Effect of perductal paclitaxel exposure on the development of MNU-induced mammary carcinoma in female S-D rats.

Abstract

BACKGROUND: Breast carcinoma and precancer are thought to start in the lining of the milk duct or lobule. METHODS: At 5weeks of age, rats received a intraperitoneal (ip) injection of MNU for carcinogenesis. After mammary tumors were identified macroscopically using fiberscope, the rats were treated with perductal (pd) or ip injection of paclitaxel tri-weekly. At 36 weeks after MNU injection, tumor burden (No. of >1cm palpable mammary tumors/rat), total number of mammary carcinoma, apoptosis (AI), and microvessel density (MVD) were measured. RESULTS: The administration of paclitaxel through the duct did not produce any toxic side effect. The tumor burden and total number of mammary carcinoma in the pd paclitaxel-treated group were significantly reduced compared to those seen in the ip paclitaxel-treated group. In addition, in the pd paclitaxel-treated group, AI was also increased and MVD was decreased, compared to those in the ip paclitaxel-treated group. CONCLUSION: Local administration of paclitaxel may be useful for treatment of breast cancer.