Reproduction rates after cancer treatment: experience from the Norwegian radium hospital

Abstract

Purpose: Most studies on postcancer reproduction are limited in patient numbers and lack of control group. We have computed 10-year first postdiagnosis cumulative reproduction rates (10-PDRs) and hazard ratios (HRs) avoiding these limitations.

Patients and methods: Six thousand seventy-one patients with cancer age 15 to 45 years at diagnosis, treated from 1971 to 1997, and 30,355 controls from the general population, all born after 1950, were observed from the true (patients) or assigned (controls) date of diagnosis for a median of 10 years (range, 0 to 35). The primary focus of the study was the 10-PDR before and after 1988+ based on data from the Medical Birth Registry of Norway. Cox proportional hazards regression models were adjusted for age and calendar year at diagnosis, stratified by sex and prediagnosis parenthood.

Results: Across all cancer types, HRs of females were approximately 50% lower than those of the controls, the comparable percentage for male patients being approximately 30%, with some improvement after 1988+ for selected diagnoses. The highest 10-PDRs were observed in childless patients, with more favorable HRs in male than in female patients. In survivors with at least one child at diagnosis, the post-1988+ HRs improved significantly in patients with testicular and localized cervical cancer compared to pre-1988+ reproduction, with borderline improvement in localized ovarian cancer.

Conclusion: Postcancer reproduction is lower than that of the general population and influenced by sex, age at diagnosis, prediagnosis parenthood, and diagnostic period with more favorable rates in males than in females. Post-1988+ fertility-saving strategies may have improved the reproduction rates for select genital cancers.