The meaning of the c-kit proto-oncogene product in malignant transformation in human mammary epithelium.

To evaluate the relationship between the c-kit proto-oncogene product and malignant transformation of human breast tissue, we examined the immunohistochemical expression of the c-kit proto-oncogene product in both malignant and non-malignant breast tissues. The immunohistochemical expression of the c-kit proto-oncogene product in 40 primary breast cancer tissues (22 axillary lymph nodes negative, 18 lymph nodes positive), in 18 corresponding axillary lymph nodes, and in 10 distant metastastic tissues were studied using an anti-c-kit proto-oncogene product antibody in comparison with 20 normal and 20 benign breast tissues. The mean values of immunoreactive score (IRS) were compared.