Am I at Risk of Getting Breast Cancer?
- Hormonal Risk Factors
Starting Periods Before the Age of 11 Years
Women who have a history of starting their periods (menses) before the age of 11 years have a higher chance of developing breast cancer. This is thought to be due to their longer exposure to the female sex hormone oestrogen, which is an established risk factor for breast cancer.
Later Pregnancy
The risk of developing breast cancer increases by 5% for each year of delay in having the first full-term pregnancy. Women who have their first child before the age of 30 years have a lower risk of developing breast cancer than those whose first pregnancy occurs after the age of 35 years. Recent research indicates that breast-feeding also reduces the risk of developing breast cancer.
There is no scientific evidence that pregnancies which end in a spontaneous or induced miscarriage increase the risk of developing breast cancer.
Later Menopause
The average age of a woman upon reaching the menopause in western Europe is 50 years. Women who reach the menopause after the age of 53 years have a higher chance of developing breast cancer. Delayed menopause prolongs a women’s exposure to oestrogen – just as does starting periods before the age of 11 years.
The Oral Contraceptive Pill
The taking of the oral contraceptive pill that contains oestrogen within the previous 10 years slightly increases the chance of developing breast cancer. The greater the oestrogen-content in the pill, the higher the risk of developing breast cancer. Again, this is because oestrogen increases the risk of breast cancer. However, breast cancer that develops in contraceptive pill users seems to be less advanced than in non-users.
Hormone Replacement Therapy (HRT)
Taking HRT after the menopause seems to increase the risk of developing breast cancer, especially if it is continued for more than 10 years.
HRT, however, reduces the risk of brittle-bone disease (osteoporosis), bone fractures and large bowel cancer. It also improves the symptoms of the menopause, such as vaginal dryness, hot flushes and depression. It is currently thought that HRT should be avoided where possible in women with a personal or a significant family history of breast cancer. A recent American study (Women’s Health Initiative) has shown that taking HRT increases the risk of breast cancer and coronary heart disease. Therefore the author believes that the benefit–risk balance for HRT is negative and that the lowest dose should be used for the shortest time if required.