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RB1 gene mutations are a distinct predictive factor in Merkel cell carcinoma
Author(s) -
Muto Yusuke,
Ryo Eijitsu,
Namikawa Kenjiro,
Takahashi Akira,
Ogata Dai,
Fujimura Taku,
Yatabe Yasushi,
Aiba Setsuya,
Yamazaki Naoya,
Mori Taisuke
Publication year - 2021
Publication title -
pathology international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.73
H-Index - 74
eISSN - 1440-1827
pISSN - 1320-5463
DOI - 10.1111/pin.13090
Subject(s) - merkel cell carcinoma , merkel cell polyomavirus , immunohistochemistry , cytokeratin , merkel cell , pathology , exon , metastasis , carcinoma , biology , gene duplication , medicine , cancer , gene , genetics
Merkel cell carcinoma (MCC) is a rare cutaneous neuroendocrine carcinoma that tends to show local recurrence and metastasis. Typically, MCC is polyomavirus (MCPyV)‐associated and cytokeratin 20 (CK20) positive. However, little is known about this tumor and its origins. Here, we aimed to determine the developmental origins of MCC and to identify prognostic clinicopathologic factors. Initial examinations revealed that CK20 and MCPyV expression (CK20+, MCPyV+ (60%); CK20+, MCPyV− (10%); CK20−, and MCPyV− (30%)) did not affect overall survival. With RB1 gene sequencing of FFPE specimens, which covered an entire exon, all RB1 mutation‐positive cases showed positive regional lymph node and/or distant metastases (8/8 cases, 100%), whereas the frequency of the metastasis was statistically significantly lower in RB1 mutation‐negative cases, (10/16 cases, 62%, P = 0.033). The results were also confirmed with immunohistochemistry, and either RB1 alterations, entire exon sequencing, or immunohistochemistry was associated with the metastasis ( P = 0.007). RB1 alterations may be used to access the aggressive clinical course of MCC.