Unplanned Readmission among Patients with Advanced Cancer on Active Treatment: Multi-Center, Retrospective Study

Purpose Unplanned readmissions of patients with cancer increase healthcare costs and disrupt care. Although well-studied in surgical oncology, data on patients receiving active treatment for advanced cancer remain limited. This study examined the causes, clinical characteristics, and outcomes of unplanned readmissions. Materials and Methods This retrospective, multicenter study included patients with advanced solid tumors from six South Korean university hospitals who had unplanned readmissions within 1 month of prior hospitalization in 2019. Patients with terminal cancer who did not receive active treatment were excluded. Readmissions were categorized as Cancer Progression (e.g., worsening symptoms), treatment-related (e.g., therapy complications), or other (e.g., non-cancer conditions). Additional unplanned hospital use within 1 month post-discharge was analyzed in survivors with 6-month follow-up data. Results Among the 542 patients, readmissions were classified as cancer progression (42.6%), treatment-related (37.3%), or other (20.1%). The cancer progression group had the longest hospital stay (median, 12 days) and the highest mortality (23.4%). The Treatment-Related group had shorter stays (8 days) and lower mortality (8.4%). Among the 445 survivors, 24.9% had unplanned hospital visits within 1 month post-discharge. Home discharge increased the likelihood of these events (adjusted odds ratio: 4.82 for readmissions, 2.65 for emergency department visits). Conclusion Cancer progression was the leading cause of readmission and was associated with prolonged hospital stays and high mortality rates. Home discharge is a key predictor of early additional unplanned hospital visits, indicating the need for careful post-discharge monitoring in this population.