Value of both WHO and TNM classification systems for patients with pancreatic endocrine tumors: results of a single-center series

Abstract

Objectives: This study was designed to evaluate the clinical relevance of the World Health Organization (WHO) and tumor node metastasis (TNM) classifications in patients affected by pancreatic endocrine tumors.

Methods: Data from 76 consecutive patients with pancreatic endocrine tumors who underwent surgery were analyzed.

Results: Well-differentiated tumors were observed more frequently (57.9%) than well or poorly differentiated carcinomas (26.3% and 15.8%, respectively). The TNM stage was I in 27.6%, II in 39.5%, III in 19.7%, and IV in 13.2%. Univariate analysis of disease-specific survival showed that patients with stages I-II had a significantly better survival rate than those with stages III-IV (hazard ratio (HR), 12.46; 95% confidence interval (CI), 1.53-101.32; P = 0.018; HR, 25.74; 95% CI, 3.07-216.07; P = 0.003, respectively). Regarding the WHO classification, poorly differentiated carcinomas had the worst prognosis (HR, 79.13; 95% CI, 9.99-626.60; P < 0.001). Multivariate Cox regression analysis of disease-specific survival showed that the WHO classification is the only independent factors of improved survival: both poorly and well-differentiated carcinomas had an increased risk of death compared with WDTs (HR, 100.42; 95% CI, 12.16-829.40; P < 0.001; HR, 10.73; 95% CI, 1.12-104.17; P = 0.040, respectively). TNM classification and the WHO system are highly correlated (P < 0.001).

Conclusions: TNM stage and the WHO classification seems to be equally reliable, even if TNM classification tends to understage the patients classified using the WHO system.