OBJECTIVES: This study aimed to reveal the geographic pattern of hospital selection among cancer inpatients in Japan, focusing on the existence of designated regional cancer hospitals (DRCHs) in the secondary healthcare service areas (SHSAs) of patients' residence.METHODS: We combined the individual data from the Patient Survey and Survey of Medical Institutions carried out by the Ministry of Health, Labour and Welfare, Japan, in 2011, and added information about SHSAs and DRCHs to the combined data set. We categorized the inpatients' hospital selection into four patterns: within the municipality they lived in, out of the municipality but within the SHSA they lived in, out of the SHSA but within the prefecture they lived in, and out of the prefecture they lived in. Additionally, we categorized the location of the cancer inpatients' residence into two groups: living in an SHSA with a DRCH, or living in an SHSA without a DRCH. Subsequently, we descriptively analyzed the relationship between the hospital selection pattern and geographical area where the patients lived. In addition to cancer, the analyzed disease groups included all-cause diseases, diabetes mellitus, and cardiovascular diseases.RESULTS: The estimated number of cancer inpatients was 132,700, 47.6% of whom selected a hospital within the municipality they lived in. The percentage of selecting hospitals out of their SHSA was 27.5%, 18.2%, and 20.1% for patients with cancer, diabetes mellitus, and cardiovascular diseases, respectively (P<0.01). Inpatients who selected geographically farther hospitals tended to be younger. Further, 114,200 cancer inpatients lived in an SHSA with a DRCH, accounting for 86.5% of all cancer inpatients. It was revealed that inpatients living in the SHSAs with a DRCH were less likely to select hospitals out of the SHSA they lived in, than were those living in the SHSAs without a DRCH (23.2% and 55.1%, respectively, P<0.01). Inpatients living in the SHSAs with a DRCH were more likely to select a DRCH, than were those living in the SHSAs without a DRCH (40.6% and 28.9%, respectively, P<0.01).CONCLUSION: Cancer inpatients tended to select hospitals out of the SHSA they lived in than did inpatients with other diseases. The pattern of hospital selection among cancer inpatients was associated with whether they lived in SHSAs with or without a DRCH, as well as with patients' age and cancer sites. It is possible that the existence of a DRCH in the neighborhood affects inpatients' accessibility to standard cancer care.