Resected pancreatic adenosquamous carcinoma: clinicopathologic review and evaluation of adjuvant chemotherapy and radiation in 38 patients

Wnt-deficient and hypoxic environment orchestrates squamous reprogramming of human pancreatic ductal adenocarcinoma

Human pancreatic cancer is characterized by the molecular diversity encompassing native duct-like and squamous cell-like identities, but mechanisms underlying squamous transdifferentiation have remained elusive. To comprehensively capture the molecular diversity of human pancreatic cancer, we here profiled 65 patient-derived pancreatic cancer organoid lines, including six adenosquamous carcinoma lines. H3K27me3-mediated erasure of the ductal lineage specifiers and hijacking of the TP63-driven squamous-cell programme drove squamous-cell commitment, providing survival benefit in a Wnt-deficient environment and hypoxic conditions. Gene engineering of normal pancreatic duct organoids revealed that GATA6 loss and a Wnt-deficient environment, in concert with genetic or hypoxia-mediated inactivation of KDM6A, facilitate squamous reprogramming, which in turn enhances environmental fitness. EZH2 inhibition counterbalanced the epigenetic bias and curbed the growth of adenosquamous cancer organoids. Our results demonstrate how an adversarial microenvironment dictates the molecular and histological evolution of human pancreatic cancer and provide insights into the principles and significance of lineage conversion in human cancer.

Successful pancreatectomy after conversion-intended chemotherapy using gemcitabine and nab-paclitaxel for unresectable adenosquamous carcinoma of the pancreas: a case report

BACKGROUND

Adenosquamous carcinoma of the pancreas (ASCP) accounts for only 1-4% of all pancreatic exocrine cancers and has a particularly poor prognosis. The efficacy of chemotherapy for ASCP remains unknown because of the small number of cases, and few studies have evaluated conversion-intended chemotherapy.

CASE PRESENTATION

A 76-year-old woman was referred to our hospital because of epigastric pain and nausea. A preoperative contrast-enhanced multidetector row computed tomography (MDCT) scan revealed a 17 × 17 mm low-density tumor with an ill-defined margin at the arterial phase in the pancreatic head. The tumor involved the common hepatic artery, left hepatic artery bifurcated from the common hepatic artery, and gastroduodenal artery, and was in contact with the portal vein. Fluorodeoxyglucose-positron emission tomography (FDG-PET) showed an uptake in the pancreatic head but no evidence of distant metastasis. The tumor was diagnosed as an adenocarcinoma of the pancreatic head and staged unresectable because the common and left hepatic arteries were involved. Hence, the patient underwent seven courses of conversion-intended chemotherapy using gemcitabine and nab-paclitaxel for pancreatic ductal adenocarcinoma over 7 months. After chemotherapy, the tumor shrank to 10 × 10 mm on contrast-enhanced MDCT. Consequently, the boundary between the tumor and major vessels of the common and left hepatic arteries and the portal vein became clear, and the involvement of the arteries with the tumor was evaluated to be released. The contact of the tumor to the portal vein also reduced to less than half the circumference of the portal vein. FDG-PET showed decreased accumulation in the tumor. Hence, the tumor was judged resectable, and pancreaticoduodenectomy was performed. The tumor and major blood vessels were easily dissected and R0 resection was achieved. The patient experienced no major complications and was discharged on postoperative day 28. The tumor was revealed as ASCP via pathological examination. The patient is alive and recurrence-free seven months after surgery. This is the first report of successful R0 resection for an initially unresectable ASCP following conversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen.

CONCLUSIONS

Conversion-intended chemotherapy using gemcitabine and nab-paclitaxel regimen may be effective for ASCP.

A narrative review on rare types of pancreatic cancer: should they be treated as pancreatic ductal adenocarcinomas?

Pancreatic cancer is one of the deadliest malignancies in humans and it is expected to play a bigger part in cancer burden in the years to come. Pancreatic ductal adenocarcinoma (PDAC) represents 85% of all primary pancreatic malignancies. Recently, much attention has been given to PDAC, with significant advances in the understanding of the mechanisms underpinning disease initiation and progression, along with noticeable improvements in overall survival in both localized and metastatic settings. However, given their rarity, rare histological subtypes of pancreatic cancer have been underappreciated and are frequently treated as PDAC, even though they might present non-overlapping molecular alterations and clinical behavior. While some of these rare histological subtypes are true variants of PDAC that should be treated likewise, others represent separate clinicopathological entities, warranting a different therapeutic approach. In this review, we highlight clinical, pathological, and molecular aspects of rare histological types of pancreatic cancer, along with the currently available data to guide treatment decisions.

Case report: a case report of neoadjuvant mFOLFIRINOX leading to a partial pathologic response in pancreatic adenosquamous carcinoma

A female in her 60s with vague abdominal symptoms was found to have a pancreatic mass in her CT scan. A core needle biopsy done endoscopically demonstrated a poorly differentiated adenocarcinoma. The patient completed nine cycles of neoadjuvant systemic mFOLFIRINOX. Repeat staging demonstrated a partial radiographic response. She underwent an open pylorus-preserving pancreatoduodenectomy with segmental superior mesenteric vein resection with primary reconstruction (ISGPS Type 3). The final pathology demonstrated a poorly differentiated adenosquamous carcinoma, R1 margin status. The case report demonstrates the effect of mFOLFIRINOX on pancreatic adenosquamous (PASC) carcinoma with a review of the microscopic pictures following the neoadjuvant therapy. It can be postulated that glandular component being the major component in a PASC has a good response to mFOLFIRINOX like that seen in pancreatic ductal adenocarcinoma with some presumed effect on the squamous component as well. From the above case report, we are proposing that mFOLFIRINOX can be an effective chemotherapy regime in the management of PASC.

PD-L1 expression in pancreaticobiliary adenosquamous carcinoma: a single-institution case series

Background

The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) pathway is a potent negative regulator of T-cell-mediated immune response that is upregulated in many neoplasms. Pancreaticobiliary adenosquamous carcinoma (PB-ASC) is an aggressive cancer that carries a poorer prognosis compared with pure pancreaticobiliary adenocarcinoma (PB-AC). To date, there is little published information regarding PD-L1 expression in PB-ASC. The aim of the study was to examine the relationship between PD-L1 expression and tumor-infiltrating lymphocytes in PB-ASC and PB-AC.

Methods

We evaluated 15 PB-ASCs (10 pancreatic, 5 gallbladder) and 34 control PB-ACs (22 pancreatic ductal, and 12 gallbladder) for tumor expression of PD-L1 using anti-PD-L1 (E1L3N) antibody. All tumors were classified into three immune phenotypes: immune inflamed (II), immune excluded (IE), and immune desert (ID) according to the distribution of tumor-infiltrating lymphocytes in tumor tissues.

Results

The frequency of PD-L1 expression was significantly higher in PB-ASC (10/15; 66.7%) than in PB-AC (3/34; 8.8%). In PB-ASC, PD-L1 expression occurred exclusively in the squamous component in six cases, exclusively in the glandular component in one case, and in both the squamous and the glandular components in three cases. PD-L1 expression in PB-ASC was irrespective of the tumor immune status, whereas its expression in PB-AC was observed only in tumors with the II or IE phenotype. The ID phenotype was relatively rare (4/15; 26.7%) in PB-ASC compared with PB-AC (22/34; 65%; P=0.02).

Conclusions

PB-ASCs are notably enriched in inflammatory response and showed significantly higher PD-L1 expression than PB-AC (P<0.001), suggesting a potential therapeutic role for immune checkpoint inhibitors in managing patients with PB-ASC.

A case of pancreatic adenosquamous cell carcinoma with a pseudocyst following curative surgery

BACKGROUND

Pancreatic adenosquamous cell carcinoma (PASC) is a relatively rare histological type of pancreatic malignancy, and preoperative diagnosis is difficult because of its rarity. PASC accounts for 1-4% of all pancreatic cancers, and even after curative surgery, its prognosis is poorer than that of ordinary pancreatic adenocarcinoma. Pathologically, it shows glandular and squamous differentiation of cells. Complete resection is the only method to achieve a good long-term prognosis, and an increasing doubling time of PASC is considered to indicate early recurrence after surgery. Here, we report a rare case of PASC with an infected pancreatic cyst that was difficult to treat, along with a review of the literature.

CASE PRESENTATION

A woman in her 80s with a history of breast cancer presented with pericardial pain. Computed tomography revealed a 20-mm hypovascular tumor in the body of the pancreas and a 27-mm pseudocyst. Endoscopic retrograde cholangiopancreatography showed a severe main pancreatic duct stenosis in the body of the pancreas that made cannulation impossible, and contrast media extravasation was due to pancreatic duct disruption in the pancreatic tail. Endoscopic fine-needle aspiration revealed that the tumor was a PASC. Because the patient had an infected pancreatic cyst, central intravenous nutrition and antibiotics were administered, which stabilized her general condition. She was diagnosed with resectable PASC and underwent distal pancreatectomy with lymphadenectomy. The postoperative course was uneventful. Immunohistochemical analysis of the resected specimen confirmed T2N0M0 stage IB. Systemic adjuvant chemotherapy with S-1 is ongoing.

CONCLUSION

Appropriate preoperative management and preoperative accurate staging (T2N0M0 stage IB) of PASC with curative surgery can ensure predictable outcomes.

Pathologic Features of Primary Pancreatic Malignancies

This chapter explores the pathologic features of benign and malignant lesions of the pancreas. As pathologic classifications evolve particularly for cystic lesions and neuroendocrine tumors, it is important for physicians who treat patients with gastrointestinal malignance to fully evaluate these pathologic classifications.

Rare Solid Pancreatic Lesions on Cross-Sectional Imaging

Several solid lesions can be found within the pancreas mainly arising from the exocrine and endocrine pancreatic tissue. Among all pancreatic malignancies, the most common subtype is pancreatic ductal adenocarcinoma (PDAC), to a point that pancreatic cancer and PDAC are used interchangeably. But, in addition to PDAC, and to the other most common and well-known solid lesions, either related to benign conditions, such as pancreatitis, or not so benign, such as pancreatic neuroendocrine neoplasms (pNENs), there are solid pancreatic lesions considered rare due to their low incidence. These lesions may originate from a cell line with a differentiation other than exocrine/endocrine, such as from the nerve sheath as for pancreatic schwannoma or from mesenchymal cells as for solitary fibrous tumour. These rare solid pancreatic lesions may show a behaviour that ranges in a benign to highly aggressive malignant spectrum. This review includes cases of an intrapancreatic accessory spleen, pancreatic tuberculosis, solid serous cystadenoma, solid pseudopapillary tumour, pancreatic schwannoma, purely intraductal neuroendocrine tumour, pancreatic fibrous solitary tumour, acinar cell carcinoma, undifferentiated carcinoma with osteoclastic-like giant cells, adenosquamous carcinoma, colloid carcinoma of the pancreas, primary leiomyosarcoma of the pancreas, primary and secondary pancreatic lymphoma and metastases within the pancreas. Therefore, it is important to determine the correct diagnosis to ensure optimal patient management. Because of their rarity, their existence is less well known and, when depicted, in most cases incidentally, the correct diagnosis remains challenging. However, there are some typical imaging features present on cross-sectional imaging modalities that, taken into account with the clinical and biological context, contribute substantially to achieve the correct diagnosis.

Chemotherapy in advanced pancreatic adenosquamous carcinoma: A retrospective multicenter AGEO study

Pancreatic adenosquamous carcinoma (PASC) account for <5% of pancreatic malignancies. The efficacy of modern chemotherapy regimens in patients with advanced PASC is unknown. Patients with advanced PASC from 2008 to 2021 were consecutively included in this retrospective multicenter study. Overall survival (OS) and progression-free survival (PFS) were evaluated by Kaplan-Meier method. Ninety-four PASC from 16 French centers were included (median age, 67.3 years; males, 56.4%; metastatic disease, 85.1%). The first-line treatment was chemotherapy for 79 patients (84.0%) (37 FOLFIRINOX (FX), 7 Gemcitabine-nab paclitaxel (GN) and 35 for all other regimen) or best supportive care (BSC) alone for 15 patients (16.0%). No significant difference was observed between FX and GN in terms of PFS (P = .67) or OS (P = .5). Modern regimens pooled together (FX and GN) as compared to all others chemotherapy regimens showed an improvement of overall response rate (39.5% and 9.7%, P = .002), PFS (median, 7.8 vs 4.7 months, P = .02) and OS (median, 12.7 vs 9.2 months, P = .35). This large study evaluating first-line treatment regimens in advanced PASC suggests that modern regimens as FX or GN may be preferable to all other chemotherapy regimens. These results deserve confirmation in prospective studies.

Fully automated magnetic resonance imaging-based radiomics analysis for differentiating pancreatic adenosquamous carcinoma from pancreatic ductal adenocarcinoma

PURPOSE

To develop and validate an automated magnetic resonance imaging (MRI)-based model to preoperatively differentiate pancreatic adenosquamous carcinoma (PASC) from pancreatic ductal adenocarcinoma (PDAC).

METHODS

This retrospective study included patients with surgically resected, histopathologically confirmed PASC or PDAC who underwent MRI between January 2011 and December 2020. According to time of treatment, they were divided into training and validation sets. Automated deep-learning-based artificial intelligence was used for pancreatic tumor segmentation. Linear discriminant analysis was performed with conventional MRI and radiomic features to develop clinical, radiomics, and mixed models in the training set. The models' performances were determined from their discrimination and clinical utility. Kaplan-Meier and log-rank tests were used for survival analysis.

RESULTS

Overall, 389 and 123 patients with PDAC (age, 61.37 ± 9.47 years; 251 men) and PASC (age, 61.99 ± 9.82 years; 78 men) were included, respectively; they were split into the training (n = 358) and validation (n = 154) sets. The mixed model showed good performance in the training and validation sets (area under the curve: 0.94 and 0.96, respectively). The sensitivity, specificity, and accuracy were 76.74%, 93.38%, and 89.39% for the training set, respectively, and 67.57%, 97.44%, and 90.26% for the validation set, respectively. The mixed model outperformed the clinical (p = 0.001) and radiomics (p = 0.04) models in the validation set. Log-rank test revealed significantly longer survival in the predicted PDAC group than in the predicted PASC group (p = 0.003), according to the mixed model.

CONCLUSION

Our mixed model, which combined MRI and radiomic features, can be used to differentiate PASC from PDAC.

Adenosquamous carcinoma coexisting with intraductal papillary mucinous neoplasm of the pancreas: a case report

BACKGROUND

Adenosquamous carcinoma of the pancreas is a rare variant, with a worse prognosis than pancreatic ductal adenocarcinoma; moreover, it has characteristic clinical and histopathological features. Studies have mentioned the differentiation of intraductal papillary mucinous neoplasms into mucinous/tubular adenocarcinomas; however, their transdifferentiation into adenosquamous carcinoma remains unclear.

CASE PRESENTATION

An 80-year-old Japanese woman was referred to our hospital for further examination of multiple pancreatic cysts. Enhanced computed tomography after close follow-up for 6 years revealed a new nodule with poor enhancement on the pancreatic body. Distal pancreatectomy and splenectomy were performed. Histopathological examination revealed an adenosquamous carcinoma with coexisting intraductal papillary mucinous neoplasms; moreover, the intraductal papillary mucinous neoplasms lacked continuity with the adenosquamous carcinoma. Immunohistochemical analysis revealed squamous cell carcinoma and differentiation from adenocarcinoma to squamous cell carcinoma. Gene mutation analysis revealed KRASG12D and KRASG12R mutations in adenosquamous carcinoma components and intraductal papillary mucinous neoplasm lesions, respectively, with none showing the mutation of GNAS codon 201. The final histopathological diagnosis was adenosquamous carcinoma with coexisting intraductal papillary mucinous neoplasms of the pancreas.

CONCLUSIONS

This is the rare case of adenosquamous carcinoma with coexisting intraductal papillary mucinous neoplasms of the pancreas. To investigate the underlying transdifferentiation pathway of intraductal papillary mucinous neoplasms into this rare subtype of pancreatic cancer, we explored gene mutation differences as a clinicopathological parameter.

Research advances and treatment perspectives of pancreatic adenosquamous carcinoma

BACKGROUND

As a malignant tumor, pancreatic cancer has an extremely low overall 5-year survival rate. Pancreatic adenosquamous carcinoma (PASC), a rare pancreatic malignancy, owns clinical presentation similar to pancreatic ductal adenocarcinoma (PDAC), which is the most prevalent pancreatic cancer subtype. PASC is generally defined as a pancreatic tumor consisting mainly of adenocarcinoma tissue and squamous carcinoma tissue. Compared with PDAC, PASC has a higher metastatic potential and worse prognosis, and lacks of effective treatment options to date. However, the pathogenesis and treatment of PASC are not yet clear and are accompanied with difficulties.

CONCLUSION

The present paper systematically summarizes the possible pathogenesis, diagnosis methods, and further suggests potential new treatment directions through reviewing research results of PASC, including the clinical manifestations, pathological manifestation, the original hypothesis of squamous carcinoma and the potential regulatory mechanism. In short, the present paper provides a systematic review of the research progress and new ideas for the development mechanism and treatment of PASC.

Pancreatic Adenosquamous Carcinoma: A Rare Pathological Subtype of Pancreatic Cancer

Pancreatic adenosquamous carcinoma (PASC) is a rare pathological subtype of pancreatic cancer (PC), with a worse prognosis than pancreatic ductal adenocarcinoma (PDAC). Due to its rarity, our knowledge of PASC and its biological characteristics are limited. In this review, we provide an overview of the histogenesis, genetic features, diagnosis, treatment, and prognosis of PASC, as well as pancreatic squamous cell carcinoma (PSCC). The information provided here may help to clarify our understanding of PASC and provide useful avenues for further research on this disease.

Chemotherapy is associated with improved survival in a national cohort of stage IV pancreatic adenosquamous carcinoma

Background

Pancreatic adenosquamous carcinoma (PASC) is a rare cancer that often presents with advanced disease and carries a grim prognosis. PASC is defined by the presence of at least 30% malignant squamous cells in the presence of malignant ductal adenocarcinoma. The utility of chemotherapy in the setting of metastatic disease is unknown.

Methods

In this cross-sectional analysis, patients with stage IV PASC diagnosed between 2006 and 2016 were abstracted from the National Cancer Data Base. Patients were then categorized according to whether they received chemotherapy. Multivariable logistic regression analysis was done to determine the odds of receiving palliative chemotherapy. Overall survival analysis was performed using Kaplan-Meier analysis. A Cox proportional hazard multivariable model was generated to account for potential confounders.

Results

There were 698 patients with metastatic PASC available for analysis, including 400 patients (57.3%) who received chemotherapy and 298 patients (42.3%) who did not receive chemotherapy. Median overall survival was significantly longer for patients who received chemotherapy (5.2 vs. 1.5 months, P<0.001; HR 0.328, 95% CI: 0.272-0.397). Compared to patients who did not receive chemotherapy, patients who received chemotherapy were younger (mean 62.6 vs. 70.1 years old; P<0.001) and more likely to have no comorbidities (72.0% vs. 58.7%; P<0.001). In multivariate analysis, chemotherapy was the only factor independently associated with improved survival.

Conclusions

This is the largest study on PASC conducted to date and the first to evaluate whether chemotherapy is associated with improved survival for patients with metastatic disease. We found that palliative chemotherapy was associated with significant prolongation of life. However, overall prognosis remained dismal despite chemotherapy and novel treatment approaches are needed to improve long-term survival.

Delayed local recurrence of pancreatic adenosquamous cell carcinoma after curative surgery: A case report

Introduction

Pancreatic adenosquamous cell carcinoma (PASC) is a rare histological type of pancreatic malignancy with a particularly poor prognosis, even after curative surgery. Here, we describe the long-term prognosis of PASC in a patient who developed delayed local recurrence of the remnant pancreas after successful distal pancreatectomy, together with a literature review.

Presentation of case

A 59-year-old woman had a history of hepatitis C. Computed tomography revealed a hypointense mass in the pancreatic body in the arterial phase of the study. Magnetic resonance imaging revealed a tumor (20 mm) in the pancreatic body and dilatation of the main pancreatic duct at the periphery of the tumor. The patient was diagnosed with resectable pancreatic ductal adenocarcinoma and underwent distal pancreatectomy with lymphadenectomy; her postoperative course was uneventful. Immunohistochemical analysis of the resected specimen confirmed the diagnosis of tumor node metastasis [TNM] classification T2N1M0 stage IIB. Five years after curative surgery, following adjuvant systemic chemotherapy with S-1, local recurrence in the remnant pancreas occurred, which invaded the common hepatic artery and celiac pleural plexus. Systemic chemotherapy with gemcitabine and abraxiane is currently underway.

Discussion

Curative surgery significantly affects the prognosis of patients with PASC. Adjuvant chemotherapy may prolong the survival of these patients. Delayed remnant pancreatic recurrence should be considered during the surveillance of pancreatic cancer after curative resection.

Conclusion

We present a case of PASC in a patient who developed local recurrence in the remnant pancreas 5 years after successful distal pancreatectomy. Special attention should be paid not only to early recurrence but also to delayed local recurrence in PASC.

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Pancreatic adenosquamous cell carcinoma (PASC) is a rare histological type of pancreatic malignancy

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We describe the long-term prognosis of PASC in a patient who developed delayed local recurrence of the remnant pancreas after distal pancreatectomy.

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Delayed remnant pancreatic recurrence should be considered during the surveillance of pancreatic cancer after curative resection.

Survival Analysis and Prediction Model of ASCP Based on SEER Database

Background

This study aims to compare the incidence and clinical and survival characteristics of adenosquamous carcinoma of the pancreas (ASCP) and adenomatous carcinoma of the pancreas (ACP), analyze the survival factors of ASCP and construct a prognostic model.

Method

Patients diagnosed with pancreatic cancer from 2000 to 2018 are selected from the SEER database. ASCP and ACP are compared in terms of epidemiology, clinical characteristics and prognosis. Cases are matched in a 1:2 ratio, and survival analysis is performed. The Cox proportional hazard model is used to determine covariates related to overall survival (OS), and an ASCP prognosis nomogram is constructed and verified by consistency index (C-index), calibration chart and decision curve analysis (DCA). The accuracy of the model is compared with that of AJCC.Stage and SEER.Stage to obtain the area under the receiver operating characteristic (ROC) curve.

Results

the age-adjusted incidence of ACP increased significantly over time from 2000 to 2008 and from 2008 to 2018 (P < 0.05). APC was 2.01% (95% CI: 1.95–2.21) and 1.08% (95% CI: 0.93–1.25) respectively. The age-adjusted incidence of ASCP increased with time from 2000 to 2018 (P < 0.05) and APC was 3.64% (95% CI: 3.25–4.01).After propensity score matching (PSM), the OS and cancer-specific survival (CSS) of ACP are better than those of ASCP. The survival time of ASCP is significantly improved by the combined treatment of surgery + chemotherapy + radiotherapy, with a median OS of 31 months. Cox proportional hazard regression analysis shows that age, race, surgery, radiotherapy, chemotherapy and tumor size are independent factors affecting the prognosis. DCA and area under the curve (AUC) value shows that the model has good discrimination ability.

Conclusion

The OS prognosis of ASCP is worse than that of ACP, and the nomogram has high accuracy for the prognosis prediction of ASCP.

A phase II trial of the super-enhancer inhibitor Minnelide™ in advanced refractory adenosquamous carcinoma of the pancreas

Adenosquamous carcinoma of the pancreas (ASCP) is a very rare and highly aggressive variant of pancreatic ductal adenocarcinoma, accounting for 0.5-4% of all pancreatic cancer cases in the USA. Current data indicate that epigenetic changes and MYC overexpression lead to squamous transdifferentiation of pancreatic tumor cells and development of ASCP. Minnelide™, an oral anti-super-enhancer drug that inhibits MYC expression in preclinical models of ASCP, has demonstrated safety in a phase I study. We describe the design for a phase II, open-label, single-arm trial of Minnelide in patients with advanced refractory ASCP.

Application of Unenhanced Computed Tomography Texture Analysis to Differentiate Pancreatic Adenosquamous Carcinoma from Pancreatic Ductal Adenocarcinoma

OBJECTIVE

The objective of this study was to investigate the application of unenhanced computed tomography (CT) texture analysis in differentiating pancreatic adenosquamous carcinoma (PASC) from pancreatic ductal adenocarcinoma (PDAC).

METHODS

Preoperative CT images of 112 patients (31 with PASC, 81 with PDAC) were retrospectively reviewed. A total of 396 texture parameters were extracted from AnalysisKit software for further texture analysis. Texture features were selected for the differentiation of PASC and PDAC by the Mann-Whitney U test, univariate logistic regression analysis, and the minimum redundancy maximum relevance algorithm. Furthermore, receiver operating characteristic (ROC) curve analysis was performed to evaluate the diagnostic performance of the texture feature-based model by the random forest (RF) method. Finally, the robustness and reproducibility of the predictive model were assessed by the 10-times leave-group-out cross-validation (LGOCV) method.

RESULTS

In the present study, 10 texture features to differentiate PASC from PDAC were eventually retained for RF model construction after feature selection. The predictive model had a good classification performance in differentiating PASC from PDAC, with the following characteristics: sensitivity, 95.7%; specificity, 92.5%; accuracy, 94.3%; positive predictive value (PPV), 94.3%; negative predictive value (NPV), 94.3%; and area under the ROC curve (AUC), 0.98. Moreover, the predictive model was proved to be robust and reproducible using the 10-times LGOCV algorithm (sensitivity, 90.0%; specificity, 71.3%; accuracy, 76.8%; PPV, 59.0%; NPV, 95.2%; and AUC, 0.80).

CONCLUSION

The unenhanced CT texture analysis has great potential for differentiating PASC from PDAC.

Morphological and p40 immunohistochemical analysis of squamous differentiation in endoscopic ultrasound guided fine needle biopsies of pancreatic ductal adenocarcinoma

The basal-like molecular subtype of pancreatic ductal adenocarcinoma (PDAC) is associated with poor prognosis and upregulation in TP63ΔN (p40) network. Adenosquamous histology can be observed. This study assessed immunohistochemical p40 expression in fine needle biopsy (FNB) samples with PDAC and association with cytomorphological features of squamous differentiation and clinical data. 106 EUS FNBs with PDAC were assessed for eight cytomorphological features of squamous differentiation. P40 H-score (intensity 0-3 × percentage positive nuclei) was analysed for association with morphological features, patient age, gender, operability, chemotherapy and survival. P40 H-score in 14 paired FNBs and resections was compared. P40 h-score was 1-3 in 31%, 4-30 in 16% and > 30 in 13% of FNBs. It was significantly associated with intercellular bridges, elongated cell shape, sharp cell borders, angular nuclei with homogenous chromatin (p < 0.001) and dense cytoplasm (p = 0.002). Keratinisation was not seen. Inoperable patients (n = 81) had a shorter median survival for h-score > 30 (n = 9, 1.8 months) than for h-score ≤ 30 (n = 66, 6.7 months) not quite reaching statistical significance (p = 0.08). P40 was significantly associated with squamous morphology in FNBs with PDAC. P40 H-score > 30 showed a trend towards shorter survival in inoperable patients. Squamous differentiation may be a treatment target in PDAC.

PD-L1 expression and surgical outcomes of adenosquamous carcinoma of the pancreas in a single-centre study of 56 lesions

OBJECTIVE

Adenosquamous carcinoma of the pancreas (ASCP) is a rare histologic subtype of pancreatic carcinoma. The clinicopathologic characteristics and surgical outcomes of ASCP are poorly understood due to the rarity of this disease. Recently, promising clinical responses in patients with pancreatic cancer have been obtained for antibodies against programmed death-1/programmed death-ligand 1 (PD-1/PD-L1). This study investigated the prevalence of PD-L1 expression and surgical outcomes of 56 ASCPs compared to 100 pancreatic ductal adenocarcinomas (PDACs).

METHODS

A total of 56 resected cases of ASCPs were retrospectively reviewed; after matching for the T category, 100 PDACs were selected as a control group for comparison. Immunohistochemistry for p53, Smad4, and PD-L1 was performed in both groups.

RESULTS

The ASCPs exhibited distinct clinicopathologic features, such as larger tumour, location in the distal pancreas, frequent vascular invasion and distant metastasis. In survival analysis, 1-and 2-year overall survival (OS) rates were 51.8% and 17.9%, respectively, with a median follow-up 13 months. According to multivariate analysis, vascular invasion and T category remained independent predictors of OS. Patients with ASCPs showed poorer survival than patients with PDACs after matching for the T category (p = 0.03). p53 and Smad4 were aberrantly expressed in 42 (75%) and 28 (50%) cases, respectively. Under the condition of a 10% cut-off value for PD-L1 positivity, approximately 11% of ASCPs were positive for PD-L1.

CONCLUSIONS

Approximately 11% of patients with ASCPs are assumed to be potential candidates for the application of antibodies against PD-1/PD-L1, as based on the immunohistochemical results for PD-L1.

Benign vs malignant pancreatic lesions: Molecular insights to an ongoing debate

Several benign conditions such as chronic pancreatitis, autoimmune pancreatitis, and paraduodenal pancreatitis can present as mass lesions and may mimic pancreatic ductal adenocarcinoma (PDAC) clinically and radiologically. Thorough histologic examination with attention to certain morphologic features can assist in deciphering neoplastic from reactive, however small biopsies often remain a challenge. Variable histologic patterns in conventional PDAC may also confound the diagnosis of PDAC. Uncommon subtypes of pancreatic carcinoma such as adenosquamous and squamous cell carcinoma, colloid carcinoma, medullary carcinoma, hepatoid carcinoma and signet ring cell carcinoma necessitate excluding metastasis from other sites prior to rendering the diagnosis of pancreatic carcinoma. The use of immunohistochemical staining and molecular markers can aid in separating benign from malignant and PDAC from metastasis. PDAC expresses a few non-specific epithelial and mucin immunomarkers such as CK7, CK19, MUC1, MUC4 and MUC5AC. However, the only immunohistochemical marker that is specific for PDAC in the right clinical context is SMAD4. Loss of SMAD4 within atypical glands and ducts supports the diagnosis of PDAC in a limited sample. Unfortunately, this finding is seen only in 50% of PDAC cases. The identification of certain mutations can help support a diagnosis of PDAC when benign conditions are in the differential. At the molecular level, KRAS oncogene mutations are seen in approximately 93% of PDACs. Subsequent neoplastic progression is driven by additional mutations of tumor suppressor genes, such as CDKN2A, TP53, and SMAD4. Molecular markers can also provide an insight to the prognosis. For instance, the loss of SMAD4 is associated with a poor outcome whereas mutations in MLL, MLL2, MLL3, and ARID1A are associated with improved survival.

Clinical presentation and prognosis of adenosquamous carcinoma of the pancreas - Matched-pair analysis with pancreatic ductal adenocarcinoma

INTRODUCTION

Adenosquamous carcinoma of the pancreas (ASCP) is a rare subtype of pancreatic adenocarcinoma. The aim of this study was to investigate the characteristics and outcomes of ASCP in comparison to pancreatic ductal adenocarcinoma (PDAC).

MATERIALS AND METHODS

All patients with ASCP treated between December 2001 and December 2017 were identified from a prospective database. Clinicopathological and follow-up data were analyzed. A nested case-control-study with matched-pair analysis was performed to compare overall survival of ASCP and PDAC.

RESULTS

Of 4009 patients undergoing surgery for pancreatic adenocarcinoma 91 patients had ASCP. Compared to PDAC ASCP were larger (4.0 vs. 3.2 cm; p < 0.0001), more frequently involved lymph nodes (88% vs. 78%; p = 0.0216), more frequently showed poor differentiation (G3: 79% vs. 36%; p < 0.0001) and more frequently were located in the pancreatic tail (19% vs. 10%; p = 0.0179). Overall median post-resection-survival was shorter in ASCP (10.8 vs. 20.5 months in PDAC; p = 0.0085), but 5-year survival rates were comparable (18.2% vs. 17.5%). After matching for the unevenly distributed prognostic factors survival after resection of ASCP and PDAC was comparable (p = 0.8301). Localization in the head or several parts of the pancreas, high CA 19-9 levels, and M1 disease were independent predictors of survival in patients with ASCP.

CONCLUSION

ASCP is more aggressive with poorer differentiation and higher rates of lymph node metastases compared to PDAC. In spite of a shorter median survival, 5-year survival rates after surgical resection of about 18% can be expected in ASCP and support resection as part of a multimodal therapy as the treatment of choice in this rare cancer.

The importance of multimodal therapy in the management of nonmetastatic adenosquamous carcinoma of the pancreas: Analysis of treatment sequence and strategy

BACKGROUND

Adenosquamous carcinoma of the pancreas has historically poor survival. We analyzed survival outcomes stratified by treatment regimen and sequence using an administrative dataset.

METHODS

Adult patients with nonmetastatic adenosquamous carcinoma of the pancreas were identified using the National Cancer Database (2010-2016). Multivariable analyses were used to determine factors associated with receipt of neoadjuvant or adjuvant chemotherapy. Overall survival was estimated by Kaplan-Meier analysis and a multivariable Cox model was used to evaluate factors associated with survival.

RESULTS

A total of 838 patients with adenosquamous carcinoma of the pancreas were included in the analysis. The median age was 69 years and 64.7% of patients underwent pancreatectomy. Among patients who underwent pancreatectomy, 60.5% received adjuvant chemotherapy, 14.8% received neoadjuvant chemotherapy, and 24.7% underwent surgery alone. Older age and increasing comorbidity index were associated with a reduced likelihood of receiving neoadjuvant or adjuvant chemotherapy. Median survival of patients who received chemotherapy alone was similar compared with patients who underwent pancreatectomy alone (9.2 vs 7.2 months, P = .504). Survival was improved if patients received both chemotherapy and pancreatectomy (neoadjuvant = 19.6 months, hazard ratio = 0.58; adjuvant = 19.4 months, hazard ratio = 0.64) compared with pancreatectomy alone.

CONCLUSION

Patients with adenosquamous carcinoma of the pancreas who do not receive multimodal therapy have poor survival. The sequence of chemotherapy and pancreatectomy is not associated with survival, but 25% of patients who undergo surgery do not receive chemotherapy. Given that there is no difference in median survival between patients who undergo pancreatectomy alone or receive chemotherapy alone, our data question whether neoadjuvant chemotherapy should be considered in patients with potentially resectable adenosquamous carcinoma of the pancreas.

Adenosquamous carcinoma of the digestive system: a literature review

Adenosquamous carcinoma (ASC), containing both adenocarcinoma and squamous cell carcinoma components, is rare in the digestive system. Limited data is available on ASC of the digestive system (AS-ASC), and the current evidence is available mainly in the form of case reports and case series. We performed a thorough search of the available literature and compiled a review on the epidemiology, histopathology, pathogenesis, clinical manifestations, diagnosis, treatment, and prognosis of AS-ASC. Non-specific clinical and imaging presentations and low diagnostic accuracy of biopsy lead to difficulties in preoperative diagnosis in a high proportion of patients and high malignancy. The pathogenesis remains obscure. Surgery remains the mainstay of treatment for AS-ASC. The role of chemoradiotherapy as an adjuvant treatment is still inconclusive. Key messages Metastatic linings and the lack of efficacious treatments lead to an unfavorable outcome in AS-ASC patients. Further research could help us understand the pathophysiology of AS-ASCand the unique needs of AS-ASC patients.

Increased proportion of the squamous cell carcinoma component is associated with worse survival in resected gastric adenosquamous carcinoma: A STROBE compliant cohort study

For the diagnosis of gastric adenosquamous carcinoma (ASC), discrepancies regarding a rational diagnostic proportion of the squamous cell carcinoma (SCC) component exist among different organizations. Our study aimed to evaluate the impact of the SCC component on the survival of gastric cancer patients and identify the optimal cutoff value for the SCC component necessary for diagnosing gastric ASC.Cases of gastric cancer with an SCC component were obtained from our center and from case reports and series extracted from Medline. Univariate and multivariate analyses were conducted to compare the overall survival between groups and examine the prognostic value of various clinical parameters.We identified 45 qualified cases in published literature and 13 in our center. Forty-two of them were males and 16 females (M: F = 2.6:1). Thirty of them were Asian patients and the rest were mainly from the United States and Europe. The mean age was 61.1 years (median 64 years, range 32-84 years). The average tumor size was 6.9 cm (median 6.0 cm, range 2.0-16.0 cm). The most common location of the cancer was the lower third (39.7%). Although a statistical difference was not achieved, the Kaplan-Meier curve demonstrated that as the proportion of the SCC component in the primary lesion increased, the patients' survival risk increased (P = .489), and the presence of the SCC component in metastatic lymph nodes also increased the risk of survival (P = .259); both of these findings indicated a negative impact of the SCC component on survival. Furthermore, we identified the optimal cutoff for the SCC component as 35% (χ = 6.544, P = .011), which was subsequently validated in a Cox regression model as an independent prognostic factor (P = .026).An increased proportion of the SCC component is associated with worse survival in gastric cancer patients with an SCC component. The optimal cutoff for the proportion of the SCC component necessary for the diagnosis of gastric ASC is 35%.

One size does not fit all for pancreatic cancers: A review on rare histologies and therapeutic approaches

Exocrine pancreatic neoplasms represent up to 95% of pancreatic cancers (PCs) and are widely recognized among the most lethal solid cancers, with a very poor 5-year survival rate of 5%-10%. The remaining < 5% of PCs are neuroendocrine tumors that are usually characterized by a better prognosis, with a median overall survival of 3.6 years. The most common type of PC is pancreatic ductal adenocarcinoma (PDAC), which accounts for roughly 85% of all exocrine PCs. However up to 10% of exocrine PCs have rare histotypes, which are still poorly understood. These subtypes can be distinguished from PDAC in terms of pathology, imaging, clinical presentation and prognosis. Additionally, due to their rarity, any knowledge regarding these specific histotypes is mostly based on case reports and a small series of retrospective analyses. Therefore, treatment strategies are generally deduced from those used for PDAC, even if these patients are often excluded or not clearly represented in clinical trials for PDAC. For these reasons, it is essential to collect as much information as possible on the management of PC, as assimilating it with PDAC may lead to the potential mistreatment of these patients. Here, we report the most significant literature regarding the epidemiology, typical presentation, possible treatment strategies, and prognosis of the most relevant histotypes among rare PCs.

Pancreatic Ductal Adenocarcinoma and Its Variants: Pearls and Perils

Pancreatic ductal adenocarcinoma (PDAC), an epithelial neoplasm derived from the pancreatic ductal tree, is the most common histologic type of pancreatic cancer and accounts for 85%-95% of all solid pancreatic tumors. As a highly lethal malignancy, it is the seventh leading cause of cancer death worldwide and is responsible for more than 300 000 deaths per year. PDAC is highly resistant to current therapies, affording patients a 5-year overall survival rate of only 7.2%. It is characterized histologically by its highly desmoplastic stroma embedding tubular and ductlike structures. On images, it typically manifests as a poorly defined hypoenhancing mass, causing ductal obstruction and vascular involvement. Little is known about the other histologic subtypes of PDAC, mainly because of their rarity and lack of specific patterns of disease manifestation. According to the World Health Organization, these variants include adenosquamous carcinoma, colloid carcinoma, hepatoid carcinoma, medullary carcinoma, signet ring cell carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, and undifferentiated carcinoma. Depending on the subtype, they can confer a better or even worse prognosis than that of conventional PDAC. Thus, awareness of the existence and differentiation of these variants on the basis of imaging and histopathologic characteristics is crucial to guide clinical decision making for optimal treatment and patient management.

Adenosquamous Carcinoma of the Pancreas Comprise a Heterogeneous Group of Tumors With the Worst Outcome: A Clinicopathological Analysis of 25 Cases Identified in 562 Pancreatic Carcinomas Resected With Curative Intent

OBJECTIVES

Information of the clinicopathological characteristics and outcome data of patients with adenosquamous carcinoma of the pancreas (ASCAP) remains limited. This study's aim is to describe the clinical, pathological, and molecular characteristics of 25 resected ASCAPs.

METHODS

Of all 25 cases, patient characteristics, follow-up data, and pathological/immunohistological features were reviewed and analyzed.

RESULTS

In this 3-institutional retrospective analysis of 562 pancreatic cancer patients, we identified 25 cases with histologically confirmed ASCAP (4.4%). Follow-up was available in 21 ASCAP and 50 pancreatic ductal adenocarcinoma control patients with a median overall survival of 8.2 and 21 months, respectively. Age, tumor size, localization in the tail, lymph node status, and resection margin seem to be the most significant factors of survival in our ASCAP cohort. In contrast to pancreatic ductal adenocarcinoma, positive expression of p63, keratins K5/14, and the epidermal growth factor receptor are a robust marker profile of these tumors.

CONCLUSIONS

Adenosquamous carcinoma of the pancreas comprises a group of neoplasms in which stage and adverse morphological features contribute to its bad prognosis. Further work must be pursued to improve detection and treatment options to reduce mortality. Specifically, differences in biology might become a target for the development of possible therapies.

Cellular organization and histogenesis of adenosquamous carcinoma of the pancreas: evidence supporting the squamous metaplasia concept

Adenosquamous carcinoma of the pancreas (ASCAP) is characterized by conventional pancreatic ductal adenocarcinoma (PDAC) and squamous carcinoma components with at least 30% of the tumour showing squamous differentiation. To get further insight into the histogenesis of these lesions, we analysed the cellular organization of ASCAP compared to PDACs. Using Immunohistochemistry and triple immunofluorescence labelling studies for keratins, p63, p40, MUC1, MUC2, MUC5AC, Ki67, and EGFR we demonstrate that many ASCAPs contain a transitional zone between the K8/18-positive adenocarcinomatous component and the p63+ /p40+ /K5/K14+ squamous component initiated by the expression of p63 in K8/18+ adenocarcinomatous cells and the appearance of basally located p63+ K5/14+ cells. p63+ K5/14+ cells give rise to fully developed squamous differentiation. Notably, 25% of conventional PDACs without histologically recognizable squamous component contain foci of p63+ p40+ and K5/14+ cells similar to the transitional zone. Our data provide evidence that the squamous carcinoma components of ASCAPs originate from pre-existing PDAC via transdifferentiation of keratin K8/18-positive glandular cells to p63-, p40-, and keratin K5/14-positive squamous carcinoma cells supporting the squamous metaplasia hypothesis. Thus our findings provide new evidence about the cellular process behind squamous differentiation in ASCAPs.

Metastatic pancreatic adenosquamous carcinoma to the scalp: A case report and review of the literature

Metastatic carcinoma to the skin occurs in only a minority of patients with a visceral or internal malignancy, with breast, lung, and colorectum accounting for the majority of cases. We present the case of a 66-year-old man with a recent violaceous nodule of the left scalp (1.2 × 1.0 × 0.2 cm) that was a metastatic pancreatic adenosquamous carcinoma, representing a seemingly rare event. Two months prior, after complaining of right hip pain, an image revealed a right femoral lesion. A biopsy of that lesion showed moderately differentiated adenocarcinoma. Subsequent imaging showed a mass in the pancreatic tail and also markedly elevated serum tumor markers, CA 19-9 and carcinoembryonic antigen (5325 and 111.5 U/mL, respectively). Before the appearance of the scalp nodule, the patient received radiotherapy and was started on chemotherapy, which was continued after diagnosis and resection of the nodule. Subsequent metastases developed in the liver, lung and additional cutaneous lesions. He died 11 months after initial presentation with right hip pain. As this case shows, cutaneous metastases confer a poor prognosis, often with less than a year survival following their appearance.

Adenosquamous Carcinoma of the Pancreas

A 60-year-old woman presented to hospital with abdominal pain and massive weight loss. Imaging studies confirmed the presence of a tumor of the pancreas. Histologic analysis of the sampling performed by echoendoscopic ultrasound fine-needle aspiration found aspects evocative of adenosquamous carcinoma. This case report highlights the difficulties of clinical pathologic diagnosis for these occasionally composite tumors. The patient underwent palliative chemotherapy based on platinum and 5-fluorouracil, followed by second-line chemotherapy with FOLFIRI after progression. Adenosquamous carcinoma of the pancreas remains a rare tumor with very poor prognosis and limited therapeutic options.

Chemoradiotherapy is associated with improved survival for resected pancreatic adenosquamous carcinoma: a retrospective cohort study from the SEER database

Background

The prognosis of pancreatic adenosquamous carcinoma (PASC) after surgery is poor. The purpose of this study was to clarify the prognostic factors of PASC and evaluate the efficacy of combination chemoradiotherapy.

Methods

The patients' data retrieved from the Surveillance, Epidemiology, and End Results database (SEER) between 2004 and 2015 were stratified and analyzed in this study. The univariate and multivariate analysis were used for overall survival (OS) and cancer-specific survival (CSS).

Results

T staging, M staging, chemotherapy and radiotherapy is the independent prognostic indicator after PASC resection for both OS and CSS. In the total cohort, 44 patients had both chemo and radiotherapy, with median OS 23 months and CSS 29 months, which was significantly better than neither chemo nor radiotherapy group (68 patients, median OS 8 months and CSS 11 months), and either chemotherapy or radiotherapy group (91 patients, median OS 13 months and CSS 15 months). The survival benefit of chemoradiotherapy was validated in the specific group (n=159) who had only primary PASC. PASC patients receiving chemoradiotherapy had longer OS and CSS than those with neither chemo nor radiotherapy in TNM stage I, II and IV subgroups.

Conclusions

The chemoradiotherapy revealed its prognostic superiority in PASC treatment.

Dissecting the presence of malignant squamous cells in pancreatic cytopathology: A case series

The presence of malignant squamous cells in pancreatic cytopathology is a rare phenomenon that results either from a primary or a metastatic process. Pancreatic adenosquamous carcinoma (PASC) represents the most common variant of pancreatic ductal adenocarcinoma and is associated with a dismal prognosis. Within the period of 2013-2018, the archives of "Hygeia and Mitera Hospital" were searched for pancreatic cytopathology-related diagnoses that included the interpretation of "malignant squamous cells present." All fine needle aspirations (FNAs) of pancreatic lesions, including liver metastases in patients with known pancreatic primaries, were retrieved along with their relevant clinical information. Five pancreatic and two liver FNAs acquired from a total of six patients were reexamined. None of these patients had any documented history of primary squamous malignancy elsewhere. All pancreatic and one of the two liver FNAs showed malignant squamous cells, identified based on either morphology or immunochemistry. The other liver FNA represented a metastatic deposit which comprised of only a glandular component, whereas the associated pancreatic FNA exhibited both squamous and glandular counterparts. Most cases characteristically showed necrosis and keratinization. Of interest, two cases revealed the presence of tumor-associated giant cells. In conclusion, the presence of malignant squamous cells in pancreatic FNAs could mean the presence of PASC, especially when there is no documented history of a primary malignancy and a complete clinical and imaging workup has been performed. Immunochemistry on cell block material could help to confirm squamous differentiation in the absence of overt keratinization.

CT and MR imaging features of pancreatic adenosquamous carcinoma and their correlation with prognosis

PURPOSE

To retrospectively investigate the computed tomography (CT) and magnetic resonance (MR) imaging features of pancreatic adenosquamous carcinoma (PASC) and the association between imaging findings and prognosis.

MATERIALS AND METHODS

CT, MR images of 26 patients with PASC were analyzed. Clinical symptoms, tumor markers, and patients' survival were recorded. Tumor attenuation, enhancement pattern and degree, vessel involvement, adjacent tissue invasion and metastasis were evaluated. The association between imaging features and overall survival (OS) were also assessed using Cox proportional hazards ratio model.

RESULTS

Fourteen masses were found in the head of the pancreas and 12 in the body/tail. The mean tumor size was 4.47 ± 1.76 cm. PASC usually showed ill-defined (96.2%), lobulated (76.9%) and predominantly solid mass (92.3%). Ring enhancement in the peripheral area of the tumor was commonly seen (76.9%). Vessel invasion was seen in 17 cases (65.4%), encasement of adjacent arteries in 7 cases (26.9%), upstream main pancreatic duct (MPD) dilatation in 16 cases (61.5%) and double duct sign in 9 cases (34.6%). Multivariate Cox proportional hazards model demonstrated that patients with vessel invasion may predict a poor prognosis (p = 0.037).

CONCLUSION

PASC tends to be an ill-defined solid mass with peripheral ring enhancement, and relatively poor enhancement in the central area. PASC may also show vessel invasion, vessel encasement and upstream MPD dilatation. Vessel invasion may indicate a poor prognosis.

Long-term outcomes after an aggressive resection of adenosquamous carcinoma of the pancreas

PURPOSE

Adenosquamous carcinoma (ASC) of the pancreas is a rare malignancy, associated with a poor prognosis after surgical resection, with reported median survival times (MSTs) ranging from 4.4 to 13.1 months. We conducted this study to investigate the long-term outcomes of patients after the resection for ASC.

METHODS

Between 2002 and 2016, a total of 456 patients underwent resection for ASC or adenocarcinoma (AC) of the pancreas. ASC was confirmed in 17 (3.7%) of these patients. We analyzed the clinicopathological characteristics and survival of these 17 patients in comparison with those of patients with AC of the pancreas.

RESULTS

The operative procedures performed were pancreaticoduodenectomy (n = 6) and distal pancreatectomy (n = 11). Seven (41.2%) of the 17 patients underwent combined organ resection. R0 resection was achieved in 16 (94.1%) patients. The 5-year overall survival (OS) rate and MST were 40.3% and 20.9 months, respectively. A squamous component of ≥ 60% (P = 0.001) and R1 resection (P < 0.001) were significantly associated with poor OS for patients with ASC CONCLUSION: This study revealed longer survival and a higher R0 resection rate after aggressive combined resection in our ASC patients than those in previous studies. Although this was only a small series, our findings suggest that local control with aggressive resection may be an effective treatment protocol for ASC patients.

Comparative outcomes of adenosquamous carcinoma of the pancreas: An analysis of the National Cancer Database

BACKGROUND

A paucity of data exists regarding the natural history and outcome measures of adenosquamous carcinoma of the pancreas (ASCP), a histology distinct from pancreatic adenocarcinoma (PDAC). The aim of this study is to characterize the clinicopathological features of ASCP in a large cohort of patients comparing outcome measures of surgically resected patients to PDAC.

METHODS

We identified patients diagnosed with ASCP or PDAC from the National Cancer Database from 2004 to 2012. Patient demographics, tumor characteristics, treatment regimens, and overall survival were analyzed between the groups.

RESULTS

We identified 207 073 patients: 205 328 (99%) in the PDAC group and 1745 (1%) in the ASCP group. ASCP tumors were larger, located more frequently in a body/tail location (36% vs 24%, P < 0.001), undifferentiated/anaplastic histology (41% vs 17%, P < 0.001), and early stage presentation, (39% vs 32%, P < 0.001). There was no significant difference in OS when comparing all patients with PDAC and ASCP (6.2 months and 5.7 months, P = 0.601). In surgical patients ASCP histology was associated with worse OS (14.8 months vs 20.5 months, P < 0.001) but had lower nodal involvement (55% vs 61%, P < 0.001). ASCP histology was independently associated with worse OS, after adjusting for tumor characteristics, treatment, and patient demographics. In patients with only resected ASCP histology, negative lymph node status, R0 surgical resection, and receipt of chemotherapy was independently associated with improved overall survival following surgical resection.

CONCLUSION

Although patients with ASCP and PDAC tumors have similar survival when non-surgical and surgical patients are combined, ASCP is associated with worse survival in stage I/II resected patients.

Pancreatic adenosquamous carcinoma and intraductal papillary mucinous neoplasm in a CDKN2A germline mutation carrier

A 69-year-old woman from a kindred with familial atypical multiple mole melanoma and carrier of a germline mutation in CDKN2A, presented with abdominal pain caused by a solid-cystic pancreatic mass. The patient had an abdominal computed tomography three years before in which there was no evidence of pancreatic lesion. The endoscopic ultrasound guided fine needle aspiration showed adenocarcinoma with squamous component. After surgical resection the final diagnosis was adenosquamous pancreatic carcinoma (ASPC) arising in an intraductal papillar mucinous neoplasm (IPMN). Adenosquamous carcinomas are uncommon in the pancreas and have rarely been described in association with IPMNs. It has worse prognosis than the ordinary pancreatic ductal adenocarcinoma and some distinct features. We review the clinical, imaging, pathologic and molecular aspects of ASPC. Differential diagnosis with contamination, squamous metaplasia and pancreatic metastases from a distant squamous carcinoma is discussed. Besides, the case is an accelerated model of the adenoma (IPMN)-carcinoma sequence probably due to the CDKN2A germline mutation. Somatic CDKN2A mutations are common events in the early steps of sporadic pancreatic cancer, but germline mutation carriers have a significantly higher risk of pancreatic carcinoma.

Clinical implications of the proliferative ability of the squamous component regarding tumor progression of adenosquamous carcinoma of the pancreas: A preliminary report

OBJECTIVES

The objectives of this study were to examine the clinicopathological characteristics of patients with adenosquamous carcinoma of the pancreas (ASCP) and assess whether the proliferative ability of the squamous cell carcinoma (SCC) component contributes to either its proportion within the tumor or tumor progression.

METHODS

We retrospectively reviewed 12 patients with resected ASCP and compared their clinicopathological characteristics with those of 161 patients with adenocarcinoma of the pancreas (ACP). The Ki-67 indexes of the separate ASCP components were assessed.

RESULTS

All the clinicopathological characteristics and outcomes were similar between the ASCP patients and ACP patients. Among the 12 ASCP cases, nine exhibited higher Ki-67 levels in the SCC component than in the corresponding adenocarcinoma (AC) component at primary sites (P = 0.022). The component with a higher Ki-67 level coincided with the predominant component at the primary site in nine of 11 patients. In all 10 patients who presented lymph node metastasis, the metastases almost entirely consisted of either the SCC or AC component. The SCC component was absent from metastatic lymph nodes in five of 10 patients even though the Ki-67 levels at the primary site in four of these patients were higher in the SCC component than in the AC component.

CONCLUSIONS

The enhanced proliferative ability of the SCC component of ASCP is reflected by its proportion within the tumor. However, other biological factors might contribute to metastasis in ASCP.

Adenosquamous carcinoma in the biliary tract: association of the proliferative ability of the squamous component with its proportion and tumor progression

OBJECTIVES

The purpose of this study was to evaluate the association of the proliferative ability of squamous cell carcinoma (SCC) component with its proportion and tumor progression in adenosquamous carcinoma (ASC) in the biliary tract.

METHODS

Nine patients with ASC in the biliary tract (four each in the gallbladder and the extrahepatic bile duct and one in the ampulla of Vater) who underwent surgical resection were retrospectively reviewed.

RESULTS

The proportion of the SCC component in the primary sites ranged from 30% to 95%. The Ki-67 index of the SCC component was higher than that of the adenocarcinoma component in all cases, regardless of the component ratio in the patients' primary lesions. Predominance of the SCC component in the advancing region of the tumor, in angiolymphatic invasion and in perineural invasion was observed in most of the cases. The component ratio in metastatic lymph nodes differed from that in the corresponding primary lesions in all six cases with lymph node metastasis. Among these cases, the proportion of the SCC component was increased in the metastatic lymph nodes compared with that in the corresponding primary lesion in two cases, whereas the proportion was decreased in four cases.

CONCLUSIONS

The SCC component of ASC in the biliary tract displayed a relatively higher proliferative ability, which might be associated with local invasiveness. However, not only the high proliferative ability of the SCC component but also other biological factors might contribute to tumor progression and metastasis in ASC of the biliary tract.

Pancreatic cancer

Pancreatic cancer is a major cause of cancer-associated mortality, with a dismal overall prognosis that has remained virtually unchanged for many decades. Currently, prevention or early diagnosis at a curable stage is exceedingly difficult; patients rarely exhibit symptoms and tumours do not display sensitive and specific markers to aid detection. Pancreatic cancers also have few prevalent genetic mutations; the most commonly mutated genes are KRAS, CDKN2A (encoding p16), TP53 and SMAD4 - none of which are currently druggable. Indeed, therapeutic options are limited and progress in drug development is impeded because most pancreatic cancers are complex at the genomic, epigenetic and metabolic levels, with multiple activated pathways and crosstalk evident. Furthermore, the multilayered interplay between neoplastic and stromal cells in the tumour microenvironment challenges medical treatment. Fewer than 20% of patients have surgically resectable disease; however, neoadjuvant therapies might shift tumours towards resectability. Although newer drug combinations and multimodal regimens in this setting, as well as the adjuvant setting, appreciably extend survival, ∼80% of patients will relapse after surgery and ultimately die of their disease. Thus, consideration of quality of life and overall survival is important. In this Primer, we summarize the current understanding of the salient pathophysiological, molecular, translational and clinical aspects of this disease. In addition, we present an outline of potential future directions for pancreatic cancer research and patient management.

Adenosquamous carcinoma of the ampulla of Vater: a case report and literature review

Background

Adenosquamous carcinoma of the ampulla of Vater is extremely rare, and its clinicopathological features are limited and described in few previous case reports. Here, we report curative resection of adenosquamous carcinoma of the ampulla of Vater at an early stage.

Case presentation

An 81-year-old woman was referred to our hospital for investigation of the frequent elevation of hepatic and biliary enzymes and dilatation of the intrahepatic bile ducts. Preoperative examinations revealed an exposed reddish tumor in the ampulla of Vater, which was diagnosed on biopsy to be adenocarcinoma with squamous cell carcinoma component. Pylorus-preserving pancreaticoduodenectomy with regional lymph node dissection was performed. Pathological examinations revealed the presence of two malignant components in the lesion, including poorly differentiated tubular adenocarcinoma and squamous cell carcinoma, without invasion beyond the sphincter of Oddi or into the duodenal submucosa. These squamous cell carcinoma and adenocarcinoma components in the tumor comprised approximately 30 and 70 % of the lesion, respectively. No metastasis into regional lymph nodes was observed, and the patient experienced no tumor recurrence or metastasis until 20 months after surgery.

Conclusion

We identified only six reported cases of adenosquamous carcinoma of the ampulla of Vater in the English literature, and all of these patients died of recurrence within 14 months after surgery. To the best of our knowledge, this is the first report of adenosquamous carcinoma of the ampulla of Vater that was curatively resected at an early stage. Although more number of studies on clinicopathological findings are required to determine the appropriate surgical indication, we suggest that surgery remains the mainstay therapy for adenosquamous carcinoma of the ampulla of Vater detected at an early stage.

Adenosquamous carcinoma of the pancreas: Molecular characterization of 23 patients along with a literature review

Adenosquamous carcinoma of the pancreas (ASCP) is a rare entity. Like adenocarcinoma of the pancreas, overall survival is poor. Characteristics of ASCP include central tumor necrosis, along with osteoclasts and hypercalcemia. Various theories exist as to why this histological subtype exists, as normal pancreas tissue has no benign squamous epithelium. Due to the rarity of this disease, limited molecular analysis has been performed, and those reports indicate unique molecular features of ASCP. In this paper, we characterize 23 patients diagnosed with ASCP through molecular profiling using immunohistochemistry staining, fluorescent in situ hybridization, chromogenic in situ hybridization, and gene sequencing, Additionally, we provide a comprehensive literature review of what is known to date of ASCP. Molecular characterization revealed overexpression in MRP1 (80%), MGMT (79%), TOP2A (75), RRM1 (42%), TOPO1 (42%), PTEN (45%), CMET (40%), and C-KIT (10%) among others. One hundred percent of samples tested were positive for KRAS mutations. This analysis shows heretofore unsuspected leads to be considered for treatments of this rare type of exocrine pancreas cancer. Molecular profiling may be appropriate to provide maximum information regarding the patient’s tumor. Further work should be pursued to better characterize this disease.

A histomorphologic comparison of familial and sporadic pancreatic cancers

BACKGROUND

It is estimated that approximately 10% of pancreatic cancers have a familial component. Many inheritable genetic syndromes are associated with increased risk of pancreatic cancer, such as Peutz-Jeghers syndrome, hereditary breast-ovarian cancer and familial atypical multiple mole melanoma, but these conditions account for only a minority of familial pancreatic cancers. Previous studies have identified an increased prevalence of noninvasive precursor lesions, including pancreatic intraepithelial neoplasia, in the pancreata of patients with a strong family history of pancreatic cancer. A detailed investigation of the histopathology of invasive familial pancreatic cancer could provide insights into the mechanisms responsible for familial pancreatic cancer, as well as aid early detection and treatment strategies.

METHODS

We have conducted a blinded review of the pathology of 519 familial and 651 sporadic pancreatic cancers within the National Familial Pancreas Tumor Registry. Patients with familial pancreatic cancer were defined as individuals from families in which at least a pair of first-degree relatives have been diagnosed with pancreatic cancer.

RESULTS

Overall, there were no statistically significant differences in histologic subtypes between familial and sporadic pancreatic cancers (p > 0.05). In addition, among surgical resection specimens within the study cohort, no statistically significant differences in mean tumor size, location, perineural invasion, angiolymphatic invasion, lymph node metastasis and pathologic stage were identified (p > 0.05).

CONCLUSIONS

Similar to sporadic pancreatic cancer, familial pancreatic cancer is morphologically and prognostically a heterogeneous disease.

Efficacy of platinum chemotherapy agents in the adjuvant setting for adenosquamous carcinoma of the pancreas

BACKGROUND

Pancreatic adenosquamous carcinoma (PASC) accounts for only 1-4% of all exocrine pancreatic cancers and carries a particularly poor prognosis. This retrospective study was performed to determine whether inclusion of a platinum agent as part of adjuvant therapy is associated with improved survival in patients with resected PASC.

METHODS

Records of all patients who underwent pancreatic resection at Johns Hopkins Hospital from 1986 to 2012 were reviewed to identify those with PASC. Multivariable Cox proportional hazards modeling was used to assess for significant associations between patient characteristics and survival.

RESULTS

In total, 62 patients (1.1%) with resected PASC were identified among 5,627 cases. Median age was 68 [interquartile range (IQR), 57-77] and 44% were female. Multivariate analysis revealed that, among all patients (n=62), the following factors were independently predictive of poor survival: lack of adjuvant therapy [hazard ratio (HR) =3.6; 95% confidence interval (CI), 1.8-7.0; P<0.001], margin-positive resection (HR =3.5; 95% CI, 1.8-6.8; P<0.001), lymph node involvement (HR =3.5; 95% CI, 1.5-8.2; P=0.004), and age (HR =1.0; 95% CI, 1.0-1.1; P=0.035). There were no significant differences between patients who did and did not receive adjuvant therapy following resection (all P>0.05). A second multivariable model included only those patients who received adjuvant therapy (n=39). Lack of inclusion of a platinum agent in the adjuvant regimen (HR =2.4; 95% CI, 1.0-5.8; P=0.040) and larger tumor diameter (HR =1.3; 95% CI, 1.0-1.6; P=0.047) were independent predictors of inferior survival.

CONCLUSIONS

Addition of a platinum agent to adjuvant regimens for resected PASC may improve survival among these high-risk patients, though collaborative prospective investigation is needed.

Salvage pancreaticoduodenectomy after complete response to chemoradiotherapy for a previously unresectable pancreatic adenosquamous carcinoma: a case report

Pancreatic cancer is known for its typically late presentation and poor survival rates, with overall 5-year survival of less than 5%. The role of chemotherapy alone or with radiotherapy in the management of locally advanced tumors continues to be an area of debate.We report a case of locally advanced, pancreatic adenosquamous carcinoma that was initially deemed unresectable intraoperatively. Nonetheless, the tumor was resected after radiological response to gemcitabine-capecitabine chemoradiotherapy regimen similar to the Selective Chemoradiation in Advanced LOcalised Pancreatic cancer trial. Histological examination revealed complete pathological response with extensive fibrosis (ypT0 N0). On 12-month follow-up CT, a single liver lesion in the left lateral segment was identified and confirmed to be a metastasis with cytological diagnosis via EUS and FNA. The disease remained stable and confined to the solitary hepatic metastasis after further gemcitabine chemotherapy. Therefore, a further successful resection was performed.The 2 main strategies for the management of locally advanced unresectable pancreatic cancer are chemotherapy induction followed by consolidation chemoradiotherapy or chemotherapy alone, with conflicting published evidence. Evidence for the optimal management of the rare histological type of adenosquamous carcinoma is scant. We present a case of such tumor with a complete pathological response to chemoradiotherapy. The results of future studies in the area are eagerly awaited.

A histomorphologic comparison of familial and sporadic pancreatic cancers

BACKGROUND

It is estimated that approximately 10% of pancreatic cancers have a familial component. Many inheritable genetic syndromes are associated with increased risk of pancreatic cancer, such as Peutz-Jeghers syndrome, hereditary breast-ovarian cancer and familial atypical multiple mole melanoma, but these conditions account for only a minority of familial pancreatic cancers. Previous studies have identified an increased prevalence of noninvasive precursor lesions, including pancreatic intraepithelial neoplasia, in the pancreata of patients with a strong family history of pancreatic cancer. A detailed investigation of the histopathology of invasive familial pancreatic cancer could provide insights into the mechanisms responsible for familial pancreatic cancer, as well as aid early detection and treatment strategies.

METHODS

We have conducted a blinded review of the pathology of 519 familial and 651 sporadic pancreatic cancers within the National Familial Pancreas Tumor Registry. Patients with familial pancreatic cancer were defined as individuals from families in which at least a pair of first-degree relatives have been diagnosed with pancreatic cancer.

RESULTS

Overall, there were no statistically significant differences in histologic subtypes between familial and sporadic pancreatic cancers (p > 0.05). In addition, among surgical resection specimens within the study cohort, no statistically significant differences in mean tumor size, location, perineural invasion, angiolymphatic invasion, lymph node metastasis and pathologic stage were identified (p > 0.05).

CONCLUSIONS

Similar to sporadic pancreatic cancer, familial pancreatic cancer is morphologically and prognostically a heterogeneous disease.

Clinical characteristics of adenosquamous carcinoma of the pancreas: a matched case-control study

OBJECTIVES

Adenosquamous carcinoma of the pancreas (ASC) is a variant of pancreatic ductal adenocarcinoma (PDAC), but the prognosis remains unclear. The purpose of this study was to clarify the prognosis of ASC using a matched case-control design.

METHODS

We evaluated clinical characteristics of ASC treated between 2001 and 2011 in our institution. As controls, PDAC cases matched with ASC cases for sex, age, pretreatment Eastern Cooperative Oncology Group performance status, location, initial therapy and American Joint Committee on Cancer TNM staging for pancreatic cancer were also evaluated.

RESULTS

Of the 914 cases of pancreatic neoplasm, 28 cases (3.06%) of ASC were identified, and 56 cases of PDAC were matched as controls. Median overall survival (OS) was significantly worse for ASC (8.38 months) than for PDAC (15.75 months; hazard ratio [HR], 1.94; 95% confidence interval, 1.07-3.51; P = 0.026). Of the 22 unresected cases, median OS was again significantly worse for ASC (4.67 months) than for PDAC (12.36 months; HR, 2.39; 95% confidence interval, 1.27-4.51; P = 0.007).

CONCLUSION

These results demonstrate that ASC is more aggressive than PDAC.