Impact of Macroscopic Tumour Consistency and EPIC in Low-grade Appendiceal Neoplasms With Pseudomyxoma Peritonei

Background/Aim: Low-grade appendiceal mucinous neoplasm (LAMN) with pseudomyxoma peritonei (PMP), otherwise known as disseminated peritoneal adenomucinosis (DPAM), is treated with cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) with or without early postoperative intraperitoneal chemotherapy (EPIC). These tumours can vary significantly intraoperatively in terms of macroscopic appearance and consistency, and this may have an effect on survival outcomes. This study examines the differences between soft and hard tumours in terms of shortterm outcomes and long-term survival and whether this can change with the use of EPIC. Patients and Methods: Patients were classified into having macroscopically soft or hard tumours. A comparison of short-term outcomes (major morbidity, mortality, length of ICU stay and length of hospital stay) and long-term outcomes (overall survival) was performed. Survival sub analysis was performed in the patients who received EPIC. Results: Soft tumours behaved differently, with lower morbidity, mortality, shorter ICU stay and hospitalisation. They also demonstrated greater overall survival (86.7% at 5 years, p<0.001). EPIC improved the overall survival for both soft and hard tumours. Conclusion: Tumour consistency has an impact on the outcomes of patients with DPAM and this can be used for prognostication.