RT Journal Article SR Electronic T1 739 Diagnostic, management and neonatal outcomes of pregnancy-associated colorectal cancer: a case report and literature review JF International Journal of Gynecologic Cancer JO Int J Gynecol Cancer FD BMJ Publishing Group Ltd SP A242 OP A243 DO 10.1136/ijgc-2024-ESGO.471 VO 34 IS Suppl 1 A1 Galante, Arianna A1 Cerbone, Marco A1 Mannavola, Francesco A1 Marinaccio, Marco A1 Dellino, Miriam A1 Schonauer, Luca Maria A1 Damiani, Gianluca Raffaello A1 Pinto, Vincenzo A1 Cormio, Gennaro A1 Cicinelli, Ettore A1 Vimercati, Antonella YR 2024 UL http://ijgc.bmj.com/content/34/Suppl_1/A242.2.abstract AB Introduction/Background Managing pregnancy-associated colorectal cancer (PACrC) poses substantial challenges: the diagnosis is complicated due to symptom overlap with pregnancy-related manifestations and medical imaging, chemotherapy and surgery are constrained by safety concerns for the foetus.Methodology The case report was extracted from our hospital records. The literature review was conducted with PRISMA methodology.Results A 33-year-old, 19 weeks-of-gestation (WG) pregnant patient presented to the emergency room due to severe abdominal pain and underwent urgent laparotomy with Hartmann sigmoid resection and colostomy due to sigmoid volvulus; the histopathology unveiled a sigmoid adenocarcinoma G2pT3bN0. At 23WG, an abdominal MRI showed a placental neoformation and multiple hepatic nodules suggestive of neoplastic lesions (Figure 1). Our multidisciplinary team proposed adjuvant chemotherapy with infusion of five cycles of FOLFOX biweekly (75%dosage). The foetus exhibited steady growth throughout-the-treatment and the caesarean section was conducted at 37WG, resulting in the birth of a 2940 g infant with arterial pH of 7.32, Apgar 8–10. The placental histopathology was negative. Given the favourable response to first-line-chemotherapy, hepatic metastasectomy was performed and twelve cycles of FOLFOX (100%dosage) plus BEVACIZUMAB were administered. One-year post-diagnosis, the patient continues the chemotherapy, with optimal performance-status. Additionally, her infant achieved normal developmental milestones.Conclusion PACrC poses unique diagnostic and therapeutic challenges. Our statistical analysis on 66 studies revealed the importance of early diagnosis of PACrC: a delay of diagnosis often led to urgent surgery, and poor maternal\neonatal outcomes with higher caesarean rates and earlier WG at-delivery. We found that women with an early diagnosis were more likely to undergo chemotherapy during pregnancy, resulting in better control of the disease and later WG at-delivery. Chemotherapy during pregnancy is a feasible and safe treatment for PACrC: despite the uncertainties about the effects on the foetus, we did not find different neonatal outcomes between those exposed those who did not.Disclosures The authors declare no conflicts of interests.Abstract 739 Figure 1 A: MRI images showing the formation in amniotic sac; B: TC image showing the hepatic metastases