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©The Author(s) 2017. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Sep 15, 2017; 9(9): 354-362
Published online Sep 15, 2017. doi: 10.4251/wjgo.v9.i9.354
Stratification of outcomes for mucinous appendiceal adenocarcinoma with peritoneal metastasis by histological grade
Travis Edward Grotz, Richard E Royal, Paul F Mansfield, Michael James Overman, Gary N Mann, Kristen Ashlee Robinson, Karen A Beaty, Safiea Rafeeq, Auerlio Matamoros, Michelle W Taggart, Keith Francis Fournier
Travis Edward Grotz, Richard E Royal, Paul F Mansfield, Gary N Mann, Kristen Ashlee Robinson, Karen A Beaty, Safiea Rafeeq, Keith Francis Fournier, Department of Surgical Oncology at the University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Michael James Overman, Department of Medical Oncology at the University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Auerlio Matamoros, Department of Radiology at the University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Michelle W Taggart, Department of Pathology at the University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States
Author contributions: Grotz TE, Royal RE, Mansfield PF, Matamoros A, Taggart MW and Fournier KF contributed to conceptualization; Grotz TE, Royal RE, Mansfield PF, Overman MJ, Mann GN, Taggart MW and Fournier KF contributed to methodology; Grotz TE contributed to formal analysis; Grotz TE, Robinson KA, Beaty KA and Rafeeq S contributed to data curation; Grotz TE and Taggart MW contributed to writing; Royal RE, Mansfield PF, Overman MJ, Mann GN, Robinson KA, Beaty KA, Rafeeq S, Matamoros A and Fournier KF contributed to editing; Fournier KF contributed to supervision.
Institutional review board statement: This study was approved by an Institutional Review Board at University of Texas, MD Anderson Cancer Center.
Informed consent statement: All patients included in this study signed informed consent to have their electronic medical record utilized for research purposes.
Conflict-of-interest statement: Dr. Taggart has received a small educational grant from Bristol-Meyers Squibb. The other authors have no disclosures.
Data sharing statement: None.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Keith Francis Fournier, MD, Associate Professor, Department of Surgical Oncology at the University of Texas MD Anderson Cancer Center, Houston, TX 77030, United States.
kffourni@mdanderson.org
Telephone: +1-713-7928826
Received: April 13, 2017
Peer-review started: April 13, 2017
First decision: May 8, 2017
Revised: May 13, 2017
Accepted: May 30, 2017
Article in press: May 31, 2017
Published online: September 15, 2017
Processing time: 150 Days and 22.3 Hours
AIM
To investigate the importance of a three-tiered histologic grade on outcomes for patients with mucinous appendiceal adenocarcinoma (MAA).
METHODS
Two hundred and sixty-five patients with MAA undergoing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy were identified from a prospective database from 2004 through 2014. All pathology was reviewed by our gastrointestinal subspecialty pathologists and histological grade was classified as well-differentiated, moderately differentiated, and poorly differentiated. Survival analysis was performed using Cox proportional hazards regression.
RESULTS
There were 201 (75.8%) well-, 45 (16.9%) moderately- and 19 (7.2%) poorly-differentiated tumors. Histological grade significantly stratified the 5-year overall survival (OS), 94%, 71% and 30% respectively (P < 0.001) as well as the 5-year disease-free survival (DFS) 66%, 21% and 0%, respectively (P < 0.001). Independent predictors of DFS included tumor grade (HR = 1.78, 95%CI: 1.21-2.63, P = 0.008), lymph node involvement (HR = 0.33, 95%CI: 0.11-0.98, P < 0.02), previous surgical score (HR = 1.31, 95%CI: 1.1-1.65, P = 0.03) and peritoneal carcinomatosis index (PCI) (HR = 1.05, 95%CI: 1.02-1.08, P = 0.002). Independent predictors of OS include tumor grade (HR = 2.79, 95%CI: 1.26-6.21, P = 0.01), PCI (HR = 1.10, 95%CI: 1.03-1.16, P = 0.002), and complete cytoreduction (HR = 0.32, 95%CI: 0.11-0.92, P = 0.03). Tumor grade and PCI were the only independent predictors of both DFS and OS. Furthermore, histological grade and lymphovascular invasion stratified the risk of lymph node metastasis into a low (6%) and high (40%) risk groups.
CONCLUSION
Our data demonstrates that moderately differentiated MAA have a clinical behavior and outcome that is distinct from well- and poorly-differentiated MAA. The three-tier grade classification provides improved prognostic stratification and should be incorporated into patient selection and treatment algorithms.
Core tip: The natural history of mucinous appendiceal adenocarcinoma encompasses a wide spectrum of clinical outcomes. This study illustrates that classification of these tumors using tumor cellularity, architectural features and cytologic abnormalities into three distinct histological grades; well-, moderately- and poorly-differentiated allows the clinician to better estimate relative risk of recurrence and death. Thus facilitating patient selection, education and comparison of different treatments.
