Who Undergoes Cytoreductive Surgery and Perioperative Intraperitoneal Chemotherapy for Appendiceal Cancer? An Analysis of the National Cancer Database.

ABSTRACT

BACKGROUND: We sought to identify patterns of care for patients with appendiceal cancer and identify clinical factors associated with patient selection for multimodality treatment, including cytoreductive surgery and perioperative intraperitoneal chemotherapy (CRS/PIC). MATERIALS AND METHODS: National Cancer Database (NCDB) data from 2004 to 2014 of all diagnoses of appendiceal cancers were examined. We examined treatment modalities, as well as demographic, tumor-specific, and survival data. A multivariate logistic regression analysis was performed to determine the patient cohort most likely to receive CRS/PIC. Kaplan-Meier was used to estimate survival for all treatment groups. Significance was evaluated at P ≤ 0.05. RESULTS: We analyzed data on 18,055 patients. Nine thousand nine hundred ninety-two (55.3%) were treated with surgery only, 5848 (32.4%) received surgery and systemic chemotherapy, 1393 (7.71%) received CRS/PIC, 520 (2.88%) received chemotherapy alone, and 302 (1.67%) received neither surgery nor chemotherapy. Significant predictors of receiving CRS/PIC included male sex (OR 1.33, 95% CI 1.11-1.59), white race (OR 2.00, 95% CI 1.40-2.86), non-Hispanic ethnicity (OR 1.92, 95% CI 1.21-3.05), private insurance (OR 1.52, 95% CI 1.26-1.84), and well-differentiated tumors (OR 4.25, CI 3.39-5.32) (P < 0.05). Treatment with CRS/PIC was associated with a higher 5-year survival for mucinous malignancies, when compared to surgery alone (65.6% versus 62.4%, P < 0.01). Treatment with CRS/PIC was also associated with higher 5-year survival for well-differentiated malignancies, when compared to all other treatment modalities (74.9% versus 65.4%, P < 0.01). CONCLUSIONS: Patients were more likely to undergo CRS/PIC if they were male, white, privately insured, and with well-differentiated tumors. CRS/PIC was associated with improved survival in patients with mucinous and low-grade tumors.