Pregnancy-associated cancer refers to diagnosis during pregnancy or within the first year postpartum (1). With rising maternal age and increasing young-onset colorectal cancer (yo-CRC), there is a notable increase in pregnancy associated CRC (pa-CRC) cases. This, coupled with delayed diagnoses and advanced disease stages, lead to high morbidity and mortality for mother and foetus (2,3).
Due to the lack of centralised registries for pa-CRC, a consumer-initiated data collection process was undertaken via social media and online patient platforms to highlight the need for further research into pa-CRC. Participants consented to anonymised data collection and utilisation.
Data was available for 28 cases diagnosed 2017 to 2023. Median age 35 years. Delayed/mis-diagnosis was highly prevalent with only 35% of the cases (10/28) diagnosed within 3 months of presenting symptoms. Majority were diagnosed at advanced stage with stage 3 at 32% (9/28), and stage 4 at 54% (15/28). BRAF and/or KRAS prevalence was higher than anticipated at 60% (9/15 mCRC cases). Metastatic distribution, 20% - M1a, 40% - M1b and 13% - M1c (26% unknown). 71% of the cancers were left sided. 39% of the cases were diagnosed during pregnancy with 32% diagnosed after delivery. 60% of the metastatic cases received multi-modality treatment. Of the 15 metastatic patients, 3 patients are deceased with survival durations of 3.5, 48, and 70 months.
There is a growing need to comprehensively collect data on pa-CRC in relation to incidence, interventions and outcomes. Our findings highlight the critical issue of delayed diagnosis, particularly relevant in pregnancy where symptom overlap occurs. Given the rising incidence of yo-CRC, increased awareness of concurrent CRC in pregnancy is essential. Onco-foetal immune tolerance may accelerate cancer growth during pregnancy, explaining the higher prevalence of advanced disease (4). Implementing ctDNA testing during prenatal blood tests offers an opportunity for early detection (5,6).