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

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.

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.

Antitumor mechanisms and future clinical applications of the natural product triptolide

Triptolide (TPL) is a compound sourced from Tripterygium wilfordii Hook. F., a traditional Chinese medicinal herb recognized for its impressive anti-inflammatory, anti-angiogenic, immunosuppressive, and antitumor qualities. Notwithstanding its favorable attributes, the precise mechanism through which TPL influences tumor cells remains enigmatic. Its toxicity and limited water solubility significantly impede the clinical application of TPL. We offer a comprehensive overview of recent research endeavors aimed at unraveling the antitumor mechanism of TPL in this review. Additionally, we briefly discuss current strategies to effectively manage the challenges associated with TPL in future clinical applications. By compiling this information, we aim to enhance the understanding of the underlying mechanisms involved in TPL and identify potential avenues for further advancement in antitumor therapy.

Pancreatic Adenosquamous Carcinoma Discovered Upon a Resection for Neck Tuberculous Lymphadenitis: A Case Report

Cancer (including pancreatic cancer) can develop following a Mycobacterium tuberculosis infection within one year of tuberculosis infection. However, it is unclear whether tuberculosis infection increases the risk of developing adenosquamous carcinoma of the pancreas (ASCP), an extremely rare cancer with a poorer prognosis than pancreatic ductal adenocarcinoma (PDAC). Herein, we report a case of rapid growing ASCP discovered upon a resection for neck tuberculous lymphadenitis. The patient was a 57-year-old woman. An excisional biopsy of the swollen right neck lymph nodes revealed tuberculous lymphadenitis. One month after the biopsy, an abdominal computed tomography scan showed a 2.0 cm (diameter) ischemic tumor in the pancreatic tail. The tissue obtained using endoscopic ultrasonography-guided fine-needle aspiration led to the pathological diagnosis of ASCP. Two months after the biopsy, the tumor had grown to 3.5 cm (diameter), and invasion of the stomach and colon was suspected. Distal pancreatectomy, splenectomy, partial gastrectomy, and transverse colectomy were performed. The final diagnosis was ASCP (4.7 cm, pT3, pN0, cM0, and pStage IIA). Postoperative adjuvant combination chemotherapy combined with antituberculosis drugs was administered orally. We report the first case of rapidly growing adenosquamous carcinoma resected from the pancreas in association with tuberculous lymphadenitis. Additional evidence is needed to confirm that tuberculosis infection increases the risk of developing pancreatic adenosquamous cell carcinoma because its potential role in promoting squamous metaplasia is unclear.

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.

Pancreatic Adenosquamous Carcinoma Presenting as a Gastric Lesion

Pancreatic adenosquamous carcinoma, an uncommon subtype of pancreatic adenocarcinoma, is characterized by an aggressive course and poor prognosis, with the only method of cure being surgical resection at the time of diagnosis. It is a complex condition, as it presents nonspecifically and remains indistinguishable from pancreatic adenocarcinoma without imaging techniques despite its aggressive nature. We report an atypical case of pancreatic adenosquamous carcinoma, presenting with marked anemia, found on endoscopy to have a gastric mass. This is of interest to readers as a reminder that pancreatic cancers may present with gastric invasion and should remain on the differential diagnosis for gastric lesions.

Decoding the basis of histological variation in human cancer

Molecular abnormalities that shape human neoplasms dissociate their phenotypic landscape from that of the healthy counterpart. Through the lens of a microscope, tumour pathology optically captures such aberrations projected onto a tissue slide and has categorized human epithelial neoplasms into distinct histological subtypes based on the diverse morphogenetic and molecular programmes that they manifest. Tumour histology often reflects tumour aggressiveness, patient prognosis and therapeutic vulnerability, and thus has been used as a de facto diagnostic tool and for making clinical decisions. However, it remains elusive how the diverse histological subtypes arise and translate into pleiotropic biological phenotypes. Molecular analysis of clinical tumour tissues and their culture, including patient-derived organoids, and add-back genetic reconstruction of tumorigenic pathways using gene engineering in culture models and rodents further elucidated molecular mechanisms that underlie morphological variations. Such mechanisms include genetic mutations and epigenetic alterations in cellular identity codes that erode hard-wired morphological programmes and histologically digress tumours from the native tissues. Interestingly, tumours acquire the ability to grow independently of the niche-driven stem cell ecosystem along with these morphological alterations, providing a biological rationale for histological diversification during tumorigenesis. This Review comprehensively summarizes our current understanding of such plasticity in the histological and lineage commitment fostered cooperatively by molecular alterations and the tumour environment, and describes basic and clinical implications for future cancer therapy.

Loss of chromosome 9p21 is associated with a poor prognosis in adenosquamous carcinoma of the pancreas

Adenosquamous carcinoma of the pancreas (ASCP) is a rare histological subtype of pancreatic cancer with a poor prognosis and a high metastasis rate. However, little is known about its genomic landscape and prognostic biomarkers. A total of 48 ASCP specimens and 98 pancreatic ductal adenocarcinoma (PDAC) tumour specimens were sequenced to explore the genomic landscape and prognostic biomarkers. The homozygous deletion of the 9p21.3 region (including CDKN2A, CDKN2B, and MTAP) (9p21 loss) occurred in both ASCP and PDAC, and a higher frequency of 9p21 loss was observed in ASCP (12.5% vs 2.0%, P = 0.022). Notably, 9p21 loss was significantly associated with poor disease-free survival (DFS) in ASCP patients (mDFS (Median DFS) = 4.17 vs 7.33 months, HR (Hazard Ratio) = 3.70, P = 0.009). The most common gene alterations in patients with ASCP were KRAS (96%), TP53 (81%), CDKN2A (42%), SMAD4 (21%), CDKN2B (13%), and FAT3 (13%). The mutation rates of ACVR2A (6.25% vs 0%), FANCA (6.25% vs 0%), RBM10 (6.25% vs 0%), and SPTA1 (8.33% vs 1.02%) were significantly higher in ASCP than in PDAC. In conclusion, we have comprehensively described the genomic landscape of the largest cohort of ASCP patients to date and highlight that 9p21 loss may be a promising prognostic biomarker for ASCP, which provides a molecular basis for prognosis prediction and new therapeutic strategies for ASCP.

Single-cell mapping identifies MSI+ cells as a common origin for diverse subtypes of pancreatic cancer

Identifying the cells from which cancers arise is critical for understanding the molecular underpinnings of tumor evolution. To determine whether stem/progenitor cells can serve as cells of origin, we created a Msi2-CreERT2 knock-in mouse. When crossed to CAG-LSL-MycT58A mice, Msi2-CreERT2 mice developed multiple pancreatic cancer subtypes: ductal, acinar, adenosquamous, and rare anaplastic tumors. Combining single-cell genomics with computational analysis of developmental states and lineage trajectories, we demonstrate that MYC preferentially triggers transformation of the most immature MSI2+ pancreas cells into multi-lineage pre-cancer cells. These pre-cancer cells subsequently diverge to establish pancreatic cancer subtypes by activating distinct transcriptional programs and large-scale genomic changes, and enforced expression of specific signals like Ras can redirect subtype specification. This study shows that multiple pancreatic cancer subtypes can arise from a common pool of MSI2+ cells and provides a powerful model to understand and control the programs that shape divergent fates in pancreatic cancer.

A Simple Overview of Pancreatic Cancer Treatment for Clinical Oncologists

Pancreatic cancer (PDAC) is one of the most aggressive solid tumors and is showing increasing incidence. The aim of our review is to provide practical help for all clinical oncologists and to summarize the current management of PDAC using a simple "ABC method" (A-anatomical resectability, B-biological resectability and C-clinical conditions). For anatomically resectable PDAC without any high-risk factors (biological or conditional), the actual standard of care is represented by surgery followed by adjuvant chemotherapy. The remaining PDAC patients should all be treated with initial systemic therapy, though the intent for each is different: for borderline resectable patients, the intent is neoadjuvant; for locally advanced patients, the intent is conversion; and for metastatic PDAC patients, the intent remains just palliative. The actual standard of care in first-line therapy is represented by two regimens: FOLFIRINOX and gemcitabine/nab-paclitaxel. Recently, NALIRIFOX showed positive results over gemcitabine/nab-paclitaxel. There are limited data for maintenance therapy after first-line treatment, though 5-FU or FOLFIRI after initial FOLFIRINOX, and gemcitabine, after initial gemcitabine/nab-paclitaxel, might be considered. We also dedicate space to special rare conditions, such as PDAC with germline BRCA mutations, pancreatic acinar cell carcinoma and adenosquamous carcinoma of the pancreas, with few clinically relevant remarks.

Pancreatic Cancer and Detection Methods

The pancreas is a vital organ with exocrine and endocrine functions. Pancreatitis is an inflammation of the pancreas caused by alcohol consumption and gallstones. This condition can heighten the risk of pancreatic cancer (PC), a challenging disease with a high mortality rate. Genetic and epigenetic factors contribute significantly to PC development, along with other risk factors. Early detection is crucial for improving PC outcomes. Diagnostic methods, including imagining modalities and tissue biopsy, aid in the detection and analysis of PC. In contrast, liquid biopsy (LB) shows promise in early tumor detection by assessing biomarkers in bodily fluids. Understanding the function of the pancreas, associated diseases, risk factors, and available diagnostic methods is essential for effective management and early PC detection. The current clinical examination of PC is challenging due to its asymptomatic early stages and limitations of highly precise diagnostics. Screening is recommended for high-risk populations and individuals with potential benign tumors. Among various PC screening methods, the N-NOSE plus pancreas test stands out with its high AUC of 0.865. Compared to other commercial products, the N-NOSE plus pancreas test offers a cost-effective solution for early detection. However, additional diagnostic tests are required for confirmation. Further research, validation, and the development of non-invasive screening methods and standardized scoring systems are crucial to enhance PC detection and improve patient outcomes. This review outlines the context of pancreatic cancer and the challenges for early detection.

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.

Genomic landscape and clinical features of rare subtypes of pancreatic cancer: analysis with the national database of Japan

BACKGROUND

Special subtypes of pancreatic cancer, such as acinar cell carcinoma (ACC), adenosquamous carcinoma (ASC), and anaplastic carcinoma of the pancreas (ACP), are rare, and so data on them are limited. Using the C-CAT database, we analyzed clinical and genomic characteristics of patients with these and evaluated differences on comparison with pancreatic ductal adenocarcinoma (PDAC) patients.

METHODS

We retrospectively reviewed data on 2691 patients with unresectable pancreatic cancer: ACC, ASC, ACP, and PDAC, entered into C-CAT from June 2019 to December 2021. The clinical features, MSI/TMB status, genomic alterations, overall response rate (ORR), disease control rate (DCR), and time to treatment failure (TTF) on receiving FOLFIRINOX (FFX) or GEM + nab-PTX (GnP) therapy as first-line treatment were evaluated.

RESULTS

Numbers of patients with ACC, ASC, ACP, and PDAC were 44 (1.6%), 54 (2.0%), 25 (0.9%), and 2,568 (95.4%), respectively. KRAS and TP53 mutations were prevalent in ASC, ACP, and PDAC (90.7/85.2, 76.0/68.0, and 85.1/69.1%, respectively), while their rates were both significantly lower in ACC (13.6/15.9%, respectively). Conversely, the rate of homologous recombination-related (HRR) genes, including ATM and BRCA1/2, was significantly higher in ACC (11.4/15.9%) than PDAC (2.5/3.7%). In ASC and ACP, no significant differences in ORR, DCR, or TTF between FFX and GnP were noted, while ACC patients showed a trend toward higher ORR with FFX than GnP (61.5 vs. 23.5%, p = 0.06) and significantly more favorable TTF (median 42.3 vs. 21.0 weeks, respectively, p = 0.004).

CONCLUSIONS

ACC clearly harbors different genomics compared with PDAC, possibly accounting for differences in treatment efficacy.

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.

Pancreatic adenosquamous carcinoma: A population level analysis of epidemiological trends and prognosis

BACKGROUND

The incidence and mortality of pancreatic adenosquamous carcinoma (PASC) have received little attention. The goal of our study was to explore the overall epidemiological trend of PASC at the population level.

METHODS

The Surveillance, Epidemiology, and End Results database was used to collect the incidence, incidence-based (IB) mortality, and patient details for PASC from 2000 to 2017. The Joinpoint regression tool was used to examine the trends in incidence and IB mortality. The Kaplan-Meier approach was used for survival analysis. Univariate and multivariate Cox regression analyses were used to determine the independent prognostic factors.

RESULTS

We included 815 patients with PASC in the study. The incidence of PASC continuously increased from 2000 to 2017, with an annual percentage change (APC) of 3.9% (95% CI: 2.2%-5.7%, p < 0.05). IB mortality also increased continuously, with an APC of 5.0% (95% CI: 2.5%-7.6%, p < 0.05). Multivariate Cox regression analysis revealed that age, treatment, regional lymph node involvement, and tumor size were independent prognostic factors. Nomograms were created for PASC to predict 1- and 2-year survival probabilities, respectively.

CONCLUSIONS

The incidence and IB mortality of PASC had a sustained and rapid increase, indicating that the preventive and treatment measures for PASC were not ideal. We must identify the significance of this condition as soon as possible, and commit greater attention and resources to PASC research.

The PD-L1 Expression and Tumor-Infiltrating Immune Cells Predict an Unfavorable Prognosis in Pancreatic Ductal Adenocarcinoma and Adenosquamous Carcinoma

The tumor microenvironment (TME) plays a vital role in the development, progression, and metastasis of pancreatic cancer (PC). The composition of the TME and its potential prognostic value remains to be fully understood, especially in adenosquamous carcinoma of pancreas (ASCP) patients. Immunohistochemistry was used to explore the clinical significance of CD3, CD4, CD8, FoxP3, and PD-L1 expression within the TME and to identify correlations with the prognosis of PC in a series of 29 patients with ASCP and 54 patients with pancreatic ductal adenocarcinoma (PDAC). Data from the Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) were accessed to obtain the scRNA-seq data and transcriptome profiles. Seurat was used to process the scRNA-seq data, and CellChat was used to analyze cell-cell communication. CIBERSORT was used to approximate the constitution of tumor-infiltrating immune cell (TICs) profiles. Higher levels of PD-L1 were linked with a shorter overall survival in ASCP (p = 0.0007) and PDAC (p = 0.0594). A higher expression of CD3+ and CD8+ T-cell infiltration was significantly correlated with a better prognosis in PC. By influencing the composition of tumor-infiltrating immune cells (TICs), high levels of PD-L1 expression are linked with a shorter overall survival in ASCP and PDAC.

Cytokeratin 13 (CK13) expression in cancer: a tissue microarray study on 10,439 tumors

Cytokeratin 13 (CK13) is a type I acidic low molecular weight cytokeratin, which is mainly expressed in urothelium and in the squamous epithelium of various sites of origin. Loss of CK13 has been implicated in the development and progression of squamous epithelial neoplasms. To comprehensively determine CK13 expression in normal and neoplastic tissues, a tissue microarray containing 10,439 samples from 131 different tumor types and subtypes as well as 608 samples of 76 different normal tissue types was analyzed by immunohistochemistry. CK13 immunostaining was detectable in 42 (32.1%) of the 131 tumor categories including 24 (18.3%) tumor types with at least one strongly positive case. The highest rate of positive staining was found in various urothelial neoplasms (52.1-92.3%) including Brenner tumor of the ovary (86.8%) and in squamous cell carcinomas from various sites of origin (39.1-77.6%), Warthin tumors of parotid glands (66.7%), adenosquamous carcinomas of the cervix (33.3%), thymomas (16.0%), and endometroid carcinomas of the ovary (15.3%). Twenty other epithelial or germ cell neoplasms showed - a usually weak - CK13 positivity in less than 15% of the cases. In bladder cancer, reduced CK13 expression was linked to high grade and advanced stage (p < 0.0001 each). In squamous cell carcinoma of the cervix, reduced CK13 immunostaining was related to high grade (p = 0.0295) and shortened recurrence-free (p = 0.0094) and overall survival (p = 0.0274). In a combined analysis of 1,151 squamous cell carcinomas from 11 different sites of origin, reduced CK13 staining was linked to high grade (p = 0.0050). Our data provide a comprehensive overview on CK13 expression in normal and neoplastic human tissues. CK13 expression predominates in urothelial neoplasms and in squamous cell carcinomas of different organs, and a loss of CK13 expression is associated with aggressive disease in these tumors.

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.

LY6D marks pre-existing resistant basosquamous tumor subpopulations

Improved response to canonical therapies requires a mechanistic understanding of dynamic tumor heterogeneity by identifying discrete cellular populations with enhanced cellular plasticity. We have previously demonstrated distinct resistance mechanisms in skin basal cell carcinomas, but a comprehensive understanding of the cellular states and markers associated with these populations remains poorly understood. Here we identify a pre-existing resistant cellular population in naive basal cell carcinoma tumors marked by the surface marker LY6D. LY6D+ tumor cells are spatially localized and possess basal cell carcinoma and squamous cell carcinoma-like features. Using computational tools, organoids, and spatial tools, we show that LY6D+ basosquamous cells represent a persister population lying on a central node along the skin lineage-associated spectrum of epithelial states with local environmental and applied therapies determining the kinetics of accumulation. Surprisingly, LY6D+ basosquamous populations exist in many epithelial tumors, such as pancreatic adenocarcinomas, which have poor outcomes. Overall, our results identify the resistant LY6D+ basosquamous population as an important clinical target and suggest strategies for future therapeutic approaches to target them.

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.

Adenosquamous carcinoma of the pancreas: two case reports and review of the literature

Background

Among the total reported cases of pancreatic duct adenocarcinomas, around 1–2.9% are adenosquamous carcinomas of the pancreas. Due to limited data, preoperative diagnosis is a great challenge for physicians, and it is usually set post-operational, based on the pathologist report. We operated on two cases of adenosquamous carcinoma of the pancreas, which we present alongside the operation and treatment planning.

Case report

A 69-year-old Caucasian female and a 63-year-old Caucasian male presented themselves with jaundice in our department. The abdomen computed tomography and magnetic resonance imaging scans revealed lesions of the pancreas. A pancreas–duodenumectomy was performed in both patients, and the post-operational histology analysis revealed adenosquamous carcinoma of the pancreas head. The patients were discharged in good condition and received further chemotherapy treatment after surgery.

Conclusions

Two case reports of adenosquamous carcinoma of the pancreas are described here, which both underwent surgery resection. The limited available literature on this topic substantially limits the knowledge and guidance on treatment. A summarization of the available literature is attempted, alongside a description of possible fields of future research.

Correlation of transcriptional subtypes with a validated CT radiomics score in resectable pancreatic ductal adenocarcinoma

OBJECTIVES

Transcriptional classifiers (Bailey, Moffitt and Collison) are key prognostic factors of pancreatic ductal adenocarcinoma (PDAC). Among these classifiers, the squamous, basal-like, and quasimesenchymal subtypes overlap and have inferior survival. Currently, only an invasive biopsy can determine these subtypes, possibly resulting in treatment delay. This study aimed to investigate the association between transcriptional subtypes and an externally validated preoperative CT-based radiomic prognostic score (Rad-score).

METHODS

We retrospectively evaluated 122 patients who underwent resection for PDAC. All treatment decisions were determined at multidisciplinary tumor boards. Tumor Rad-score values from preoperative CT were dichotomized into high or llow categories. The primary endpoint was the correlation between the transcriptional subtypes and the Rad-score using multivariable linear regression, adjusting for clinical and histopathological variables (i.e., tumor size). Prediction of overall survival (OS) was secondary endpoint.

RESULTS

The Bailey transcriptional classifier significantly associated with the Rad-score (coefficient = 0.31, 95% confidence interval [CI]: 0.13-0.44, p = 0.001). Squamous subtype was associated with high Rad-scores while non-squamous subtype was associated with low Rad-scores (adjusted p = 0.03). Squamous subtype and high Rad-score were both prognostic for OS at multivariable analysis with hazard ratios (HR) of 2.79 (95% CI: 1.12-6.92, p = 0.03) and 4.03 (95% CI: 1.42-11.39, p = 0.01), respectively.

CONCLUSIONS

In patients with resectable PDAC, an externally validated prognostic radiomic model derived from preoperative CT is associated with the Bailey transcriptional classifier. Higher Rad-scores were correlated with the squamous subtype, while lower Rad-scores were associated with the less lethal subtypes (immunogenic, ADEX, pancreatic progenitor).

KEY POINTS

• The transcriptional subtypes of PDAC have been shown to have prognostic importance but they require invasive biopsy to be assessed. • The Rad-score radiomic biomarker, which is obtained non-invasively from preoperative CT, correlates with the Bailey squamous transcriptional subtype and both are negative prognostic biomarkers. • The Rad-score is a promising non-invasive imaging biomarker for personalizing neoadjuvant approaches in patients undergoing resection for PDAC, although additional validation studies are required.

Development and external validation of a dynamic nomogram to predict the survival for adenosquamous carcinoma of the pancreas

Objective

We aimed to develop a nomogram to predict the survival and prognosis of adenosquamous carcinoma of the pancreas (ASCP).

Background

Adenosquamous carcinoma of the pancreas (ASCP) is a relatively rare histological subtype of pancreatic exocrine neoplasms. It was reported a worse survival in ASCP than in pancreatic adenocarcinoma (PDAC). Prediction of ASCP prognosis is of great importance.

Methods

Histologically confirmed ASCP patients from the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program database were finally enrolled and divided into development and internal validation cohorts. Moreover, a multi-center cohort of 70 patients from China was registered as the external validation. A nomogram was developed based on independent predictors of ASCP determined in multivariable analysis.

Results

A total of 233 patients from SEER were finally included. Univariate and Multivariate analysis showed that tumor size, radiotherapy, chemotherapy, and lymph node ratio (LNR) were considered the independent prognostic indicators. We developed a nomogram according to these four parameters. The C index of the nomogram in the development cohort was 0.696. Through analysis of the area under the curve (AUC) of the different cohorts, we observed that the predictive efficacy of the nomogram for 1-, and 2-year overall survival (OS) were better than those of the American Joint Committee on Cancer (AJCC) TNM (8th) staging system both in the development and validation cohort. External validation confirmed that 1-year survival is 67.2% vs. 29.7%, similar to the internal cohort analysis.

Conclusion

The nomogram showed good performance in predicting the survival of ASCP. It could help surgeons to make clinical decisions and develop further plans.

Proteomic analysis reveals key differences between squamous cell carcinomas and adenocarcinomas across multiple tissues

Squamous cell carcinoma (SCC) and adenocarcinoma (AC) are two main histological subtypes of solid cancer; however, SCCs are derived from different organs with similar morphologies, and it is challenging to distinguish the origin of metastatic SCCs. Here we report a deep proteomic analysis of 333 SCCs of 17 organs and 69 ACs of 7 organs. Proteomic comparison between SCCs and ACs identifies distinguishable pivotal pathways and molecules in those pathways play consistent adverse or opposite prognostic roles in ACs and SCCs. A comparison between common and rare SCCs highlights lipid metabolism may reinforce the malignancy of rare SCCs. Proteomic clusters reveal anatomical features, and kinase-transcription factor networks indicate differential SCC characteristics, while immune subtyping reveals diverse tumor microenvironments across and within diagnoses and identified potential druggable targets. Furthermore, tumor-specific proteins provide candidates with differentially diagnostic values. This proteomics architecture represents a public resource for researchers seeking a better understanding of SCCs and ACs.

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.

Basic pancreatic lesions: Radiologic-pathologic correlation

The basic pancreatic lesions include location, size, shape, number, capsule, calcification/calculi, hemorrhage, cystic degeneration, fibrosis, pancreatic duct alterations, and microvessel. One or more basic lesions form a kind of pancreatic disease. As recognizing the characteristic imaging features of pancreatic basic lesions and their relationships with pathology aids in differentiating the variety of pancreatic diseases. The purpose of this study is to review the pathological and imaging features of the basic pancreatic lesions.

Development and Validation of Nomograms to Predict Overall Survival and Cancer-Specific Survival in Patients With Pancreatic Adenosquamous Carcinoma

Background

Pancreatic adenosquamous carcinoma (PASC) is a heterogeneous group of primary pancreatic cancers characterized by the coexistence of both glandular and squamous differentiation. The aim of this study was to develop nomograms to predict survival outcomes in patients with PASC.

Methods

In this retrospective study, data on PASC, including clinicopathological characteristics, treatments, and survival outcomes, were collected from the SEER database between 2000 and 2018. The primary endpoints were overall survival (OS) and cancer-specific survival (CSS). The eligible patients were randomly divided into development cohort and validation cohort in a 7:3 ratio. The nomograms for prediction of OS and CSS were constructed by the development cohort using a LASSO-Cox regression model, respectively. Besides the model performance was internally and externally validated by examining the discrimination, calibration, and clinical utility.

Results

A total of 632 consecutive patients who had been diagnosed with PASC were identified and randomly divided into development (n = 444) and validation (n = 188) cohorts. In the development cohort, the estimated median OS was 7.0 months (95% CI: 6.19-7.82) and the median CSS was 7.0 months (95% CI: 6.15-7.85). In the validation cohort, the estimated median OS was 6.0 months (95% CI: 4.46-7.54) and the median CSS was 7.0 months (95% CI: 6.25-7.75). LASSO-penalized COX regression analysis identified 8 independent predictors in the OS prediction model and 9 independent risk factors in the CSS prediction model: age at diagnosis, gender, year of diagnosis, tumor location, grade, stage, size, lymph node metastasis, combined metastasis, surgery, radiation, and chemotherapy. The Harrell C index and time-dependent AUCs manifested satisfactory discriminative capabilities of the models. Calibration plots showed that both models were well calibrated. Furthermore, decision curves indicated good utility of the nomograms for decision-making.

Conclusion

Nomogram-based models to evaluate personalized OS and CSS in patients with PASC were developed and well validated. These easy-to-use tools will be useful methods to calculate individualized estimate of survival, assist in risk stratification, and aid clinical decision-making.

Adenosquamous cancer of the pancreas: A multicenter retrospective study

INTRODUCTION

Adenosquamous cancer of the pancreas (ASCP) is an aggressive, infrequent subtype of pancreatic cancer that combines a glandular and squamous component and is associated with poor survival.

METHODS

Multicenter retrospective observational study carried out at three Spanish hospitals. The study period was: January 2010- August 2020. A descriptive analysis of the data was performed, as well as an analysis of global and disease-free survival using the Kaplan-Meier statistic.

RESULTS

Of a total of 668 pancreatic cancers treated surgically, twelve were ASCP (1.8%). Patient mean age was 69.2±7.4 years. Male/female ratio was 1:1. The main symptom was jaundice (seven patients). Correct preoperative diagnosis was obtained in only two patients. Nine pancreatoduodenectomies and three distal pancreatectosplenectomies were performed. 25% had major complications. Mean tumor size was 48.6±19.4 mm. Nine patients received adjuvant chemotherapy. Median survival time was 5.9 months, and median disease-free survival was 4.6 months. 90% of patients presented recurrence. Ten of the twelve patients in the study (83.3%) died, with disease progression being the cause in eight. Of the two surviving patients, one is disease-free and the other has liver metastases.

CONCLUSION

ASCP is a very rare pancreatic tumor with aggressive behavior. It is rarely diagnosed preoperatively. The best treatment, if feasible, is surgery followed by the standard chemotherapy regimens for pancreatic adenocarcinoma.

On the Origin of Pancreatic Cancer: Molecular Tumor Subtypes in Perspective of Exocrine Cell Plasticity

Pancreatic ductal adenocarcinoma (PDAC) is a devastating type of cancer. While many studies have shed light into the pathobiology of PDAC, the nature of PDAC's cell of origin remains under debate. Studies in adult pancreatic tissue have unveiled a remarkable exocrine cell plasticity including transitional states, mostly exemplified by acinar to ductal cell metaplasia, but also with recent evidence hinting at duct to basal cell transitions. Single-cell RNA sequencing has further revealed intrapopulation heterogeneity among acinar and duct cells. Transcriptomic and epigenomic relationships between these exocrine cell differentiation states and PDAC molecular subtypes have started to emerge, suggesting different ontogenies for different tumor subtypes. This review sheds light on these diverse aspects with particular focus on studies with human cells. Understanding the "masked ball" of exocrine cells at origin of PDAC and leaving behind the binary acinar vs duct cell classification may significantly advance our insights in PDAC biology.

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.

Targeted-Gene Sequencing and Bioinformatics Analysis of Patients with Pancreatic Mucoepidermoid Carcinoma: A Case Report and Literature Review

Background

Primary pancreatic mucoepidermoid carcinoma (MEC) is an extremely rare malignant tumor with unclear etiology and pathogenesis. There are only eleven reported cases in English papers published from 1959 to 2020. MEC generally occurs in the salivary gland, but cases in the pancreas have also been reported. Although being considered as a low-grade indolent carcinoma, pancreatic MEC always invades the surrounding lymph node and metastasizes. The prognosis of pancreatic MEC is unsatisfactory. To date, the genetic alterations, mechanistic relationships among mutated genes and signaling pathways of pancreatic MEC are unclear.

Patient and Methods

This paper presents a case of rare primary pancreatic MEC in a 56-year-old male patient with liver metastasis. Radical surgery of distal pancreatectomy and radiofrequency ablation (RFA) of two liver metastatic lesions is conducted. Targeted-gene sequencing and bioinformatics analysis tools, including STRING, DAVID, cBioPortal, DGidb and Human Protein Atlas database (HPA), are used to clarify the biological functions and features of mutated genes in pancreatic MEC.

Results

Eight gene mutations (TP53, KRAS, ATR, FLI1, FLT4, MAGI2, RBM10, and TNFAIP3) were observed, and a tumor mutation burden (TMB) of 5.6 muts/Mb was calculated in the pancreatic MEC using targeted-gene sequencing. The patient subsequently underwent adjuvant chemotherapy and died three months after surgery. Gene–gene interaction network was constructed, which showed the significant interactions among eight mutated genes. In terms of the functions and pathways of eight gene mutations based on GO and KEGG, 20 tumor-related results are presented in this paper, Furthermore, the biological functions and features of pancreatic MEC are further compared with pancreatic ductal adenocarcinoma.

Conclusion

Pancreatic MEC requires early and effective treatment, and lymph node metastases and multiple organ metastases were unfavorable prognostic factors. Pancreatic MEC can be compared with other pancreatic cancers that have characteristic clinical phenotype, molecular alterations, functional information and enrichment pathway.

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.

The origins and consequences of UPF1 variants in pancreatic adenosquamous carcinoma

Pancreatic adenosquamous carcinoma (PASC) is an aggressive cancer whose mutational origins are poorly understood. An early study reported high-frequency somatic mutations affecting UPF1, a nonsense-mediated mRNA decay (NMD) factor, in PASC, but subsequent studies did not observe these lesions. The corresponding controversy about whether UPF1 mutations are important contributors to PASC has been exacerbated by a paucity of functional studies. Here, we modeled two UPF1 mutations in human and mouse cells to find no significant effects on pancreatic cancer growth, acquisition of adenosquamous features, UPF1 splicing, UPF1 protein, or NMD efficiency. We subsequently discovered that 45% of UPF1 mutations reportedly present in PASCs are identical to standing genetic variants in the human population, suggesting that they may be non-pathogenic inherited variants rather than pathogenic mutations. Our data suggest that UPF1 is not a common functional driver of PASC and motivate further attempts to understand the genetic origins of these malignancies.

Morphologic and Molecular Landscape of Pancreatic Cancer Variants as the Basis of New Therapeutic Strategies for Precision Oncology

To date, pancreatic cancer is still one of the most lethal cancers in the world, mainly due to the lack of early diagnosis and personalized treatment strategies. In this context, the possibility and the opportunity of identifying genetic and molecular biomarkers are crucial to improve the feasibility of precision medicine. In 2019, the World Health Organization classified pancreatic ductal adenocarcinoma cancer (the most common pancreatic tumor type) into eight variants, according to specific histomorphological features. They are: colloid carcinoma, medullary carcinoma, adenosquamous carcinoma, undifferentiated carcinoma, including also rhabdoid carcinoma, undifferentiated carcinoma with osteoclast-like giant cells, hepatoid carcinoma, and signet-ring/poorly cohesive cells carcinoma. Interestingly, despite the very low incidence of these variants, innovative high throughput genomic/transcriptomic techniques allowed the investigation of both somatic and germline mutations in each specific variant, paving the way for their possible classification according also to specific alterations, along with the canonical mutations of pancreatic cancer (KRAS, TP53, CDKN2A, SMAD4). In this review, we aim to report the current evidence about genetic/molecular profiles of pancreatic cancer variants, highlighting their role in therapeutic and clinical impact.

TOP2A expression predicts responsiveness to carfilzomib in myeloma and informs novel combinatorial strategies for enhanced proteasome inhibitor cell killing

Microarray was utilized to determine if a genetic signature associated with resistance to carfilzomib (CFZ) could be identified. Twelve human myeloma (MM) cell lines (HMCLs) were treated with CFZ and a cell-viability profile was assessed categorizing HMCLs as sensitive or resistant to CFZ. The gene expression profiles (GEP) of untreated resistant versus sensitive HMCLs revealed 29 differentially expressed genes. TOP2A, an enzyme involved in cell cycle and proliferation, was overexpressed in carfilzomib-resistant HMCLs. TOP2A protein expression levels, evaluated utilizing trephine biopsy specimens acquired prior to treatment with proteasome inhibitors, were higher in patients failing to achieve a response when compared to responding patients. Logistic-regression analysis confirmed that TOP2A protein expression was a highly significant predictor of response to PIs (AUC 0.738). Further, the combination of CFZ with TOP2A inhibitors, demonstrated synergistic cytotoxic effects in vitro, providing a rationale for combining topoisomerase inhibitors with CFZ to overcome resistance in MM.

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.

Genomic and Epigenomic Landscaping Defines New Therapeutic Targets for Adenosquamous Carcinoma of the Pancreas

Adenosquamous cancer of the pancreas (ASCP) is a subtype of pancreatic cancer that has a worse prognosis and greater metastatic potential than the more common pancreatic ductal adenocarcinoma (PDAC) subtype. To distinguish the genomic landscape of ASCP and identify actionable targets for this lethal cancer, we applied DNA content flow cytometry to a series of 15 tumor samples including five patient-derived xenografts (PDX). We interrogated purified sorted tumor fractions from these samples with whole-genome copy-number variant (CNV), whole-exome sequencing, and Assay for Transposase-Accessible Chromatin using sequencing (ATAC-seq) analyses. These identified a variety of somatic genomic lesions targeting chromatin regulators in ASCP genomes that were superimposed on well-characterized genomic lesions including mutations in TP53 (87%) and KRAS (73%), amplification of MYC (47%), and homozygous deletion of CDKN2A (40%) that are common in PDACs. Furthermore, a comparison of ATAC-seq profiles of three ASCP and three PDAC genomes using flow-sorted PDX models identified genes with accessible chromatin unique to the ASCP genomes, including the lysine methyltransferase SMYD2 and the pancreatic cancer stem cell regulator RORC in all three ASCPs, and a FGFR1-ERLIN2 fusion associated with focal CNVs in both genes in a single ASCP. Finally, we demonstrate significant activity of a pan FGFR inhibitor against organoids derived from the FGFR1-ERLIN2 fusion-positive ASCP PDX model. Our results suggest that the genomic and epigenomic landscape of ASCP provide new strategies for targeting this aggressive subtype of pancreatic cancer. SIGNIFICANCE: These data provide a unique description of the ASCP genomic and epigenomic landscape and identify candidate therapeutic targets for this dismal cancer.

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.

18F-FDG PET/CT feature of pancreatic adenosquamous carcinoma with pathological correlation

PURPOSE

To investigate ¹⁸F-FDG PET/CT feature of pancreatic adenosquamous carcinoma (PASC) in contrast with conventional pancreatic ductal adenocarcinoma (PDAC), and its correlation with pathological findings.

PATIENTS AND METHODS

Patients with PASC or PDAC confirmed by surgical pathology, who underwent FDG PET/CT scanning before surgical resection, were retrospectively studied. PASC group and conventional PDAC group included 13 and 104 patients, respectively. Delayed phase of PET/CT scanning was performed in 12 patients with PASC and 99 with PDAC. Maximum standardized value (SUVmax) was measured, and the mean retention index (RI) was calculated by ([PET_120min SUVmax]-[PET _60min SUVmax]) ÷ PET _60min SUVmax × 100%.

RESULTS

On PET/CT, all lesions of PASC group showed intense FDG uptake, and the SUVmax were significantly higher than the lesions of conventional PDAC group both on the early [10.43 ± 5.10 (4.37-24.00) vs. 7.31 ± 3.86 (1.93-21.08), P = 0.011] and delayed phase [13.29 ± 6.04 (5.72-28.16) vs. 8.84 ± 5.14 (1.92-27.58), P = 0.005]. On the delayed phase, all lesions of PASC group had increased SUVmax with positive RI value (27.04% ± 8.87%, 7.14-39.27%). For conventional PDAC group, 81 lesions had increased SUVmax with positive RI value (27.25% ± 19.10%, 1.09-104.49%), while eighteen (18.18%) lesions of PDAC group had slightly decreased SUVmax, and their RI value were negative (- 11.35% ± 13.50%, - 43.17 to - 0.14%). The proliferative index (Ki-67) of lesions of PASC group was positively correlated with both the early (P = 0.034, r = 0.671) and delayed SUVmax (P = 0.019, r = 0.721). The RI value of lesions with adjacent organ invasion in PASC group was significantly higher than those without invasion (33.25% ± 4.92% vs. 20.83% ± 7.49%, P = 0.007).

CONCLUSION

PASC has more intense FDG uptake than conventional PDAC both on early and delayed phase. RI value of PASC was positive. Negative RI value may be helpful for differentiating PDAC from PASC. SUVmax and RI value may be helpful for prediction of its malignancy and invasion.

Early relapse on adjuvant gemcitabine associated with an exceptional response to 2nd line capecitabine chemotherapy in a patient with pancreatic adenosquamous carcinoma with strong intra-tumoural expression of cytidine deaminase: a case report

BACKGROUND

Pancreatic adenosquamous carcinoma has a poor prognosis, with limited prospective trial data to guide optimal treatment. The potential impact of drug metabolism on the treatment response of patients with pancreatic adenosquamous carcinoma is largely unknown.

CASE PRESENTATION

We describe the case of a 51 year old woman with pancreatic adenosquamous carcinoma who, following surgical resection, experienced early disease relapse during adjuvant gemcitabine therapy. Paradoxically, this was followed by an exceptional response to capecitabine therapy lasting 34.6 months. Strong expression of cytidine deaminase was detected within the tumour.

CONCLUSIONS

This case study demonstrates that early relapse during adjuvant chemotherapy for pancreatic adenosquamous carcinoma may be compatible with a subsequent exceptional response to second line chemotherapy, an important observation given the poor overall prognosis of patients with adenosquamous carcinoma. Cytidine deaminase is predicted to inactivate gemcitabine and, conversely, catalyze capecitabine activation. We discuss strong intra-tumoural expression of cytidine deaminase as a potential mechanism to explain this patient's disparate responses to gemcitabine and capecitabine therapy, and highlight the benefit that may be gained from considering similar determinants of response to chemotherapy in clinical practice.

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.

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.

Squamous cell carcinoma-A rare pancreatic exocrine malignancy

A 65-year-old Caucasian female presented with abdominal symptoms and obstructive jaundice. She reported a significant pancreatic cancer history in her family. Her CT of the abdomen and pelvis showed 3.9 × 3.5 cm centrally necrotic mass within the pancreatic head, occluding the superior mesenteric and splenic veins; peripancreatic lymph nodes were enlarged, and there were many hepatic lesions. She underwent biopsy of the hepatic lesions showing metastatic tumor cells, arranged in the form of nests, with enlarged and hyperchromatic irregular nuclei with some nucleoli and moderate eosinophilic cytoplasm. Immunohistochemical staining on cancer cells was positive for CK7, P40, GATA3. These findings were concerning for poorly differentiated metastatic squamous cell carcinoma (SCC). PET-CT showed no other hypermetabolic lesions, suggestive of another primary except pancreatic head with SUV of 17.8, hepatic metastasis and 1 cm right retroperitoneal lymph node. The patient was diagnosed with metastatic SCC of the pancreas. Contrary to the well-known genetic mutations of pancreatic adenocarcinoma, the data on pancreatic SCC-related mutations is limited; however, one such mutation is BRCA-2 exon 15 germline mutation reported in a locally advanced SCC of the pancreas. The index patient is one of those rare cases in which a significant family history of pancreatic cancer was reported. We believe that some familial mutation could be responsible for this finding, i.e., occurrence of pancreatic cancer in multiple family members. Further research is necessary to explore such association.

Systemic Chemotherapy for Advanced Rare Pancreatic Histotype Tumors: A Retrospective Multicenter Analysis

OBJECTIVES

Two issues were put forth by clinicians in the management of the advanced stages of rare variants of pancreatic ductal adenocarcinoma and other exocrine histotypes with peculiar clinical and pathological features: Do chemotherapy regimens recommended in pancreatic ductal adenocarcinoma patients have a clinical activity in rare pancreatic tumors? Or should other chemotherapy combinations be considered in this subset of patients?

METHODS

We conducted a multicenter retrospective study that collected data from 2005 to 2016 at 14 Italian cancer centers with the aim to evaluate tumor response and time to progression for first- and second-line and overall survival.

RESULTS

Of approximately 4300 exocrine pancreatic cancer patients, 79 advanced cases affected by rare histological types were identified, with pancreatic acinar cell cancer (n = 23), pancreatic adenosquamous cancer (n = 16), and mucinous cystic neoplasm with an associated invasive mucinous cystadenocarcinoma (n = 15) most represented. Survival analyses for each subgroup in relation with the different chemotherapy regimens showed the lack of statistical significance correlations.

CONCLUSIONS

Because of the lack of clinical trials in patients affected by these rare pancreatic histotypes, only their molecular classification would help clinicians in future therapeutic choice.