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Validation of the AJCC 8th Edition Staging System for Disseminated Appendiceal Cancer Patients Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: A Multi-institutional Analysis. Ann Surg Oncol 2023 Sep;30(9):5743-5753



Pubmed ID




Scopus ID

2-s2.0-85161360327 (requires institutional sign-in at Scopus site)   3 Citations


BACKGROUND: The AJCC 8th edition stratifies stage IV disseminated appendiceal cancer (dAC) patients based on grade and pathology. This study was designed to externally validate the staging system and to identify predictors of long-term survival.

METHODS: A 12-institution cohort of dAC patients treated with CRS ± HIPEC was retrospectively analyzed. Overall survival (OS) and recurrence-free survival (RFS) were analyzed by using Kaplan-Meier and log-rank tests. Univariate and multivariate cox-regression was performed to assess factors associated with OS and RFS.

RESULTS: Among 1009 patients, 708 had stage IVA and 301 had stage IVB disease. Median OS (120.4 mo vs. 47.2 mo) and RFS (79.3 mo vs. 19.8 mo) was significantly higher in stage IVA compared with IVB patients (p < 0.0001). RFS was greater among IVA-M1a (acellular mucin only) than IV M1b/G1 (well-differentiated cellular dissemination) patients (NR vs. 64 mo, p = 0.0004). Survival significantly differed between mucinous and nonmucinous tumors (OS 106.1 mo vs. 41.0 mo; RFS 46.7 mo vs. 21.2 mo, p < 0.05), and OS differed between well, moderate, and poorly differentiated (120.4 mo vs. 56.3 mo vs. 32.9 mo, p < 0.05). Both stage and grade were independent predictors of OS and RFS on multivariate analysis. Acellular mucin and mucinous histology were associated with better OS and RFS on univariate analysis only.

CONCLUSIONS: AJCC 8th edition performed well in predicting outcomes in this large cohort of dAC patients treated with CRS ± HIPEC. Separation of stage IVA patients based on the presence of acellular mucin improved prognostication, which may inform treatment and long-term, follow-up strategies.

Author List

SenthilKumar G, Kothari AN, Maduekwe UN, Fournier K, Abbott DE, Wilson GC, Patel SH, Greer J, Johnston F, Dineen SP, Powers BD, Baumgartner J, Veerapong J, Leiting J, Grotz TE, Maithel SK, Staley C, Raoof M, Lambert L, Lee A, Kim A, Cloyd JM, Mogal H


Anai N. Kothari MD Assistant Professor in the Surgery department at Medical College of Wisconsin
Ugwuji N. Maduekwe MD Associate Dean, Associate Professor in the Surgery department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Antineoplastic Combined Chemotherapy Protocols
Appendiceal Neoplasms
Cytoreduction Surgical Procedures
Hyperthermia, Induced
Neoplasm Staging
Peritoneal Neoplasms
Retrospective Studies
Survival Rate