Abstract
Background: For very-rare cancers such as pheochromocytoma and paraganglioma (PPGL), center-level case volume is uniformly low, rendering the traditional volume-outcome paradigm uninformative. This study examines whether cancer programs' institutional resources, after adjusting for tumor-specific case volume, impact overall survival (OS) after surgery. Methods: The 2004-2021 National Cancer Database was queried for patients with a diagnosis of PPGL with malignant potential. Demographics, clinicopathologic characteristics, socioeconomic status, and treatment and survival variables-together with program resource tier (high resource = Academic/Research + Comprehensive Community Cancer Programs; low resource = Community Cancer + Integrated Network Programs), were extracted. IPW-Cox proportional hazard model and survival analysis were performed. Results: 1306 patients were identified, of whom 1066 (81.6%) were treated at high-resource programs. Mean age was 59.0 years and 55.1% were female (n = 719). Median follow-up was 61.7 months (maximum 207 months). Mortality was 28.3% (n = 278). Age, race, median income, tumor size, and surgical approach did not differ by resource tier. Patients treated at high- vs. low-resource programs differed by Charlson- Deyo score (p = 0.008), gender (p = 0.033), insurance status (p = 0.004), and distance traveled to facility (p < 0.001). On adjusted survival analysis, treatment at a high-resource program was associated with improved OS (HR = 0.64, p = 0.043) and a mean survival advantage of 23 months (p = 0.009) vs. a low-resource program. Age (HR = 1.03), tumor size >10 cm (HR = 4.18), and metastasis (HR = 4.17) independently predicted worse OS. Conclusions: Despite uniformly low PPGL case volumes nationally, treatment at high-resource cancer programs was associated with a 23-month longer mean survival and a 36% lower risk of death compared with low-resource cancer programs. Further studies are needed to identify the specific institutional factors that drive this survival advantage in rare cancers.