Sysmex Journal International

2019Vol.29 No.2


Cytokeratin19 mRNA as a Universal Marker for Detecting Metastatic Lymph Nodes, Irrespective of Racial Groups or Cancer Types


Mayuko KOBAYASHI*1, Shuichi KANEMITSU*2, Motonari DAITO*1 and Yasuyo OHI*3

*1 Gene Testing Business, LS Business, Sysmex Corporation
*2 Department of Breast Surgical Oncology, Hakuaikai Sagara Hospital
*3 Department of Pathology, Hakuaikai Sagara Hospital


The mRNA of cytokeratin (CK) 19 in lymph nodes (LNs) has been used as a clinical marker for predicting disease progression and as an aid for deciding therapeutic strategy. Although it has been reported that CK19 mRNA is a useful marker to detect metastasis positive or negative through races and cancers, racial or cancer-related differences in CK19 mRNA which may affect cut-off value have not been evaluated by comparing cohorts directly. The objective of this study was to validate the applicability of CK19 mRNA as a clinical marker and its cut-off value by comparing the distribution of CK19 mRNA expression level per unit of metastasis volume in LNs from Japanese breast cancer patients and Caucasian breast, colon, and gastric cancer patients. Frozen serial sections of lymph nodes were tested both in the OSNA assay and by histopathological examination, and CK19 mRNA expression level per unit of metastasis volume was calculated for each LN. The average (±standard deviation) level (expressed as log number of copies/μL) in Japanese breast (30LNs), Caucasian breast (29LNs), colon (21LNs), and gastric cancer (30LNs) lymph nodes was 3.714 (0.599), 3.433 (0.610), 3.457 (0.574), and 3.599 (0.644), respectively, indicating no significant difference between races or cancer types.

This result confirmed the applicability of CK19 mRNA expression level for Japanese/Caucasian patients as a clinical marker for breast, colon, and gastric cancer. It is expected that further clinical research to assess disease progression using CK19 mRNA will be investigated and that CK19 mRNA will be proved to be a more valuable clinical marker than the standard practice when defining the optimal treatment method for patients.


Cytokeratin, CK19 mRNA Expression, the OSNA Assay, Lymph Node, Metastasis, Race, Breast Cancer, Colon Cancer, Gastric Cancer


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