We know that women who had radiation to the chest as children to treat a cancer other than breast cancer, such as Hodgkin lymphoma (cancer of the immune system) or non-Hodgkin lymphoma, have a higher risk of breast cancer.
Now, a study suggests that women who had childhood cancer have a much higher-than-average risk of breast cancer even if they never had radiation to the chest.
The research was presented on June 1, 2014 at the American Society of Clinical Oncology 2014 Annual Meeting. Read the abstract of “Breast cancer in childhood cancer survivors not treated with chest-directed radiation in the Childhood Cancer Survivor Study (CCSS).”
In recent decades, some of the most important medical discoveries have been in treating childhood cancer. Still, some childhood cancer patients develop a second cancer or another serious medical condition later in life that's believed to be related to treatment for childhood cancer. Doctors don’t completely understand why childhood cancer survivors are more likely to be diagnosed with a different cancer later in life. For some, it could be genetics that make them more likely to develop cancer. For others, the higher cancer risk is probably related to the childhood cancer treatment. For example, radiation used to treat childhood cancer also can affect normal cells that are exposed to the radiation, causing a new, different cancer -- like breast cancer -- to develop decades later.
As part of the Childhood Cancer Survivor Study, researchers reviewed the records of 3,768 women who survived childhood cancer. None of the women had radiation to the chest to treat the childhood cancer. The women have been followed for between 8 and 39 years.
The researchers found that 47 of the women developed breast cancer about 10 to 34 years after their childhood cancer diagnosis. These women tended to be diagnosed with breast cancer at a younger age -- half the women were older than 38 when diagnosed and half were younger -- and were more likely to be diagnosed with breast cancer in both breasts.
Compared to women at average risk, the childhood cancer survivors were about four times more likely to develop breast cancer. Some specific groups of childhood cancer survivors had a breast cancer risk that was higher than that, including:
- women who were between age 10 and 20 when they were diagnosed with childhood cancer
- women who were diagnosed with leukemia as children
- women who were diagnosed with sarcoma (cancer of the connective tissues) as children
Other research has shown that childhood cancer survivors are at much higher risk for a number of health problems in adulthood, including cancer. Because of these risks, people who have been treated for childhood cancer should take aggressive steps to minimize their risk of another cancer. These people also should have regular screenings for any complications of earlier treatment, including heart and lung disease as well as cancer.
If you've been treated in the past for cancer, it's important to regularly see a doctor who:
- is familiar with your past medical history
- understands your special risks
- can give you the necessary counseling, monitoring, and screening for possible complications of your earlier treatment
If you were diagnosed with cancer as a child, your risk of breast cancer is most likely higher than average. You and your doctor should consider a more aggressive breast cancer screening plan. This plan might include more frequent mammograms starting at an earlier age and possibly using different screening techniques, such as breast MRI.