Female Survivors of Childhood Cancer Have Increased Risk of Infertility
Decreased pregnancy rates and early menopause have been reported in female cancer survivors, although there is less information on infertility rates and reproductive interventions in these patients. In a study reported in Lancet Oncology, Sara E. Barton, MD, of Brigham and Women’s Hospital and Harvard Medical School and colleagues analyzed risk of infertility and time to pregnancy in female childhood cancer survivors. They found that survivors had a significantly increased risk of clinical infertility compared with sibling controls. Although survivors had increased time to pregnancy, the majority of those with clinical infertility eventually achieved pregnancy.
The analysis was performed in the Childhood Cancer Survivor Study cohort of 5-year cancer survivors from 26 Canadian and U.S. institutions and a sibling control group. Women aged 18 to 39 years who had ever been sexually active were eligible for inclusion. Overall, 3,531 survivors and 1,366 female sibling controls who enrolled between November 1992 and April 2004 were included in the analysis.
Increased Risk of Clinical Infertility
Compared with their siblings, survivors had an increased adjusted risk of clinical infertility, defined as > 1 year of attempts at conception without success (relative risk [RR] = 1.48, P < .0001). Risk of infertility among survivors was greatest at early reproductive ages, with relative risks of 2.92 (P = .020) for those aged ≤ 24 years, 1.61 (P = .029) for those aged 25 to 29 years, and 1.37 (P = .0035) for those aged 30 to 40 years. Survivors were equally likely to seek treatment for infertility (69% vs 73%) but were significantly less likely than their siblings to be prescribed drugs for treatment of infertility (42% vs 75%, RR = 0.57, P < .0001).
Factors Increasing Risk
In adjusted models, risk of infertility was significantly increased by uterine radiotherapy doses greater than 5 Gy (RR = 2.48, P = .0002 for 5.1–10.0 Gy; RR = 2.02, P = .0032 for 10.1–20.0 Gy; and RR = 1.95, P = .0080 for > 20.0 Gy) and by an alkylating agent score of 3 (highest tertile of drug doses) compared with a score of 0 (RR = 1.48, P = .0093).
Cancer survivors took significantly longer to become pregnant than did their siblings (P = .032), with 13% of survivors vs 8% of siblings taking longer than 12 months to become pregnant. Overall, 292 (64%) of 455 survivors with self-reported clinical infertility achieved a pregnancy.
The authors concluded, “A more comprehensive understanding of infertility after cancer is crucial for counseling and decision making about future conception attempts and fertility preservation.”
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
