ABSTRACT
BACKGROUND: The relative probability of pregnancy and parenthood in cancer survivors is reduced. Studies have shown that cancer survivors are concerned about the health of their offspring and the recurrence of their own cancer. This could lead to an increased risk of induced abortion. The aim of this study was to examine whether pregnancies of childhood cancer survivors (CCSs) who were 0 to 14 years old at diagnosis in 1971-2012 were more likely to result in induced abortions in comparison with population controls. METHODS: Data from Finnish registries for cancer, births, and induced abortions were merged to identify 420 first pregnancies of CCSs and 2508 first pregnancies of age-matched population controls in 1987-2013. Poisson regression and logistic regression modeling were used to estimate incidence rates and relative risks (RRs) with 95% confidence intervals (CIs) of first pregnancies and induced abortions in CCSs in comparison with population controls. RESULTS: The risk of first pregnancy was reduced in CCSs in comparison with population controls (RR, 0.72; 95% CI, 0.64-0.80), whereas the risk of a first pregnancy resulting in an induced abortion was similar in CCSs and population controls (RR, 1.01; 95% CI, 0.77-1.33). In subanalyses stratifying by decade of diagnosis and cancer treatment, the risk of induced abortion was similar in CCSs and population controls. CONCLUSIONS: Female CCSs do not have an overall increased risk of induced abortions. The reduced probability of pregnancy among CCSs highlights the continued need for interventions to preserve fertility at the time of a cancer diagnosis.
Subject(s)
Abortion, Induced/statistics & numerical data , Cancer Survivors , Adolescent , Adult , Age Factors , Case-Control Studies , Child , Child, Preschool , Confidence Intervals , Female , Finland , Humans , Infant , Infant, Newborn , Pregnancy , Registries , Regression Analysis , Risk AssessmentABSTRACT
Cancer treatments have the potential to cause germline mutations that might increase the risk of cancer in the offspring of former cancer patients. This risk was evaluated in a population-based study of early onset cancer patients in Finland. Using the nationwide registry data, 26,331 children of pediatric and early onset cancer patients (diagnosed under age 35 between 1953 and 2004) were compared to 58,155 children of siblings. Cancer occurrence among the children was determined by linkage with the cancer registry, and the standardized incidence ratios (SIRs) were calculated comparing the observed number of cancers with that expected, based on rates in the general population of Finland. Among the 9,877 children born after their parent's diagnosis, cancer risk was increased (SIR 1.67; 95% CI 1.29-2.12). However, after removing those with hereditary cancer syndromes, this increase disappeared (SIR 1.03; 95% CI 0.74-1.40). The overall risk of cancer among the offspring of siblings (SIR 1.07; 95% CI 0.94-1.21) was the same as among the offspring of the patients with non hereditary cancer. Risk of cancer in offspring, born before their parents cancer diagnosis, was elevated (SIR 1.37, 95% CI 1.20-1.54), but removing hereditary syndromes resulted in a diminished and nonsignificant association (SIR 1.08, 95% CI 0.93-1.25). This study shows that offspring of cancer patients are not at an increased risk of cancer except when the patient has a cancer-predisposing syndrome. These findings are directly relevant to counseling cancer survivors with regard to family planning.
