Abstract
From 2003 to 2008, we performed mass surveys using abdominal ultrasonography for a total of 40,306 people. To evaluate the quality control for upper abdominal cancer screening by the ultrasonic method, five indicators were obtained. The recall rate, the percentage of examinees who underwent detailed examination and the percentage of replies to the letters of introduction to the hospitals were 3.2%, 90.7% and 94.2%, respectively. The number of detected malignant diseases was 23, including 11 renal cell carcinomas, 5 hepatocellular carcinomas, 2 retroperitoneal cancers, 1 cholangiocellular carcinoma, 1 gallbladder cancer, 1 bile duct cancer, 1 pancreatic cancer and 1 duodenal carcinoma. The cancer detection rate was 0.057%. The prognosis was confirmed in all malignant cases. To assess the validity of the screening, the data of the mass survey from 1996 to 2004 were matched with that of the Miyagi Cancer Registry. The sensitivity, specificity, false negative rate and positive predictive value were 81.4%, 97.6%, 18.6% and 3.0%, respectively. The false negative rates were 6.3%, 9.1%, 20.0% and 55.6% for renal cell carcinoma, hepatocellular carcinoma, gallbladder cancer and pancreatic cancer, respectively. These results were similar to those of the gastric cancer screening and colon cancer screening. Although it can be concluded that the accuracy of the abdominal screening by the ultrasonic method is almost satisfactory, it is necessary to establish an early detection method for pancreatic cancer.
