Prognosis of patients with adult T‐cell leukemia/lymphoma in Japan: A nationwide hospital‐based study

Abstract

Adult T‐cell leukemia/lymphoma (ATL) is a mature T‐cell neoplasm and is classified into four subtypes (acute, lymphoma, chronic, and smoldering) according to the Shimoyama classification, established in 1991 through several nationwide surveys based on the clinical diversity of patients diagnosed in 1983‐1987 in Japan. Thereafter, no such studies have been conducted. Recently, we conducted a nationwide hospital survey using the method of the 1980s studies, collected baseline data on 996 ATL patients diagnosed in 2010‐2011 from 126 hospitals, and reported their unique epidemiological characteristics. Here, we report the follow‐up results of registered ATL patients with the goal of evaluating current prognoses and treatment modalities as of 2016‐2017. Of 770 evaluable patients, 391 (50.8%) had acute‐type, 192 (24.9%) had lymphoma‐type, 106 (13.8%) had chronic‐type, and 81 (10.5%) had smoldering‐type ATL. The initial therapy regimens used for acute/lymphoma‐type ATL were vincristine, cyclophosphamide, doxorubicin and prednisone, followed by doxorubicin, ranimustine, and prednisone and then by vindesine, etoposide, carboplatin, and prednisone (VCAP‐AMP‐VECP)‐like in 38.5/41.7% and cyclophosphamide, doxorubicin, vincristine, and prednisone (CHOP)‐like in 14.6/13.7% of patients. Allogeneic hematopoietic stem cell transplantation was used to treat 15.9/10.4% of acute/lymphoma‐type ATL patients. The 4‐year survival rates (the median survival time, days) for acute‐, lymphoma‐, unfavorable chronic‐, favorable chronic‐, and smoldering‐type ATL were 16.8% (252), 19.6% (305), 26.6% (572), 62.1% (1937), and 59.8% (1851), respectively. The 4‐year survival rates for acute‐ and lymphoma‐type ATL improved compared with those reported in 1991, but those for chronic‐ and smoldering‐type ATL were not. Further efforts are warranted to develop more efficient therapeutic strategies to improve the prognosis of ATL in Japan.

Clinical Applications of Genomic Alterations in ATLL: Predictive Markers and Therapeutic Targets

“…Regarding this point, a recent study of clinical characteristics of Caribbean ATLL cases found that median age at presentation was 54 years [44]. In a recent national survey in Japan, the median age was 68 years old [45]. Interestingly, the age at ATLL diagnosis is gradually increasing in Japan, and the same trend may be observed in the Caribbean cases in future.…”

“…Interestingly, the age at ATLL diagnosis is gradually increasing in Japan, and the same trend may be observed in the Caribbean cases in future. Prognosis of ATLL also differed between Caribbean and Japanese ATLL cases (median survival time; 5.5 months in the Caribbean acute and lymphoma types, 8.3 months in the Japanese acute type, and 10.0 months in the Japanese lymphoma type) [44,45]. This may be related that number of cases with allogeneic SCT were higher in the Japanese cases than in the Caribbean cases.…”

“…One of the regional variations in ATLL is age at diagnosis. In fact, ATLL cases in South America and the Caribbean islands tend to be younger than ATLL cases in Japan [43][44][45]. Regarding this point, a recent study of clinical characteristics of Caribbean ATLL cases found that median age at presentation was 54 years [44].…”

Comprehensive genomic analysis identifying heterogeneity in peripheral T‐cell lymphoma

“…As described above, ATLL frequently develops in the elderly, although it has been reported that the age at onset is gradually increasing. 5,29 HTLV-1 is mainly transmitted from mother to child through breastfeeding. [30][31][32] It is, therefore, believed that ATLL develops due to the accumulation of genetic abnormalities over a long period of time after HTLV-1 infection.…”

“…57 According to a recent, nationwide, hospital-based study, the acute subtype was the most common, followed by the lymphoma subtype, which was also frequently observed. 29 Among the subtypes, chronic and smoldering are regarded to be indolent ATLL, whereas the lymphoma and acute subtypes are considered to be aggressive ATLL. The chronic subtype is further divided into unfavorable or favorable groups based on laboratory findings.…”