Specific Growth Rate as a Predictor of Survival in Pancreatic Neuroendocrine Tumors: A Multi-institutional Study from the United States Neuroendocrine Study Group

• Authors: Jordan J Baechle, Vanderbilt University; Paula M Smith, Vanderbilt University; Marcus Tan, Vanderbilt University; Carmen C Solorzano, Vanderbilt University; Alexandra G Lopez-Aguiar, Emory University; Mary Dillhoff, Ohio State University; Eliza W Beal, Ohio State University; George Poultsides, Stanford University; Elefherios Makris, Stanford University; Flavio G Rocha, Virginia Mason Medical Center; Angelena Crown, Virginia Mason Medical Center; Clifford Cho, University of Michigan; Megan Beems, University of Michigan; Emily R Winslow, University of Wisconsin; Victoria R Rendell, University of Wisconsin, Madison; Bradley A Krasnick, Washington University; Ryan Fields, Washington University; Shishir Maithel, Emory University; Christina E Bailey, Vanderbilt University; Kamran Idrees, Vanderbilt University
• Journal Title: ANNALS OF SURGICAL ONCOLOGY
• Volume: Volume 27, Number 10
• Publisher: SPRINGER | 2020-04-23, Pages 3915-3923
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1245/s10434-020-08497-4
• Subjects: Health Sciences, Medicine and Surgery
• Keywords: Science & Technology; Life Sciences & Biomedicine; Oncology; Surgery; DOUBLING TIME; CLINICAL-COURSE; RISK-FACTORS; MANAGEMENT; SURGERY; CANCER; PROGNOSIS; NEOPLASMS; MENIN; TERM

Abstract

Background: Pancreatic neuroendocrine tumors (PNETs) are often indolent; however, identifying patients at risk for rapidly progressing variants is critical, particularly for those with small tumors who may be candidates for expectant management. Specific growth rate (SGR) has been predictive of survival in other malignancies but has not been examined in PNETs. Methods: A retrospective cohort study of adult patients who underwent PNET resection from 2000 to 2016 was performed utilizing the multi-institutional United States Neuroendocrine Study Group database. Patients with ≥ 2 preoperative cross-sectional imaging studies at least 30 days apart were included in our analysis (N = 288). Patients were grouped as “high SGR” or “low SGR.” Demographic and clinical factors were compared between the groups. Kaplan–Meier and log-rank analysis were used for survival analysis. Cox proportional hazard analysis was used to assess the impact of various clinical factors on overall survival (OS). Results: High SGR was associated with higher T stage at resection, shorter doubling time, and elevated HbA1c (all P ≤ 0.01). Patients with high SGR had significantly decreased 5-year OS (63 vs 80%, P = 0.01) and disease-specific survival (72 vs 91%, P = 0.03) compared to those with low SGR. In patients with small (≤ 2 cm) tumors (N = 106), high SGR predicted lower 5-year OS (79 vs 96%, P = 0.01). On multivariate analysis, high SGR was independently associated with worse OS (hazard ratio 2.67, 95% confidence interval 1.05–6.84, P = 0.04). Conclusion: High SGR is associated with worse survival in PNET patients. Evaluating PNET SGR may enhance clinical decision-making, particularly when weighing expectant management versus surgery in patients with small tumors.