Bayesian Mapping of Cancer Mortality in Japan: A Small Area Analysis

1. Bayesian Mapping of Cancer Mortality in Japan: A Small Area Analysis Megumi Hori1, Eiko Saito1, Tomoki Nakaya2, Kota Katanoda1 1 Division of Cancer Statistics Integration, Center for Cancer Control & Information Services, National Cancer Center, Japan 2 Department of Frontier Sciences for Advanced Environment, Graduate School of Environmental Studies, Tohoku University, Japan

2. Motivation - 1 Geographic disparities in incidence and mortality of cancer In Japan, Cancer incidence and mortality have large variation across prefectures. Incidence in 2015Mortality in 2015 All cancer, Males All cancer, Males ≧120 ≧120 100 - 120 100 - 120 SMR SIR 80 - 100 80 - 100 ＜80 ＜80

3. Motivation - 1 Monitoring of disparities by small areas The pattern of exposure to cancer risk has differed across smaller units than prefectures. • Education, occupation and general lifestyle behaviors(ie, dietary patterns, physical activity and smoking status) may vary by small regions • Population-based screening programs have been conducted by municipal authorities(wards, cities, towns, and villages), with government support The number of prefecturesand municipalitiesin Japan, 2015

4. Motivation - 2 Reliability in small population statistics General issues of small-area estimation • extreme risks might be shown in low populated areas • significant risks tend to be shown in highly populated areas • areas next to each other might show completely opposite risks Bayesian approach has been widely used since the 2000’s and has proved to be robust • borrowing information from neighboring areas with a spatial smoothing process • enabling to generate more stable and accurate estimates of rates for geographic areas

5. Aim To promote a better understanding the geographic disparities To estimate the small-area cancer mortality based on Bayesian approach To develop an interactive mapping tool for cancer mortality

6. Data Sources Using open data and GIS Mortality and population • Vital statistics in Japan • Between 2008-2012 • By municipality • By sex (Male, Female) • By site (stomach, colon, liver and lung）**only for mortality Available from: https://www.e-stat.go.jp/stat-search/files?page=1&layout=datalist&toukei=00450013&tstat=000001063680&cycle=0&cycle_facet=cycle&second=1&second2=1&tclass1val=0 GIS data and map in Japan • ESRI shapefiles data • For municipality boundarymap Available from: https://www.esrij.com/products/japan-shp/

7. Method-1 Empirical Bayes estimation of SMR Empirical Bayesian(EB) approach with nearest neighbor procedure • Hyperparameters were estimated by the MLE method.  :municipality : 10-nearest neighbors of municipality , : standardized mortality ratio based on EB approach for , : observed number of cancer death, : expected number of cancer death , : hyperparameters, : weights reflecting the population size of , where : standardized mortality ratio for , where

8. Method-2 Interactive mapping tool for cancer mortality Interactive mapping tool for cancer mortality Features of the tool • Create and customize municipality level of cancer mortality • number, rate, age-adjusted rate, standardized rate • by year, site, gender, • View graph and report data by area • Download the data • as a csv file, including GIS file (shapefile ) • Show the location of hospitals

9. Results - A1 Empirical Bayes Estimate of SMR: All cancer Cancer mortality varied at the municipality level even within same prefecture. Japan Prefectures Map high Male Female Hokkaido and Tohoku Region Hokkaido and Tohoku Region low

10. Results - A2 Empirical Bayes Estimate of SMR : Stomach cancer Large spatial variation in stomach cancer mortality. Higher rates were seen in the Western part of Tohoku region. Japan Prefectures Map high Male Female Hokkaido and Tohoku Region Hokkaido and Tohoku Region low

11. Results - A3 Empirical Bayes Estimate of SMR : Lung cancer SMR of lung cancer varied at the smaller area unit. For female, higher SMRs were seen in urban areas. Japan Prefectures Map high Male Female Chugoku Region Chugoku Region low

12. Results - A4 Empirical Bayes Estimate of SMR : Liver cancer Higher rates were seen in the Western Japan. Especially, SMRs were high on the sea side. Japan Prefectures Map high Male Female Kinki Region Kinki Region low

13. Results – B1 Interactive mapping tool for cancer mortality Prefecture-level map • Report data • by prefecture • Bar graph • by prefecture

14. Results – B2 Interactive mapping tool for cancer mortality Municipality-level map • Location of designated • cancer care hospitals • Bar graph • by municipality

15. Results – B3 Interactive mapping tool for cancer mortality Municipality-level map • Changing • the base map

16. Discussion We showed small-area variation in cancer mortality by mapping visualization based on Bayesian estimation. The Japanese government introduced a national cancer registry (NCR) in 2016 and started providing the data in 2018 • NCR enables us to obtain highly reliable incidence data • We will be able to develop an interactive mapping tool that show small-area cancer incidence The empirical Bayesian mapping will be useful for planning more focused cancer control policies. Enter your footer text here

17. Thank you for your attention! E-mail: mhori@ncc.go.jp