Clinicopathologic characteristics of pancreatic neuroendocrine tumors and relation of somatostatin receptor type 2A to outcomes
Kosuke Okuwaki, Mitsuhiro Kida, Tetuo Mikami, Hiroshi Yamauchi, Hiroshi Imaizumi, Shiro Miyazawa, Tomohisa Iwai, Miyoko Takezawa, Makoto Saegusa, Masahiko Watanabe, Wasaburo Koizumi, Kosuke Okuwaki, Mitsuhiro Kida, Tetuo Mikami, Hiroshi Yamauchi, Hiroshi Imaizumi, Shiro Miyazawa, Tomohisa Iwai, Miyoko Takezawa, Makoto Saegusa, Masahiko Watanabe, Wasaburo Koizumi
Abstract
Background: The impact of somatostatin receptor type 2 (SSTR-2a) expression levels on outcomes in patients with pancreatic neuroendocrine tumors (PNETs) has not been evaluated.
Methods: Correlations between clinicopathologic characteristics, including SSTR-2a expression and outcomes, were retrospectively studied in 79 patients with pancreatic neuroendocrine tumors (PNETs).
Results: The SSTR-2a score was 0 in 27% of patients, 1 in 24% of patients, 3 in 30% of patients, and 4 in 18% of patients. The overall survival rate was 87% at 1 year, 77% at 3 years, and 71% at 5 years. On univariate analysis, a pancreatic tumor that measured ≥ 20 mm in greatest dimension, stage IV disease, vascular invasion, neuroendocrine carcinoma (NEC), and an SSTR-2a score of 0 were associated significantly with poor outcomes. On multivariate analysis, NEC (P = .000; hazard ratio, 28.8; 95% confidence interval, 7.502-111.240) and an SSTR-2a score of 0 (P = .001; hazard ratio, 3.611; 95% confidence interval, 1.344-9.702) were related independently to poor outcomes.
Conclusions: The current analysis of prognostic factors in patients with PNETs demonstrated that NEC and an SSTR-2a score of 0 both were significant independent predictors of poor outcomes. The results suggest that the assessment of SSTR-2a may facilitate the selection of treatment regimens and the prediction of outcomes. Because a considerable proportion of patients with NEC have SSTR-2a-positive tumors, further analyses of the usefulness of somatostatin analogues are warranted in patients who have SSTR-2a-positive NEC.
Keywords: 2010 World Health Organization classification; SSTR-2a; neuroendocrine tumor; pancreatic neuroendocrine tumors; somatostatin receptor type 2A.
© 2013 American Cancer Society.
Source: PubMed