Radiation dose linked to breast cancer risk after Hodgkin's
Tuesday, July 22nd 2003, 12:00 am
News On 6
CHICAGO (AP) _ Young women who received high doses of chest radiation to treat Hodgkin's disease face up to an eight times higher risk of breast cancer than those exposed to lower levels, a study suggests.
Researchers found that when women were treated with breast-area radiation alone, their risk of breast cancer increased as the radiation doses did, although the risk was lower than what other studies have found.
Hodgkin's disease is a type of cancer involving the lymph nodes. Unlike most other cancers, it strikes young people about as often as it does older ones.
The study by researchers from the National Cancer Institute, along with others from Canada, the Netherlands, Sweden, Denmark, Finland and the United States, was published in Wednesday's Journal of the American Medical Association.
Researchers estimate that 83 out of 1,000 women may develop breast cancer over 25 years if they were treated for Hodgkin's disease with high-dose chest radiation alone when they were 30 or younger.
Nonetheless, the benefits of Hodgkin's disease treatment far outweigh the risks, the researchers said. Fifty years ago, the typical patient survived only a few years, while modern-day treatment including radiation, chemotherapy or both has boosted the five-year survival rate to 85 percent.
Moreover, lower, more targeted doses of radiation have come into use against Hodgkin's during the past decade, and these women may not face as high a risk of breast cancer as their predecessors, said lead researcher Dr. Lois Travis of the National Cancer Institute.
Researchers looked at breast cancer within a group of 3,817 women diagnosed with Hodgkin's disease at age 30 or younger between 1965 and 1994. Breast cancer occurred in 105 women.
The American Cancer Society suggests that women who have undergone such radiation treatment consider starting yearly mammograms at age 30 instead of 40.
The researchers found a lower risk of cancer in women whose ovaries had been damaged by radiation or older types of chemotherapy used against Hodgkin's. The study suggests that damage to the ovaries stopped the hormonal stimulation that can lead to radiation-induced breast cancer.
Dr. Herman Kattlove, medical editor at the American Cancer Society, said newer types of chemotherapy are less likely to damage the ovaries.
An estimated 200,000 U.S. women are diagnosed each year with breast cancer.