Childbearing in women diagnosed with cancer during reproductive age.

INTRODUCTION: Fertility after cancer represents a growing clinical concern. This study assessed childbearing outcomes among women diagnosed with cancer during reproductive age between 2012 and 2017 in Lombardy, the largest region in Italy. MATERIAL AND METHODS: Women aged 15-45 years with a primary diagnosis of cancer recorded in hospital discharge records from regional healthcare databases were selected. Each woman diagnosed with cancer was matched with up to five cancer-free women of the same age at diagnosis. The cumulative probability of childbirth up to December 31, 2022 was estimated using the Kalbfleisch-Prentice cumulative incidence function estimator. Cox regression models were used to estimate the cause-specific hazard ratios (HRs) and the 95% confidence intervals (CIs) of childbirth according to the cancer diagnosis. Furthermore, in the group of cancer survivors, exposure to antineoplastic treatment was considered and included in the model as a time-dependent covariate. Finally, a log-binomial regression model was used to assess the association between antineoplastic therapy and medically assisted reproduction. RESULTS: A total of 13,877 women were diagnosed with cancer at reproductive age during the study period (1.16 per 1000 person-years). The cumulative probability of childbirth was lower among women diagnosed with cancer compared to cancer-free women across all age groups: 31.4% vs 32.2% (p = 0.02) among those diagnosed under 30, 13.3% vs 22.7% (p < 0.01) among those aged 30-39, and 0.8% vs 1.6% (p < 0.01) among those aged 40 and over. The corresponding HRs were 0.93 (95% CI: 0.83-1.05), 0.58 (95% CI: 0.53-0.64), and 0.52 (95% CI: 0.40-0.68). When analyses were stratified by time since diagnosis, the reduced probability among cancer survivors was confirmed to be significant only within the first 5 years after diagnosis, also for younger individuals. Antineoplastic treatment was associated with a reduced probability of subsequent birth (HR = 0.46, 95% CI: 0.39-0.52). Moreover, the therapy was positively associated with medically assisted reproduction (RR = 1.71, 95% CI: 1.14-2.56). CONCLUSIONS: The probability of childbearing was reduced within the first 5 years of diagnosis, regardless of the patient's age. A more pronounced reduction was observed in women diagnosed after the age of 30. Age and antineoplastic therapy were key factors in determining childbearing in women diagnosed with cancer.