[Molecular biological and biochemical features of breast cancer]

Some molecular genetic and biochemical features of malignant breast tumors were studied in females living in North-Western Russia. ERBB-2 oncogene amplification frequently (25%) occurred and was associated with poor outcomes. The frequency of C-MYC extra copies was lower (3%) than that in Europe and the USA. Deletions at chromosome 17p were associated with ERBB-2 amplification and the lack of nodal involvement. Moreover, it is concluded that endogenous hormonal and metabolic parameters, as well their changes due to some environmental factors (smoking), plays a great role in the modification both of breast cancer risk and autocrine-paracrine relationships in the very tumor tissue and of the hormone sensitivity of the latter.