In a Canadian population–based retrospective cohort study reported in JAMA Oncology, Cairncross et al found that patients diagnosed with cancer during pregnancy or postpartum had worse 5-year survival than those diagnosed at a time remote from pregnancy.
Study Details
The study included data from premenopausal patients in three Canadian provinces (Alberta, British Columbia, and Ontario) diagnosed with cancer between January 2003 and December 2016, with follow-up through December 2017 or date of death.
Key Findings
Among the 24,257 patients included in the analysis, 1,014 received a cancer diagnosis during pregnancy (conception to delivery), 3,074 had a postpartum diagnosis (up to 1 year after delivery), and 20,219 received their diagnosis at times remote from pregnancy. Mean age at cancer diagnosis was 31.9, 32.6, and 36.5 years in the three groups, respectively.
For all cancers, 1-year overall survival was similar across the three groups (97%, 96%, and 98%). Overall survival at 5 years was lower with diagnosis during pregnancy (87%) and postpartum (89%) vs remote diagnosis (93%).
In analysis adjusting for age at cancer diagnosis, cancer stage, cancer site, and days from diagnosis to first treatment, diagnosis during pregnancy (hazard ratio [HR] = 1.79, 95% confidence interval [CI] = 1.51–2.13) and postpartum (HR = 1.49, 95% CI = 1.33–1.67) were associated with a significantly increased risk of mortality vs remote diagnosis.
Findings varied across cancer sites. Increased risk of mortality was observed for breast cancer (HR = 2.01, 95% CI = 1.58–2.56), ovarian cancer (HR = 2.60, 95% CI = 1.12–6.03), and stomach cancer (HR = 10.37, 95% CI = 3.56–30.24) diagnosed during pregnancy. Increased risk of mortality was observed for brain cancer (HR = 2.75, 95% CI = 1.28–5.90), breast cancer (HR = 1.61, 95% CI = 1.32–1.95), and melanoma (HR = 1.84, 95% CI = 1.02–3.30) diagnosed postpartum.
The investigators concluded, “This population-based cohort study found that pregnancy-associated cancers had increased overall 5-year mortality, though not all cancer sites presented the same risk.”
Amy Metcalfe, PhD, of the Department of Obstetrics and Gynecology, University of Calgary, is the corresponding author for the JAMA Oncology article.
Disclosure: The study was funded by the Canadian Institutes of Health Research (CIHR). For full disclosures of the study authors, visit jamanetwork.com.
