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Comparative Study
. 2019 May 15;25(10):3096-3103.
doi: 10.1158/1078-0432.CCR-18-3388. Epub 2019 Jan 28.

Molecular Profiling of Appendiceal Adenocarcinoma and Comparison with Right-sided and Left-sided Colorectal Cancer

Affiliations
Comparative Study

Molecular Profiling of Appendiceal Adenocarcinoma and Comparison with Right-sided and Left-sided Colorectal Cancer

Ryuma Tokunaga et al. Clin Cancer Res. .

Abstract

Purpose: The natural history and prognosis of appendiceal adenocarcinomas differ from those of adenocarcinomas arising in other large bowel sites. We aimed to compare the molecular profiles exhibited by appendiceal adenocarcinomas and colorectal cancers, or between the histopathologic subtypes of appendiceal adenocarcinoma.

Experimental design: A total of 183 samples from appendiceal adenocarcinoma [46 adenocarcinoma, not otherwise specified (NOS), 66 pseudomyxoma peritonei (PMP), 44 mucinous adenocarcinoma (MU), and 27 signet ring cell carcinoma (SR)], 994 from right-sided colorectal cancer (R-CRC), and 1,080 from left-sided CRC (L-CRC) were analyzed by next-generation sequencing (NGS) and IHC markers. Microsatellite instability (MSI) and tumor mutational burden (TMB) were tested by NGS, and programmed death ligand 1 (PD-L1) by IHC.

Results: We observed high mutation rates in appendiceal adenocarcinoma samples for KRAS (55%), TP53 (40%), GNAS (31%), SMAD4 (16%), and APC (10%). Appendiceal adenocarcinoma exhibited higher mutation rates in KRAS and GNAS, and lower mutation rates in TP53, APC, and PIK3CA (6%) than colorectal cancers. PMP exhibited much higher mutation rates in KRAS (74%) and GNAS (63%), and much lower mutation rates in TP53 (23%), APC (2%), and PIK3CA (2%) than NOS. Alterations associated with immune checkpoint inhibitor response (MSI-high, TMB-high, PD-L1 expression) showed similar frequency in appendiceal adenocarcinoma compared with L-CRC, but not R-CRC, and those of NOS were higher than other subtypes of appendiceal adenocarcinoma and L-CRC.

Conclusions: Molecular profiling of appendiceal adenocarcinoma revealed different molecular characteristics than noted in R-CRC and L-CRC, and molecular heterogeneity among the histopathologic subtypes of appendiceal adenocarcinoma. Our findings may be critical to developing an individualized approach to appendiceal adenocarcinoma treatment.

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Conflict of interest statement

Conflict of interests: Dr. Xiu, Dr. Johnston, and Dr. Korn are employed by Caris Life Sciences. Dr. Marshall and Dr. Seeber are consultants for Caris Life Sciences. The other authors declare that they have no competing interests. The content is solely the responsibility of the authors.

Figures

Figure 1.
Figure 1.. CONSORT diagram.
Flow chart showing the inclusion/exclusion criteria in this study.
Figure 2.
Figure 2.. Immune profiling (the status of MSI, TMB, and PD-L1 expression) of AA, R-CRC and L-CRC, and the histopathological subtypes of AA.
A: The characteristics of immune profiles in AA, R-CRC, and L-CRC. B: The characteristics of immune profiles in the histopathological subtypes of AA. Abbreviations: AA, appendiceal adenocarcinoma; L-CRC, left-sided colorectal cancer; MSI, microsatellite instability; PD-L1, programmed death-ligand 1; R-CRC, right-sided colorectal cancer; TMB, tumor mutational burden.

References

    1. Compton C, Fenoglio-Preiser CM, Pettigrew N, Fielding LP. American Joint Committee on Cancer Prognostic Factors Consensus Conference: Colorectal Working Group. Cancer. 2000;88:1739–57. - PubMed
    1. Turaga KK, Pappas SG, Gamblin T. Importance of histologic subtype in the staging of appendiceal tumors. Ann Surg Oncol. 2012;19:1379–85. - PubMed
    1. Pietrantonio F, Maggi C, Fanetti G, Iacovelli R, Di Bartolomeo M, Ricchini F, et al. FOLFOX-4 chemotherapy for patients with unresectable or relapsed peritoneal pseudomyxoma. Oncologist. 2014;19:845–50. - PMC - PubMed
    1. Carr NJ, Finch J, Ilesley IC, Chandrakumaran K, Mohamed F, Mirnezami A, et al. Pathology and prognosis in pseudomyxoma peritonei: a review of 274 cases. J Clin Pathol. 2012;65:919–23. - PubMed
    1. Carr NJ, Bibeau F, Bradley RF, Dartigues P, Feakins RM, Geisinger KR, et al. The histopathological classification, diagnosis and differential diagnosis of mucinous appendiceal neoplasms, appendiceal adenocarcinomas and pseudomyxoma peritonei. Histopathology. 2017;71:847–58. - PubMed

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