What are the risk factors for breast cancer?

ARISK factor is anything that increases a person’s chance of getting a disease. Different cancers have different risk factors. However, having a cancer risk factor, or even several of them, does not necessarily mean that a person will get cancer. Some women with one or more breast cancer risk factors never develop breast cancer, while about half of the women with breast cancer have no apparent risk factors.

SIGNIFICANTLY HIGHER RISK

History – A woman with a history of cancer in one breast, such as ductal carcinoma in situ (DCIS) or invasive breast cancer, is three to four times more likely to develop a new breast cancer, unrelated to the first one, in either the other breast or in another part of the same breast. This is different from a recurrence of the previous breast cancer. Age – Your risk for breast cancer increases as you age. About 77 per cent of women diagnosed with breast cancer each year are over age 50, and almost 50 per cent are ages 65 and older. Consider this: In women ages 40 to 50, there is a one in 68 risk of developing breast cancer. From ages 50 to 60, that risk increases to one in 42. In the 60 to 70 age group, the risk is one in 28. In women ages 70 and older, one in 26 is at risk of developing the disease.

MODERATELY HIGHER RISK

Direct family history – Having a mother, sister, or daughter (‘first-degree’ relative) who has breast cancer puts a woman at higher risk for the disease. The risk is even greater if this relative developed breast cancer before menopause and had cancer in both breasts. Having one first-degree relative with breast cancer approximately doubles a woman’s risk, and having two first-degree relatives triples her risk. Having a male blood relative with breast cancer will also increase a woman’s risk of the disease.

Genetics – About five per cent to 10 per cent of breast cancer cases are thought to be hereditary. Carriers of alterations in either of two familial breast cancer genes called BRCA1 or BRCA2 are at higher risk. Women with an inherited alteration in the BRCA1 gene have a 55 per cent to 65 per cent chance of developing breast cancer during her lifetime, and those with an inherited alteration in the BRCA2 gene have up to a 45 per cent chance of developing breast cancer.

Breast lesions – A previous breast biopsy result of atypical hyperplasia (lobular or ductal) or lobular carcinoma in situ increases a woman’s breast cancer risk by four to five times.

SLIGHTLY HIGHER RISK

Distant family history – This refers to breast cancer in second- or third-degree relatives such as aunts, grandmothers, and cousins.

Previous abnormal breast biopsy – Women with earlier biopsies showing any of the following have a slightly increased risk: fibroadenomas with complex features, hyperplasia without atypia, sclerosing adenosis, and solitary papilloma.

Age at childbirth – Having your first child after age 35 or never having children puts you at higher risk.

Early menstruation – Longer lifetime exposure to endogenous (your own) estrogen increases your risk, such as starting to menstruate before age 12, starting menopause after age 55, and never having had a pregnancy.

Weight – Being overweight (especially in the waist), with excess caloric and fat intake, increases your risk, especially after menopause.

Excessive radiation – This is especially true for women who were exposed to a large amount of radiation before age 30, usually as treatment for cancers such as lymphoma.

Other cancer in the family – If a family member had ovarian cancer under age 50, your risk is increased.

Alcohol – Use of alcohol is linked to increased risk of developing breast cancer. Compared with non-drinkers, women who consume one alcoholic drink a day have a very small increase in risk, and those who have two to five drinks daily have about 1.5 times the risk of women who do not drink.

Race – Caucasian women are at a slightly higher risk of developing breast cancer than are African-American, Asian, Hispanic, and Native American women. The exception to this is African-American women, who are more likely than Caucasians to have breast cancer under age 40.

Hormone Replacement Therapy (HRT) – Long-term use of combined estrogen and progesterone increases the risk of

breast cancer. This risk seems to return to that of the general population after discontinuing them for five years or longer.

LOW RISK

Less lifetime exposure to endogenous estrogen – Having a pregnancy before age 18, starting menopause early, and having the ovaries removed before age 37 decreases the risk of developing breast cancer.

Factors not related to breast cancer: Fibrocystic breast changes Multiple pregnancies Coffee or caffeine intake Use of antiperspirants Wearing underwire bras Using hair dye Having an abortion or miscarriage

Using breast implants

BREAST CANCER is a kind of cancer that develops from breast cells.

Breast cancer usually starts off in the inner lining of milk ducts or the lobules that supply them with milk. A malignant tumour can spread to other parts of the body. A breast cancer that started off in the lobules is known as lobular carcinoma, while one that developed from the ducts is called ductal carcinoma.

The vast majority of breast cancer cases occur in females. Breast cancer is the most common invasive cancer in females worldwide. It accounts for 16 per cent of all female cancers and 22.9 per cent of invasive cancers in women; 18.2 per cent of all cancer deaths worldwide,