Genes contain the hereditary information that is passed down from parent to child. They serve as the blueprint for many features. Everyone has two copies of a gene called BRCA1 in the cells of their body, one inherited from their mother and one from their father. In most people, both BRCA1 genes function normally. But in some individuals, one copy carries a misspelling. This change, or alteration, can occur at hundreds of different sites along the BRCA1 gene. Some of these changes make a person more at risk for developing breast or ovarian cancer, and may possibly be associated with cancers of the colon and prostate.

In a recent research study, one particular alteration in BRCA1, known as 185delAG, was found to occur more frequently in a group of Jews of Eastern European descent (Ashkenazi Jews) than among other ethnic groups in the study. Approximately 1 percent of Ashkenazi individuals were found to carry this alteration in this preliminary study. The National Cancer Institute and the National Center for Human Genome Research will soon begin another research study of the Ashkenazi Jewish population to determine exactly how common this alteration is and how often this alteration is related to the incidence of breast cancer and ovarian cancer.

What we know and don't know about BRCA1 alterations:
Known: Most people who develop breast cancer, including those in the Jewish population, have normal BRCA1 genes. In fact, only about 5-10 percent of all breast cancer cases appear to be inherited and not all of these are related to BRCA1. BUT, Although certain to be fairly low, the exact percentage of inherited breast and ovarian cancers in the Jewish population is not known.

Known: Women with a strong family history of breast and/or ovarian cancer who have inherited an alteration in BRCA1 have a substantial risk of developing breast and/or ovarian cancer. This often occurs at an unusually early age, for instance, before menopause. BUT, The cancer risks for an individual without a strong family history who is found to carry the 185delAG alteration is not known. There are other factors such as lifestyle, hormonal factors, environmental influences, and other inherited traits that affect cancer risks. As testing for alterations in the BRCA1 gene becomes available to researchers, the interaction of these factors can be studied.

Known: Not all women who carry the BRCA1 alteration will develop breast or ovarian cancer BUT, the alteration is not the single cause of disease, only a contributing factor. There must be other factors, yet unknown, that affect the development of cancer in addition to having an altered BRCA1 gene. Therefore, people who carry the altered gene are said to have a susceptibility to breast and ovarian cancer.

Known: If a woman tests negative for an alteration in BRCA1, she may still get breast cancer. On average, a woman has a one in eight lifetime risk of developing breast cancer. BUT, All the genes that may increase a woman's risk of breast and ovarian cancer have not been identified and, therefore, cannot be tested for.

Your chance of recovery (prognosis) and choice of treatment depend on the stage of your cancer (the size of the tumor and whether it is just in the breast or has spread to other places in the body), the type of breast cancer, certain characteristics of the cancer cells, and whether the cancer is found in your other breast. Your age, weight, menopausal status (whether or not you still have menstrual periods), and general health can also affect your prognosis and choice of treatment.

Breast Cancer and the Women's Health Initiative. Because of the Women's Health Initiative (WHI), many women have taken themselves off of the Hormone Replacement Therapy (HRT). The results have been remarkable - dramatic;
2.5 % drop in breast cancer cases in 2002, and 7% drop in 2003 - overall a 15% drop. This is the first drop since 1945. These percentages equate to between 14,000 and 30,000 women each year who will not get breast cancer.

References: American Cancer Society, the National Cancer Institute, the Centers for Disease Control and the Journal of Clinical Oncology.

There were 2 large French studies done which followed women for 9 to 20 years who were taking estradiol and oral progesterone and found no increase risk of breast cancer and one showed a slight decrease of breast cancer.

References:
1. de Lingnieres et al, Climacteric, 2002
2. Fournier A, et al, Int J. Cancer, 114-2005

Main points of authors on paper regarding Breast Cancer

1. It's the synthetic progestins that contribute to causing breast cancer-not progesterone.

2. Even one full-term pregnancy is remarkably protective against breast cancer.

3. Women with the highest progesterone levels, and the highest progesterone/estradiol levels during pregnancy, have the lowest risk of breast cancer.

4. It's the estrogen, not progesterone, that stimulates proliferation of breast cells.

5. Menstruating women who have the lowest mid-cycle progesterone levels, have the highest risk of breast cancer.

6. "It is probable that the increase in Breast Cancer risk found in other studies with HRT is related to the fact that synthetic progestins, rather than progesterone, were used" - French Study.

7. Insulin resistance, hyperinsulinemia and high blood glucose are associated with an increased risk of breast cancer.

Reference:
"Pregnancy, progesterone and progestins in relation to breast cancer risk", by Carlo Campagnoli.