The Prefectural Participation Rates of Lung Cancer Screening Had a Negative Correlation with the Lung Cancer Mortality Rates

Background: The participation rate is one of the most important indexes in the cancer screening. Historically in Japan, each local government has developed their own equations to calculate the subjects for population-based screening, which were different from each other, and therefore the participation rates of screening were not comparable. Recently, local governments were ordered to use the standardized equation in reporting data, which made it possible to compare the participation rates of cancer screening nationwide for the first time. We therefore investigated the correlation between the prefectural lung cancer mortality and several indicators of lung cancer screening. Methods: The prefectural participation rates of lung, gastric and colonic cancer screening, test positive rates, attendance rates for further examination, lung cancer detection rates and positive predictive values of lung cancer screening were collected from “Cancer Registration and Statistics” of the National Cancer Research Center website. The age-adjusted lung, gastric and colonic cancer mortality rates, smoking rates were also collected. The EZR software program was used for statistical analyses. Results: The participation rates of lung cancer screening had a strong positive correlation with the participation rates of gastric/colonic cancer screening (P<0.001). The prefectural lung cancer mortality rates had a moderate to weak negative correlation with the participation rates of lung cancer screening (P=0.009). A little correlation was noted between other quality assurance indicators of lung cancer screening and lung cancer mortality rates. Conclusion: These results suggested that participating in lung cancer screening might help reduce lung cancer mortality rates in some extent.