奈良県のがん罹患者数とがん登録精度 2000年奈良県がん登録結果

Abstract

Nara Cancer Registry was established in 1985 as a population-based cancer registry. Medical doctors in all medical facilities in Nara Prefecture are encouraged to report cancer patients with a registration form to Nara Cancer Registry. Additionally, of all death certificates submitted to the local authority, those recording the existence of any cancer are conveyed to the Registry. Reported cancer cases are referred to a database updated continuously since 1985 and then only incident cases are newly registered. The present study aimed at investigating cancer incidence and evaluating the quality of the registration uslng the data for the most recent year 2000 in Nara. We calculated age-adjusted incidence rates based on Japan standard population in 1985, the proportion of registered cancer patients who were reported by death certificate only (DCN ％) and the ratio of the number of incident cases to that of deceased ones (I/Dratio). In 2000, a total of 4,992 cancer patients (2,898 males and 2,094 females) were newly registered. Age-adjusted incidence rates were 315.9 among males and 190.1 among females for all sites. Sex ratio (315.9/190.1=1.7) was similar to the national average (365.3/224.7=1.6), but incident rates themselves for both sexes were O.85 times lower than the respective values ofJapan. Site specific and age-adjusted incidence rates showed the highest value in stomach cancer followed by lung cancer among males, and in breast cancer followed by stomach cancer among females. These descending orders were the same as those in the whole of Japan, but ranks of colon cancer in both sexes in Nara were unexpectedly low. DCN ％ was 50.9％, and I/D ratio was 1.52 for all cancers. These results suggest that not a few cancer patients may be underreported and that much effort is needed to improve the quality of cancer registration in Nara.