For women who have survived childhood cancer, the impact of modern chemotherapy regimens on the likelihood of becoming pregnant is generally small, and most have a good chance of conceiving, according to a study in The Lancet Oncology.
In contrast, male survivors of childhood cancer are significantly less likely to have children, especially if they are treated with chemotherapy regimens containing high doses of commonly used alkylating drugs and cisplatin.
Now that more than 80% of children with cancer are living into adulthood, whether they can have children is a major concern for them.
Growing awareness of the adverse effects of radiotherapy has led to the use of more intensive chemotherapy regimens for the treatment of childhood cancers.
Previous research has shown that fertility can be compromised by several types of chemotherapy, mainly alkylating drugs. However, little is known about the dose effects on pregnancy from newer drugs, such as ifosfamide and cisplatin, in survivors of childhood cancer.
Dr Eric Chow from the Fred Hutchinson Cancer Research Center, Seattle, US and colleagues used data from the Childhood Cancer Survivor Study (CCSS) which tracks people who were diagnosed with the most common types of childhood cancer before the age of 21 and treated at 27 institutions across the USA and Canada between 1970 and 1999, and who had survived at least 5 years after diagnosis.
By age 45, 70% of female cancer survivors became pregnant, compared to over 80% of siblings. For male cancer survivors, the figure was 50% compared to 80% for siblings.
In male survivors, the likelihood of fathering a child generally decreased as cumulative exposure to alkylating drugs increased. High cumulative doses of several alkylating drugs (cyclophosphamide, ifosfamide, procarbazine) and cisplatin were linked with a significantly reduced likelihood of pregnancy.
Chow said: “We think these results will be encouraging for most women who were treated with chemotherapy in childhood. However, I think, we, as paediatric oncologists, still need to do a better job discussing fertility and fertility preservation options with patients and families upfront before starting cancer treatment. In particular, all boys diagnosed post-puberty should be encouraged to bank their sperm to maximize their reproductive options in the future. The current options for post-pubertal girls remain more complicated, but include oocyte and embryo cryopreservation.”