Jong Lyul Lee1, Meejeong Kim2, Jihun Kim2, Chan Wook Kim1, Ye Jin Ha3, Seon-Young Kim4, Dong-Hyung Cho5, Jin Cheon Kim6. 1. Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea; Institute of Innovative Cancer Research, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea. 2. Department of Pathology, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea. 3. Institute of Innovative Cancer Research, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea. 4. Medical Genomics Research Center, Korea Research Institute of Bioscience & Biotechnology, Daejeon, South Korea. 5. School of Life Science, Kyungpook National University, Daegu, South Korea. 6. Department of Surgery, University of Ulsan College of Medicine, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea; Institute of Innovative Cancer Research, Asan Medical Center, 88, Olympic-ro 43-gil, Songpa-gu, Seoul, 05505, South Korea. Electronic address: jckim@amc.seoul.kr.
Abstract
BACKGROUND: Pseudomyxoma peritonei (PMP) is a rare disease characterized by mucinous ascites and deposits on the peritoneal surfaces. The study aimed to assess PMP patients according to the Peritoneal Surface Oncology Group International (PSOGI) classification, as a part of standardization of this rare disease. METHODS: This retrospective study analyzed PMP patients who underwent surgery between January 2007 and December 2017. All histologic slides were re-evaluated and the clinical data were collected. According to the PSOGI, PMP was retrospectively classified into three categories: low-grade (LG-PMP), high-grade (HG-PMP), and signet-ring cells (SRC-PMP). The extent of peritoneal involvement was quantified by the peritoneal cancer index (PCI). The completeness of cytoreduction (CCR) was dichotomized as complete or incomplete. RESULTS: Fifty-seven patients were included in this study, consisted of 39 patients with LG-PMP (74.0%), 14 with HG-PMP (20.8%), and 4 with SRC-PMP (5.2%). There was no operative mortality and major complications occurred in 24 patients (31.2%). The 5-year overall survival was 56.2% ± 8.1% for LG-PMP, 37.5% ± 12.1% for HG-PMP, and 25.0% ± 21.7% for SRC-PMP. Concerning CCR, the 5-year overall (complete: 59.5% ± 8.4% vs. incomplete: 12.7% ± 8.1%, p = 0.001) and disease-free survival (complete: 38.6% ± 8.9% vs. incomplete: 7.7% ± 6.8%, p = 0.001) were significantly different. In a multivariable analysis, PSOGI classification and CCR independently correlated with survival (p = 0.011 and 0.018, respectively). CONCLUSIONS: The PSOGI classification provides prognostic stratification, hopefully requiring further validation including every single case of PMP established as a standard criteria.
BACKGROUND:Pseudomyxoma peritonei (PMP) is a rare disease characterized by mucinous ascites and deposits on the peritoneal surfaces. The study aimed to assess PMP patients according to the Peritoneal Surface Oncology Group International (PSOGI) classification, as a part of standardization of this rare disease. METHODS: This retrospective study analyzed PMP patients who underwent surgery between January 2007 and December 2017. All histologic slides were re-evaluated and the clinical data were collected. According to the PSOGI, PMP was retrospectively classified into three categories: low-grade (LG-PMP), high-grade (HG-PMP), and signet-ring cells (SRC-PMP). The extent of peritoneal involvement was quantified by the peritoneal cancer index (PCI). The completeness of cytoreduction (CCR) was dichotomized as complete or incomplete. RESULTS: Fifty-seven patients were included in this study, consisted of 39 patients with LG-PMP (74.0%), 14 with HG-PMP (20.8%), and 4 with SRC-PMP (5.2%). There was no operative mortality and major complications occurred in 24 patients (31.2%). The 5-year overall survival was 56.2% ± 8.1% for LG-PMP, 37.5% ± 12.1% for HG-PMP, and 25.0% ± 21.7% for SRC-PMP. Concerning CCR, the 5-year overall (complete: 59.5% ± 8.4% vs. incomplete: 12.7% ± 8.1%, p = 0.001) and disease-free survival (complete: 38.6% ± 8.9% vs. incomplete: 7.7% ± 6.8%, p = 0.001) were significantly different. In a multivariable analysis, PSOGI classification and CCR independently correlated with survival (p = 0.011 and 0.018, respectively). CONCLUSIONS: The PSOGI classification provides prognostic stratification, hopefully requiring further validation including every single case of PMP established as a standard criteria.