RB1 gene mutations are a distinct predictive factor in Merkel cell carcinoma

Yusuke Muto, Eijitsu Ryo, Kenjiro Namikawa, Akira Takahashi, Dai Ogata, Taku Fujimura, Yasushi Yatabe, Setsuya Aiba, Naoya Yamazaki, Taisuke Mori

Research output: Contribution to journalArticlepeer-review

3 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)337-347
Number of pages11
JournalPathology international
Issue number5
Publication statusPublished - 2021 May


  • Merkel cell carcinoma
  • RB1
  • clinicopathological examination

ASJC Scopus subject areas

  • Pathology and Forensic Medicine


Dive into the research topics of 'RB1 gene mutations are a distinct predictive factor in Merkel cell carcinoma'. Together they form a unique fingerprint.

Cite this