Pregnancy-associated cancers pose elevated mortality risk

Individuals diagnosed with cancer during pregnancy or postpartum appear to have increased overall 5-year mortality, although this is only true for specific cancer sites, according to a study.

For the study, researchers reviewed the medical records of premenopausal women (aged 18–50 years) living in three Canadian provinces (Alberta, British Columbia, and Ontario) and diagnosed with cancer. These women were grouped according to the time of their cancer diagnosis: during pregnancy (from conception to delivery), during the postpartum period (up to 1 year after delivery), or during a time that was remote from pregnancy.

Cox proportional hazard models were used to estimate overall survival at 1 and 5 years and time from diagnosis to death due to any cause, with adjustments for multiple covariates. Meta-analysis was used to pool data across all three provinces.

Cancer was diagnosed during pregnancy in 1,014 women, postpartum in 3,074 women, and periods remote from pregnancy in 20,219 women. One-year survival was comparable across the three groups. However, 5-year survival was lower among those diagnosed with cancer during pregnancy or postpartum.

Overall, the risk of death due to pregnancy-associated cancer was markedly higher among women diagnosed during pregnancy (adjusted hazard ratio [aHR], 1.79, 95 percent confidence interval [CI], 1.51–2.13) and postpartum (aHR, 1.49, 95 percent CI, 1.33–1.67). However, this was only observed for specific cancer sites: breast (aHR, 2.01, 95 percent CI, 1.58–2.56), ovarian (aHR, 2.60, 95 percent CI, 1.12–6.03), and stomach (aHR, 10.37, 95 percent CI, 3.56–30.24) cancers diagnosed during pregnancy; and brain (aHR, 2.75, 95 percent CI, 1.28–5.90), breast (aHR, 1.61, 95 percent CI, 1.32–1.95), and melanoma (aHR, 1.84, 95 percent CI, 1.02–3.30) cancers diagnosed postpartum.