Causes and Risk Factors in Breast Cancer

Conditions & Diseases: Cancers

Breast Cancer

Causes and Risk Factors in Breast Cancer
There are several categories of risk factors that can cause breast cancer, but the way in which these factors transform healthy cells into cancerous cells is not entirely known.

Age and Gender: Age represents a significant factor for breast cancer and statistics show that a high percentage of breast cancer cases (77% of new cancer cases and 84% of breast cancer death) occur in women age 50 and older.

Genetic Factors and Family History of Breast Cancer: For many years, researchers noticed that patients that develop cancer have a family history of breast cancer. The latest clinical trials and research shows that this genetic breast cancer tendency that runs in the family can be explained by the structure of DNA. DNA is a chemical code that carries all the instructions needed for the normal functioning of nearly every cell of the body. Thus, certain changes in DNA structure were noticed to be responsible with changes in normal breast cells that become cancerous.

Certain parts of the DNA, called genes, contain instructions to control the cells growth process, division process, and dying process. Those genes responsible for the division process of the cells are called oncogenes. Those genes that decrease the cells division process or cause cells to die are called tumor suppressor genes. When a mutation appears in the DNA structure causing cancer, the oncogenes are turned on and the tumor suppressor genes are turned off.

The genes involved in breast cancer are BRCA1 and BRCA2. These BRCA genes are two tumor suppressor genes. When they suffer a mutation, they no longer function normally to suppress abnormal cell growth thereby causing cancer to develop. Researchers have identified some other tumor suppressor genes that are responsible for breast cancer, including p53 and BARD1, CHEK-2, and BRCA3 and Noey2 (inherited only from the father's family).

An inherited DNA change (like those mentioned above) can increase the risk for developing cancer in those people that carry this mutation and explains the genetic cancer family connection. In order for the cancer to develop, several gene mutations are required. These mutations of oncogenes or tumor suppressor genes are not inherited, but can be caused by radiation or exposure to different cancer-causing chemicals. However, for now, these carcinogens are unknown.

Hormone changes: Hormones can increase the growth rate of cells. High level of hormones specific to the reproductive years' of a woman, especially if they are not interrupted by the normal hormone changes of the pregnancy, appear to increase the risk for breast cancer. Some studies suggest that even breast feeding can decrease the risk for developing breast cancer if continued until the 18th to 24th month. Pregnancies and breast feeding reduce the number the total number of menstrual cycles during a woman's lifetime.

Early menstruation and late menopause: Women who have their first menstruation at an early age (before 12) or went through menopause later then normal (after 55) are at a higher risk of developing breast cancer.

Oral Contraceptives: The use of birth control pills can increase the risk of developing breast cancer - depending on the age, length of use and side effects.

Use of alcohol: The use of alcohol increases the risk of developing cancer, a risk that increases proportional to the amount of alcohol consumed.

Obesity and high-fat diets: All studies report obesity as a risk factor for breast cancer, especially for women after menopause. The presence of fat tissue increases the level of estrogen produced by the body. The risk of developing cancer is higher for women that gain weight in the adult years. Also, fat tissue deposited in the waist area may increase the risk, more than the same amount of fat tissue in the hips and thighs area.

Lack of physical activities: In the last few years, clinical studies proved that lack of physical activity can increase the risk of developing cancer. According to a study published in the Women's Health Initiative, an hour and 25 minutes to 2 hours and 50 minutes per week of rapid walking reduces cancer risk by 18 percent.

Exposure to chemicals: Some research proves that exposure to an estrogen-like chemical found in different industrial products is possible of increasing a woman's risk of getting breast cancer.

Exposure to radiation: Those people that are exposed to radiation during childhood or chest radiation for prior cancer treatments, may face an increased risk of developing breast cancer.

Article by Alina Morrow, MS
Medical Writer,
OmniMedicalSearch.com