Relations between Radiotherapy Resources and Breast CancerPatient Survival Rates

In Japan, the number of patients that have been treated with radiotherapy (RT), particularly those withbreast cancer, has increased in the past decade, and is expected to double in the next decade. There is, however, ashortage of RT resources, particularly personnel, which represents a social problem. The shortage of RT resourcesmight cause a difference in survival rate among treated patients. This study analyzed the characteristics of RTresources in RT facilities from Osaka based on the Japanese Society for Therapeutic Radiology and Oncology(JASTRO) database with principle component analysis and cluster analysis. In addition, the relation between RTresources and treatment outcome of breast cancer patients was investigated by linking together Osaka CancerRegistry (OCR) and JASTRO data via a stratified key cord. By using the linked dataset it was shown that theprognosis of breast cancer patients was highly correlated with the scale of RT resources available at the RTfacilities collaterally. From cluster analysis, four groups were identified based on RT facility information. Thebreast cancer survival rates for localized stage patients obtained in classified hospital groups showed a similarpattern, however, large differences (up to 20%) were seen in regional stage patients. Additional findings were:RT facilities with less than 1 radiation oncologist had the poorest outcome; RT was performed primarily atUniversity hospitals; and differences in RT resources within the RT facilities had an effect on breast cancerpatient prognosis in Osaka, Japan.