Prognostic factors and characteristics of pancreatic neuroendocrine tumors: single center experience

Predictive Factors of Response to Streptozotocin in Neuroendocrine Pancreatic Neoplasms

Pancreatic neuroendocrine neoplasms (Pan-NENs) may exhibit a heterogeneous clinical course, ranging from indolent to progressive/metastatic behavior. In the latter scenario, streptozocin (STZ) is considered the cornerstone of systemic treatment; however, response to STZ-based chemotherapy may vary among individuals. In this narrative review, we aimed to identify the predictive factors of response to STZ in advanced Pan-NENs. We performed an extensive search in international online databases for published studies and ongoing clinical trials evaluating STZ in Pan-NENs. We found 11 pertinent studies evaluating 17 patient-, tumor-, or treatment-related factors. Age, CgA blood levels, tumor grade, Ki-67% index, anatomical location of the primary tumor, tumor stage, site of metastasis origin, liver tumor burden, extrahepatic spread, functional status, O6-methylguanine-methyltransferase (MGMT) status, line of therapy, and response to previous treatments were all statistically associated with radiological response and/or survival. The identified predictors may help clinicians make appropriate treatment decisions, in this way improving clinical outcomes in patients with advanced Pan-NENs.

Combined Infiltrative Macroscopic Growth Pattern and Infiltrative Microscopic Tumor Border Status Is a Novel Surrogate Marker of Poor Prognosis in Patients With Pancreatic Neuroendocrine Tumor

CONTEXT.—

Pancreatic neuroendocrine tumors (PanNETs) are heterogeneous tumors with a wide range of malignant potential. Therefore, identification of prognostic factors is essential.

OBJECTIVE.—

To systematically assess the significance of tumor border, a well-known prognostic indicator in other cancers, in PanNETs.

DESIGN.—

We evaluated the macroscopic growth pattern (expansile [Exp] versus infiltrative [Inf]) and the microscopic tumor border (pushing [Pus] versus Inf) of 203 surgically resected PanNETs and compared them with other clinicopathologic factors.

RESULTS.—

Based on macroscopic growth pattern, 83 cases had Exp patterns whereas 84 had Inf patterns. According to microscopic tumor border, 122 PanNETs had Pus borders whereas 81 had Inf borders. Combining macroscopic growth pattern and microscopic tumor border, 65 PanNETs had Exp/Pus, 34 had Inf/Pus, 18 had Exp/Inf, and 50 had Inf/Inf status. PanNETs with Inf/Inf status were associated with higher tumor grade, pT classification, and American Joint Committee on Cancer stage grouping; lymph node metastasis; and lymphovascular and perineural invasions (all P < .001). Patients with PanNET having Inf/Inf status had significantly shorter overall survival (OS) and recurrence-free survival (RFS; all P < .001). Further, using multivariate analysis, Inf/Inf status was identified as an independent poor prognostic factor of OS (P = .02) and RFS (P = .03).

CONCLUSIONS.—

In summary, combined Inf/Inf status was observed in approximately 25% of PanNETs and was associated with aggressive biological behavior and short OS and RFS. Therefore, assessing combined macroscopic growth pattern and microscopic tumor border can provide additional information regarding survival and recurrence in PanNET patients.

Usefulness of partial splenic embolization for left-sided portal hypertension in a patient with a pancreatic neuroendocrine neoplasm: a case report and review of the literature

Left-side portal hypertension (LSPH) is caused by isolated obstruction of the splenic vein and is associated with esophagogastric varices that extend from the lower esophagus to the greater curvature of the gastric body. Here, we report on a 74-year-old man with a pancreatic neuroendocrine neoplasm (NEN) in the pancreatic tail with multiple liver metastases. We decided that partial splenic embolization (PSE) was the best course of treatment to prevent rupture of the gastric varices, which were classified as markedly enlarged, nodular, or tumor-shaped and showed erosion of the mucosa. After PSE, the patient had no major complications and was discharged. At 3 and 6 months after the procedure, esophagogastroduodenoscopy and enhanced computerized tomography showed that the gastric varices had improved. This case demonstrates the usefulness of PSE for LSPH in patients with unresected pancreatic NEN.

Biliary Neuroendocrine Neoplasms: Analysis of Prognostic Factors and Development and Validation of a Nomogram

Background

For this study, we explored the prognostic profiles of biliary neuroendocrine neoplasms (NENs) patients and identified factors related to prognosis. Further, we developed and validated an effective nomogram to predict the overall survival (OS) of individual patients with biliary NENs.

Methods

We included a total of 446 biliary NENs patients from the SEER database. We used Kaplan-Meier curves to determine survival time. We employed univariate and multivariate Cox analyses to estimate hazard ratios to identify prognostic factors. We constructed a predictive nomogram based on the results of the multivariate analyses. In addition, we included 28 biliary NENs cases from our center as an external validation cohort.

Results

The median survival time of biliary NENs from the SEER database was 31 months, and the value of gallbladder NENs (23 months) was significantly shorter than that of the bile duct (45 months) and ampulla of Vater (33.5 months, p=0.023). Multivariate Cox analyses indicated that age, tumor size, pathological classification, SEER stage, and surgery were independent variables associated with survival. The constructed prognostic nomogram demonstrated good calibration and discrimination C-index values of 0.783 and 0.795 in the training and validation dataset, respectively.

Conclusion

Age, tumor size, pathological classification, SEER stage, and surgery were predictors for the survival of biliary NENs. We developed a nomogram that could determine the 3-year and 5-year OS rates. Through validation of our central database, the novel nomogram is a useful tool for clinicians in estimating individual survival among biliary NENs patients.

Tumour stem cell markers CD133 and CD44 are useful prognostic factors after surgical resection of pancreatic neuroendocrine tumours

The aim of the present study was to investigate the expression profiles and prognostic values of CD133 and CD44 in a cohort of patients with pancreatic neuroendocrine tumours (PNETs). PNET data from patients who underwent radical resection at the Guangdong Provincial People's Hospital were retrospectively analysed. Immunohistochemistry was performed on PNET samples, and CD133 and CD44 expression was examined. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. A total of 71 cases were included in the study. The mean age of the patients was 45.2 years, and the mean tumour size was 3.3 cm. CD44 expression was positively associated with poor tumour differentiation (P=0.007), high Ki-67 index (P=0.001), added mitotic count (P=0.003), high histological grade (P=0.001) and advanced stage (P=0.025). Similarly, CD133 expression was positively associated with high Ki-67 index (P=0.014) and added mitotic count (P=0.012). However, CD133 expression was not associated with tumour differentiation (P=0.118), histological grade (P=0.126) and stage (P=0.203). Survival analysis revealed that both CD44 and CD133 were prognostic factors for overall survival (OS) and/or disease-free survival (DFS), and that increased co-expression of CD44 and CD133 indicated poor OS and DFS rates in patients with PNET. In patients with no expression or low expression of either CD44 or CD133, a DFS rate of 100% was observed, indicating a low recurrence risk. The present findings suggested that high CD44 and CD133 expression was associated with a poor prognosis in patients with PNET. CD44 and CD133 may be used as prognostic indicators of OS and/or DFS in patients with PNETs.

Novel scoring system for recurrence risk classification of surgically resected G1/2 pancreatic neuroendocrine tumors - Retrospective cohort study

BACKGROUND

Existing staging systems for pancreatic neuroendocrine neoplasms only provide accuracy in stratifying disease severity without enough sensitivity in prognosis predicting. Previously presented models mainly set overall survival as endpoint but ignore the importance of recurrence.

METHODS

Univariate and multivariate analyses were retrospectively conducted on the potential prognostic factors of 245 patients who underwent curable surgery of G1/2 pancreatic neuroendocrine tumors from December 2002 to May 2018 in our institute. Proposed model based on statistically significant factors were tested for recurrence risk classification estimation validity as measured by discrimination (receiver operator characteristic [ROC] curve and Harrell's c-index [HCI]) and calibration.

RESULTS

Multivariate analyses found lymph node metastasis, larger tumor size and grade 2 independent risk factors of disease-free survival (DFS). The novel scoring system for recurrence risk classification sorted patients into three groups: score<15.4 for low risk (79.0%, 3- and 5-year recurrence risk 0.8% and 4.3%, median DFS not reached), score>15.4, <24.5 for intermediate risk (20.8%, 3- and 5-year recurrence risk 11.6% and 21.4%, median DFS 70 months) and score >24.5 for high risk (10.2%, 3- and 5-year recurrence risk 37.3% and 68.7%, median DFS 49 months).The area under curve (AUC) and HCI of our system were 0.871 and 0.929, superior to those of European Neuroendocrine Tumor Society (AUC 0.833, HCI 0.806).

CONCLUSION

The presented system can be utilized to identify G1/2 pancreatic neuroendocrine tumors patients with high recurrence risk, which might be appropriate for peri-operative adjuvant therapy.

A New Scoring System to Predict Recurrent Disease in Grade 1 and 2 Nonfunctional Pancreatic Neuroendocrine Tumors

OBJECTIVE

The aim of this study was to predict recurrence in patients with grade 1 or 2 nonfunctioning pancreatic neuroendocrine tumors (NF-pNET) after curative resection.

BACKGROUND

Surgical resection is the preferred treatment for NF-pNET; however, recurrence occurs frequently after curative surgery, worsening prognosis of patients.

METHODS

Retrospectively, patients with NF-pNET of 3 institutions were included. Patients with distant metastases, hereditary syndromes, or grade 3 tumors were excluded. Local or distant tumor recurrence was scored. Independent predictors for survival and recurrence were identified using Cox-regression analysis. The recurrence score was developed to predict recurrence within 5 years after curative resection of grade 1 to 2 NF-pNET.

RESULTS

With a median follow-up of 51 months, 211 patients with grade 1 to 2 NF-pNET were included. Thirty-five patients (17%) developed recurrence. The 5- and 10-year disease-specific/overall survival was 98%/91% and 84%/68%, respectively. Predictors for recurrence were tumor grade 2, lymph node metastasis, and perineural invasion. On the basis of these predictors, the recurrence score was made. Discrimination [c-statistic 0.81, 95% confidence interval (95% CI) 0.75-0.87] and calibration (Hosmer Lemeshow Chi-square 11.25, P = 0.258) indicated that the ability of the recurrence score to identify patients at risk for recurrence is good.

CONCLUSIONS

This new scoring system could predict recurrence after curative resection of grade 1 and 2 NF-pNET. With the use of the recurrence score, less extensive follow-up could be proposed for patients with low recurrence risk. For high-risk patients, clinical trials should be initiated to investigate whether adjuvant therapy might be beneficial. External validation is ongoing due to limited availability of adequate cohorts.

Head and Body/Tail Pancreatic Carcinomas Are Not the Same Tumors

The association between pancreatic ductal adenocarcinoma (PDAC) location (head vs. Body/Tail (B/T)) and clinical outcome remains controversial. We collected clinicopathological and gene expression data from 249 resected PDAC samples from public data sets, and we compared data between 208 head and 41 B/T samples. The 2-year overall survival (OS) was better for the head than for the B/T PDACs (44 vs. 27%, p = 0.043), especially when comparing tumors with similar TNM classification (T3/4N0M0: 67% vs. 17%, p = 0.002) or from the same molecular class (squamous subtype: 31% vs. 0%, p < 0.0001). Bailey's molecular subtypes were differentially distributed within the two groups, with the immunogenic subtype being underrepresented in the "B/T" group (p = 0.005). Uni- and multivariate analyses indicated that PDAC anatomic location was an independent prognostic factor. Finally, the supervised analysis identified 334 genes differentially expressed. Genes upregulated in the "head" group suggested lymphocyte activation and pancreas exocrine functions. Genes upregulated in the "B/T" group were related to keratinocyte differentiation, in line with the enrichment for squamous phenotype. We identified a robust gene expression signature (GES) associated with B/T PDAC location, suggesting that head and B/T PDAC are different. This GES could serve as an indicator for differential therapeutic management based on PDAC location.

Surgical resection of the primary tumor leads to prolonged survival in metastatic pancreatic neuroendocrine carcinoma

BACKGROUND

Palliative resection of the primary tumor for metastatic pancreatic neuroendocrine carcinoma (pNEC) patients is not recommended because of the poor prognosis compared to that of patients with well-differentiated, lower grade tumors. However, the published data supporting this recommendation regarding pNEC are limited. In the present study, we assessed whether palliative primary tumor resection in stage IV pNEC patients affects survival and identified other factors that affect survival in these patients.

METHODS

We collected data from stage IV pNEC patients registered in the Surveillance, Epidemiology, and End Results (SEER) database between 1988 and 2014. Univariate and multivariate Cox regression analysis were used to compare overall survival (OS) and cancer-specific survival (CSS) of patients who did or did not undergo primary tumor resection.

RESULTS

We identified 350 patients with metastatic, poorly differentiated, and undifferentiated pNEC. A total of 14.3% (50/350) of patients underwent primary tumor resection. Multivariate Cox regression analysis showed that primary tumor resection provided a significant benefit for both OS and CSS in stage IV pNEC patients. Additionally, chemotherapy and the presence of the primary tumor in the pancreatic tail were independent positive prognostic factors for metastatic pNEC patients in the multivariate Cox regression analysis.

CONCLUSIONS

The present study suggests that chemotherapy, location of the primary tumor in the pancreatic tail, and, most importantly, surgical removal of the primary tumor are associated with prolonged survival in stage IV pNEC patients.

Factors Affecting Survival in Neuroendocrine Tumors: A 15-Year Single Center Experience

Background: Neuroendocrine tumors are a heterogeneous group of tumors that can originate from all of the neuroendocrine cells in the body, mostly from the gastrointestinal tract. In addition to early diagnosis, streaming patients into appropriate prognostic groups is an important component of treatment. In this study, we examined the factors that affect survival in patients we followed in our center between 2000-2016. Methods: The demographic data, clinical and pathological features of patients were obtained from their medical files. TNM staging and tumor grading were performed according to AJCC and WHO 2010 classification. SPSS 15.0 for Windows programme was used for statistical analysis. Results: 85 patients (32 male, 53 female) were included into the study. The median age of the patients was 55,7 (27-83) years. Eighty percent of the tumors were of gastroenteropancreatic system, most commonly stomach (27.1%) origin. Nineteen patients (22.4%) died during follow-up. In univariate analysis; age (p<0,001), stage (p=0.002), primary tumor localization (p=0.005), grade (p<0.001), Ki-67 value (p<0.001), number of metastases (p=0.001) and type of surgery (p<0.001) were found to be factors affecting survival. Age (p=0.024) and Ki67 (p <0.001) were the independent prognostic factors for survival in multivariate analysis. For the cut-off value of 6%, Ki-67 had a sensitivity of 83.3% and specifity of 71.4% for survival determination. Conclusion: Ki-67 ratio and age were the most important factors affecting survival in neuroendocrine tumors in our study. Ki-67 ratio has a high sensitivity and specificity for predicting survival, a cut-off value of 6% may be used to predict survival.

Systematic review of current prognostication systems for pancreatic neuroendocrine neoplasms

BACKGROUND

Pancreatic neuroendocrine neoplasms are a heterogenous group of rare tumors whose natural history remains poorly defined. Accurate prognostication of pancreatic neuroendocrine neoplasms is essential for guiding clinical decisions. This paper aims to summarize all the commonly utilized and recently proposed prognostication systems for pancreatic neuroendocrine neoplasms published in the literature to date.

METHODS

A systematic review of Pubmed, Scopus, and Embase databases, of the period from January 1, 2000-November 29, 2016, was conducted to identify all published articles reporting on prognostication systems of pancreatic neuroendocrine neoplasms.

RESULTS

A total of 23 articles were included in our review, and a total of 25 classification systems were identified. There were 2 modifications of the World Health Organization 2004 criteria, 4 modifications of the World Health Organization 2010 criteria, 2 modifications of the American Joint Committee on Cancer 2010 staging system, 3 modifications of the European Neuroendocrine Tumor Society 2006 tumor, node, metastasis staging system, 7 novel categorial classification systems, and 2 novel proposed continuous classifications. The most commonly included variables included age, size of tumor, presence of distant and lymph node metastases, Ki-67 index, and mitotic count.

CONCLUSION

Numerous prognostication systems have been proposed for pancreatic neuroendocrine neoplasms, of which the most commonly used systems presently include the World Health Organization 2010 criteria and the two tumor, node, metastasis staging systems by the European Neuroendocrine Tumor Society and the American Joint Commission on Cancer. However, prognostication systems for pancreatic neuroendocrine neoplasms continue to evolve with time as more prognostication factors are identified. More validation and comparative studies are needed to identify the most effective prognostication system.

Prognostic factors and survival after surgical resection of pancreatic neuroendocrine tumor with validation of established and modified staging systems

BACKGROUND

Pancreatic neuroendocrine tumors (PNETs) display wide heterogeneity with highly variable prognosis. This study aimed to identify variables related to survival after surgical resection of PNET.

METHODS

A total of 143 patients were identified from a prospectively maintained database. Patient characteristics were analyzed and prognostic factors for overall survival and progression-free survival were evaluated. The WHO, ENETS and AJCC scoring systems were applied to the cohort, and their ability to predict patient outcomes were compared.

RESULTS

Multivariate analysis found that female gender, lymph node metastases and increasing WHO 2010 grade to be independently associated with reduced overall survival (P < 0.05). Patients requiring multi-visceral resection or debulking surgery found to be associated with shortest survival. ROC analysis found the ENETS and AJCC scoring systems to be similarly predictive of 5-year overall survival. Modified Ki67 significantly improved its accuracy in predicting 5-year overall survival (AUROC: 0.699 vs 0.605; P < 0.01).

CONCLUSIONS

Multi-visceral or debulking surgery is associated with poor outcomes. There seems to be no significant difference between enucleation and anatomical segmental resection. Available scoring systems have reasonable accuracy in stratifying disease severity, with no system identified as being superior. Prognostic stratification with modified grading systems needs further validation before applied in clinical practice.

Outcomes and prognostic factors of patients with stage IB and IIA pancreatic cancer according to the 8th edition American Joint Committee on Cancer criteria

AIM

To evaluate the changes in the 8^th edition American Joint Committee on Cancer (AJCC) for defining stage IB and IIA pancreatic cancer and identify their prognostic factors.

METHODS

Pancreatic cancer patients were selected from the Surveillance Epidemiology and End Results database (1973-2013). The enrolled patients were divided into IB and IIA groups based on tumor size according to the 8^th edition AJCC criteria. Clinical characteristics, including age, gender, race, tumor size, primary site, and grade were summarized. Univariate and multivariate analyses were performed to explore the prognostic factors of the IB and IIA stages of pancreatic cancer under new criteria.

RESULTS

A total of 1349 pancreatic cancer patients were included. More patients had stage IB rather than stage IIA. Stage IB tumors (54.85%) were mainly located in the head of the pancreas, while stage IIA tumors were more often located in the tail and head of the pancreas (35.21% and 31.75%, respectively). The survival time of stage IB and IIA patients had no significant difference. Univariate and multivariate analyses indicated that the prognostic factors of survival for stage IB and IIA patients were different. For stage IB patients, age and primary site were the independent prognostic factors; for stage IIA patients, age and grade were the independent prognostic factors. The risk of death was lower among patients aged ≤ 65 years than those aged > 65 years.

CONCLUSION

The prognostic factors for stage IB and IIA patients are different, but age is the independent prognostic factor for all patients. The survival time of stage IB and IIA patients has no significant difference.

Prognostic Validity of the American Joint Committee on Cancer and the European Neuroendocrine Tumors Staging Classifications for Pancreatic Neuroendocrine Tumors: A Retrospective Nationwide Multicenter Study in South Korea

OBJECTIVES

Pancreatic neuroendocrine tumors (pNETs) are diverse diseases with different prognosis. The American Joint Committee on Cancer (AJCC) and the European Neuroendocrine Tumor Society (ENETS) introduced 2 different tumor node metastasis (TNM) stages, and the World Health Organization (WHO) proposed WHO 2010 grading system for pNETs. Therefore, we aimed to validate the prognostic relevance of these 3 systems for pNETs in South Korea.

METHODS

The Korean Society of Gastrointestinal Cancer created a retrospective registry of pNETs in 153 patients from 15 hospitals between 2002 and 2012.

RESULTS

On the basis of the WHO 2010 grade, 2-year progression-free-survival (PFS) rates for G1, G2, and G3 were 92%, 62%, and 25% (P < 0.01). According to ENETS and AJCC staging, 2-year PFS rates for stages I through IV were 94%, 87%, 49%, 20%, and 92%, 61%, 60%, 20%, respectively (P < 0.01). A Cox multivariate regression analysis revealed that the only statistically significant prognostic factor was the TNM classification of either the AJCC or the ENETS stage (P < 0.01). In addition, the κ value between the AJCC and the ENETS stages was 0.46 indicating a "moderate" agreement (P < 0.01).

CONCLUSIONS

The AJCC and ENETS TNM classifications for pNETs are prognostic for PFS and can be adopted in clinical practice in South Korea.

Practical management and treatment of pancreatic neuroendocrine tumors

Pancreatic neuroendocrine tumors (NETs) are uncommon disease, about which little is known. Pancreatic NETs are usually slow growing and their malignant potential are often underestimated. The management of this disease poses a challenge because of the heterogeneous clinical presentation and varying degrees of aggressiveness. Recently, several guidelines for the management of pancreatic NETs have been established and help to devise clinical strategy. In the treatment algorithms, however, a lot of uncertain points are included. Practical treatment decisions of pancreatic NETs are still sometimes made in a patient- and/or physicians-oriented manner. The tumor grading system proposed by the European Neuroendocrine Tumor Society (ENETS) gives important prognostic information, however, the implication of grading regarding medical treatment strategies to choose has not yet been clarified. Moreover, the place of surgical treatment is unclear in the overall management course of advanced pancreatic NETs. In some cases, practical management and treatment have to be individualized depending on predominant symptoms, tumor spread, and general health of the patients. Current issues and a few points to make a strategy in the management of pancreatic NETs would be reviewed.

Survival and prognostic factors in well-differentiated pancreatic neuroendocrine tumors

OBJECTIVES

Pancreatic neuroendocrine tumors (P-NETs) account for 2-3% of all pancreatic neoplasms. The aim of our study was to investigate survival and prognostic factors in patients with P-NETs.

MATERIAL AND METHODS

We retrospectively reviewed the medical records of 114 patients diagnosed with well-differentiated P-NETs from 1982 through 2010. We studied demographical, clinical, radiological, and histopathological characteristics.

RESULTS

Median age at diagnosis was 57 years (range 32-83); 53% were men and 78% had nonfunctional tumors. The most common presenting symptoms were abdominal pain (41%), weight loss (36%), and diarrhea (25%); 19% of the tumors were incidental findings. Median duration of symptoms before diagnosis was 4 months, 3 months for nonfunctional, and 12 months for functional tumors (p < 0.001). At diagnosis, 32.5% patients had local, 22.8% had regional, and 44.7% had distant disease. Men had more often distant disease at diagnosis (p = 0.02). Median survival was 6.6 years (95% confidence interval [CI]: 4.0-9.2). Overall 5-year survival was 53.9% (95% CI: 43.4-63.3). For those with local disease and those with distant disease at diagnosis, the 5-year survivals were 70.2% (95% CI: 49.9-83.6) and 33.0% (95% CI: 19.7-46.7), respectively. Surgery with curative intent was performed on 46 patients. Newly detected liver metastases were diagnosed up to 10 years after surgery in this group. In patients with metastases, palliative surgery (debulking) did not have a significant effect on survival compared to those who had no surgery.

CONCLUSION

Distant metastases, Ki-67 > 2%, nonfunctional tumors, elevated level of chromogranin A, and palliative treatment were associated with poor survival.

The diversity between pancreatic head and body/tail cancers: clinical parameters and in vitro models

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) can be divided into head, body and tail cancers according to the anatomy. Distinctions in tissue composition, vascularization and innervations have been clearly identified between the head and body/tail of the pancreas both in embryological development and in histopathology. To understand the postulated genotype difference, we present comprehensive information on two PDAC cell lines as typical representatives originating from pancreatic head and body/tail cancers, respectively.

DATA SOURCE

In the present review, we compare the difference between pancreatic head and body/tail cancers regarding clinical parameters and introducing an in vitro model.

RESULTS

Increasing evidence has shown that tumors at different locations (head vs body/tail) display different clinical presentation (e.g. incidence, symptom), treatment efficiency (e.g. surgery, chemotherapy) and thus patient prognosis. However, the genetic or molecular diversity (e.g. mutations, microRNA) between the two subtypes of PDAC has not been elucidated so far. They present different chemo- and/or radio-resistance, extracellular matrix adhesion and invasiveness, as well as genetic profiles.

CONCLUSION

Genetic and tumor biological diversity exists in PDAC according to the tumor localization.