Appendiceal pseudomyxoma peritonei: predictors of recurrence and iterative surgery.

AIM: Appendiceal pseudomyxoma peritonei (PMP) is a rare entity, with recurrence rates up to 26% despite optimal cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Evidence specific to PMP originating from non-infiltrative appendiceal mucinous neoplasms (low grade - LAMN and high grade - HAMN) is lacking. The aim of this study was to identify patterns of recurrence and predictive factors for patients appropriate for iterative surgery. METHOD: A bi-institutional retrospective analysis was performed on patients undergoing complete cytoreduction and HIPEC for PMP derived from perforated LAMN or HAMN. Multivariate logistic regression was performed to identify independent predictors for re-do CRS. Five-year overall survival (OS) was stratified according to surgical intervention, and 5-year disease-free survival (DFS) was stratified according to histological PMP grade. Cox regression analysis was performed to identify independent predictors for OS and DFS. RESULTS: Sixty of 239 (25.1%) patients developed peritoneal recurrence between 2007 and 2020. The median time to recurrence was 20.7 months. The risk of disease recurrence was highest with high-grade PMP (P <0.001) and increasing PCI (P <0.001). Patients with high-grade histology from their index procedure and aged over 60 years were less likely to be offered iterative surgery on multivariate analysis. Patients who underwent iterative CRS and HIPEC had a 5-year survival of 100%. CONCLUSION: Iterative CRS and HIPEC is feasible in selected patients with recurrent PMP, displaying good oncological outcomes. Age, index histology and level of abdominal quadrant involvement are predictive of proceeding to re-do surgery.

Cytoreductive surgery and heated intraperitoneal chemotherapy for peritoneal carcinomatosis secondary to mucinous adenocarcinoma of the appendix.

Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a radical but effective treatment option for select peritoneal malignancies. We sought to determine our early experience with this method for peritoneal carcinomatosis secondary to mucinous adenocarcinomas of appendiceal origin. As such, we performed a retrospective clinical study of 30 consecutive patients undergoing CRS with planned HIPEC at the Princess Alexandra Hospital, between June 2009 to December 2012, with mucinous adenocarcinomas of the appendix. CRS was performed in 30 patients, 13 received HIPEC intraoperatively and 17 received early postoperative intra-peritoneal chemotherapy (EPIC) in addition. Mean age was 52.3 years and median hospital stay was 26 days (range 12-190 days). Peritoneal cancer index scores were 0-10 in 6.7% of patients, 11-20 in 20% of patients and >20 in 73.3% of patients. Complete cytoreduction was achieved overall in 21 patients. In total, 106 complications were observed in 28 patients. Ten were grade 3-A, five were grade 3-B and one grade-5 secondary to a fatal PE on day 97. In patients who received HIPEC, there was no difference in disease-free survival (P = 0.098) or overall survival (P = 0.645) between those who received EPIC versus those who did not. This study demonstrates that satisfactory outcomes with regards to morbidity and survival can be achieved with CRS and HIPEC, at a single-centre institution with growing expertise in the technique. Our results are comparable with outcomes previously described in the international literature.