IGF as a Cause of Breast Cancer:

Insulin like growth factor

GOT IGF-I? Milk is loaded with a hormone that's been identified as the

key factor in breast cancer's growth.

Insulin like growth factors are mitogens for breast and prostate epithelial cells,

therefore the inevitable question must be what is the relationship between cancer of

these organs and the level of IGF-1 in the blood? Does the stimulation of growth

hormone production induce malignancy? The answer to these questions are not

known.What is reported in the literature is the following. A controlled prospective study

of 152 patients with prostatic cancer and controls from the Physicians Health Study showed that the patients had higher IGF-1 levels tha the controls (Chan JM et al

Plasma insulin like growth factor 1 and prostate cancer risk: a prospective study.

Science 1998; 279:563-6). An earlier study of patients from Athens showed that

increased values of IGF-1 were associated with an increased risk or prostate cancer,

with some associated evidence of interaction with high levels of testosterone.

(Mantozoros C.S. et al Insulin like growth factor-1 in relation to prostate cancer and

benign prostatic hypertrophy Br J Cancer 1997, 76:1115-8).

So far breast cancer studies have yield conflicting data, other than showing indeed

that invitro IGF-1 is a powerful stimulator, and is indeed expressed in high levels by

cancer cells. A report from Sweden showed that in premenopausal women high levels

of IGF-1 in the foliicular phase were significantly correlated to breast cancer (Olsson,

& Borg A, Reduced testosterone, 17 beta estradiol, sex hormone binding proteins,

and increased IGF-1 concentration in healthy first degree relatives to breast cancer

patients, Eur J Cancer Prev. 1997;6:330-40). There is no doudt that estrogen

theraphy in conjunction with growth hormone stimulation must be performed with

caution and carefully monitored, with IGF-1, estradiol, estrone, and estrone

measurements and perhaps mammography.