Utilization and Treatment Patterns of Cytoreduction Surgery and Intraperitoneal Chemotherapy in the United States.

INTRODUCTION: Cytoreductive surgery (CRS) and intraperitoneal chemotherapy (IPC) is an effective treatment option for selected patients with peritoneal metastases (PM), but national utilization patterns are poorly understood. The objectives of this study were to (1) describe population-based trends in national utilization of CRS/IPC; (2) define the most common indications for the procedure; and (3) characterize the types of hospitals performing the procedure.

METHODS: The National Inpatient Sample (NIS) was used to identify patients from 2006 to 2015 who underwent CRS/IPC, and to calculate national estimates of procedural frequency and oncologic indication. Hospitals performing CRS/IPC were classified based on size and teaching status.

RESULTS: The estimated annual number of CRS/IPC cases increased significantly from 189 to 1540 (p < 0.001). Overall, appendiceal cancer was the most common indication (25.7%), followed by ovarian cancer (23.3%), colorectal cancer (22.5%), and unspecified PM (15.0%). Remaining cases (13.5%) were performed for other indications. Most cases were performed in large teaching hospitals (65.9%), compared with smaller teaching hospitals (25.1%), large non-teaching hospitals (5.3%), or small non-teaching hospitals (3.2%). Patients were more likely to undergo CRS/IPC without a diagnosis based on level I evidence (appendiceal, ovarian, or colorectal) at large non-academic hospitals (odds ratio 2.00, 95% confidence interval 1.18-3.38, p = 0.010) compared with large academic hospitals.

CONCLUSIONS: Utilization of CRS/IPC is increasing steadily in the US, is performed at many types of facilities, and often for a variety of indications that are not supported by high-level evidence. Given associated morbidity of CRS/IPC, a national registry dedicated to cases of IPC is necessary to further evaluate use and outcomes.