Cutaneous lymphoma in Japan, 2012-2017: A nationwide study.

BACKGROUND: The types of cutaneous lymphoma (CL) and their incidences can vary among geographic areas or ethnic groups. OBJECTIVE: This study aimed to investigate the incidence of various CL types in Japan using epidemiological data from a nationwide registration system for CL. METHODS: A questionnaire was sent to participating hospitals, all of which had been approved to conduct residency programs for board-certified dermatologists by the Japanese Dermatological Association. Data from patients newly diagnosed with CL were collected electronically. RESULTS: Between 2012 and 2017, 2547 new patients with CL from the dermatological institutes were registered. In total, 2090 patients had primary CL and 453 had secondary CL. Those with primary CL included 1609 (77.0 %) patients with mature T- and natural killer (NK)-cell neoplasms, 442 (21.1 %) with B-cell neoplasms, and 39 (1.9 %) with blastic plasmacytoid dendritic cell neoplasms. Mycosis fungoides (MF) was the most common CL subtype in the present study (1003 patients, 48.0 %), and 72.4 % of MF patients had early-stage disease, similar to observations in previous studies on other cohorts. Primary cutaneous CD30+ T-cell lymphoproliferative disorders and adult T-cell leukemia/lymphoma were the second and third most common subtypes, respectively. CONCLUSION: Compared to that in our previous cohort (2007-2011), the number of registered T- and NK-cell CL cases decreased, whereas that of B-cell CL cases increased from 44.8-73.7 patients/year. These results provide insight into CL trends within the Japanese population, which might contribute to a better understanding of the disease.

[Analysis of mature T-cell and NK-cell lymphoma with CD30 expression based on latest WHO classification].

OBJECTIVE: To investigate the frequency of different types of mature T- and NK-cell lymphomas diagnosed in a 4-year period at Sun Yat-sen University Cancer Center, and to study baseline CD30 for potential anti-CD30 targeted therapy in mature T- and NK-cell lymphoma. METHODS: All cases of mature T- and NK-cell lymphoma diagnosed at Sun Yat-sen University Cancer Center from September 1, 2009 to August 31, 2013, were reviewed. Paraffin-blocks of available 164 consecutive cases were stained for CD30 immunohistochemistry using EnVision protocol. RESULTS: A total of 625 cases of mature T- and NK-cell lymphomas were diagnosed and the most common type was extranodal NK/T cell lymphoma (ENKTL), nasal type 319 (51.0%) cases, followed by angioimmunoblastic T-cell lymphoma (AITL) (119 cases, 19.0%), peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS) (81 cases, 13.0%), and anaplastic large-cell lymphoma (ALCL), including 48 cases (7.7%) of systematic ALCL and 11 cases (1.8%) of primary cutaneous ALCL. Besides ALCL, ENKTL had the highest expression rate of CD30 among the 164 cases, with positivity observed in 41 cases (62.1%, 41/66). Only 1 case of PTCL-NOS was CD30 positive. CD30 was not expressed in all 28 cases of AITL and other rare types of mature T- and NK-cell lymphoma. CONCLUSIONS: The frequency of different types of mature T- and NK-cell lymphoma encountered at Sun Yat-sen University Cancer Center was similar to that seen in other areas of China and other Asia countries. CD30 expression is different among several types of mature T- and NK-cell lymphoma. In addition to ALCL, ENKTL has the highest expression rate of CD30, which may be a candidate disease for anti-CD30 targeted therapy.