Abstract P074: Pregnancy and neonatal outcomes among early-onset colorectal cancer survivors: a nationwide case-control study

Abstract

Abstract Purpose: Early-onset colorectal cancer (CRC diagnosed before age 50) has risen worldwide, with an increasing number of survivors of reproductive age. We aimed to investigate the risk of adverse pregnancy and neonatal outcomes among early-onset CRC survivors. Methods: We conducted a nationwide case-control study of 207 births in women with early-onset CRC and 1019 births in women without CRC from the general Swedish population (1992-2019), matched on age, calendar year of birth, parity, and county of residence. To control for genetic susceptibility and shared childhood exposures, we additionally identified 146 births in female siblings of the CRC survivors. Early-onset CRC cases were identified through the Swedish Cancer Register (1969-2019), and siblings were identified through the Swedish Multi-generation Register. Maternal characteristics and neonatal outcomes were retrieved from the Swedish Medical Birth Register and National Patient Register. Using conditional logistic regression, we estimated adjusted odds ratios (aORs) and 95% confidence intervals (CIs). Results: Compared to women without prior CRC, early-onset CRC survivors who gave birth had increased risk of pre-eclampsia (aOR 2.52, 95% CI 1.25 to 5.08), induced labor (aOR 1.64, 95% CI 1.09 to 2.46) and emergency Cesarean section (aOR 1.79, 95% CI 1.17 to 2.75), after adjustment for maternal education level, country of birth, body mass index and smoking in early pregnancy, and comorbidities. Sibling analyses showed similar trends, especially for higher risk of induced labor (aOR 2.58, 95% CI 1.03 to 6.49). Maternal history of early-onset CRC was also associated with offspring preterm birth (aOR 2.31, 95% CI 1.34 to 3.99) and low birth weight (aOR 2.95, 95% CI 1.40 to 6.21), and risks were particularly pronounced for medically indicated preterm birth (aOR 4.48, 95% CI 2.05 to 9.79). No significant associations were found for small for gestational age birth, low Apgar score, and congenital malformations. Conclusion: In this population-based study, history of early-onset CRC was associated with increased risk of adverse pregnancy outcomes, including pre-eclampsia, induction of labor, and emergency Cesarean section. Offspring to mothers with early-onset CRC also had increased risk of medically indicated preterm birth and neonatal low birth weight. Citation Format: Yin Cao, Stephanie Zhao, Tomas S. Bexelius, Jonas Söderling, Mengyao Shi, Bjorn Roelstraete, Barbara B. Warner, Olof Stephansson, Jonas F. Ludvigsson. Pregnancy and neonatal outcomes among early-onset colorectal cancer survivors: a nationwide case-control study. [abstract]. In: Proceedings of the AACR Special Conference: Precision Prevention, Early Detection, and Interception of Cancer; 2022 Nov 17-19; Austin, TX. Philadelphia (PA): AACR; Can Prev Res 2023;16(1 Suppl): Abstract nr P074.