Relations between radiotherapy resources and breast cancer patient survival rates.

In Japan, the number of patients that have been treated with radiotherapy (RT), particularly those with breast cancer, has increased in the past decade, and is expected to double in the next decade. There is, however, a shortage of RT resources, particularly personnel, which represents a social problem. The shortage of RT resources might cause a difference in survival rate among treated patients. This study analyzed the characteristics of RT resources 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 RT resources and treatment outcome of breast cancer patients was investigated by linking together Osaka Cancer Registry (OCR) and JASTRO data via a stratified key cord. By using the linked dataset it was shown that the prognosis of breast cancer patients was highly correlated with the scale of RT resources available at the RT facilities collaterally. From cluster analysis, four groups were identified based on RT facility information. The breast cancer survival rates for localized stage patients obtained in classified hospital groups showed a similar pattern, 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 at University hospitals; and differences in RT resources within the RT facilities had an effect on breast cancer patient prognosis in Osaka, Japan.