Late Effects of the Reproductive System
Of 3,390 eligible participants in the Childhood Cancer Survivor Study (CCSS), 215 (6.3%) developed acute ovarian failure. Survivors with acute ovarian failure were older (aged 13–20 years vs. aged 0–12 years) at cancer diagnosis and more likely to have been diagnosed with Hodgkin lymphoma or to have received abdominal or pelvic radiation therapy than survivors without acute ovarian failure. Of survivors who developed acute ovarian failure, 75% had received abdominal-pelvic irradiation. Radiation doses to the ovary of at least 2,000 cGy were associated with the highest rate of acute ovarian failure with over 70% of such patients developing acute ovarian failure. In a multivariable logistic regression model, increasing doses of ovarian irradiation, exposure to procarbazine at any age, and exposure to cyclophosphamide at ages 13 to 20 years were independent risk factors for acute ovarian failure.
The presence of apparently normal ovarian function at the completion of chemotherapy should not be interpreted as evidence that no ovarian injury has occurred. Premature menopause is well documented in childhood cancer survivors, especially in women treated with both an alkylating agent and abdominal irradiation.[45,46,47] A total of 126 childhood cancer survivors and 33 control siblings who participated in the CCSS developed premature menopause. Of these women, 61 survivors (48%) and 31 siblings (94%) had surgically-induced menopause (relative risk [RR] = 0.8; 95% confidence interval [CI] = 0.52–1.23). However, the cumulative incidence of nonsurgical premature menopause was substantially higher for survivors than for siblings (8% vs. 0.8%; RR = 13.21; 95% CI, 3.26–53.51; P < .001).
Figure 6. Cumulative incidence curves of nonsurgical premature menopause in survivors (solid line) compared with siblings (broken line). Vertical bars indicate 95% confidence intervals. Sklar C A et al. JNCI J Natl Cancer Inst 2006;98:890-896. ©Sklar 2006. Published by Oxford University Press.
A multiple Poisson regression model showed that risk factors for nonsurgical premature menopause included attained age, exposure to increasing doses of radiation to the ovaries, increasing alkylating agent dose score, and a diagnosis of Hodgkin lymphoma. For survivors who were treated with alkylating agents plus abdominal-pelvic radiation, the cumulative incidence of nonsurgical premature menopause approached 30%.