Trends in disease indications for hematopoietic stem cell transplantation in the Asia-Pacific region: A report of the Activity Survey 2017 from APBMT

The Asia-Pacific Blood and Marrow Transplantation Group (APBMT) has been conducting annual surveys on the activity of hematopoietic stem cell transplants since 2007. The APBMT Data Center collected the following data in 2017. A total of 21,504 transplants were registered from 733 transplant centers of 20 countries/regions in the Asia-Pacific (AP) region. Five countries/regions comprised 89.4% of all transplants - China (6,979), Japan (5,794), South Korea (2,626), India (2,034), and Australia (1,789). The number of centers in these five countries/regions also comprised 88.9% of all centers: Japan (373), China (123), India (66), Australia (45), and South Korea (44). The overall ratio between autologous and allogeneic transplants was 37.0% and 63.0%, respectively, but the ratios varied significantly among countries/regions. Autologous transplants have surpassed allogeneic transplants in Thailand, Australia, Vietnam, New Zealand, Singapore, and Iran. In contrast, the proportion of allogeneic transplants comprised over 70% of all transplants in Pakistan, China, and Hong Kong. These ratios were compared by the Data Center among countries/regions that performed more than 50 transplants. The proportion of related and unrelated transplants also differed among countries/regions. The number of unrelated transplants was more than related ones in Japan (2,551 vs. 1,202) and Australia (329 vs. 291), whereas more than 80% of all transplants were related transplants in Malaysia (90.9%), India (89.5%), Iran (87.2%), Vietnam (85.7%), China (80.9%), and Thailand (80.6%). All transplant activities were related transplants in Pakistan, the Philippines, Myanmar, and Nepal, and no allogeneic transplants were performed in Bangladesh and Mongolia. Regarding the indications for transplants, acute myeloid leukemia (AML) was the most common disease for allogeneic transplant (4,759, 35.1% of allogeneic transplants), while plasma cell disorder (PCD) was the most common disease for autologous transplant (3,701, 27.3% of all autologous transplants). Furthermore, the number of transplants for hemoglobinopathy has steeply increased in this region compared with the rest of disease indications (677, 3.1% of all transplants). APBMT covers a broad area globally, including countries/regions with diverse disease distribution, development of HSCT programs, population, and economic power. Consistent and continuous activity surveys considering those elements in each country/region revealed the HSCT field's diverse characteristics and background factors in this region.