1. Monitoring of Incidence and Mortality of Cancers around Fukushima Nuclear Plant Accident Area: inter-regional analysis
Tomohiro Matsuda 1, Kumiko Saika 1, Eisaku Sasaki 2, Emiko Ando 3 and Tomotaka Sobue 3
1 National Cancer Center, 2 Fukushima Medical University, 3 Osaka University
This work was supported by Research on the Health Effects of Radiation organized by Ministry of the Environment, Japan
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2. COI Disclosure Information
I have no financial relationships to disclose.
Lead Presenter/Responsible Researcher:
Tomohiro Matsuda
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3. Background
The Great East Earthquake on March 11th in 2011, has given enormous damage to the northern part of Japan, The following tsunami led to the serious accident in the 1st Fukushima nuclear power station.
The government issued an evacuation order for residents within 20 km radius, and an evacuation instruction within 30 km.
We observed a trend of incidence of cancers in several prefectures around Fukushima and between the regions in Fukushima in order to figure out the effect of the nuclear plant accident.
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4. Map of Japan/ Fukushima
Tokyo
3 Naka-dori
4 Aizu
2 Hama-dori
1 Evacuated Area (EA)
Fukushima 1st Nuclear Plant
20km
9 neighboring prefectures
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5. Methods
In consideration of refugees from Fukushima, we have observed the figures in 9 neighboring prefectures and entire country as a reference.
In view of the successive quality improvement of PBCR data, we confirmed quality indicators in association with APC.
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6. Methods
PBCR data between 2008 and 2015 divided into two periods, before ( ) and after ( ) the accident.
Age standardized incidence rate (ASIR) and annual percentage of change (APC, geometric mean) by sex, and by age-group,
by 9 neighboring prefectures
by 4 regions in Fukushima pref.; 1. Evacuated area 2. Hama-dori, 3. Naka-dori and 4. Aizu.
by major primary sites; stomach, colorectum, lung, liver, female breast, cervix, prostate, thyroid and leukemia.
Statistical significance of the trend before and after the earthquake was judged by including 1 in the 95% confidence interval of the APC.
We conducted a t-test on the difference between the average values ​​of the APC before and after the disaster.
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7. Trend of ASIR and ASMR in the 9 neighboring pref., All sites
No clear trend was seen in the 9 neighboring prefectures.
Male
Female
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8. AAPC in Fukushima All sites (Male) All sites (Female)
After-to-before ratio of AAPC 1.01 ( )
After-to-before ratio of AAPC 1.04 ( )
ASIR of all sites in Fukushima leveled off from 2008 to 2015 in male. In female, ASIR of colorectal cancer increased significantly after the accident.
No significant increasing or decreasing trend for both before and after the earthquake
No significant difference between before and after the earthquake
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9. ASIR (/100,000, <80 yrs) Fukushima EA Hama-dori Nakadori Aizu
Quality Indicator has been stable (DCN9.2%, DCO1.6%, M/I=0.44, in 2015) since a decade in Fukushima.
By region, 4. Aizu showed the highest ASIR, followed by 3. Naka-dori, 2. Hama-dori and the 1. EA.
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10. ASIR (Male, /100,000, <80 yrs) Fukushima EA Hama-dori Nakadori Aizu
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11. ASIR (Female, /100,000, <80 yrs)
Fukushima EA
Hama-dori
Nakadori
Aizu
ASIR (Female, /100,000, <80 yrs)
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12. Male Female APC Before APC After
Difference before and after the earthquake
Male
All sites →
N.S.
Stomac
Colo-rectum
→ ↑ (1. EA, AAPC=1.12)
Lung
Liver
Prostate
Thyroid
Leukaemia
Female
→ ↑ (Fukushima, AAPC=1.05)
Significant (Fukushima, AAPC ratio=1.07)
→ ↓ (4. Aizu, AAPC=0.79)
Breast
Cervix
↓ (Fukushima, AAPC=0.95)
Increase in ASIR of colorectal cancer (EA) observed in male before the accident, and decreasing trend observed in liver (Aizu) in female before the accident
No statistically significant change of APC before and after the accident
In the entire prefecture of Fukushima, ASIR of some tumor sites (colo-rectum and thyroid), showed increasing or decreasing trend, and APC demonstrated a significant change in Colorectal cancer.
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13. Discussion
The areas closest to the nuclear power plant (1. EA and 2. Hama-dori) showed the lowest ASIR. The furthest area (4. Aizu) had originally higher ASIR.
We only observed original geographical gaps in cancer incidence and a probable effect of organized screening programs for thyroid cancers in the figures.
Limitations
Address at diagnosis according to self-reporting of the patients
Limited statistical methods due to the short observation period
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