Host heterogeneity in female breast cancer: possible significance for pathophysiology, therapy, and prevention.

Longitudinal studies on human growth have revealed seasonal patterns in the gain of height in 1/3 of the population. Seasonal sensitivity of growth velocity is apparently linked with a lean body structure. This being so, a subgroup with specific biological features could be isolated, including specific endocrine mechanisms (e.g. shorter interval between menarche and menopause, higher incidence of irregular early postmenstrual cycles, and higher concentration of growth hormone secretion) and specific metabolic pathways (more frequent drinking, smoking, and use of the contraceptive pill). This biological specificity may be responsible for behavioral heterogeneity in cancer in general and in breast malignancies in particular. One third of the breast cancer patient population is hormone responsive. The response to all the methods of cancer adjuvant therapy (including ablation of hormone producing organs, chemotherapy, and immunologic manipulation) used up till now does not surpass 33% in the long run. Breast cancer risk reduction by 1/3 due to full-term teenage pregnancies suggests that this may be a consequence of the interruption of a premalignant process initiated in women of the aforementioned subgroup. Simulation of early pregnancy might therefore lead to prevention of breast cancer in women who had seasonal growth patterns as children.