Many Women Who Had Childhood Cancer Do Not Undergo Breast Cancer Screening

Despite recommendations and being at an increased risk of breast cancer, most young women who were treated with chest radiation for a childhood cancer do not undergo appropriate mammography screening, according to a study in the January 28 issue of JAMA.

Women treated with chest radiation for a pediatric malignancy face a significantly increased risk of breast cancer at a young age. “The risk of breast cancer begins to increase as early as 8 years after radiation and the median [midpoint] age of breast cancer diagnosis ranges from 32 to 35 years,” the authors write. By age 45 years, it is estimated that from 12 percent to 20 percent of women treated with moderate- to high-dose chest radiation will be diagnosed with breast cancer.

Experts recommend annual screening mammography for women exposed to moderate- to high-dose chest radiation, starting at 25 years of age or 8 years after radiation, whichever occurs last. It is estimated that in the United States there are approximately 20,000 to 25,000 women who are 25 years or older and were treated for a pediatric malignancy with moderate- to high-dose chest radiation. There is limited published information regarding the breast cancer screening practices of women who were treated with chest radiation for a childhood malignancy, according to background information in the article.

Kevin C. Oeffinger, M.D., of Memorial Sloan-Kettering Cancer Center, New York, and colleagues conducted a study that included 625 women, age 25 through 50 years, who had survived pediatric cancer, had been treated with chest radiation and were participating in the Childhood Cancer Survivor Study (CCSS), a North American group of long-term survivors diagnosed from 1970-1986. Participants received a 114-item questionnaire. Comparisons were made with similarly aged pediatric cancer survivors not treated with chest radiation (n = 639) and the siblings of the CCSS group (n = 712). Of 1,976 cancer survivors and siblings who were contacted, 87.9 percent participated.

Among women age 25 through 39 years who had received chest radiation therapy (RT), 36.5 percent reported a screening mammogram within the past 2 years; 47.3 percent had never had a mammogram; and only 23.3 percent had a screening or diagnostic mammogram within the previous year.

Women age 40 through 50 years who had received chest RT were more likely to report mammography than their younger counterparts, with 76.5 percent reporting a screening mammogram within the past 2 years compared with 70.0 percent for the group without chest RT and 67.0 percent for the CCSS sibling group. Only 52.6 percent of women in this age group with chest RT had regular screening (at least 2 mammograms within 4 years). This was not significantly higher than for women with no chest RT and only modestly higher than the CCSS siblings.

In all groups, women who were older were more likely to have been screened in the prior 2 years or to have received regular screening. For each 5-year incremental increase in age, the likelihood of reporting a mammogram increased nearly 2-fold. The strongest predictor of mammography in women ages 25 through 39 years was having a physician recommend the test, with the likelihood of reporting a mammogram 3 times higher among women who reported a physician recommendation than women who did not.