Do “Bad Genes” Cause Most Cases of Breast Cancer?
Much research has been done to elucidate the genetic causes, and predispositions, for breast cancer, however it still remains true that approximately 90% of cases of breast cancer are so-called, “sporadic cases”, in which the person with the cancer has no family history of breast cancer. While it is possible that unknown genetic factors can increase a person’s risk for breast cancer, these additional factors have not yet been discovered by scientists and increased interest is focused on discovering environmental causes of breast cancer.
Does it just come down to bad luck? Or could it be that there is something in the environment which increases a woman’s risk of being diagnosed with breast cancer. Approximately 200 chemicals have been identified which cause breast cancer in animal models, and epidemiologists are concerned that the large number of chemicals in the environment will make it difficult to figure out which ones to avoid. Many of these chemicals affect the human endocrine system as many of them mimic the effects of estrogen on the body. Scientists do know that increased exposure to estrogen inside a woman’s body increases her risk of breast cancer.
Research done in europe has shown that when children are adopted out of their biologic family into another family, their rate of breast cancer most closely mimics that of their new family-not their biologic family, thus lending credence to the idea that the environment may play a much bigger role in most cases of breast cancer than genetics.
Some groups recommend that people make efforts to limit their exposure to chemicals by not storing food in plastic containers (chemicals can leach out of the plastic material), and that people limit their exposure to chemicals, such as home and garden pesticides as much as possible.
What else predisposes a woman to breast cancer besides chemicals in the environment?
However, outside of unknown environmental factors there are a number of known risk factors for breast cancer which include:
1. Female gender
2. Older Age
3. Family history of breast cancer
4. History of benign breast problems, such as having a previous breast biopsy
5. Exposure to Ionizing radiation
6. Being obese or overweight
7. Never having children, or having them late in life
8. Alcohol consumption-even a drink or two a day can increase by 51% a woman’s chance of developing the most common type of breast cancer.
9. Not eating enough fresh fruit, fresh vegetables, whole grains and fiber
10. Lack of exercise
11. Never having breast fed an infant
12. Longer exposure to estrogen and progesterone
13. Eating a high fat diet
14. Smoking, especially in combination with alcohol consumption
There is even an online breast cancer risk calculator which can be found here http://www.cancer.gov/bcrisktool/. This tool only provides an estimated risk of breast cancer, and women who are low risk for breast cancer do get breast cancer, and being high risk doesn’t necessarily mean that a woman will get breast cancer in her lifetime.