AB190. SOH25_AB_241. Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) for pseudomyxoma peritonei: current standards and emerging therapies

Background: Cytoreductive surgery (CRS) involves the removal of all visible tumour masses, with the goal of leaving no residual disease larger than 2.5 mm, thereby enhancing the effectiveness of hyperthermic intraperitoneal chemotherapy (HIPEC). HIPEC administers heated chemotherapy agents, such as mitomycin C or platinum-based drugs, directly into the peritoneal cavity at a temperature of 42 ℃. This approach improves the penetration of the chemotherapy while minimising systemic toxicity, thanks to the protective plasma-peritoneum barrier.

Methods: We present the case of a 70-year-old female who underwent CRS and HIPEC for pseudomyxoma peritonei (PMP), a rare condition characterised by gelatinous ascites resulting from a mucus-producing neoplasm. Risk factors include familial adenomatous polyposis and KRAS exon 2 mutation, with higher incidence in middle-aged women. Patients often remain asymptomatic until later stages, complicating diagnosis. While computed tomography (CT) thorax, abdomen and pelvis (CT TAP) and tumour markers [carcinoembryonic antigen (CEA)/carbohydrate antigen 19-9 (CA19-9)] are useful for monitoring/prognosis, histopathological confirmation is required for diagnosis.

Results: CRS and HIPEC represent the current gold standard for PMP treatment. Prognosis varies by subtype, with 10-year survival ranging from 0–65%.

Conclusions: Emerging therapies, such as pressurised intraperitoneal aerosolized chemotherapy (PIPAC) and BromAc^®, are being explored. PIPAC administers normothermic aerosolized chemotherapy at high pressures to enhance drug distribution in unresectable peritoneal carcinomatosis. BromAc^® is a minimally invasive treatment that administers a mucolytic agent directly into mucinous deposits, showing promising results. This case underscores the importance of CRS and HIPEC in managing PMP while highlighting the potential of novel therapies for improving patient outcomes. Further research is essential to optimise treatment protocols and identify suitable candidates for these emerging therapies.

Keywords: Cytoreductive surgery (CRS); hyperthermic intraperitoneal chemotherapy (HIPEC); pseudomyxoma peritonei (PMP); pressurised intraperitoneal aerosolized chemotherapy; BromAc^®