| Popis: |
To date there were only a few risk factors for developing prostate cancer (Pca) like advanced age, skin color and family history (Crawford, 2003). For the long time obesity was considered a negative feature which may contribute to chronic diseases like hypertension or diabetes, but its relationship with cancers was unknown. Last years revealed the obvious truth that such relationship exists and may be very strong. The problem seems to be very important given that obesity is very common, especially in western countries. Over the past 25 years, the number of obese men has increased from 15% to 30% in USA. In 2000 66% of adults in U.S were classified as overweight or obese (Flegal et al., 2002) Nowadays no one denies that overweight and obesity is an independent risk factor for developing colon cancer or post-menopausal breast cancer. Relationship with other cancers is still discussed especially in case of Pca. While the connection between obesity and chronic internal diseases is simple to explain, its relation to cancers is not so unequivocal. Most theories indicate the permanent chronic inflammation in obese which may contribute to oncogenesis. Dishormonose observed in obese consists of high levels of insulin, insulin growth factor – 1 (IGF-1) (Chan et al., 1998, 2002), leptin, estrogens, and low levels of androgens. Insulin and IGF -1 are strong mitosis activators which may explain such ”oncopotential”. On the other hand low levels of testosterone and high of estrogen should protect men from developing Pca. It is only a simple example why the relation between obesity and prostate cancer may be very complex. |
