Intestinal and pancreatobiliary differentiation in periampullary carcinoma: the role of immunohistochemistry

Prognostic Impact of Mucin Expression in Curatively Resected Ampulla of Vater Cancer

Introduction: Mucins play a pivotal role in epithelial carcinogenesis; however, their role remains elusive in ampulla of Vater (AoV) cancer, regardless of histological subtype. Therefore, we investigated the clinical significance of MUC1, MUC2, MUC5AC, and MUC6 expression in AoV cancer. Methods: Using samples from 68 patients with AoV cancer, we performed immunohistochemical staining for MUC1, MUC2, MUC5AC, and MUC6 using a tissue microarray. Subsequently, we analyzed their expression patterns in relation to clinicopathological parameters and patient outcomes. Results: Of the patients, 98.5% exhibited positive expression for MUC1, while MUC2, MUC5AC, and MUC6 were expressed in 44.1%, 47.1%, and 41.2% of the patients, respectively. Correlation analyses between mucin expression and clinicopathological factors revealed no significant associations, except between MUC5AC expression and N stage. Univariate analysis demonstrated significant associations between MUC5AC expression and overall survival (OS). Multivariate analysis further confirmed that MUC5AC expression was a significant predictor of OS, along with the N stage. However, MUC5AC expression was not meaningfully associated with recurrence-free survival (RFS). The patients positive for MUC5AC expression had a considerably shorter OS than those with negative expression. Conclusions: Our study provides insights into the clinical impact of mucins on AoV cancer, regardless of the histological subtype. Although MUC1 expression is universal, MUC5AC expression is a significant prognostic indicator that correlates with lymph node metastasis and poor OS. These results emphasize the possible utility of MUC5AC as a biomarker for extensive lymph node dissection and the prognostic evaluation of patients with AoV cancer.

PD-L1 Expression in Ampullary Adenocarcinoma

INTRODUCTION

Ampullary adenocarcinoma is a rare neoplasm often treated by the complex Whipple's procedure. Several histological factors predict poor prognosis including pancreatobiliary morphology, presence of lymphovascular, perineural invasion and local or distant metastasis. Systemic therapy with gemcitabine, 5-fluorouracil regimens are given with variable benefits. Immunotherapy checkpoint inhibitors have shown beneficial anti-tumor effects in several carcinomas, the most remarkable being in non-small cell lung cancer. Administration of these novel drugs is based on immunohistochemical expression (which may or may not be indicative of response to therapy) along with meticulous decision making by the multidisciplinary team. Immunohistochemistry (IHC) is an effective means of immune marker demonstration and has been used in various tumor types for predictive and prognostic purposes.

METHODS

PD-L1 IHC (clone E1L3N) was applied in 101 cases of ampullary adenocarcinoma. Tumor infiltrating lymphocytes were also evaluated. The immunoreactivity was assessed and categorized into following staining thresholds: <1%, <5%, <10% and ≥10% for tumor cells (membranous and/or cytoplasmic staining pattern), and 5% and 10% cut-offs for immune cells.

RESULTS

We found that at a 10% cut-off, 73.3% (74/101) patients were men (P  =  .006) older than 50 years of age (P < .001) presenting with a tumor measuring <3 cm (P  =  .001). It was significantly associated with intestinal differentiation (P  =  .004) and grade 1 tumors (P  =  .001). Twelve patients presented with recurrence as well (P  =  .03).

CONCLUSION

In the context of ampullary adenocarcinoma, this study highlights the positivity observed with the PD-L1 IHC clone E1L3N at different thresholds, with the particularly stronger associations being evident at a 10% cut-off.

Machine learning for differentiating between pancreatobiliary-type and intestinal-type periampullary carcinomas based on CT imaging and clinical findings

PURPOSE

To develop a diagnostic model for distinguishing pancreatobiliary-type and intestinal-type periampullary adenocarcinomas using preoperative contrast-enhanced computed tomography (CT) findings combined with clinical characteristics.

METHODS

This retrospective study included 140 patients with periampullary adenocarcinoma who underwent preoperative enhanced CT, including pancreaticobiliary (N = 100) and intestinal (N = 40) types. They were randomly assigned to the training or internal validation set in an 8:2 ratio. Additionally, an independent external cohort of 28 patients was enrolled. Various CT features of the periampullary region were evaluated and data from clinical and laboratory tests were collected. Five machine learning classifiers were developed to identify the histologic type of periampullary adenocarcinoma, including logistic regression, random forest, multi-layer perceptron, light gradient boosting, and eXtreme gradient boosting (XGBoost).

RESULTS

All machine learning classifiers except multi-layer perceptron used achieved good performance in distinguishing pancreatobiliary-type and intestinal-type adenocarcinomas, with the area under the curve (AUC) ranging from 0.75 to 0.98. The AUC values of the XGBoost classifier in the training set, internal validation set and external validation set are 0.98, 0.89 and 0.84 respectively. The enhancement degree of tumor, the growth pattern of tumor, and carbohydrate antigen 19-9 were the most important factors in the model.

CONCLUSION

Machine learning models combining CT with clinical features can serve as a noninvasive tool to differentiate the histological subtypes of periampullary adenocarcinoma, in particular using the XGBoost classifier.

Clinical impact of ampulla of Vater cancer subtype classification based on immunohistochemical staining

BACKGROUND

The histological subtype is an important prognostic factor for ampulla of Vater (AoV) cancer. This study proposes a classification system for the histological subtyping of AoV cancer based on immunohistochemical (IHC) staining and its prognostic significance.

METHODS

Seventy-five AoV cancers were analyzed for cytokeratin 7 (CK7), CK20, and causal-type homeobox transcription factor 2 (CDX2) expression by IHC staining. We differentiated the subtypes (INT, intestinal; PB, pancreatobiliary; MIX, mixed; NOS, not otherwise specified) into classification I: CK7/CK20, classification II: CK7/CK20 or CDX2, classification III: CK7/CDX2 and examined their associations with clinicopathological factors.

RESULTS

Classifications I, II, and III subtypes were INT (7, 10, and 10 cases), PB (43, 37, and 38 cases), MIX (13, 19, and 18 cases), and NOS (12, 9, and 9 cases). Significant differences in disease-free survival among the subtypes were observed in classifications II and III using CDX2; the PB and NOS subtype exhibited shorter survival time compared with INT subtype. In classification III, an association was revealed between advanced T/N stage, poor differentiation, lymphovascular invasion (LVI), the PB and NOS subtypes, and recurrence risk. In classification III, the subtypes differed significantly in T/N stage and LVI. Patients with the PB subtype had advanced T and N stages and a higher incidence of LVI.

CONCLUSIONS

Classification using CDX2 revealed subtypes with distinct prognostic significance. Combining CK7 and CDX2 or adding CDX2 to CK7/CK20 is useful for distinguishing subtypes, predicting disease outcomes, and impacting the clinical management of patients with AoV cancer.

The Diagnosis and Treatment of Ampullary Carcinoma

BACKGROUND

Ampullary or papillary carcinoma is a malignant tumor arising from the mucosa in the region of the major duodenal papilla, also known as the ampulla of Vater. Uniform treatment recommendations are lacking both for the adjuvant situation and for palliative care.

METHODS

A selective literature search was carried out in PubMed in order to identify the most informative publications concerning the epidemiology, clinico-pathological background, and surgical and medical treatment of this condition.

RESULTS

Ampullary carcinoma has an incidence of 0.5 to 0.9 per 100 000 persons and a poor prognosis, with a 5-year survival rate of 41% to 45% for locally confined and 4% to 7% for metastatic disease. Most such tumors are of an intestinal or a pan - creaticobiliary immunohistochemical subtype; the latter has a worse prognosis (median survival, 72-80 vs. 33-41 months). Targeted treatment is not yet available for either subtype, nor is there enough scientific evidence available for the formulation of specific therapeutic recommendations in either the adjuvant or the palliative situation. The treatment of choice for ampullary carcinoma is radical oncological resection of the head of the pancreas with systematic lymphadenectomy. Five-year overall survival is between 10% and 75% depending on the stage. No definitive recommendation for adjuvant therapy can be given. Palliative therapy can be oriented to the published treatment strategies for cancer of the colon, pancreas, and bile duct.

CONCLUSION

The current state of the evidence on the treatment of ampullary carcinoma is poor. Therapeutic decisions should be discussed in an interdisciplinary tumor board and should, in our opinion, take the histological subtype into account.

[Treatment of Ampullary Adenocarcinoma]

The ampulla of Vater is a small projection formed by the confluence of the main pancreatic duct and common bile duct in the second part of the duodenum. Primary ampullary adenocarcinoma is a rare malignancy, accounting for only 0.2% of gastrointestinal cancers and approximately 7% of all periampullary cancers. Jaundice from a biliary obstruction is the most common symptom of ampullary adenocarcinoma. In the early stages, radical pancreatoduodenectomy is the standard surgical approach. On the other hand, no randomized controlled trial has provided evidence to guide physicians on the choice of adjuvant/palliative chemotherapy because of the rarity of the disease and the paucity of related research. This paper reports the biology, histology, current therapeutic strategies, and potential future therapies of ampullary adenocarcinoma.

Analysis of Pancreatobiliary and Intestinal Type Periampullary Carcinomas Using Volumetric Apparent Diffusion Coefficient Histograms

RATIONALE AND OBJECTIVES

Magnetic resonance imaging plays an important role in the evaluation of patients with known or suspected periampullary masses. The utilization of volumetric apparent diffusion coefficient (ADC) histogram evaluation for the entire lesion eradicates the potential for subjectivity in the region of interest placement, thus guaranteeing the accuracy of computation and repeatability.

PURPOSE

To investigate the value of volumetric ADC histogram analysis in the differentiation of intestinal-type (IPAC) and pancreatobiliary-type periampullary adenocarcinomas (PPAC).

MATERIALS AND METHODS

This retrospective study included 69 patients with histopathologically confirmed periampullary adenocarcinoma (54 PPAC and 15 IPAC). Diffusion-weighted imaging was obtained at b values of 1000 mm²/s. The histogram parameters of ADC values, comprising the mean, minimum, maximum, 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles, as well as skewness, kurtosis, and variance, were calculated independently by two radiologists. Using the interclass correlation coefficient, the interobserver agreement was evaluated.

RESULTS

The ADC parameters for the PPAC group were all lower than those of the IPAC group. The PPAC group had higher variance, skewness, and kurtosis than the IPAC group. However, the difference between the kurtosis (P = .003), the 5th (P = .032), 10th (P = .043), and 25th (P = .037) percentiles of ADC values was statistically significant. The area under the curve (AUC) of the kurtosis was the highest (AUC=0.752; cut-off value=-0.235; sensitivity=61.1%; specificity=80.0%).

CONCLUSION

Volumetric ADC histogram analysis with b values of 1000 mm²/s can discriminate subtypes noninvasively before surgery.

Evaluation of Imaging Findings of Pancreatobiliary and Intestinal Type Periampullary Carcinomas with 3.0T MRI

RATIONALE AND OBJECTIVES

The aim of this study was to differentiate pancreatobiliary and intestinal type periampullary carcinomas using dynamic contrast MRI and MRCP (Magnetic Resonance Cholangiopancreatography) with diffusion-weighted imaging (DWI) MATERIALS AND METHODS: MRI and MRCP images of 70 patients with pathologically proven periampullary adenocarcinoma were included. MRCP image features, extra-ampullary features, enhancement patterns, and apparent diffusion coefficient (ADC) values derived from b-values of 1000 s/mm² were evaluated by two radiologists independently. The interclass correlation coefficient (ICC) or Cohen's kappa statistic was used to evaluate the interobserver agreement.

RESULTS

51 patients were diagnosed with pancreatobiliary type carcinomas, and 19 with intestinal type. In the pancreatobiliary subtype, the distal wall of the common bile duct was usually irregular (p = 0.047). Although the progressive enhancement pattern was evident in the pancreatobiliary type, an oval filling defect in the distal common bile duct was found to be more common in the intestinal type (p<0.001). The pancreatic duct cut-off sign (p<0.001), gastroduodenal artery involvement (p <0,001), and lymphadenopathy (p<0.05) were mostly observed in pancreatobiliary carcinomas. The ADCmin, ADCmean, and ADCmax values of the pancreatobiliary type carcinomas were all lower compared to the intestinal type carcinomas (p <0.05).

CONCLUSION

The oval filling defect seen in MRI and MRCP examinations suggests intestinal type, whereas the progressive contrasting pattern of the masses with irregular narrowing in the distal margin of the common bile duct, the pancreatic duct cut-off sign, gastroduodenal artery involvement, lymphadenopathy, and low ADC values indicate pancreatobiliary type carcinomas.

Impact of histopathological type on the prognosis of ampullary carcinoma: A systematic review and meta-analysis

Histologically, ampullary carcinomas (ACs) can be classified into intestinal (INT-AC) and pancreatobiliary (PB-AC) subtypes. However, the prognostic implications of these subtypes remain unclear. This study aimed to evaluate the impact of the histopathologic phenotype of ACs on survival following pancreaticoduodenectomy. We searched PubMed, Embase, and Medline for studies published in English from 1994 to 2021. A meta-analysis was performed using Review Manager 5.3. The primary endpoint was overall survival (OS). We identified 3,890 articles; of these, 37 articles involving 3,455 participants (1,659 INT-ACs and 1,796 PB-ACs) were included. Patients in the PB-ACs group had significantly shorter OS than those in the INT-ACs group (hazard ratio [HR]: 1.79, 95% confidence interval [95% CI]: 1.51-2.13, p < 0.001, I² = 61%). A similar tendency was observed in the immunohistochemistry staining group (HR: 1.76, 95% CI: 1.33-2.33, p < 0.001, I² = 67%), which included 24 studies and 1,638 patients, and the non-immunohistochemistry group (HR: 1.84, 95% CI: 1.53-2.22, p = 0.04, I² = 46%), which included 13 studies and 1,817 patients. Subgroup analysis revealed that patients with PB-AC had higher frequencies of advanced (III, IV) and pT3-4 stage AC, lymph node metastasis, poorly differentiated tumor, positive surgical margins, lymphovascular invasion, and perineural invasion, than those with INT-AC. Patients with PB-AC had a significantly shorter OS than those with INT-AC due to a higher aggressiveness. Because the histopathologic subtype is a major prognostic factor in patients with resected AC, routine histopathologic classification should be considered even in clinical settings without immunohistochemistry.

The use of histopathological subtyping in patients with ampullary cancer: a nationwide analysis

BACKGROUND

Recent guidelines advise to subtype adenocarcinoma at the ampulla and papilla of Vater (here: ampullary cancer) as intestinal, pancreatobiliary, and mixed, because this has consequences for both prognosis and treatment. This nationwide study aimed to investigate how often histopathological subtyping is performed in daily clinical practice in patients with ampullary cancer.

METHODS

Pathology reports of all patients with ampullary cancer were retrieved from the Dutch nationwide pathology database (PALGA, 1991-2020). Reports were assessed for the presence and methods used for the classification of these tumors into intestinal, pancreatobiliary, and mixed subtypes. The use of immunohistochemical markers was recorded.

RESULTS

Overall, 5246 patients with ampullary cancer were included. In 1030 (19.6%) patients, a distinction between intestinal, pancreatobiliary, and mixed subtypes was made. Use of subtyping increased from 3% in 1991-1993 to 37% in 2018-2020. In 274 of the 1030 (26.6%) patients, immunohistochemistry was used to make this distinction. A gradual increase in the use of various immunohistochemical markers was seen over time since 2008, with cytokeratin 7, cytokeratin 20, and CDX2 being the most common. Staining of DPC4/SMAD4 was increasingly used since 2012.

CONCLUSION

Despite recent improvements in the use of subtyping in ampullary cancer, the distinction between intestinal, pancreatobiliary, and mixed subtypes is only made in a minority of patients. Nationwide efforts are required to standardize the pathological distinction of the various subtypes of ampullary cancer.

Identification and prevalence of potentially therapeutic targetable variants of major cancer driver genes in ampullary cancer patients in India through deep sequencing

Ampulla is a complex region located at the confluence of pancreatic and common bile duct and intestinal epithelium. Tumors arising in this region are anatomically and morphologically heterogenous, however they show unique as well as overlapping molecular features. Cancers of both these anatomic sites share morphological as well as genetic profile despite having few unique differences. Targeted therapies are currently emerging as one of the demanding approaches for treatment in most cancer types especially for malignant epithelial tumors and therefore genetic profiling of cancers is the key for identification of potentially therapeutic targetable mutations to know their prevalence and prognostic impact. We studied 97 resected cases of formalin fixed paraffin-embedded AC by deep targeted sequencing using Ampliseq cancer hotspot panel comprising of 50 oncogenes and tumor suppressor genes. Potentially therapeutic targetable mutations were observed in 58/83 (70%) cases. Fourteen patients did not show any pathogenic mutation. TP53 (48.1%), KRAS (37.3%), APC (25.3%), SMAD4 (22.8%), MET (16.8%), CTNNB1 (15.6%) and PIK3CA (10.8%) were the major mutated potential therapeutic targets. KRAS mutation (43.2 Vs. 32.6%) was more prevalent in pancreatobiliary subtype, while TP53 (58.6 Vs 35.1), APC (36.9 Vs 10.8), SMAD4 (28.2 Vs 16.2), MET (21.7 Vs 10.8) and CTNNB1 (19.5 Vs 10.8) were more prevalent in intestinal subtype. WNT signaling pathway was the major altered pathway in intestinal subtype. These mutated genes and pathways may be targeted with currently available drugs and may be explored for future development of targetable agents to improve the disease course in patients of AC.

Identification of PI3K-AKT signaling as the dominant altered pathway in intestinal type ampullary cancers through whole-exome sequencing

Background

The genetic landscape of intestinal (INT) and pancreatobiliary (PB) type ampullary cancer (AC) has been evolving with distinct as well as overlapping molecular profiles.

Methods

We performed whole-exome sequencing in 37 cases of AC to identify the targetable molecular profiles of INT and PB tumors. Paired tumor-normal sequencing was performed on the HiSeq 2500 Illumina platform.

Results

There were 22 INT, 13 PB, and two cases of mixed differentiation of AC that exhibited a total of 1,263 somatic variants in 112 genes (2–257 variants/case) with 183 somatic deleterious variants. INT showed variations in 78 genes (1–31/case), while PB showed variations in 51 genes (1–29/case). Targetable mutations involving one or more major pathways were found in 86.5% of all ACs. Mutations in APC, CTNNB1, SMAD4, KMT2, EPHA, ERBB, and Notch genes were more frequent in INT tumors, while chromatin remodeling complex mutations were frequent in PB tumors. In the major signaling pathways, the phosphoinositide 3-kinase (PI3)/AKT and RAS/mitogen-activated protein kinase (MAPK) pathways were significantly mutated in 70% of cases (82% INT, 46% PB, p = .023), with PI3/AKT mutation being more frequent in INT and RAS/MAPK in PB tumors. Tumor mutation burden was low in both differentiation types, with 1.6/Mb in INT and 0.8/Mb in PB types (p = .217).

Conclusions

The exome data suggest that INT types are genetically more unstable than PB and involve mutations in tumor suppressors, oncogenes, transcription factors, and chromatin remodeling genes. The spectra of the genetic profiles of INT and PB types suggested primary targeting of PI3/AKT in INT and RAS/RAF and PI3/AKT pathways in PB carcinomas.

Prevalence and spectrum of pathogenic germline variants in intestinal and pancreatobiliary type of ampullary cancer

BACKGROUND

Ampullary cancer may occur as a component of hereditary cancer syndromes. Mutations in inherited cancer susceptibility genes play a therapeutic role and its knowledge in ampullary cancer is lacking.

METHODS

Thirty-seven cases of ampullary carcinoma were subjected to tumor-normal whole exome sequencing with mean coverage of 100X (blood) and 200X (tumor). Data were analyzed and correlated with intestinal and pancreatobiliary differentiation.

RESULTS

There were 22 intestinal, 13 pancreatobiliary and 2 cases of mixed differentiation. One hundred and forty-three germline variations with at least >1 pathogenic germline variants (PGVs) across 83 genes were found in 36 of 37 patients. Twelve genes (14.5 %) showed >3, 20 genes (24.1 %) showed two and 51 genes (61.4 %) showed one PGVs. Intestinal differentiation showed higher PGVs (117 variants, 73 genes) than pancreatobiliary differentiation (85 variants, 62 genes). PGVs in ERCC5, MEN1, MSH3, CHEK1, TP53, APC, FANCA, ERBB2, BRCA1, BRCA2, RTEL1, HNF1A and PTCH1 were seen in >50 % of cases. Nine genes harbored somatic second hits in 14 cases. PGVs in DNA damage-repair, homologous recombination repair, TP53 transcriptional regulation, DNA double stranded breaks, cell cycle and nucleotide excision repair genes were seen in all cases of intestinal and pancreatobiliary differentiation, while DNA mismatch repair genes were found in 81.8 % of intestinal and 84.6 % of pancreatobiliary cancers. Functional pathway analysis showed that DNA damage-repair, double stranded break repair, mismatch repair, homologous recombination repair and TP53 transcriptional regulation genes were altered in both while nucleotide-excision repair was significantly mutated in intestinal type and cell-cycle genes in pancreatobiliary type (p < 0.05).

CONCLUSION

This study reports spectrum of PGVs in intestinal and pancreatobiliary differentiation of ampullary carcinoma at higher frequency through whole exome sequencing. PGVs were most frequently found in DNA repair genes. Detecting PGVs through tumor-normal sequencing may identify therapeutically actionable and double-hit mutations that can guide towards appropriate management.

Tissue microarray-chip featuring computerized immunophenotypical characterization more accurately subtypes ampullary adenocarcinoma than routine histology

BACKGROUND

Ampullary adenocarcinomas (AACs) are heterogeneous tumors currently classified into three important sub-classes (SC): Intestinal (INT), Pancreato-Biliary (PB) and Mixed-Type (MT). The different subgroups have similar clinical presentation and are treated by pancreatoduodenectomy with curative intent. However, they respond differently to chemotherapy and have different prognostic outcomes. The SC are often difficult to identify with conventional histology alone. The clinical outcome of all three remains unclear, particularly for MT.

AIM

To identify two main subtypes of AACs, using an immunohistochemical (IHC) score based on CDX2, CK7 and CK20.

METHODS

Tissue samples from 21 patients who had undergone resection of AAC were classified by HE histology and IHC expression of CDX2, CK7 and CK 20. An IHC score was obtained for each marker by counting the number of positive cells (0 = no stained cells; 1 < 25%; 2 < 50% and 3 > 50%) and their intensity (1 = weak; 2 = moderate and 3 = strong). A global score (GS) was then obtained by summation of the IHC scores of each marker. The MT tumors were grouped either with the INT or PB group based on the predominant immuno-molecular phenotype, obtaining only two AACs subtypes. The overall survival in INT and PB patients was obtained by Kaplan-Meier methods.

RESULTS

Histological parameters defined the AACs subtypes as follows: 15% INT, 45% PB and 40% MT. Using IHC expression and the GS, 75% and 25% of MT samples were assigned to either the INT or the PB group. The mean value of the GS was 9.5 (range 4-16). All INT samples had a GS above the average, distinct from the PB samples which had a GS score significantly below the average (P = 0.0011). The INT samples were identified by high expression of CDX2 and CK20, whereas PB samples exhibited high expression of CK7 and no expression of CK20 (P = 0.0008). The INT group had a statistically significant higher overall survival than in the PB group (85.7 mo vs 20.3 mo, HR: 8.39; 95%CI: 1.38 to 18.90; P = 0.0152).

CONCLUSION

The combination of histopathological and molecular criteria enables the classification of AACs into two clinically relevant histo-molecular phenotypes, which appear to represent distinct disorders with potentially significant changes to the current therapeutic strategies.

A novel hotspot and rare somatic mutation p.A138V, at TP53 is associated with poor survival of pancreatic ductal and periampullary adenocarcinoma patients

BACKGROUND

Pancreatic Ductal Adenocarcinoma (PDAC) is a cancer of the exocrine pancreas and 5-year survival rates remain constant at 7%. Along with PDAC, Periampullary Adenocarcinoma (PAC) accounts for 0.5-2% of all gastrointestinal malignancies. Genomic observations were well concluded for PDAC and PACs in western countries but no reports are available from India till now.

METHODS

Targeted Next Generation Sequencing were performed in 8 (5 PDAC and 3 PAC) tumour normal pairs, using a panel of 412 cancer related genes. Primary findings were replicated in 85 tumour samples (31 PDAC and 54 PAC) using the Sanger sequencing. Mutations were also validated by ASPCR, RFLP, and Ion Torrent sequencing. IHC along with molecular dynamics and docking studies were performed for the p.A138V mutant of TP53. Key polymorphisms at TP53 and its associated genes were genotyped by PCR-RFLP method and association with somatic mutations were evaluated. All survival analysis was done using the Kaplan-Meier survival method which revealed that the survival rates varied significantly depending on the somatic mutations the patients harboured.

RESULTS

Among the total 114 detected somatic mutations, TP53 was the most frequently mutated (41%) gene, followed by KRAS, SMAD4, CTNNB1, and ERBB3. We identified a novel hotspot TP53 mutation (p.A138V, in 17% of all patients). Low frequency of KRAS mutation (33%) was detected in these samples compared to patients from Western counties. Molecular Dynamics (MD) simulation and DNA-protein docking analysis predicted p.A138V to have oncogenic characteristics. Patients with p.A138V mutation showed poorer overall survival (p = 0.01). So, our finding highlights elevated prevalence of the p53p.A138V somatic mutation in PDAC and pancreatobiliary PAC patients.

CONCLUSION

Detection of p.A138V somatic variant in TP53 might serve as a prognostic marker to classify patients. It might also have a role in determining treatment regimes. In addition, low frequency of KRAS hotspot mutation mostly in Indian PDAC patient cohort indicates presence of other early drivers in malignant transformation.

Clinical outcomes of patients with duodenal adenocarcinoma and intestinal-type papilla of Vater adenocarcinoma

BACKGROUND

Duodenal adenocarcinoma (DA) and intestinal-type papilla of Vater adenocarcinoma (it-PVA) are rare malignancies of the gastrointestinal tract. Current therapeutic options are translated nowadays from treatment strategies for patients with colorectal cancer due to histopathological similarities.

AIM

To retrospectively investigate the clinical outcome of patients with DA and it-PVA.

METHODS

All patients with DA and it-PVA diagnosed between 2000 and 2017 were included at two academic centers in the Netherlands. All patients with histopathologically-confirmed DA or it-PVA were eligible for inclusion. Clinical outcome was compared between DA and it-PVA per disease stage. In the subgroup of stage IV disease, survival after local treatment of oligometastases was compared with systemic therapy or supportive care.

RESULTS

In total, 155 patients with DA and it-PVA were included. Patients with it-PVA more often presented with stage I disease, while DA was more often diagnosed at stage IV (P < 0.001). Of all patients, 79% were treated with curative intent. The median survival was 39 mo, and no difference in survival was found for patients with DA and it-PVA after stratification for disease stage. Seven (23%) of 31 patients with synchronous stage IV disease underwent resection of the primary tumor, combined with local treatment of oligometastases. Local treatment of metastases was associated with an overall survival of 37 mo, compared to 14 and 6 mo for systemic therapy and supportive care, respectively.

CONCLUSION

Survival of patients with DA and it-PVA is comparable per disease stage. These results suggest a potential benefit for local treatment strategies in selected patients with oligometastases, although additional prospective studies are needed.

Apparent diffusion coefficient-based histogram analysis differentiates histological subtypes of periampullary adenocarcinoma

BACKGROUND

For periampullary adenocarcinoma, the histological subtype is a better prognostic predictor than the site of tumor origin. Intestinal-type periampullary adenocarcinoma (IPAC) is reported to have a better prognosis than the pan-creatobiliary-type periampullary adenocarcinoma (PPAC). However, the classification of histological subtypes is difficult to determine before surgery. Apparent diffusion coefficient (ADC) histogram analysis is a noninvasive, non-enhanced method with high reproducibility that could help differentiate the two subtypes.

AIM

To investigate whether volumetric ADC histogram analysis is helpful for distinguishing IPAC from PPAC.

METHODS

Between January 2015 and October 2018, 476 consecutive patients who were suspected of having a periampullary tumor and underwent magnetic resonance imaging (MRI) were reviewed in this retrospective study. Only patients who underwent MRI at 3.0 T with different diffusion-weighted images (b-values = 800 and 1000 s/mm²) and who were confirmed with a periampullary adenocarcinoma were further analyzed. Then, the mean, 5th, 10th, 25th, 50th, 75th, 90th, and 95th percentiles of ADC values and ADC_min, ADC_max, kurtosis, skewness, and entropy were obtained from the volumetric histogram analysis. Comparisons were made by an independent Student's t-test or Mann-Whitney U test. Multiple-class receiver operating characteristic curve analysis was performed to determine and compare the diagnostic value of each significant parameter.

RESULTS

In total, 40 patients with histopathologically confirmed IPAC (n = 17) or PPAC (n = 23) were enrolled. The mean, 5th, 25th, 50th, 75th, 90th, and 95th percentiles and ADC_max derived from ADC₁₀₀₀ were significantly lower in the PPAC group than in the IPAC group (P < 0.05). However, values derived from ADC₈₀₀ showed no significant difference between the two groups. The 75th percentile of ADC₁₀₀₀ values achieved the highest area under the curve (AUC) for differentiating IPAC from PPAC (AUC = 0.781; sensitivity, 91%; specificity, 59%; cut-off value, 1.50 × 10^-3 mm²/s).

CONCLUSION

Volumetric ADC histogram analysis at a b-value of 1000 s/mm² might be helpful for differentiating the histological subtypes of periampullary adenocarcinoma before surgery.

Mutational profiling and immunohistochemical analysis of a surgical series of ampullary carcinomas

Aims

Knowledge regarding the genetic features of ampullary carcinoma (AC) in European patients is limited. The utility of tumour markers for the establishment of a malignant diagnosis in biopsies from the ampullary region has not been fully elucidated. We aimed to describe the clinical, pathological, immunohistochemical (IHC) and genetic features of a Danish series of surgically resected ACs.

Methods

Surgically resected ACs (n=59) were examined regarding (1) clinicopathological features, (2) histological subtypes, (3) expression of IMP3, maspin, MUC5AC and S100P and (4) next-generation sequencing using a hybrid capture-based platform (Illumina HiSeq2500), including 315 cancer-related genes plus introns from 28 genes often rearranged or altered in cancer. Tumour mutational burden (TMB) and microsatellite instability (MSI) were also evaluated.

Results

Pancreatobiliary adenocarcinomas (PB-AC), intestinal adenocarcinomas (INT-AC), other ampullary tumours and mixed adenocarcinomas represented 45.8%, 23.7%, 16.9% and 13.6%. The proportion of IHC-positive ACs (score ≥2) was: Maspin (94.9%), IMP3 (67.8%), S100P (39.0%) and MUC5AC (18.6%). Most frequently altered genes were TP53 (59.3%), KRAS (40.7%), APC (27.8%), SMAD4 (20.4%), CDKN2A (16.7%) and ARID2/PIK3CA (each 11.1%). MUC5AC and S100P were frequently expressed in PB-AC, APC alterations frequent in INT-AC, SOX9 alterations were exclusive in INT-AC and MDM2 and FRS2 alterations in PB-AC. Four of 49 ACs (8.2%) were TMB-high/MSI-high and showed loss of MLH1 and PMS2.

Conclusions

PB-AC was the most frequent histological subtype of AC. Maspin and IMP3 were the IHC tumour markers with the highest sensitivity. Adenocarcinoma subtypes differed regarding several genetic alterations, whose predictive value remains to be evaluated.

Assessment of tumor heterogeneity: Differentiation of periampullary neoplasms based on CT whole-lesion histogram analysis

PURPOSE

To investigate the utility of whole-lesion histogram analysis from multidetector computed tomography (MDCT) for discrimination of duodenal adenocarcinoma (DAC), pancreatic ductal adenocarcinoma (PDAC) and gastrointestinal stromal tumor (GIST) around the periampullary area.

MATERIALS AND METHODS

171 patients suspicious of periampullary tumors were examined by MDCT (arterial and venous phases) and treated with surgery. A total of 74 patients were finally included in this retrospective study (26 DACs, 20 PDACs, and 28 GISTs). The interobserver agreement was evaluated by intra-class correlation coefficient (ICC) test between two radiologists. Volumetric histogram analysis based on CT Kinetics software was performed on enhanced MDCT images that recorded different histogram parameters of arterial and venous phases, including mean, median, 10th, 25th, 75th, and 90th percentiles, as well as skewness, kurtosis and entropy. The extracted histogram parameters were compared between DAC, PDAC and GIST respectively by Mann-Whitney U tests with Bonferroni corrections. Receiver operating characteristic (ROC) curve analysis was used to determine the diagnostic ability of each significant parameter and the area under the curve (AUC) was calculated.

RESULTS

The whole-lesion CT histogram analysis demonstrated significant differences between DAC, PDAC, and GIST with different histogram features on both arterial and venous phase scans (all P < 0.05). In the ROC analysis, the 90th percentile of venous phase demonstrated the highest AUC of 0.854 (P < 0.001) for discriminating DAC from PDAC. Excellent discriminators of periampullary tumors were noted among the histogram features, namely the 90th percentile of arterial phase, which demonstrated AUCs of 0.809 and 0.936 (P < 0.001) respectively for distinguishing DAC and PDAC from GIST.

CONCLUSION

The whole-lesion CT histogram analysis could be useful for differential diagnosis of DAC, PDAC and GIST arising from the periampullary area. Further assessment is warranted to investigate the clinical role of histogram analysis based on MDCT.

Role of Immunohistochemistry in the Subtyping of Periampullary Adenocarcinoma

Context. Subtyping of periampullary adenocarcinoma into intestinal and pancreatobiliary subtypes has emerged as an important prognostic factor with potential therapeutic implications. This distinction on morphology alone is often difficult with significant interobserver variability. Objective. To analyze the usefulness of a panel of immunohistochemistry (IHC) markers as an aid to morphologic subtyping of periampullary adenocarcinoma. Design. A total of 172 periampullary adenocarcinomas were classified morphologically by 3 study pathologists. Interobserver agreement was assessed in each case. Cases were then typed using a predetermined IHC panel (comprising CK7, CK20, MUC1, and CDX2). Results. Morphologically, 66 (38.4%) cases were intestinal, 56 (32.6%) pancreatobiliary, 25 (14.5%) mixed, 16 (9.3%) poorly differentiated, 6 (3.5%) mucinous, and 3 (1.7%) signet ring cell adenocarcinoma. Concordant diagnosis was reached in 138 cases (80.2%) with moderate overall interobserver agreement (κ = 0.47). Concordance was higher in morphologically distinct mucinous (100%; κ = 0.94) and signet ring cell subtypes (100%; κ = 1.0) than in intestinal (84.6%; κ = 0.47) and pancreatobiliary (82.1%; κ = 0.43) types. Concordance was poor for mixed (64%; κ = 0.27) and poorly differentiated (68.8%; κ = 0.76) tumors. IHC subtyped 79 cases (46%) as pancreatobiliary, 73 (42.4%) as intestinal, and was inconclusive in 20 cases (11.6%). IHC helped classify 21 out of 25 (84%) mixed and 10 out of 16 poorly differentiated (62.5%) adenocarcinomas. Combination of histology and IHC classified 161 of the total 172 cases (93.6%). Conclusion. Use of an IHC panel aids in subtyping of periampullary adenocarcinomas, especially in tumors with mixed morphology and poor differentiation.

Clinicopathological features related to survival in adenocarcinoma of the Vaterian system in a Mexican population

Adenocarcinomas of the ampulla of Vater account for 0.5% of malignant neoplasms of the gastrointestinal tract and 6% to 20% of malignant periampullary neoplasms, with most patients being candidates for elective surgery. Our objective was to evaluate the clinicopathological prognostic factors of ampullary adenocarcinomas after surgical resection in a Mexican population. From the records of the Department of Pathology at the Instituto Nacional de Cancerología, México, cases diagnosed as adenocarcinomas of the ampulla of Vater were selected over a period of 11 years, from January 2005 to September 2015. Cases with a pancreaticoduodenectomy report were included, and from each case, demographic and pathological data of the surgical specimen were obtained. Univariate and multivariate statistical analyses were performed using the log-rank test and Cox regression. Of 157 cases diagnosed as ampullary adenocarcinomas, 104 patients were excluded as not eligible for surgical treatment at the time of diagnosis. In the remaining 53 patients, a pancreaticoduodenectomy was performed. The mean age of the entire group was 55.4 years, and most were men. Intestinal-type adenocarcinomas were more frequent (77.4%) than pancreatobiliary-type (15.1%), with most being without perineural invasion, well to moderately differentiated, and less than 3 cm in size. Lymph node metastasis and age greater than 65 years had a negative impact on overall survival of the patients. The most convenient classification of malignant epithelial tumors of the Vaterian system is according to the histopathologic phenotype grouped into intestinal-, pancreatobiliary-, and mixed-type adenocarcinomas, as well as uncommon variants.

Genetic Alterations of Periampullary and Pancreatic Ductal Adenocarcinoma: An Overview

Pancreatic Ductal AdenoCarcinoma (PDAC) is one of the most lethal malignancies of all solid cancers. Precancerous lesions for PDAC include PanIN, IPMNs and MCNs. PDAC has a poor prognosis with a 5-year survival of approximately 6%. Whereas Periampulary AdenoCarcinoma (PAC) having four anatomic subtypes, pancreatic, Common Bile Duct (CBD), ampullary and duodenum shows relative better prognosis. The highest incidence of PDAC has been reported with black with respect to white population. Similarly, incidence rate of PAC also differs with different ethnic populations. Several lifestyle, environmental and occupational exposures including long-term diabetes, obesity, and smoking, have been linked to PDAC, however, for PAC the causal risk factors were poorly described. It is now clear that PDAC and PAC are a multi-stage process resulting from the accumulation of genomic alterations in the somatic DNA of normal cells as well as inherited mutations. Approximately 10% of PDAC have a familial inheritance. Germline mutations in CDKN2A, BRCA2, STK11, PALB2, PRSS1, etc., as well as certain syndromes have been well associated with predisposition to PDAC. KRAS, CDKN2A, TP53 and SMAD4 are the 4 "mountains" (high-frequency driver genes) which have been known to earliest somatic alterations for PDAC while relatively less frequent in PAC. Our understanding of the molecular carcinogenesis has improved in the last few years due to extensive research on PDAC which was not well explored in case of PAC. The genetic alterations that have been identified in PDAC and different subgroups of PAC are important implications for the development of genetic screening test, early diagnosis, and prognostic genetic markers. The present review will provide a brief overview of the incidence and prevalence of PDAC and PAC, mainly, increased risk in India, the several kinds of risk factors associated with the diseases as well as required genetic alterations for disease initiation and progression.

Immunohistochemical Predictors for Intestinal and Pancreatobiliary Types of Adenocarcinoma of The Ampulla of Vater

OBJECTIVES

To investigate immunohistochemical predictors for intestinal and pancreatobiliary types of adenocarcinoma of ampulla of Vater and identify clinicopathological characteristics associated with the histological types and patient survival.

METHODS

Immunohistochemical markers included MUC1, MUC2, MUC5AC, CDX2, CK7, and CK20. The data were analyzed by univariate and multivariate methods. The two-step cluster method was used to determine the best immunohistochemical markers to discriminate the intestinal from the pancreatobiliary type.

RESULTS

This study identified 9 (33.3%) intestinal and 21 (66.7%) pancreatobiliary tumors. CK7 and CDX2 achieved the highest value (= 1) as predictor markers, while CK20, MUC1, and MUC2 showed degrees of importance equal to 0.77, 0.71, and 0.68, respectively. MUC5AC did not reach 0.50 of importance. In the univariate analysis, lymph node involvement, staging (TNM), and angiolymphatic and perineural invasions were associated with histological types. The independent clinicopathological variable in the multivariate model to predict the histological type was angiolymphatic invasion (p = 0.005), OR = 17 (95% CI 2.33 to 123.83). The final model showed positive nodes (N1) associated with shorter survival (HR = 9.5; p = 0.006). Overall survival at 12, 36, and 60 months was 88.5, 67.0, and 47.6%, respectively.

CONCLUSIONS

CDX2 and CK7 were the immunohistochemical markers that best discriminated the intestinal from the pancreatobiliary type. Lymph node involvement had a high impact on survival and proved to be more frequent in the pancreatobiliary type.

T-complex-associated-testis-expressed 3 (TCTE3) is a novel marker for pancreatobiliary carcinomas

Several markers of pancreatobiliary lineage have been described in the literature. However, none have demonstrated sufficient specificity and sensitivity to warrant diagnostic use. We evaluated the utility of T-complex-associated-testis-expressed 3 (TCTE3) as a pancreatobiliary marker. A set of 247 adenocarcinomas from the gastrointestinal (GI) tract was identified including 18 from the gastroesophageal junction (GEJ), 29 stomach, 17 ampullary, 62 pancreatic, and 16 common bile duct and gallbladder (CBD/GB), 13 non-ampullary small intestine, 32 colon, and 24 rectum. The remainder consisted of 16 cholangiocarcinomas and 20 hepatocellular carcinomas (HCC). Additionally, 163 adenocarcinomas from the breast, gynecologic tract, prostate, urothelium, kidney, and lung were stained for comparison. Immunohistochemistry for TCTE3 and other gastrointestinal markers was performed. Positive expression of TCTE3 was characterized by a strong, well-defined membranous pattern with or without weak cytoplasmic staining. Expression was identified in the normal epithelial cells of pancreatobiliary tree, but staining was absent in normal epithelial cells of esophagus, stomach, and intestine. Hepatocytes, pancreatic acini and islets and other non-epithelial cells were also negative for staining. TCTE3 was expressed in 93.5% of pancreatic ductal adenocarcinomas, 37.5% of CBD/GB adenocarcinomas, 50% of cholangiocarcinomas, 76.4% of ampullary adenocarcinomas, and 33.3% of GEJ adenocarcinomas. Only 3.5% of the gastric, 7.7% of non-ampullary small intestinal and 6.25% of colonic tumors exhibited positive staining. Expression was absent in rectal carcinomas and HCCs. These results suggest that TCTE3 is a useful marker of pancreatobiliary differentiation and may aid in distinguishing these tumors from gastric and intestinal primary tumors.

Ampullary cancer of intestinal origin and duodenal cancer - A logical clinical and therapeutic subgroup in periampullary cancer

Periampullary cancers include pancreatic, ampullary, biliary and duodenal cancers. At presentation, the majority of periampullary tumours have grown to involve the pancreas, bile duct, ampulla and duodenum. This can result in difficulty in defining the primary site of origin in all but the smallest tumors due to anatomical proximity and architectural distortion. This has led to variation in the reported proportions of resected periampullary cancers. Pancreatic cancer is the most common cancer resected with a pancreaticoduodenectomy followed by ampullary (16%-50%), bile duct (5%-39%), and duodenal cancer (3%-17%). Patients with resected duodenal and ampullary cancers have a better reported median survival (29-47 mo and 22-54 mo) compared to pancreatic cancer (13-19 mo). The poorer survival with pancreatic cancer relates to differences in tumour characteristics such as a higher incidence of nodal, neural and vascular invasion. While small ampullary cancers can present early with biliary obstruction, pancreatic cancers need to reach a certain size before biliary obstruction ensues. This larger size at presentation contributes to a higher incidence of resection margin involvement in pancreatic cancer. Ampullary cancers can be subdivided into intestinal or pancreatobiliary subtype cancers with histomolecular staining. This avoids relying on histomorphology alone, as even some poorly differentiated cancers preserve the histomolecular profile of their mucosa of origin. Histomolecular profiling is superior to anatomic location in prognosticating survival. Ampullary cancers of intestinal subtype and duodenal cancers are similar in their intestinal origin and form a logical clinical and therapeutic subgroup of periampullary cancers. They respond to 5-FU based chemotherapeutic regimens such as capecitabine-oxaliplatin. Unlike pancreatic cancers, KRAS mutation occurs in only approximately a third of ampullary and duodenal cancers. Future clinical trials should group ampullary cancers of intestinal origin and duodenal cancers together given their similarities and their response to fluoropyrimidine therapy in combination with oxaliplatin. The addition of anti-epidermal growth factor receptor therapy in this group warrants study.

Homeobox protein CDX2 as a prognostic biomarker in solid malignancies: a meta-analysis

Background

CDX2 is a caudal-homeobox gene and its expression is abnormal in numerous tumour cell types. Nevertheless, its prognostic value for solid tumours requires further investigation. Hence, we conducted a meta-analysis to determine the significance of CDX2 as a prognostic biomarker in solid malignancies systematically.

Materials and Methods

We performed a systematic literature search in PUBMED and EMBASE up to May 2017. Retrospective studies comparing the prognostic value of different CDX2 levels in human malignancies were included. Data extractions and methodological assessments were performed separately by two investigators using a standard procedure. The statistical procedures were performed using Review Manager 5.3 and STATA/MP 14.0.

Results

A total of 26 retrospective studies met the inclusion criteria and comprised 5008 participants. Patients with CDX2 overexpression had significantly better 3-year, 5-year, 10-year and disease-free survival outcomes in solid malignancies, regardless of the cancer type, mean age, and source region. Nevertheless, there was no significant difference in the patients from Europe. The expression level of CDX2 was not statistically associated with cancer relapse. Moreover, our analysis showed that CDX2 overexpression is correlated to better responses to chemotherapy in patients with TNM IV stage cancers. The stability of the pooled outcomes was verified by sensitivity analysis. The funnel plots, Egger's test and Begg's test jointly confirmed that there was no publication bias.

Conclusions

Overexpression of CDX2 is a reliable biomarker of a better prognosis in solid malignancies.

Clinicopathological Study of Carcinoma of the Ampulla of Vater with Special Reference to MUC1, MUC2 and MUC5AC Expression

INTRODUCTION

The ampulla of Vater consists of papilla, common channel, distal common bile duct and the distal main pancreatic duct. Ampullary carcinomas arise from two different types of mucosa, reflecting their broad histomorphological spectrum. Adenocarcinomas originating in the ampulla of Vater are classified as having either 'Intestinal' or 'Pancreatobiliary' type of differentiation. Pancreatobiliary type has consistently shown a worse prognosis. Various types of mucins are distributed in normal tissues and gastrointestinal tumours. MUC1, MUC2 and MUC5AC are known to be the most important amongst all.

AIM

To study clinicopathological features of different types of carcinoma of ampulla with MUC1, MUC2 and MUC5AC expression.

MATERIALS AND METHODS

We included 20 cases of ampullary adenocarcinoma in this study, diagnosed after radical surgery. The histopathological slides were reviewed and the tumours were classified into intestinal type, pancreatobilliary and other types. Representative block of tumours was subjected to immunohistochemical (IHC) study with MUC1, MUC2 and MUC5AC antibodies. Results were subsequently analysed.

RESULTS

Pancreaticobiliary type of ampullary carcinoma cases predominated (50%) over intestinal type (25%). Carcinomas of "other types" included one case each of mucinous carcinoma, adenosquamous carcinoma and undifferentiated carcinoma and well differentiated neuroendocrine tumours. Pancreatobiliary type of carcinomas was associated with higher tumour stage and grade and lymph node metastasis. All the pancreatobiliary type expressed MUC1 and all intestinal type carcinomas expressed MUC2. MUC 5AC expression was seen predominantly in pancreatobiliary type of ampullary carcinomas.

CONCLUSION

Mucin markers are associated with two different subtypes of ampullary carcinomas which have different prognosis. Immunohistochemical study of mucin expression can define the different types of carcinomas of ampulla of Vater with better objective criteria.

Intraductal tubulopapillary neoplasm accompanied by invasive carcinoma of the pancreas: A case report and review of the literature

Intraductal tubulopapillary neoplasms (ITPNs) are rare pancreatic neoplasms accounting for ~0.4% of pancreatic tumors. However, their clinicopathological characteristics have not been clearly determined and the number of available clinical studies on this type of tumor is limited at present. Due to the rare incidence of ITPN, diagnosis is often delayed. We herein present a unique case of a 38-year-old man who was diagnosed with ITPN accompanied with invasive carcinoma of the pancreas and underwent total pancreatectomy. The morphological characteristics of ITPN include closely packed tubular glands, without mucin secretion, accompanied with invasion of the loose connective tissue. The immunohistochemical staining suggested that the tumors did not originate from the gastrointestinal tract but rather from the bile duct. In addition, the Ki-67 positive staining rate of tumor cells was <20%. The microsatellite instability analysis demonstrated microsatellite stability, without detected gene mutations of epidermal growth factor receptor, Kirsten rat sarcoma viral oncogene homolog, neuroblastoma RAS viral oncogene homolog or B-Raf proto-oncogene. However, a mutation was identified in exon 9 of the P53 gene, the most frequently mutated gene in human cancer, which suggested the underlying mechanism of ITPN. On the basis of this case, the aim of this study was to summarize and review the relevant reports of ITPNs in recent years, in order to investigate the clinicopathological characteristics and differential diagnosis of ITPN.

Ampullary carcinoma is often of mixed or hybrid histologic type: an analysis of reproducibility and clinical relevance of classification as pancreatobiliary versus intestinal in 232 cases

Histologic classification of ampullary carcinomas as intestinal versus pancreatobiliary is rapidly becoming a part of management algorithms, with immunohistochemical classification schemes also being devised using this classification scheme as their basis. However, data on the reproducibility and prognostic relevance of this classification system are limited. In this study, five observers independently evaluated 232 resected ampullary carcinomas with invasive component >3 mm. Overall interobserver agreement was 'fair' (κ 0.39; P<0.001) with complete agreement in 23%. Using agreement by 3/5 observers as 'consensus' 40% of cases were classified as 'mixed' pancreatobiliary and intestinal. When observers were asked to provide a final diagnosis based on the predominant pattern in cases initially classified as mixed, there was 'moderate' agreement (κ 0.44; P<0.0001) with 5/5 agreeing in 35%. Cases classified as pancreatobiliary by consensus (including those with pure-pancreatobiliary or mixed-predominantly pancreatobiliary features) had shorter overall (median 41 months) and 5-year survival (38%) than those classified as pure-intestinal/mixed-predominantly intestinal (80 months and 57%, respectively; P=0.026); however, on multivariate analysis this was not independent of established prognostic parameters. Interestingly, when compared with 476 cases of pancreatic ductal adenocarcinomas, the pancreatobiliary-type ampullary carcinomas had better survival (16 versus 41 months, P<0.001), even when matched by size and node status. In conclusion, presumably because of the various cell types comprising the region, ampullary carcinomas frequently show mixed phenotypes and intratumoral heterogeneity, which should be considered when devising management protocols. Caution is especially warranted when applying this histologic classification to biopsies and tissue microarrays. While ampullary carcinomas with more pancreatobiliary morphology have a worse prognosis than intestinal ones this does not appear to be an independent prognostic factor. However, pancreatobiliary-type ampullary carcinomas have a much better prognosis than their pancreatic counterparts.

Mixed adenoneuroendocrine carcinoma of the ampulla of Vater: A case report

Mixed adenoneuroendocrine carcinomas (MANECs) are rare biphasic tumour types, which are morphologically recognisable as both gland-forming and neuroendocrine neoplasms. Within the gastrointestinal tract, MANECs occur predominantly in the stomach or colorectum. The present study described a case of a MANEC originating from the ampullary region. The patient presented with widespread metastatic disease. Biopsy samples obtained from the ampullary primary tumour disclosed a complex lesion with adenocarcinoma and neuroendocrine small cell carcinoma components, positive for the intestinal transcription factor caudal type homeobox-2 and for neuroendocrine markers, including chromogranin A, synaptophysin, cluster of differentiation 56/neural cell adhesion molecule. By contrast, biopsy samples obtained from metastatic tissue revealed pure neuroendocrine carcinoma. As exemplified by this true mixed tumour, tumour heterogeneity evolves as the major challenge in oncology today, with potentially severe implications for the choice of chemotherapy. The assessment of metastatic sites may render valuable diagnostic information that is crucial for clinical decision-making and patient management.

Exceptional Response to Nanoparticle Albumin-Bound Paclitaxel and Gemcitabine in a Patient with a Refractory Adenocarcinoma of the Ampulla of Vater

Ampullary carcinoma is a rare tumor and evidence on the treatment of recurrent metastatic disease is scarce. We report the case of a 60-year-old patient with an R0-resected node-positive adenocarcinoma of the papilla of Vater of an initially diagnosed intestinal subtype who developed pulmonary metastases 2 months after adjuvant gemcitabine chemotherapy and, subsequently, liver metastases. Palliative combination chemotherapy with standard regimens for intestinal-type adenocarcinoma (FOLFOX and FOLFIRI) failed. However, subsequent combination chemotherapy with nanoparticle albumin-bound paclitaxel and gemcitabine, a regimen with proven efficacy in metastatic adenocarcinoma of the pancreas, resulted in a durable, very good partial remission. Treatment was manageable and well tolerated. Primary tumor and metastatic tissue were reassessed by immunohistochemistry and had to be reclassified to a mixed phenotype containing predominant elements of the pancreatobiliary subtype. Our case suggests that combination chemotherapy with nanoparticle albumin-bound paclitaxel and gemcitabine could represent a promising option for the treatment of this rare disease and warrants further investigation within controlled clinical trials. Moreover, thorough characterization of ampullary carcinomas by histomorphology and additional immunohistochemistry should become mandatory in order to start a chemotherapeutic regimen tailored for the definitive subtype.

Substaging Nodal Status in Ampullary Carcinomas has Significant Prognostic Value: Proposed Revised Staging Based on an Analysis of 313 Well-Characterized Cases

BACKGROUND

Current nodal staging (N-staging) of ampullary carcinoma in the TNM staging system distinguishes between node-negative (N0) and node-positive (N1) disease but does not consider the metastatic lymph node (LN) number.

METHODS

Overall, 313 patients who underwent pancreatoduodenectomy for ampullary adenocarcinoma were categorized as N0, N1 (1-2 metastatic LNs), or N2 (≥3 metastatic LNs), as proposed by Kang et al. Clinicopathological features and overall survival (OS) of the three groups were compared.

RESULTS

The median number of LNs examined was 11, and LN metastasis was present in 142 cases (45 %). When LN-positive cases were re-classified according to the proposed staging system, 82 were N1 (26 %) and 60 were N2 (19 %). There was a significant correlation between proposed N-stage and lymphovascular invasion, perineural invasion, increased tumor size (each p < 0.001), and surgical margin positivity (p = 0.001). The median OS in LN-negative cases was significantly longer than that in LN-positive cases (107.5 vs. 32 months; p < 0.001). Patients with N1 and N2 disease had median survivals of 40 and 24.5 months, respectively (p < 0.0001). In addition, 1-, 3-, and 5-year survivals were 88, 76, 62 %, respectively, for N0; 90, 55, 31.5 %, respectively, for N1; and 68, 34, 30 %, respectively for N2 (p < 0.001). Even with multivariate modeling, the association between higher proposed N stage and shorter survival persisted (hazard ratio 1.6 for N1 and 1.9 for N2; p = 0.018).

CONCLUSIONS

Classification of nodal status in ampullary carcinomas based on the number of metastatic LNs has a significant prognostic value. A revised N-staging classification system should be incorporated into the TNM staging of ampullary cancers.

Immunophenotyping of ampullary carcinomata allows for stratification of treatment specific subgroups

BACKGROUND

Ampullary carcinomata (AC) can be separated into intestinal (IT) or pancreatobiliary (PB) subtypes. Although morphological, immunohistochemical and molecular differentiation of IT and PB have been well documented; the prognostic significance of histological subtype and whether patients with either subtype benefit from differential chemotherapeutic regimens remains unclear.

METHODS

As part of a larger cohort study, patients who underwent resection for AC or pancreatic ductal adenocarcinoma (PDAC) were retrospectively identified. Clinicopathological covariates and outcome were obtained and MUC1, MUC2, CDX2 and CK20 were assessed with immunohistochemistry.

RESULTS

Of 99 ACs, the resultant immunophenotypes indicated 48% and 22% were IT and PB, respectively. Thirty (30%) cases were quadruple negative (QN). Within the PDAC cohort (N = 257), the most prevalent immunophenotype was QN (53%). Subsequently, all QN ACs were classified as PB immunohistochemically yielding 47.5% and 52.5% classified as IT and PB, respectively. Involved regional lymph nodes and elevated T-stage were significantly associated with PB compared with IT AC (p = 0.0032 and 0.0396, respectively). Progression-free survival revealed inferior survival for PB versus IT AC (p = 0.0156).

CONCLUSIONS

AC can be classified into prognostic groups with unique clinicopathological characteristics using immunohistochemistry. Immunophenotypical similarity of PB and PDAC suggests that treatment regimens similar to those used in PDAC should be explored.

Differentiation of pancreatobiliary-type from intestinal-type periampullary carcinomas using 3.0T MRI

PURPOSE

To differentiate pancreatobiliary-type from intestinal-type periampullary carcinomas using combined magnetic resonance cholangiopancreatography (MRCP), contrast-enhanced MRI, and diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

MRI (3.0T) results of 41 patients with pathologically confirmed periampullary carcinoma were retrospectively assessed. Two radiologists, blinded to histologic type of each tumor, evaluated image findings independently. MRCP image features, enhancement pattern, and apparent diffusion coefficient (ADC) values were analyzed. Independent-sample t-test, chi-square, or Fisher's exact test were used to determine differential image findings between the pancreatobiliary-type and the intestinal-type group. Cohen's κ statistic or interclass correlation coefficient (ICC) were used to evaluate interobserver agreement between two observers. Univariate and multiple logistic regression analysis were performed to identify MRI features with predictive values.

RESULTS

On the basis of hematoxylin-eosin staining, 27 patients were classified as having pancreatobiliary-type carcinomas, and 14 patients the intestinal type. The pancreatobiliary-type carcinomas more commonly showed progressive enhancement than the intestinal type (P = 0.003). The minimum ADC (ADCmin ) value of the pancreatobiliary-type group ([0.95 ± 0.21] × 10(-3) mm(2) /s) was significantly lower than the intestinal-type group ([1.10 ± 0.25] × 10(-3) mm(2) /s) (P = 0.047). For interobserver agreement, the κ values and ICCs for all parameters exceeded 0.8, indicating almost perfect agreement. At multiple logistic regression analysis, the enhancement pattern was the only significant independent predictor (P = 0.011, odds ratio [OR] = 0.105). When the enhancement pattern and ADCmin were used in combination, we could identify 70.4% of pancreatobiliary-type and 78.6% of intestinal-type carcinomas.

CONCLUSION

Progressive enhancement and low ADCmin values suggest a pancreatobiliary-type periampullary carcinoma.

Difficult Diagnostic Problems in Pancreatobiliary Neoplasia

CONTEXT

Many common diagnostic dilemmas are encountered in pancreatobiliary pathology, frequently resulting in uncertainty on behalf of the pathologist and referral for a second opinion.

OBJECTIVES

To review 4 common diagnostic dilemmas encountered in the practice of pancreatobiliary pathology: (1) pancreatic ductal adenocarcinoma versus chronic pancreatitis; (2) pancreatic ductal carcinoma versus adenocarcinomas arising in the ampulla and intrapancreatic common bile duct; (3) the distinction of uncommon intraductal neoplasms--intraductal oncocytic papillary neoplasm, intraductal tubulopapillary neoplasm, and intraductal acinar cell carcinoma; and (4) intrahepatic cholangiocarcinoma versus metastatic carcinoma.

DATA SOURCES

A review of pertinent literature, along with the authors' personal experience, based on institutional and consultation materials.

CONCLUSIONS

Important diagnostic features for a few challenging problems in pancreatobiliary pathology are reviewed. Careful study of the microscopic features along with awareness of differential diagnoses and diagnostic pitfalls generally allows distinction of these entities. We also highlight established and novel ancillary studies that help to arrive at an accurate diagnosis.

Histomorphologic and molecular phenotypes predict gemcitabine response and overall survival in adenocarcinoma of the ampulla of Vater

BACKGROUND

The need for adjuvant chemotherapy after resection of ampullary cancer (PapCa) remains undefined. Recent data suggest that a different epithelial origin of PapCa might be associated with different tumor biology. The aim of the present study was to assess the clinical value of morphologic and immunohistochemic subclassification of PapCa into intestinal-type (IT) and pancreaticobiliary-type (PT) to predict chemotherapy response and overall survival (OS).

METHODS

Via a prospective database, 112 PapCa were identified, of which 95 could be included in the present study. Those were compared with 206 matching patients with periampullary pancreatic cancer (ie, pancreatic ductal adenocarcinoma, PDAC). IT and PT PapCa were classified morphologically, and tissue microarray was prepared with immunohistochemistry for CK7, CK20, MUC2, CDX2, ß-Catenin, and Villin. Multivariate survival analysis was performed.

RESULTS

OS of PT patients was less compared with IT patients (25 vs 98 months; P < .001), whereas it was comparable with patients with PDAC (25 vs 14 months; P = .123). PT patients receiving adjuvant gemcitabine chemotherapy featured improved OS (32 vs 13 months; P = .013), whereas gemcitabine tended to be associated with decreased OS in IT patients (35 vs 112 months; P = .193). Besides histopathologic classification, expression of CK7 and MUC2 were important prognostic variables. PT patients with CK7-positivity or MUC2-negativity were segregated into an even poorer prognostic group.

CONCLUSION

PapCa is not a separate tumor entity. We demonstrate important differences between IT-PapCa and PT-PapCa not only in long-term survival but also in response to adjuvant gemcitabine. Tumor biology and clinical course of PT tumors resemble those of PDAC. PT tumors should therefore be treated like PDAC.

The utility of immunohistochemistry in subtyping adenocarcinoma of the ampulla of vater

Histologic classification of ampullary carcinomas into intestinal, pancreatobiliary, or other subtypes is easily achievable in some cases but difficult in others. Immunohistochemical (IHC) stains may allow distinction between the subtypes; however, their added value to routine hematoxylin and eosin (H&E) evaluation has not been systematically evaluated. Inconsistent histologic subtyping has hampered current clinical research and therapeutic trials. In this study, a consecutive series of 105 ampullary carcinomas was subtyped first by H&E evaluation and then by the evaluation of an IHC panel composed of CK7, CK20, CDX2, MUC1, and MUC2, and the added value of IHC was analyzed. By H&E, a consensus diagnosis, defined as concordant subtyping among at least 3 of the 4 independent study pathologists, was achieved in 81 of the 105 (77%) cases. There was excellent agreement for poorly differentiated and mucinous subtypes (κ=0.72 and 0.89, respectively) but only good agreement for intestinal and pancreatobiliary subtypes (κ=0.57 and 0.48, respectively) and poor agreement for mixed subtype (κ=0.09). By IHC, CK7 showed no informative value (being positive in ≥70% of the cases in both intestinal and pancreatobiliary subtypes), whereas a subtyping schema incorporating the combination staining patterns of CK20, CDX2, MUC1, and MUC2 did. By this schema, "intestinal subtype" was defined as having (1) positive staining for CK20 or CDX2 or MUC2 and negative staining for MUC1, or (2) positive staining for CK20, CDX2, and MUC2, irrespective of the MUC1 result; and "pancreatobiliary subtype" was defined as having positive staining for MUC1 and negative staining for CDX2 and MUC2, irrespective of CK20 results. Cases not fitting one of these 3 categories were regarded as "ambiguous" immunohistochemically. By combining this schema with H&E evaluation, 97 of the 105 cases (92%) could be classified into either intestinal or pancreatobiliary subtype. In particular, immunophenotyping allowed categorization of 75% of poorly differentiated adenocarcinomas and 69% of cases with mixed histologic features as either intestinal or pancreatobiliary subtype. Most mucinous adenocarcinomas (88%) were clearly intestinal subtype by IHC. Thus, our IHC schema enhanced the subtyping of ampullary carcinoma and, in combination with H&E evaluation, allowed a dichotomous classification in 92% of the cases. Should further independent studies reaffirm our findings, this schema may serve as a valuable tool in both diagnostic and research settings.

Adenocarcinoma of the ampulla of Vater: what treatment options are available?

The scientific literature on adenocarcinoma of the ampulla (papilla) of Vater suggests that it either represents a distinct entity or is more closely related to small bowel adenocarcinoma than to the biliary malignancies. The ambiguity surrounding this rare cancer has kindled research exploring its immunohistochemistry aspects and gene expression profiling. While the basis of management for resectable disease remains surgical intervention, the role of adjuvant chemotherapy is not clear. A recent large phase 3 clinical trial conducted in patients with resected ampulla of Vater adenocarcinoma favored adjuvant chemotherapy over observation alone. The standards of therapy for the advanced small bowel adenocarcinoma and biliary cancer are fluoropyrimidine derivatives and gemcitabine-based combinations, respectively. In addition, new biologic and targeted agents may enhance clinical results seen in this cancer type. Therefore, diligently designed clinical trials are necessary to establish its optimal treatment strategies. We describe herein a patient with ampulla of Vater adenocarcinoma who had an exceptional response to fluoropyrimidine-based chemotherapy. We further include a discussion reviewing the clinicopathologic aspects of this neoplasm as well as focus on currently available and future therapeutic options.

MicroRNA profiling in periampullary carcinoma

BACKGROUND

MicroRNA expression patterns in many physiological and oncogenic processes have been established. However, the role of aberrant miRNA expression in periampullary carcinoma (PAC) has not been elucidated. We hypothesize that PAC may have differential expression of miRNAs which may differentiate the tumor histological subtypes.

METHODS

Fresh paired tumor and control samples were collected from the PAC patients undergoing Whipple's pancreaticoduodenectomy. Microarray miRNA profiling was performed utilizing tumor (n = 40) and control tissues; adjacent normal pancreas (n = 22), six each distal CBD, duodenum and ampulla. Data obtained was subjected to statistical and bioinformatic analysis. Differentially expressed miRNAs obtained were validated using qPCR in an independent set of samples.

RESULTS

Comparison of PAC tissue samples with controls revealed 29 common and differentially expressed miRNAs (20 upregulated and 9 downregulated) with a higher statistical significance (p < 0.001) and fold change (log2 FC > 1.5). A subset of 16 miRNAs (15 overexpressed and 1 underexpressed) differed in expression levels between pancreatobiliary and intestinal subtypes. Among these, miR-375, miR-31 and miR-196a expressions varied significantly between histological subtypes. Differential expression profiles of miRNAs specific to TNM staging was also observed in PAC subtypes. Target gene prediction for the differentially expressed miRNAs in PAC revealed that target genes are enriched for certain pathways. Particularly, Wnt signaling pathway genes appear to be relevant targets for most of the differentially expressed miRNAs.

CONCLUSION

Differentially expressed common miRNA signatures identified in PAC subgroups may have a role in pathogenesis of PAC and miR-375, miR-31 and miR-196a expression patterns may differentiate PAC subtypes.