What Are the Dietary Intakes and Nutritional Outcomes of Adults With Pseudomyxoma Peritonei/Appendix Cancer Beyond the Postoperative Period: A Systematic Review

ABSTRACT Background Pseudomyxoma Peritonei (PMP) is a rare cancer with an incidence of approximately two cases per million individuals internationally. For selected patients, curative treatments include invasive surgery with removal of digestive organs and bowel resection which significantly impacts dietary intakes and quality of life in the postoperative period. Monitoring dietary intake is important as maintaining adequate nutrition can alleviate gastrointestinal symptom burden, reduce treatment associated complications, and decrease nutritional risk that may impact survival. The aim of this systematic review is to describe the dietary intakes and nutritional outcomes of adults with PMP/appendix cancer beyond the postoperative period. Methods Published studies up to April 2025 were identified through searches of four electronic databases (CENTRAL, CINAHL, Embase and Medline). Studies were included if they were carried out in adults with a diagnosis of PMP/appendix cancer, who were postoperative and had been discharged from hospital and reported any dietary intakes and/or diet related outcomes. Risk of bias (positive, neutral, negative) was assessed using the Academy of Nutrition and Dietetics Quality Criteria Checklist for Primary Research. Results A total of 263 studies were screened with five meeting the eligibility criteria (including 324 patients). Results are presented narratively given the diversity of study design, methods and dietary/nutrition outcomes measured in included studies. Four of the included studies were observational and the other quasi‐experimental in design. Three of the five studies were conducted in clinical/outpatient cancer settings, and two studies involved a retrospective review of patient medical data. The outcomes assessed in studies included nutritional status and/or risk ( n = 2), quality of life ( n = 2), nutritional support ( n = 2), nutritional impact symptoms ( n = 1), and nutritional deficiency ( n = 1). No studies assessed food or macro/micronutrient intakes. Three studies had a positive risk of bias rating, and two studies were neutral. Conclusion Dietary intakes and nutritional outcomes following PMP/appendix cancer surgery is poorly reported in the current literature. Given the importance of nutrition in cancer and its impact on quality of life and treatment outcomes, there is a need for future studies to measure dietary intake in PMP patients using validated dietary assessment tools to improve the quality of evidence in postsurgical treatment care.