10203- COT-21 DIFFERENCES IN THE RISK OF BRAIN TUMOR OCURRENCE ACCORDING TO REGIONAL DIFFERENCES AND EMPLOYMENT HISTORY

Abstract We investigated the relationship between occupational history and regional differences in the risk of brain tumor occurrence using the Inpatient Clinico-Occupational Database of the Rosai Hospital Group. 8546 patients hospitalised with primary brain/spinal cord tumors excluding metastatic brain/spinal cord tumors from 1996 to 2021 at the Rosai Hospital Group were included. Patients were divided into two groups: ICD codes for ‘malignant’ tumors (malignant group) and benign and other ICD codes (non-malignant group), and patient backgrounds, occupational classification (current occupation) and regional characteristics were compared. 2448 patients in the malignant group and 6098 patients in the non-malignant group. Comparing the patient backgrounds of the two groups, the age at admission was higher in the malignant group and the proportion of women was higher in the non-malignant group. There was no correlation with history of smoking, alcohol and medical history. With regard to the proportion of occupational categories (current occupation) in each group, Agricultural workers were significantly more in the malignant group. (P=0.0001, Odds ratio: 1.820; 1.328 to 2.488) Also, regarding regional differences, in the majority of regions the non-malignant group had approximately 1.2-2.5 times as many cases as the malignant group, while in the Kanto region the non-malignant group had approximately five times as many cases as the malignant group (2618 vs 518, p<0.0001)The present study suggests an association between agricultural workers and the malignant group. Although there have been previous reports on the association between agricultural workers and brain tumours, none have noted an association between agricultural workers and ‘malignant’ brain/spinal cord tumours. With regard to regional characteristics, the number of cases in the non-malignant group was overwhelmingly higher in the Kanto region. This could be due to differences in the number of hospitals, characteristics between hospitals, surgeons, MRI coverage and asymptomatic lesion detection rates.