Impact of tumour size on metastasis and survival in patients with pancreatic neuroendocrine tumours (PNETs): A population based study

Larger Tumor Size and Elevated Serum Chromogranin A Levels Predict Metastatic Disease on DOTATATE Imaging in Patients with Gastroenteropancreatic Neuroendocrine Tumors

PURPOSE

DOTATATE PET/CT (DOTATATE) is superior to conventional imaging in detecting metastasis for gastroenteropancreatic neuroendocrine tumors (GEP-NETs). However, limited availability, high-cost, and additive radiation exposure necessitate guidelines for its use. This study seeks to investigate the relationship between clinical characteristics and metastasis on DOTATATE.

METHODS

This was a retrospective analysis of 815 patients who underwent DOTATATE at UCLA from 2014 to 2022. After applying inclusion and exclusion criteria, the study cohort consisted of 163 patients with pathologically diagnosed GEP-NETs, who either underwent primary tumor resection within 1-year prior, or had not undergone resection at the time of DOTATATE imaging. The presence of metastasis was determined using DOTATATE. Fisher's exact test, chi-squared test, and Mann-Whitney test were conducted to compare intergroup difference. Multivariate analysis was performed to identify clinical characteristics associated with metastasis on DOTATATE.

RESULTS

Of patients with GEP-NETs, 40.5% (n = 66) were diagnosed with metastases by using DOTATATE. Those with metastatic disease were more likely to exhibit a larger primary tumor size (median 3.4 vs. 1.2, cm, P < 0.001), elevated serum chromogranin A level (CgA, median 208 vs. 97, mg/ml, P = 0.005), and higher tumor grade (P < 0.001). Primary tumor size ≥2 cm and serum CgA level ≥150 ng/mL for metastatic disease had a sensitivity and specificity of 64% and 89%, and 72% and 59%, respectively. Multivariate analysis demonstrated that primary tumor size (≥2/<2, cm, odds ratio [OR] 47.90, P < 0.001), tumor functionality (functional/nonfunctional, adjusted OR 10.17 P = 0.008), serum CgA level (≥150/<150, ng/ml, OR 6.25, P = 0.005), and tumor grade G2 (G2/G1, OR 9.6, P < 0.001) were independently associated with metastases on DOTATATE.

CONCLUSIONS

Among patients with GEP-NETs, primary tumor size ≥2 cm, serum CgA level ≥150 ng/mL, and tumor grade G2 are associated with an increased risk of metastases on DOTATATE, and these predictors may be helpful to identify patients where DOTATATE is indicated for complete staging.

Establishment of a nomogram model for predicting distant metastasis in pancreatic ductal adenocarcinoma: a comparative analysis of different lymph node staging systems based on the SEER database

The purpose of this study was to compare the predictive value of different lymph node staging systems and to develop an optimal prognostic nomogram for predicting distant metastasis in pancreatic ductal adenocarcinoma (PDAC). Our study involved 6364 patients selected from the Surveillance, Epidemiology, and End Results (SEER) database and 126 patients from China. Independent risk factors for distant metastasis were screened by univariate and multivariate logistic regression analyses, and a model-based comparison of different lymph node staging systems was conducted. Furthermore, we developed a nomogram for predicting distant metastasis using the optimal performance lymph node staging system. The lymph node ratio (LNR), log odds of positive lymph nodes (LODDS), age, primary site, grade, tumor size, American Joint Committee on Cancer (AJCC) 7th Edition T stage, and radiotherapy recipient status were significant predictors of distant metastasis in PDAC patients. The model with the LODDS was a better fit than the model with the LNR. We developed a nomogram model based on LODDS and six clinical parameters. The area under the curve (AUC) and concordance index (C-index) of 0.753 indicated that this model satisfied the discrimination criteria. Kaplan-Meier curves indicate a significant difference in OS among patients with different metastasis risks. LODDS seems to have a superior ability to predict distant metastasis in PDAC patients compared with the AJCC 8th Edition N stage, PLN and LNR staging systems. Moreover, we developed a nomogram model for predicting distant metastasis. Clinicians can use the model to detect patients at high risk of distant metastasis and to make further clinical decisions.

Hyperthermia Reduces Irradiation-Induced Tumor Repopulation in an In Vivo Pancreatic Carcinoma Model

Pancreatic cancer has a poor prognosis due to its aggressive nature and ability to metastasize at an early stage. Currently, its management is still a challenge because this neoplasm is resistant to conventional treatment approaches, among which is chemo-radiotherapy (CRT), due to the abundant stromal compartment involved in the mechanism of hypoxia. Hyperthermia, among other effects, counteracts hypoxia by promoting blood perfusion and thereby can enhance the therapeutic effect of radiotherapy (RT). Therefore, the establishment of integrated treatments would be a promising strategy for the management of pancreatic carcinoma. Here, the effects of joint radiotherapy/hyperthermia (RT/HT) on optimized chick embryo chorioallantoic membrane (CAM) pancreatic tumor models are investigated. This model enables a thorough assessment of the tumor-arresting effect of the combined approach as well as the quantitative evaluation of hypoxia and cell cycle-associated mechanisms by both gene expression analysis and histology. The analysis of the lower CAM allows to investigate the variation of the metastatic behaviors of the cancer cells associated with the treatments. Overall, this study provides a potentially effective combined strategy for the non-invasive management of pancreatic carcinoma.

Clinicopathological Characteristics of Nonfunctional Pancreatic Neuroendocrine Neoplasms and the Effect of Surgical Treatment on the Prognosis of Patients with Liver Metastases: A Study Based on the SEER Database

Background

The incidence of nonfunctional pancreatic neuroendocrine neoplasms (NF-pNENs) has been increasing annually. This study is aimed at investigating the clinicopathological characteristics and high-risk factors of NF-pNENs and the influence of surgical treatment on the prognosis of NF-pNEN patients with liver metastases.

Methods

pNEN patients in this study were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. This study analyzed patients diagnosed with NF-pNENs from 2000 to 2017 who met the inclusion criteria. A retrospective analysis of the clinicopathological characteristics of NF-pNEN patients was conducted. Kaplan-Meier method was used to calculate the survival time. A multivariate Cox regression model was used to analyze the survival outcomes and risk factors.

Results

From 2000 to 2017, the SEER database registered 10576 patients with pNENs and 1774 patients with liver metastases. Cox analysis revealed that age, sex, primary site, grade, tumor stage, surgery, tumor size, and liver metastasis were risk factors of prognosis, with grade being the most influential index. Patients with NF-pNENs with liver metastasis and no metastasis had different primary site, grade, and tumor size. In general, a higher grade was associated with a larger tumor and a greater risk of liver metastasis. Meanwhile, patients with liver metastasis showed that those with tumors originated from the tail of the pancreas had better prognoses than those with tumors originated from other parts. Surgical treatment can improve the prognosis of patients with liver metastases, despite the tumor grade.

Conclusions

The incidence of pNENs has been increasing annually, and the liver has been the most common site of metastasis. Liver metastasis in patients with NF-pNENs, related to tumor size and grade, affected their long-term survival. Surgery significantly improved the prognosis of patients with liver metastases secondary to NF-pNENs with different grades.

Orchestrating Treatment Modalities in Metastatic Pancreatic Neuroendocrine Tumors-Need for a Conductor

Pancreatic neuroendocrine tumors (pNETs) are a vast growing disease. Over 50% of these tumors are recognized at advanced stages with lymph node, liver, or distant metastasis. An ongoing controversy is the role of surgery in the metastatic setting as dedicated systemic treatments have emerged recently and shown benefits in randomized trials. Today, liver surgery is an option for advanced pNETs if the tumor has a favorable prognosis, reflected by a low to moderate proliferation index (G1 and G2). Surgery in this well-selected population may prolong progression-free and overall survival. Optimal selection of a treatment plan for an individual patient should be considered in a multidisciplinary tumor board. However, while current guidelines offer a variety of modalities, there is so far only a limited focus on the right timing. Available data is based on small case series or retrospective analyses. The focus of this review is to highlight the right time-point for surgery in the setting of the multimodal treatment of an advanced pancreatic neuroendocrine tumor.

Insights of Outcome after Resection of Small Nonfunctioning Neuroendocrine Pancreatic Tumors

Background

The incidence of small nonfunctioning neuroendocrine pancreatic tumors (NF-PNETs) has been increasing systematically in the last few decades. Surgical resection was once considered the treatment of choice but has been questioned in the direction of a more conservative approach for selected patients. Our aim was to analyze the outcome of surgical resection of small (≤3cm) NF-PNETs.

Methods

We retrospectively evaluated 14 patients with sporadic NF-PNETs who underwent pancreatic resection. Data were collected from patients' medical records.

Results

Of the 14 patients included, 35.71% were men, and the average age was 52.36 ± 20.36 years. Comorbidities were present in 92.86% of the cases. The incidence of postoperative complications was 42.86%, the 30-day mortality was zero, and the length of follow-up was 3.31 ± 3.0 years. The results of pathological evaluations revealed WHO grade I in 42.86% of cases, II in 21.43%, and neuroendocrine carcinoma in 35.71%. The median tumor size was 1.85cm (range, 0.5–3cm), and 2 cases had synchronous metastasis. The median TNM stage was IIa (range, I–IV). The disease-free and patient survival rates were 87.5% and 100% at 3 years and 43.75% and 75% at 10 years, respectively. The tumor pathological grade was significantly higher in head tumors than body-tail tumors, but there were no differences with respect to tumor size and TNM staging.

Conclusion

A surgical approach to treat small sporadic NF-PNETs is safe with low mortality and high patient survival. Based on these data, small pancreatic head tumors can be more aggressive, suggesting that surgical resection is still the best option to treat small nonfunctioning PNETS. Thus, conservative treatment should be indicated very cautiously for only cases with absolute contraindications for surgery.

Unique Metastatic Patterns in Neuroendocrine Neoplasms of Different Primary Origin

INTRODUCTION

Neuroendocrine neoplasms (NEN) can originate in different organs, for example, the gastroenteral tract (GE), pancreas (Pan), or lungs (L). Our aim was to examine metastatic patterns for patients with NEN of various primary origins with a special focus on brain metastases to indicate utility for screening.

METHODS

All NEN patients except for small cell lung cancer registered in the Netherlands Cancer Registry from 2008 to 2018 were selected. Metastatic patterns at initial diagnosis for NEN with different primary origins were compared. In a subcohort of patients from 2 referral hospitals (2014-2019), additional information on, for example, development of metastases after initial presentation was available.

RESULTS

In the nationwide cohort, 4,768/11,120 (43%) patients had metastatic disease at diagnosis (GE: 1,504/4,710 [32%]; Pan: 489/1,150 [43%]; and L: 1,230/2,978 [41%]). For GE- and Pan-NEN, the most prevalent metastatic site was the liver (25 and 39%), followed by distant lymph nodes (8 and 8%), whereas only few patients with brain metastases were identified (0% in both). In contrast, for L-NEN, prevalence of metastases in the liver (19%), brain (9%), lung (7%), and bone (14%) was more equal. In the reference network cohort, slightly more NEN patients had metastatic disease (260/539, 48%) and similar metastatic patterns were observed.

CONCLUSION

Almost half of NEN patients were diagnosed with synchronous metastatic disease. L-NEN have a unique metastatic pattern compared to GE- and Pan-NEN. Remarkably, an important part of L-NEN metastases was in the brain, whereas brain metastases were almost absent in GE- and Pan-NEN, indicating utility of screening in L-NEN.