Medline ® Abstracts for References 29,30
of 'Cancer of the appendix and pseudomyxoma peritonei'
Patients with pseudomyxoma peritonei associated with disseminated peritoneal adenomucinosis have a significantly more favorable prognosis than patients with peritoneal mucinous carcinomatosis.
Ronnett BM, Yan H, Kurman RJ, Shmookler BM, Wu L, Sugarbaker PH
BACKGROUND: Pseudomyxoma peritonei (PMP) is a poorly understood condition characterized by disseminated intraperitoneal mucinous tumors, often with mucinous ascites. The term PMP has been applied historically as a pathologic diagnostic term to both benign and malignant mucinous neoplasms that produce abundant extracellular mucin, resulting in a variable and poorly predictable prognosis. A recent study reported a pathologic classification that separated patients into prognostically distinct groups, but the follow-up was relatively short.
METHODS: Long-term follow-up data were analyzed for a previously reported series of 109 patients with PMP to examine the prognostic utility of a pathologic classification system that divided patients into three groups: disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), and peritoneal mucinous carcinomatosis with intermediate or discordant features (PMCA-I/D). Patients whose tumors were classified 25 DPAM (n = 65 patients) had disease that was characterized by histologically bland to low-grade adenomatous mucinous epithelium associated with abundant extracellular mucin and fibrosis, oftenwith an identifiable appendiceal mucinous adenoma that was the source of the peritoneal lesions. Patients whose tumors were classified 25 PMCA (n = 30 patients) had disease that was characterized by peritoneal lesions that displayed the cytologic and architectural features of mucinous carcinoma associated with extracellular mucin, often with an identifiable invasive mucinous adenocarcinoma of the gastrointestinal tract. Patients whose tumors were classified 25 PMCA-I (n = 11 patients) had peritoneal lesions that combined the features of DPAM and PMCA derived from well differentiated mucinous adenocarcinomas associated with adenomas. Patients whose tumors were classified 25 PMCA-D (n = 3 patients) had markedly atypical appendiceal adenomas associated with peritoneal lesions similar to PMCA.
RESULTS: Patients with DPAM had 5-year and 10-year survival rates of 75% and 68%, respectively (mean follow-up, 96 months; median follow-up, 104 months). Patients with PMCA and PMCA-I/D had a significantly worse prognosis, with 5-year and 10-year survival rates, respectively, of 50% and 21% for PMCA-I/D (mean follow-up, 58 months; median follow-up, 51 months) and 14% and 3% for PMCA (mean follow-up, 27 months; median follow-up, 16 months; P = 0.0001).
CONCLUSIONS: The term PMP should be used only as a clinical descriptor for patients who have the syndrome of mucinous ascites accompanied by a characteristic distribution of peritoneal mucinous tumors with the pathologic features of DPAM. DPAM should be used as a pathologic diagnostic term for patients with the bland peritoneal mucinous tumors associated with ruptured appendiceal mucinous adenomas and PMP. These patients should not be diagnosed with carcinoma, because they have disease that is distinct pathologically and prognostically from PMCA.
Department of Pathology, The Johns Hopkins Hospital, Baltimore, Maryland 21231, USA. firstname.lastname@example.org
Pseudomyxoma peritonei: clinical pathological and biological prognostic factors in patients treated with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC).
Baratti D, Kusamura S, Nonaka D, Langer M, Andreola S, Favaro M, Gavazzi C, Laterza B, Deraco M
Ann Surg Oncol. 2008;15(2):526. Epub 2007 Nov 28.
BACKGROUND: Surgical cytoreduction combined with hyperthermic intraperitoneal chemotherapy (HIPEC) has been recently advocated as the standard of care for pseudomyxoma peritonei (PMP). We reviewed our 10-year monoinstitutional case series to identify selection factors predicting postoperative outcome.
METHODS: One hundred and four patients with PMP were operated on with the aim of performing adequate cytoreduction (residual tumor nodules<or =2.5 mm) and closed-abdomen HIPEC with mytomicin-C and cisplatin. Previously, 26 patients had systemic chemotherapy. PMP was histologically classified into disseminated peritoneal adenomucinosis (DPAM), peritoneal mucinous carcinomatosis (PMCA), and intermediate/discordant group (ID). Immunohistochemical stains were performed for cytokeratin (CK)-7, CK-20, CDX-2, MUC-2, MUC-5AC, CD-44s. The significance of 22 potential clinical, pathological, and biological prognostic variables was assessed by multivariate analysis.
RESULTS: Adequate cytoreduction was performed in 89 patients, suboptimal cytoreduction in six, palliative surgery in nine. Operative mortality was 1%. Seventy-eight patients were diagnosed with DPAM, 26 with PMCA, and none with ID. Median follow-up was 37 months (range, 1-110) for the overall series. Five-year overall survival (OS) and progression-free survival (PFS) were 78.3% and 31.1%, respectively. At multivariate analysis, adequate cytoreduction, no previous systemic chemotherapy, and DPAM correlated to better OS and PFS, elevated serum CA19.9 correlated only to better PFS. In most cases, CK20, CDX-2, and MUC-2 were diffusely positive, while CK-7, MUC-5AC, and CD44s were variably expressed. CK20 expression correlated to prognosis at univariate analysis.
CONCLUSIONS: Favorable outcome after comprehensive treatment can be expected in patients with DPAM, not treated with preoperative systemic chemotherapy and amenable to adequate cytoreduction. MUC-2, CK-20, and CD44s expression may be related to PMP unique biologic behavior.
Department of Surgery, National Cancer Institute, Milan, Italy.