Saurabh Chandan, MD1, Babu P. Mohan, MBBS, MD2, Lauren M. Keim, MD1, Shahab R. Khan, MBBS3, Mariajose Rojas DeLeon, MD4, Daryl Ramai, MD5, Mohammad Bilal, MD6, Sumant Arora, MD7, Ishfaq Bhat, MD1, Shailender Singh, MD1, Lokesh K. Jha, MD4, Neil Sharma, MD4; 1University of Nebraska Medical Center, Omaha, NE; 2University of Utah, Salt Lake City, UT; 3Rush University Medical Center, Chicago, IL; 4Parkview Health, Fort Wayne, IN; 5The Brooklyn Hospital Medical Center, Brooklyn, NY; 6Center for Advanced Endoscopy, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA; 7University of Iowa Hospitals and Clinics, Iowa City, IA
Introduction: Increased use of cross-sectional imaging in recent years has led to a concomitant increase in the incidence of pancreatic lesions, including pancreatic neuroendocrine tumors (PNET). While curative resection may be performed for large or symptomatic hormone-producing PNET, this carries a significant risk of morbidity and mortality. Optimal management strategy for small asymptomatic non-functional/NF-PNET is not well established. We conducted a systematic review and meta-analysis to compare outcomes of surgical resection versus surveillance in patients with NF-PNET < 2 cm. Methods: We conducted a comprehensive search of several databases from inception to May 2020. Only randomized clinical trials comparing outcomes of interest were included. Pooled estimates were calculated using the random-effects model. Results: Six studies with a total of 681 patients (332 males and 349 females) were included in the final analysis. Resection cohort included 350 patients and surveillance cohort included 331 patients. Mean follow up time was 34.8-73 months and 31.1-52.5 months while tumor size ranged from 7.7-12 mm and 11.5-16.4 mm in surveillance and resection cohorts, respectively. Pooled rate of mortality was 1.1% (CI 0.4-3.4; I2=0) and 1.6% (CI 0.6-3.9; I2=0) in the surveillance and resection cohorts, respectively. Pooled rate of metastasis was 2.2% (CI 0.5-9.6; I2=51) and 4.3% (CI 1.7-10.6; I2=46) in the surveillance and resection cohorts, respectively. The difference between the two cohorts for both events was not statistically significant (p=0.9). Pooled odds of mortality was 0.99 (CI 0.2-4.6; I2=0) and of metastasis was 1.2 (CI 0.36-4.1; I2=0), Figure(s) 1-2. Pooled rate of tumor growth in the surveillance cohort was 6.9% (CI 2.2-19.2; I2=78.5) and of tumor recurrence in the resection cohort was 2.6% (CI 1.1-6.2; I2 =17). The most common post-surgical adverse event was pancreatic fistulae occurring in 92 (26.2%) patients. On meta-regression analysis, tumor location did not appear to have any significant effect on rates of overall mortality, metastasis, tumor growth or recurrence. Discussion: Our study demonstrates that surveillance is a safe and effective management strategy for NF-PNET < 2 cm. This is especially important given the risk of post-operative complications and overall morbidity associated with surgery. Further studies are needed to determine the optimal surveillance imaging modality for these patients.
Figure 1: Forest Plot for mortality: resection versus observation
Figure 2: Forest Plot for metastasis: resection versus observation
Disclosures: Saurabh Chandan indicated no relevant financial relationships. Babu Mohan indicated no relevant financial relationships. Lauren Keim indicated no relevant financial relationships. Shahab Khan indicated no relevant financial relationships. Mariajose Rojas DeLeon indicated no relevant financial relationships. Daryl Ramai indicated no relevant financial relationships. Mohammad Bilal indicated no relevant financial relationships. Sumant Arora indicated no relevant financial relationships. Ishfaq Bhat indicated no relevant financial relationships. Shailender Singh indicated no relevant financial relationships. Lokesh Jha indicated no relevant financial relationships. Neil Sharma indicated no relevant financial relationships.