Several studies have shown that women treated with radiation to the chest for cancer during childhood, adolescence, or young adulthood have an increased risk of developing breast cancer as they get older, compared to women their same age in the general population. The risk of secondary breast cancer is related to the dose of radiation. People treated with higher doses of radiation have the highest risk. Researchers are studying this problem to better understand the risk factors and find ways to prevent secondary breast cancer.
Known Risk Factors
- Early menstruation (before the age of 12)
- Late menopause (after age 55)
- Never having a baby or having a first baby after the age of 30
- Having a close relative with breast cancer
- Being overweight
- Having an inactive (sedentary) lifestyle
Possible Additional Risk Factors
- High fat diet
- Drinking too much alcohol
- Never breastfeeding
- Smoking
- Birth control pills
- Hormone replacement therapy taken for long periods of time
Occurrence of Breast Cancer Caused by Cancer Treatment
The risk of secondary breast cancer begins to increase between five and nine years following radiation therapy and continues to rise thereafter. This means that if a woman develops breast cancer following chest radiation for childhood/adolescent cancer, it usually happens at a much younger age (usually 30 to 40 years old) than in women who develop primary breast cancer (usually age 50 or older).
Protecting Health
Most patients who received radiation therapy to the chest during childhood, adolescence, or young adulthood will NOT develop breast cancer. However, if a patient received radiation to the chest, it’s important to understand that the risk IS higher than for those who did not. The best way for patients to protect their health is by taking steps to closely monitor their breasts. Treatment is most effective when cancer is detected in its earliest stages.
Recommended Monitoring
Patients treated with chest radiation therapy during childhood, adolescence, or young adulthood, should:
- Perform monthly breast self-examination. Any lumps or changes to the breast should be reported to a healthcare provider right away.
- Have a clinical breast exam performed by a healthcare provider – at least once a year until age 25 – then every 6 months thereafter.
- Have a yearly mammogram – starting at age 25 or 8 years after receiving radiation (whichever comes last).
Minimizing Risk
The following lifestyle changes may help reduce the risk of developing breast cancer, and will also help patients to stay as healthy as possible:
- Eat enough fruits and vegetables (at least 5 servings a day are recommended).
- Exercise at least 30 minutes per day on most days of the week.
- Lose any excess weight.
- Limit alcohol intake to no more than one drink per day.
- Do not smoke.
- If a female patient has a baby, she should try to breastfeed for at least four months.
- If the patient needs hormone replacement therapy or birth control pills, she should discuss the risks and benefits with her healthcare professional.
- Limit exposure to potentially harmful chemicals and pesticides. Patients should use protective equipment if they are exposed to chemicals in their workplace.