Today, thanks to advances in cancer detection and treatment, more than 70 percent of children and adolescents with cancer will survive the disease. This good news is tempered by the fact that these survivors are at increased risk of what are known as the late effects of their cancer treatment, which may include second cancers, infertility, and cardiovascular disease. A recent study conducted by Memorial Sloan-Kettering investigators has shown that women who survive childhood cancer are more likely to experience premature menopause.
In 1994, the Children's Cancer Survivorship Study (CCSS) was launched to track more than 14,000 survivors of childhood cancer and almost 4,000 of their cancer-free siblings. A report issued by the Institute of Medicine, using CCSS data, noted that up to two-thirds of childhood cancer survivors will probably experience at least one late effect of their cancer treatment.
Tapping into the study's database and its rich data on long-term effects, Charles A. Sklar, MD, Director of the Long-Term Follow-Up Program at Memorial Sloan Kettering, and colleagues from the University of Minnesota School of Medicine, the Fred Hutchinson Cancer Research Center, M.D. Anderson Cancer Center, and other research institutions, examined the incidence and risk factors for premature menopause in 2,819 female pediatric cancer survivors over the age of 18, along with 1,065 of their female siblings. (Menopause is the permanent end of a woman's menstrual cycles. Premature menopause is defined as menopause before the age of 40.)
Dr. Sklar and his group found that cancer survivors in the study developed premature menopause at a rate that was 13-times higher than their siblings. The incidence of premature menopause increased even more for survivors whose treatment had included radiation delivered to the abdomen and pelvis or administration of a class of chemotherapy drugs known as alkylating drugs. And for those women who had received both abdominal-pelvic radiation and alkylating chemotherapy drugs, the risk of developing premature menopause was nearly 30 percent. "The strengths of this study include the large numbers of survivors and the detailed treatment information that was available to us", says Dr. Sklar.
The study's findings are important for a number of reasons. Women who experience premature menopause will lose their ability to conceive children at a younger age than their peers, necessitating earlier family planning. In addition, premature menopause causes a halt in the production of ovarian sex hormones, putting women with this condition at increased risk for a variety of medical conditions such as osteoporosis and cardiovascular disease.
With increased awareness of a childhood cancer survivor's premature menopause risk, along with the factors contributing to it, doctors can help plan for and directly address these issues. According to Dr. Sklar, "The results of this study will facilitate counseling current survivors about their future risk of early menopause. In addition, these data will aid investigators in designing new protocols that, we hope, will maintain high rates of cure but minimize late toxicities."
