Lymph node sampling rates and predictors of nodal metastasis in pancreatic neuroendocrine tumor resections: the UCSF experience with 149 patients.
OBJECTIVE
The decision to perform pancreas-preserving procedures or standard resections for pancreatic neuroendocrine tumors (PNETs) is often based on the perceived risk of malignancy, including potential nodal involvement. We sought to identify clinicopathological factors that predict nodal disease.


METHODS
This is a retrospective review of pathology database for PNET resections from January 1, 1988, to March 15, 2010. Univariate analysis and multivariate logistic regression were used to identify predictors of nodal metastasis.


RESULTS
A total of 149 patients were identified. Enucleations had lower lymph node sampling rates compared to major resections. Excluding enucleations, 23% of patients had no lymph nodes sampled. For patients who did have lymph nodes evaluated, a median of 5 lymph nodes were examined. On multivariate analysis, only distant disease predicted nodal metastasis (odds ratio = 3.80, P = 0.02); tumor size did not (P = 0.48). One third of patients with lymph node metastasis had tumors less than 3 cm.


CONCLUSIONS
Lymph nodes are not evaluated in many major pancreatic resections for PNET, and preoperative prediction of nodal metastasis is difficult, even when tumor size is considered. Consequently, many patients may be understaged and undergo potentially inadequate resection. Inconsistent lymph node sampling may explain conflicting conclusions in the literature regarding the prognostic value of lymph node involvement in PNET patients.
Division of Surgical Oncology, Department of Surgery, University of California, San Francisco, San Francisco, CA, USA.
Justin R
JR
Parekh
Sam C
SC
Wang
Emily K
EK
Bergsland
Alan P
AP
Venook
Robert S
RS
Warren
Grace E
GE
Kim
Eric K
EK
Nakakura
D000328:Adult; D000368:Aged; D016009:Chi-Square Distribution; D003661:Decision Support Techniques; D005260:Female; D006801:Humans; D016015:Logistic Models; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology* / Q000601:surgery*; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D018358:Neuroendocrine Tumors / Q000556:secondary* / Q000601:surgery*; D016017:Odds Ratio; D010180:Pancreatectomy; D010190:Pancreatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D018579:Patient Selection; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012495:San Francisco; D013156:Splenectomy