Breast Cancer - Most Common Lethal Neoplasm In Women

Written by docteam Friday, 28 May 2010 08:26

Breast cancer is the most common lethal neoplasm in women. The American Cancer Society (ACS) has estimated that breast cancer will constitute 29% of all new malignant neoplasms and 16% of deaths from cancer in women. The annual incidence of breast cancer in the United States increases dramatically with age (5 per 100,000 population at 25 years of age, rising to 150 per 100,000 at 50 years of age and to more than 200 per 100,000 at 75 years of age).

The incidence of male breast cancer is about 2.5 per 100,000 population. Fewer than 1% of all breast cancer cases occur in men.Breast cancer is the result of mutations in one or more critical genes. Two genes in women on chromosome 17 have been implicated. The most important gene is called BRCA-1 (at 17q21); the other is the p53 gene (at 17p13). A third gene is the BRCA-2 gene on chromosome 13.

The variation of incidence of breast cancer in different populations is highly correlated with consumption of dietary fat, dietary sugar, or parity in 75% of cases affecting postmenopausal women and in about 50% of cases affecting premenopausal women.

1. Diet
   The risk for breast cancer increases progressively with age except in countries with low-fat diets, where the risk is stabilized or decreased in older women. The risk changes accordingly when populations move from a low-risk country to a high-risk country and adopt the dietary habits of the new country.
2. Hormones
   High prolactin levels are clearly related to the development of breast cancer in animal models, but epidemiologic evidence is conflicting, and a causative relationship between prolactin and breast cancer has not been proved in humans. Estrogens, either alone or in combination with progestins in various oral contraceptive preparations, are also of concern.
3. Links between diet and hormones
   Differences in estrogen and prolactin levels in female populations correlate with differences in dietary fat; that is, high-fat diets are associated with increased hormone secretion. Furthermore, obesity is associated with increased adrenal production of androstenedione, which is converted to estrogens in adipose tissue; this source of production and conversion continues after menopause. Finally, tumor-promoting steroid hormones are also fat soluble and likewise may be accumulated in breast tissue.
4. Hereditary breast cancer