Intra-arterial injection of this
drug alone or in conjunction with
OK-432 can also be used, even though further studies will be required to determine the optimum dosage and reduce side effects. At present, data are being collected on terminal
cancer patients for whom no other
therapy is available. In the near future this method of administration is expected to be utilized in the clinical treatment of malignant
tumors, be it early
tumor or progressive
cancer.