Estimation of cancer incidences in Aichi prefecture: use of a model area with good quality registry data.

In Japan, local government is responsible for organization of population-based cancer registries and the quality of the registration remains modest, mainly due to dependence on voluntary-based operations without legal obligations. Aichi Prefecture cancer registry covers a large population, estimated at 7 million, and its quality has yet to reach the level required internationally. The derived cancer incidences for Aichi Prefecture therefore tend to be underestimated. In the present study we set up a model area, located in the central part of Aichi Prefecture, with a good quality of registry data, covering a reasonable population, including both urban and rural areas. Our model area has typical demographic features of Aichi Prefecture. The materials were data on cancer incidence and deaths during the period of 1996-2000 in this model area of Aichi prefecture, with a population of approximately one million, under the jurisdiction of three public health centers, covering nine municipalities. The percentage of death certificated notified (DCN) cases for all sites was around 14% and the incidence/death ratio was around 1.9. Estimated age-adjusted incidence rates were found to be 256.0 (per 100,000) for males and 177.6 for females, these values being 10-15 % higher than those generated using data for the whole prefecture, and quite close to incidence rates in Japan estimated from the highest quality of data available. It is suggested that the cancer incidence in the Aichi prefecture is indeed being underestimated and that the actual figures may be closer to the estimates provided here.

Reproducibility of a food frequency questionnaire in koreans.

Objective : The present study was conducted to report upon the reproducibility of a 98-item food frequency questionnaire among Koreans. Subjects : The study subjects were recruited from among those who visited for a regular health check-up at the health centers from Samsung Hospital and Hallym University Hospital. Setting : The FFQ was administered first in April to June of 2002 to 145 Korean adults aged 40 and over residing in Seoul and its vicinity and was then re-administered to 126 three months later between July and September of 2002 (FFQ 1 and FFQ 2). Methods : Reproducibility was evaluated using the Pearson correlation coefficients of log-e and the calorie-adjusted nutrient score. Weighted kappa (k) statistics with 95% confidence limits were calculated to assess the chance adjusted level of agreement between the FFQ 1 and the FFQ 2. The proportions of correctly categorized subjects in the same or adjacent quintiles were calculated. Results : The average intake in FFQ 1 was no more than 12 percent different from the average intake in FFQ 2. Correlations varied between 0.47 for sodium and 0.72 for vitamin C. All k values exceeded 0.5 except that of fiber. The average k for all nutrients was 0.67. The percentage agreement varied from 62% for energy and potassium to 82% for vitamin B(2) and cholesterol. The average of the agreement was 72%. Conclusion : The results of this study verify that it is possible to use tailored, relatively simple, but comprehensive, self-administered food frequency questionnaires to study nutrient consumption in large-scale epidemiological studies.

Probabilities of developing cancer over the life span of a Japanese--update.

In a previous study, we investigated the probability of developing cancer in the entire life span of a Japanese using population-based cancer incidence data from 1994, to obtain a relevant index of the impact of cancer occurrence on the Japanese population (APJCP, 1: 333-336, 2000). In the present paper, we have updated the information using the latest reports on cancer incidence in Japan in 1998. A method based on the cumulative risk of cancer was employed to estimate the probability of developing cancer up to 84 years of age, the average life expectancy of a Japanese female, and 79 years of age, the average life expectancy of a Japanese male. The time trend was also analyzed from 1975-1998. The cumulative risk of developing cancer in any site up to 84 and 79 years of age was 45% and 36% for males, 27% and 21% for females, and 35% and 28% for both genders, respectively. The cumulative risk showed an increasing time trend before leveling-off after 1985. From our results, it is expected that nearly one-third of Japanese males and one-fourth of Japanese females will develop cancer by the time they reach the average life expectancy.