Therapeutic exposures and pubertal testicular dysfunction are associated with adulthood milestones and paternity after childhood cancer

Background: Childhood cancer therapy may cause long-term effects. This cross-sectional study evaluated adulthood milestones in male childhood cancer survivors (CCS).

Methods: The study population comprised 252 male CCS with 6 to 42 years of survival diagnosed at the Children's Hospital in Helsinki (1964-2000) at the age of 0 to 17 years. Sex-, age-, and area of residence-matched population controls were randomly selected from the Finnish national registries. Data on moving away from the parental home, marital status, offspring, and adoption in CCS were compared with the population controls. We analyzed the influence of chemotherapy and radiation exposures and testicular dysfunction (ever nontestosterone-substituted serum follicle stimulating hormone >15 IU/L, luteinizing hormone >15 IU/L, testosterone <2 ng/mL (5 nmol/L), need of testosterone replacement therapy, or testicular volume <12 mL at the end of puberty) during pubertal maturation on long-term social outcomes.

Results: CCS moved away from their parental home as frequently as population controls (97.8% vs. 98.5%, p = .45). CCS were less likely to marry or live in a registered relationship (46.4% vs. 57.5%, p < .001), especially when diagnosed at a young age (<4 years). Among those married, the probability of divorce was similar between CCS and population controls (27.4% vs. 23.8%, p = .41). Survivors were less likely to sire a child (38.5% vs. 59.1%, p < .001) and more likely to adopt (2% vs. 0.4%, p = .015). Lower probability of paternity was associated with hematopoietic stem cell therapy, testicular radiation dose >6 Gy, pubertal signs of testicular dysfunction (nontestosterone-substituted serum follicle stimulating hormone >15 IU/L, luteinizing hormone >15 IU/L, testosterone <2 ng/mL (5 nmol/L), or need of testosterone replacement therapy during puberty, or testicular volume <12 mL at the end of puberty) or azoospermia after puberty.

Conclusions: This study emphasizes the value of pubertal monitoring of testicular function to estimate future probability of paternity. If no signs of dysfunction occurred during pubertal follow-up, paternity was comparable to population controls. Testicular radiation dose >6 Gy appeared to be the strongest risk factor for decreased paternity.

Plain language summary: Treatment with intensive therapies, including hematopoietic stem cell therapy, testicular radiation dose >6 Gy, and signs of testicular dysfunction, during puberty are important risk factors for lower rates of fertility. Intensive therapies and testicular dysfunction itself do not similarly hamper psychosocial milestones in adulthood; cancer diagnosis at a very young age (<4 years) lower the probability of marriage. This study accentuates the importance of monitoring of pubertal development, emphasizing on testicular function, not only sperm analysis, to estimate future fertility among male childhood cancer survivors.