Tohoku J. Exp. Med., 2011, 224(2)

Clinicopathological Features of Malignant Lymphoma in Japan: The Miyagi Study

YUKIKO MIURA,¹ NORIKO FUKUHARA,¹ JOJI YAMAMOTO,¹ KATSURA KOHATA,¹ KENICHI ISHIZAWA,¹ RYO ICHINOHASAMA² and HIDEO HARIGAE¹

¹Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, Sendai, Japan
²Department of Hematopathology, Tohoku University Graduate School of Medicine, Sendai, Japan

The Miyagi Study is an epidemiological study of malignant lymphoma, including immunological and genetic analyses, constructed by a population-based registration system covering Miyagi prefecture, Japan. A total of 1,552 newly diagnosed cases in Miyagi between 2002 and 2008 were enrolled in this study; 75% were B-cell lymphomas, 19% were T-cell and natural killer-cell (T/NK-cell) lymphomas, and 5% were Hodgkin's lymphomas. The most frequent subtype of B-cell lymphoma is diffuse large B-cell lymphoma, followed by follicular lymphoma and extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (51%, 24% and 8%, respectively). Thus, follicular lymphoma accounts for 18.2% of newly diagnosed cases in Miyagi; unexpectedly, its frequency is similar to that reported in Western countries. The common subtypes of T/NK-cell lymphoma are peripheral T-cell lymphoma, angioimmunoblastic T-cell lymphoma, and adult T-cell leukemia/lymphoma (30%, 15% and 14%, respectively). Most of the data are similar to those reported in Asian countries, except for follicular lymphoma. We also analyzed the CD20 expression in B-cell lymphomas by flow cytometry for the cell membrane expression and by immunohistochemistry for the cytoplasmic expression. The cell membrane expression of CD20 protein may determine the susceptibility of B-cell lymphomas to anti-CD20 antibody therapy. The lack of CD20 expression was confirmed by both methods in 4 cases of 585 newly diagnosed cases (0.7%) and in 5 of 67 recurrent cases (7.5%). Furthermore, 23 cases (6.5%) showed the discrepancy of CD20 expression between both methods. The Miyagi Study has revealed the latest epidemiological features of malignant lymphoma in Japan.

keywords —— CD20; epidemiology; flow cytometry; malignant lymphoma; Miyagi Study

© 2011 Tohoku University Medical Press

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Tohoku J. Exp. Med., 2011, 224, 151-160

Correspondence: Noriko Fukuhara, M.D., Ph.D., Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

e-mail: nfukuhara@med.tohoku.ac.jp