Breast cancer course may be influenced by a profile of steroids and peptides produced by mammary fat. The study was concerned with assessment of hormonal (leptin and adiponectin production, adipocyte diameter and aromatase level) and progenotoxic factors which characterize DNA damage (8-OHdG) and such cancer promoters as tumor necrosis (TNF-alpha), interleukin-6 (IL-6), nitric oxide (NO), thiobarbiturate reactive products (TRP), macrophage/histiocyte infiltration, estrogen 4-hydroxylase expression (CYP1B1) in mammary fat located 1.5-2 cm or not less than 5 cm away from tumor edge. Thirty-three pairs of mammary fat samples from 23 menopausal and 10 cycling patients were used. Closer proximity of mammary fat involved intensified biosynthesis of estrogens (as shown by aromatase level) and their conversion to catechol derivatives (as shown by CYP1B1 concentration) as well as accumulation of 8-OH-dG. Smoking and hyperglycemic patients and those with considerable mammary fat volume revealed accumulations of anti-inflammatory and progenotoxic cytokines (IL-6 or TNF-alpha). Hence, hormonal/progenotoxic ratio in mammary fat can be identified both by topographic, systemic and environmental factors.