Cancer Screening and Detection of Early-Stage Pancreatic Cancer

Abstract

Cancer screening in Japan is divided into two types: organized screening and opportunistic screening. Organized screening includes five types of cancer screening: stomach, colon, lung, cervical, and breast cancer screening. According to the number of deaths by cancer site in Outline of Vital Statistics 2021 published by the Ministry of Health, Labour and Welfare, lung, colon, stomach, pancreas, and liver for men, and colon, lung, pancreas, breast, and stomach for women, are the most common sites, in that order. For stomach, colon, lung, cervical, and breast cancer, the widespread adoption of organized screening has contributed to early diagnosis and reduction of cancer mortality. On the other hand, pancreatic cancer is the fourth most common cancer among men and the third most common among women, yet cancer screening based on scientific evidence has not been established. In addition, the association of Helicobacter pylori with gastric cancer, human papillomavirus with cervical cancer, and hepatitis B and C viruses with hepatocellular carcinoma as causes of cancer has been revealed, which is useful not only for cancer prevention but also for identification of high-risk populations for cancer. However, in the carcinogenesis of pancreatic cancer, involvement of various causes makes it difficult to identify high-risk populations. Pancreatic cancer screening methods include external ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and endoscopic ultrasonography (EUS). Among these, pancreatic cancer screening using a combination of MRI and EUS has been attracting attention, and its usefulness has been demonstrated in high-risk populations such as familial pancreatic cancer families in Europe and the United States. In Japan, enrollment has begun for a clinical trial being conducted by the National Cancer Center Hospital, the results of which are awaited.