Regional Lymphadenectomy Is Indicated in the Surgical Treatment of Pancreatic Neuroendocrine Tumors (PNETs)

Abstract

Objective To explore the prognostic importance and preoperative predictors of lymph node metastasis in an effort to guide surgical decision making in patients with pancreatic neuroendocrine tumors (PNETs). Background PNETs are uncommon, and the natural history of the disease is not well described. As a result, there remains controversy regarding the optimal management of regional lymph nodes during resection of the primary tumor. Methods A retrospective review of a prospectively maintained database of patients who underwent surgery for locoregional PNET between 1994 and 2012 was performed. Logistic regression was used to identify predictors of nodal metastasis. Overall survival (OS) and disease-free survival (DFS) were calculated using Kaplan Meier method. Results were expressed as p- values and odds ratio estimates with 95% confidence intervals. Results One-hundred thirty six patients were identified, of whom 50 (38%) patients had nodal metastasis. The frequency of lymph node metastasis was higher for: larger tumors (> 1.5 cm (OR= 4.7), tumors of the head as compared to body-tail of the pancreas (OR= 2.8), tumors with Ki-67 > 20% (OR= 6.7), and tumors with lymph vascular invasion (OR= 3.6), (p value <0.05). Median DFS was lower for patients with nodal metastases (4.5 v 14.6 years, p < 0.0001). Conclusions Lymph node metastasis is predictive of poor outcomes in patients with PNETs. Preoperative variables are not able to reliably predict patients where the probability of lymph node involvement was less than 12%. These data support inclusion of regional lymphadenectmy in patients undergoing pancreatic resections for PNET.

Clinical outcomes and prognostic factors of resected pancreatic neuroendocrine neoplasms: A single-center experience in China

“…p-NEC exhibits a poor prognosis (24) and previous evidence has demonstrated the decreased survival rate of patients with p-NEC (25,26). Furthermore, increased lymph node metastasis in p-NEC was observed in the present study.…”

Pancreatic Neuroendocrine Tumors: How Much Surgery is Safe?

“…Two recent studies using the SEER tumor registry concluded that lymph node dissection is necessary, to predict the outcome of the patient. Furthermore high grade tumors and large tumors predicted nodal positivity and decreased disease specific survival [19][20]. Our findings support this data: patients with positive lymph nodes had a significantly higher risk for metastases or recurrences.…”

Tissue heterogeneity contributes to suboptimal precision of WHO 2010 scoring criteria for Ki67 labeling index in a subset of neuroendocrine neoplasms of the pancreascriteria for Ki67 labeling index in a subset of neuroendocrine neoplasms of the pancreas

“…Tumour grade was previously considered as a supplementary tool to predict presence of regional lymph node metastases [43,44,45]. In this study, G2/G3 vs. G1 grade showed at best moderate ability to detect pN1 stage.…”

“…This gives lower morbidity but is associated with a risk of metastasis in regional lymph nodes which are not resected (as discussed in [43,44,45]). Risk of LN metastasis in G2 tumours is higher than in G1 [43,44,45], but LN metastasis is not rare in G1 tumours (7.5% [45] -23.1% [43]). …”