In disease and development of a cancer of a mammary gland ethnic distinctions matter: disease of the Mammary gland Cancer in the Khakas of population of women Authentically lower (79,77±3,16), than among Slavs (110,47±3,16); middle age sick of the Mammary gland Cancer in Republic Khakasia of a slavic phenotype 56,80±0,74 years, the Asian phenotype - 53,05±2,69 years. Higher disease of Slavs can be connected with more adverse conditions of their reproductive behavior. The revealed features of occurrence and development of the Cancer of the Mammary gland are necessary for studying and considering at planning screening programs of revealing, optimization of treatment and rational supervision sick of the Mammary gland Cancer