Decrease in colorectal cancer screening participation rate in Minamisoma after 2011 Triple Disasters

Author: Hiroaki Saito

Department of Gastroenterology, Sendai Kosei Hospital

Editors:Chiharu Kawasaki, Yudai Kaneda

This article is translated from Japanese MRIC published on January 31, 2022.

Vol.22019 震災後は南相馬市の大腸がん検診参加率が減少。コロナ禍にも通じる数年に及んだ震災の影響 | MRIC by 医療ガバナンス学会 (

The decreasing rate trend of the participation of colorectal cancer screening in Minamisoma City after the earthquake lasted for several years. The same problem might happen under the COVID-19 situation we’re experiencing today.

I am a gastroenterologist working at Sendai Kosei Hospital and have been researching as a graduate student at the Department of Radiation Health Management, Fukushima Medical University, since 2017. I want to introduce the results of a survey I conducted on the status of cancer screening in the stricken areas of the Great East Japan Earthquake, which was released on December 16.

In Japan, municipal governments provide cancer screening for several types of cancer for early detection and treatment. Colorectal cancer screening is one of the essential screening methods whose effectiveness has been established internationally. The fecal occult blood test is performed to check the presence of blood in stool samples collected over two days. A colonoscopy is recommended if the results are positive because colon cancer or colon polyps are possible. More people must participate in the screening to increase the effectiveness of colorectal cancer screening (i.e., to reduce the number of colorectal cancer deaths in the target population). Having fewer participants means fewer colorectal cancers detected at an early stage.

In this study, I investigated the colorectal cancer screening participation rate in Minamisoma City, located in Fukushima Prefecture, for ten years before and after the earthquake. Minamisoma City was one of the areas severely damaged by the Great East Japan Earthquake in 2011. Many residents around the powerplant were forced to evacuate due to the Fukushima Daiichi nuclear disaster. Studies have shown that radiation exposure has little effect on health. On the other hand, subsequent studies after the disaster have revealed that evacuation and environmental changes negatively affect health, specifically lifestyle-related diseases and mental health. Based on the hypothesis that the post-disaster period may have affected cancer screening, originally designed to detect diseases before symptoms appeared, we investigated the changes in the participation rate for colorectal cancer screening.

Compared with the participation rate before the earthquake hit (12.3% in 2009 and 11.7% in 2010), the participation rate decreased significantly to 3.4% in 2011. Being under 65 years of age, living alone, and being displaced were associated with not participating in the screening.

The results of this survey are significant in two respects: first, it shows that the effects of the disaster have been long-lasting. The decreasing number of participants lasted for years, which shows the magnitude and continuity of the earthquake's impact. The second point was that isolation, such as living alone or being evacuated, was associated with non-participation in medical checkups. Losing connections with medical institutions and surroundings after the earthquake may have hindered participation in preventive medical activities.

The current situation caused by the pandemic has things in common with the post-disaster case. Access to medical facilities is limited, people tend to stay at home, and their connections with the people around them have become weaker, and all those situations are prolonged. Recently, there have been warnings that reluctance to see a doctor due to the COVID-19 prevalence affects cancer diagnosis.

In my involvement in this survey, I began to call on patients, friends, and family members I contact daily to ask them if they are getting screen-tested. Nowadays, when people are easily isolated, I believe it is essential to consider others and ask them how they are doing.

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