MONDAY, Oct. 18, 2004 (HealthDayNews) -- Having had cancer as children increased the risk among surviving adult women for breast cancer, particularly those who were treated with chest radiation, a new study says.
Survivors of Hodgkin's disease are already known to be at higher risk for breast cancer, but doctors at Dana-Farber Cancer Institute in Boston found that chest radiation exposure for other cancers, such as Wilms' tumor, the most common kidney cancer in children, also increased the risk for breast cancers.
"Hodgkin's survivors were found to be at an increased risk for breast cancer due to the association with irradiation treatment, but other survivors of other childhood cancers that are treated with chest radiation are at risk as well," said Dr. Lisa B. Kenney, a pediatric oncologist at Dana-Farber and lead author of the study, published in the Oct. 19 issue of the Annals of Internal Medicine.
In addition, one quarter of the women in the study who were diagnosed with breast cancer had not been exposed to chest radiation during childhood treatment. Many of this group had sarcomas and/or a family history of breast cancer or sarcoma, which is a cancer of the bone and soft tissues in the body.
Kenney and her colleagues reviewed the records of women who participated in a nationwide Childhood Cancer Survivors Study (CCSS) and who had childhood cancers between 1970 and 1986. Among these women, Kenney found those had received chest radiation had a relative risk of breast cancer 25 times that of women of a similar age in the general population.
"Relative" is a key word, here, said Kenney, because the risk of breast cancer for women in this age group, which is the mid-30s, is very low, so women who have survived a childhood cancer should not assume that they are going to get breast cancer.
"We don't want to overblow the concern -- most of the women treated as children will not get breast cancer -- but we want to increase awareness so that doctors know that these women need to be thought of differently and screened differently," she said.
"This study validates previous research in recommending that radiation in the breast in childhood mandates aggressive strategies in adulthood," said Dr. William Carroll, director of pediatric hematology and oncology at New York University and Mount Sinai Medical Center.
Carroll added that maintaining a balance between curing childhood cancers and reducing the long-term effects of treatment as patients survive into adulthood is something that pediatric oncologists work hard to do.
"These kids are being cured, but we're obviously quite focused on long-term consequences of therapy, and we no longer use radiation as much," he said, adding that chemotherapy is being used increasingly to successfully treat cancers.
Of the 6,068 women who survived childhood cancer, 95 developed cancer at a median age of 35, according to the study. This compares to prevalence of breast cancer in the general population at this age of three cases, Kenney said. Of those with breast cancer as adults, 65 had Hodgkin's disease, 10 had bone sarcoma, eight had suffered from soft-tissue sarcoma, four had non-Hodgkin's lymphoma, three had Wilms' tumor, three had leukemia, and two had brain tumors.
Kenney hopes that this study, appearing in a journal for general practitioners rather than for oncologists, will help to alert both patients and their doctors of the importance of screening among childhood cancer survivors, especially as they age.
This study followed women who were only in their late 40s, when breast cancer is relatively rare, she said. Most breast cancers occur after the age of 50, so aggressive screening will be particularly important at that time.
Many tips on breast cancer prevention can be found at the American Cancer Society.