Clinic-Based Lung Cancer Screening in Urayasu

Abstract

In Urayasu City, lung cancer screening was initiated in April 1988. The city has adopted a clinic-based individual screening method using chest X-ray images. Here, we present indices associated with quality control of the lung cancer screening conducted over the period of 27 years until March 2015. The total number of persons screened was 293,263. During this 27-year period, the city’s population grew 1.6 times, while the annual number of persons screened for lung cancer grew 5 times. The mean screening rate for the 6 years from 2008 through 2014 was 56.1%, higher than the percentage targeted by the Cancer Control Act. The recall rate was 1%, lower than the national average of 2.6%. Excluding those with other active pulmonary diseases from the cases recalled to undergo detailed examination, the recall rate was approximately 0.7%. The detailed examination rate among those recalled for such an examination used to be high, exceeding 80%, but has been on a declining trend in recent years. The lung cancer detection rate for the aforementioned 27-year period was 64.8/100,000 persons, higher than the national average. Since the Great East Japan Earthquake, population growth has ceased and the lung cancer detection rate has been on a declining trend. The positive predictive value fluctuates from year to year but has remained within the range of 4-7%. These indices compared favorably with those in other municipalities in Chiba Prefecture. Particularly, the city’s screening rate was higher than the rates in municipalities using mass screening.

The age-adjusted mortality from lung cancer in Urayasu is declining on an annual basis, which may be attributable to lung cancer screening, along with anti-smoking measures.