A decrease in newly diagnosed patients with adult T-cell leukemia/lymphoma in Kagoshima, a highly endemic area of HTLV-1 in southwestern Japan

Abstract

Adult T-cell leukemia/lymphoma (ATL) is a peripheral T-cell malignancy caused by human T-cell leukemia virus type-I (HTLV-1). This study investigated whether the number of newly diagnosed patients with ATL is decreasing in the background of a declining number of individuals infected by HTLV-1 in Kagoshima, Japan, one of the most endemic areas of HTLV-1 in the world. We retrospectively analyzed the number of newly diagnosed patients with ATL between January 2001 and December 2021 in three major hospitals. The number of newly diagnosed patients with B-cell non-Hodgkin lymphoma (B-NHL) in the same period was examined as an internal control. One thousand eighteen and 2,029 patients with ATL and B-NHL were registered, respectively. The age-adjusted incidence of ATL steadily increased between 2001 and 2012, whereas that between 2013 and 2021 decreased. Despite the limitation of its retrospective nature, this is the first report indicating a decrease in ATL patients in Japan.

Keywords:

• HTLV-1
• seropositivity
• ATL
• incidence

Acknowledgments

The authors are deeply grateful to the hematologists at the following institutions for their patient referrals and other contributions: Nobuhito Ohno at the Department of Hematology, Ikeda Hospital, Yoshifusa Takatsuka at the Department of Hematology, Idzuro-Imamura hospital, Kyoko Mizukami at the Department of Internal Medicine, the Kirishima Medical Center, Kosuke Obama at the Department of Hematology, Imakiire General Hospital, and Shigemi Shimotakahara at the Department of Internal Medicine, Maruta Hospital, Kagoshima, Japan.

Author contributions

SO, MI and KI contributed to the study concept, design and data interpretation. SO, MT, DN, KU, KH, NN, MY, YI, AU, MO and SH collected and analyzed data at their respective facilities. YS and HN provided data for blood donors of Kagoshima in the Japanese Red Cross Blood Center. SO and KI wrote the manuscript. All authors critically reviewed the approved the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the President’s Discretionary Expenses of Kagoshima University, and Research Program [21fk0108124h0802] on Emerging and Reemerging Infectious Diseases from the Japan Agency for Medical Research and Development, AMED.