title: Clinicopathological features of malignant lymphoma in Japan: the Miyagi Study.
abstract: 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.
authors.affiliation: Department of Hematology and Rheumatology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Miura
authors.forename: Noriko
authors.initials: N
authors.lastname: Fukuhara
authors.forename: Joji
authors.initials: J
authors.lastname: Yamamoto
authors.forename: Katsura
authors.initials: K
authors.lastname: Kohata
authors.forename: Kenichi
authors.initials: K
authors.lastname: Ishizawa
authors.forename: Ryo
authors.initials: R
authors.lastname: Ichinohasama
authors.forename: Hideo
authors.initials: H
authors.lastname: Harigae
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D018951:Antigens, CD20 / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008223:Lymphoma / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged
chemical_list: D018951:Antigens, CD20