Presentation Patterns and Treatment Outcomes in Appendix Cancer Patients Traveling to a High-Volume Peritoneal Surface Malignancy Center.

IntroductionMucinous appendix cancer (MAC) treatment is centralized at peritoneal surface malignancy centers (PSMCs), requiring patients to travel for cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS/HIPEC). We compared presentation patterns and outcomes for patients accessing a high-volume PSMC from in-state (I-S) vs out-of-state (O-S).MethodsThis cohort study of MAC patients with peritoneal metastases treated with CRS/HIPEC (1998-2023) used a prospective database. Travel distance, presentation (time from diagnosis [TFD], peritoneal cancer index [PCI], prior surgery score [PSS], and systemic chemotherapy [SCh]), quality (complete cytoreduction [CC-0/1] and grade III/IV Clavien-Dindo complications), and overall survival (OS) were compared between O-S and I-S patients. A hazard ratio (HR) with 95% confidence interval (CI) for 10-year OS was evaluated using Cox regression for O-S travel, adjusting for age, histology, PCI, and prior treatment.ResultsOverall, 369 patients were included: 223 (60.4%) O-S and 146 (39.6%) I-S, with median travel distances of 180 [IQR: 83-729] and 29 [IQR: 14-59] miles, respectively. Compared to I-S, O-S had longer TFD (median: 4.6 vs 2.8 months, P < 0.001), higher PCI (median: 32 vs 24, P = 0.001), and higher rates of PSS-2/3 (40.4% vs 28.6%, P = 0.023) and SCh (31.8% vs 19.2%, P = 0.007). CC-0/1 (84.8% vs 91.4%, P = 0.063) and major complication (15.2% vs 21.4%, P = 0.132) rates were comparable. O-S travel did not affect OS (HR: 1.08 [95% CI: 0.73, 1.61]).ConclusionTraveling to a PSMC is associated with delayed presentation, more advanced disease, and prior treatments. However, quality and survival outcomes remain unaffected. Early referral and support for travel are essential.