CHRONOLOGICAL CHANGE OF ATL INCIDENCE BETWEEN 1988 AND 1996 IN NAGASAKI PREFECTURE, JAPAN

Abstract

P082 To clarify the chronological change of ATL incidence between 1988 and 1996 in Nagasaki Prefecture, Japan, we compared age-specific incidence rate of ATL among general population between former (1988-91) and latter (1992-96) periods by sex. The data was obtained by Nagasaki Prefectural Regional Cancer Registry and 6th-8th National ATL Survey of Japan. Age-adjusted incidence rate was calculated using the world population. Furthermore, incidence rate of ATL among HTLV-I carriers in Tsushima Island, Nagasaki, was estimated by three age groups (40-59, 60-74 and 75+ years), and cumulative incidence rate of ATL was estimated from 40 to 74 years old. The estimated number of ATL cases among general population during the former and latter periods was 230 and 209 in men, and 152 and 165 in women, respectively. The age-adjusted incidence rate during the two periods was 51.7 and 43.7 in men, and 27.6 and 26.4, respectively. Age-specific incidence rate among the population younger than 50 years old decreased in the latter period, but that among women aged 70 years and over increased. The incidence rate of ATL among HTLV-I carriers in Tsushima Island was estimated to be 1.32/1,000/year in men and 0.76/1,000/year in women. The cumulative incidence rate in 40-74 age group was 37.2/1,000 in men and 25.0/1,000 in women. These results suggest that ATL incidence is decreasing among younger population in Japan.