Regional incidences of adult T-cell leukemia/lymphoma with cutaneous involvement in Japan

Acute leukemias in pregnant women: Results of a retrospective study at a local tertiary-care hospital in Japan

Leukemia may rarely develop in a woman during pregnancy, posing clinical challenges to the patient, fetus, family, and medical staff managing malignancy and pregnancy. We retrospectively analyzed cases of pregnancy-associated leukemia consecutively diagnosed and treated at a local tertiary-care hospital in Nagano, Japan, over the past 20 years. Five cases were identified among 377,000 pregnancies in the area (one in every 75,000 pregnancies), all involving acute leukemia (three acute myelogenous leukemia [AML] and two acute lymphoblastic leukemia [ALL]). The cases were diagnosed in the first trimester (n = 1), second trimester (n = 3), or third trimester (n = 1). There were no apparent pregnancy-associated delays in diagnosing and treating the cases. Three patients underwent induction chemotherapy during pregnancy, two of whom eventually delivered healthy babies. One of the five patients chose abortion before chemotherapy initiation. Two cases showing high-risk features at the diagnosis (AML with an FLT3-ITD mutation [n = 1] and relapsed ALL [n = 1]) eventually died despite consolidative allogeneic hematopoietic stem cell transplantation. Our results suggested that patients with pregnancy-associated acute leukemia can be treated similarly to nonpregnant patients, although pregnancy imposes particular clinical challenges that should be resolved with multidisciplinary care.

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.

Environmental and Other Extrinsic Risk Factors Contributing to the Pathogenesis of Cutaneous T Cell Lymphoma (CTCL)

The applications of disease cluster investigations in medicine have developed rather rapidly in recent decades. Analyzing the epidemiology of non-random aggregation of patients with a particular disease fostered identification of environmental and external exposures as disease triggers and promoters. Observation of patient clusters and their association with nearby exposures, such as Dr. John Snow's astute mapping analysis in the mid-1800's, which revealed proximity of cholera patients in London to a contaminated water pump infected with Vibrio cholerae, have paved the way for the field of epidemiology. This approach enabled the identification of triggers for many human diseases including infections and cancers. Cutaneous T-cell lymphomas (CTCL) represent a group of non-Hodgkin lymphomas that primarily affect the skin. The detailed pathogenesis by which CTCL develops remains largely unknown. Notably, non-random clustering of CTCL patients was reported in several areas worldwide and this rare malignancy was also described to affect multiple members of the same family. These observations indicate that external factors are possibly implicated in promoting CTCL lymphomagenesis. Here, we review the epidemiology of CTCL worldwide and the clinical characteristics of CTCL patients, as revealed by global epidemiological data. Further, we review the known risk factors including sex, age, race as well as environmental, infectious, iatrogenic and other exposures, that are implicated in CTCL lymphomagenesis and discuss conceivable mechanisms by which these factors may trigger this malignancy.