Operability and early outcome in 48 Irish patients with peritoneal malignancy treated by surgery and intraperitoneal chemotherapy in a specialized centre

[Incidental finding of appendiceal mucinous neoplasms]

Low-grade appendiceal mucinous neoplasms (LAMN) are rare and are diagnosed in at least 0.13% of appendectomies in Germany, although significant underreporting is likely. Perforation of the tumors can result in abdominal mucinous collections, so-called pseudomyxoma peritonei (PMP). The challenge in the treatment of LAMN is the adequate approach to the incidental finding of these tumors. If a mucinous neoplasm is preoperatively suspected in cases of an acute condition, usually appendicitis, it must be weighed up whether a conservative approach is justifiable or whether immediate appendectomy is necessary. If this is the case, an intraoperative perforation of the appendix must be avoided and the complete abdominal cavity must be inspected for mucin deposits. If conservative treatment is possible, further treatment should take place at a specialized center. If the neoplasm is first found incidentally during surgery, perforation of the appendix should also be avoided and the entire abdominal cavity should be inspected for a PMP. If a PMP is present cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) should be performed in a specialized center. If LAMN are found during the postoperative histological work-up, it should be evaluated whether a perforation was present and mucin collections are noted in the surgical report. In the case of LAMN without evidence of a PMP, appendectomy is the adequate treatment. In cases of intra-abdominal mucinous collections, samples should be taken and further treatment should be performed at a center with sufficient expertise. An ileocecal resection or oncological hemicolectomy is not indicated. After adequate treatment, all patients should receive a follow-up using cross-sectional imaging (preferably magnetic resonance imaging, MRI) and determination of the tumor markers CEA, CA 19-9 and CA 125.

The Prognostic Impact of Pathology on Patients With Pseudomyxoma Peritonei Undergoing Debulking Surgery: A Systematic Review and Meta-Analysis of Retrospective Studies

Background: Pseudomyxoma peritonei (PMP) is a rare clinical condition with fatal outcomes, which is characterized by the progressive accumulation of mucinous ascites and peritoneal implants. Some studies have reported the effect of PMP biology on patient outcome. The objective of this study was to analyze published articles focusing on the impact of pathology on the prognosis of PMP patients undergoing debulking.

Methods: Data from all studies regarding the prognosis of patients, with different pathologies, who underwent debulking surgery were analyzed. We searched PubMed, the Wiley Online Library, Ovid, and the Cochrane Library (through January 2020). Studies were confined to those articles written in English. Five studies were identified, and the differences in 5-year survival rates were analyzed according to the Kaplan–Meier survival curves. The hazard ratios (HRs) of the 5-year survival rates were calculated.

Results: The mean and median 5-year survival rates of all patients were 39 and 40%, respectively. The median overall survival was 49.3 months. The mean 5-year survival rates of low-grade PMP was 45.2%. The five studies had sufficient data to calculate HRs from the 5-year survival rates data, and three had HRs lower than 1. The total HRs was 0.54, with a 95% CI between 0.33 and 0.89 (P = 0.01).

Conclusions: Among PMP patients receiving debulking surgery who are not able to undergo complete cytoreductive surgery, low-grade biological PMP had a better prognosis than high-grade PMP.