An effective personalized approach to a rare tumor: prolonged survival in metastatic pancreatic acinar cell carcinoma based on genetic analysis and cell line development

A resected case of acinar cell carcinoma of the pancreas with liver metastasis following chemotherapy using modified FOLFIRINOX

BACKGROUND

Acinar cell carcinoma of the pancreas is a rare exocrine malignancy representing less than 1% of all pancreatic neoplasms. It has been reported that it responds to treatment differently from pancreatic ductal adenocarcinoma and the treatment algorithm for acinar cell carcinoma usually depends on the stage of the respective tumor and the patient's current status.

CASE PRESENTATION

A 60-year-old man presented with upper abdominal pain and anorexia. Abdominal ultrasonography showed a large-sized hepatic mass and he was referred to our hospital. Contrast-enhanced computed tomography demonstrated a 110-mm low-density area occupying the right hemi-liver and an enhanced mass of 70 × 56 mm in the tail of the pancreas, which seemed to directly infiltrate into the spleen. The case was diagnosed as acinar cell carcinoma with a simultaneous liver metastasis identified by liver biopsy. Upfront resection of pancreatic cancer with distant metastasis might not be considered as an optimal choice, and in this case chemotherapy was administered prior to curative resection. Chemotherapy using the modified FOLFIRINOX regimen was undertaken, resulting in a partial remission; the liver tumor reduced in size from 110 to 47 mm and the pancreatic tumor from 70 to 40 mm. The patient then safely underwent curative hepatic resection with distal pancreato-splenectomy. Histological examinations revealed small-sized atypical cells with large nuclei that had formed acinar patterns, and immunostaining with trypsin was positive in tumor cells, which was in accordance with acinar cell carcinoma. More than 3 years later, the patient is doing well without any recurrence.

CONCLUSION

Aggressive and curative surgery in combination with chemotherapy such as FOLFIRINOX could be a treatment option to achieve long-term survival in cases of acinar cell carcinoma with liver metastases.

Derivation of pancreatic acinar cell carcinoma cell line HS-1 as a patient-derived tumor organoid

Acinar cell carcinoma (ACC) of the pancreas is a malignant tumor of the exocrine cell lineage with a poor prognosis. Due to its rare incidence and technical difficulties, few authentic human cell lines are currently available, hampering detailed investigations of ACC. Therefore, we applied the organoid culture technique to various types of specimens, such as bile, biopsy, and resected tumor, obtained from a single ACC patient. Despite the initial propagation, none of these organoids achieved long-term proliferation or tolerated cryopreservation, confirming the challenging nature of establishing ACC cell lines. Nevertheless, the biopsy-derived early passage organoid developed subcutaneous tumors in immunodeficient mice. The xenograft tumor histologically resembled the original tumor and gave rise to infinitely propagating organoids with solid features and high levels of trypsin secretion. Moreover, the organoid stained positive for carboxylic ester hydrolase, a specific ACC marker, but negative for the duct cell marker CD133 and the endocrine lineage marker synaptophysin. Hence, we concluded the derivation of a novel ACC cell line of the pure exocrine lineage, designated HS-1. Genomic analysis revealed extensive copy number alterations and mutations in EP400 in the original tumor, which were enriched in primary organoids. HS-1 displayed homozygous deletion of CDKN2A, which might underlie xenograft formation from organoids. Although resistant to standard cytotoxic agents, the cell line was highly sensitive to the proteasome inhibitor bortezomib, as revealed by an in vitro drug screen and in vivo validation. In summary, we document a novel ACC cell line, which could be useful for ACC studies in the future.

Pancreatic acinar cell carcinoma: A comprehensive review

Acinar cell carcinoma (ACC) is a rare pancreatic malignancy with distinctive clinical, molecular, and morphological features. The long-term survival of ACC patients is substantially superior to that of pancreatic adenocarcinoma patients. As there are no significant patient series about ACCs, our understanding of this illness is mainly based on case reports and limited patient series. Surgical resection is the treatment of choice for patients with the disease restricted to one organ; however, with recent breakthroughs in precision medicine, medicines targeting the one-of-a-kind molecular profile of ACC are on the horizon. There are no standard treatment protocols available for people in which a total surgical resection to cure the condition is not possible. As a result of shared genetic alterations, ACCs are chemosensitive to agents with activity against pancreatic adenocarcinomas and colorectal carcinomas. The role of neoadjuvant or adjuvant chemoradiotherapy has not been established. This article aims to do a comprehensive literature study and present the most recent information on acinar cell cancer.

Exome Sequencing of Pancreatic Acinar Carcinoma Identified Distinctive Mutation Patterns

OBJECTIVES

Pancreatic acinar cell carcinoma (ACC) is a rare pancreatic cancer. The advancement of treatment is hampered because of the limited knowledge of its molecular mechanism.

METHODS

Whole-exome sequencing was performed on DNA extracted from 11 pure ACC surgical samples. Potential germline variants were removed on the basis of polymorphic databases, alternative allele frequency, coverage depth, and Catalogue of Somatic Mutations in Cancer (COSMIC) annotations after variant calling procedure. Mutation profiles and signatures were assessed through the Mutational Patterns package.

RESULTS

A median of 34 somatic mutations were detected (range, 19-60). Three novel recurrent small deletions were identified. Common pancreatic ductal adenocarcinoma mutations or neuroendocrine tumor mutants were not found. FAT atypical cadherin 4, mucin 5B, titin, and zinc finger homeobox 3 were consistently mutated across 4 independent ACC studies. A high contribution of COSMIC mutational signature 1 was seen in ACC, indicating deamination of 5-methylcytosine. The majority of the patients had COSMIC signatures 6, 15, or 20, relating to defective DNA mismatch repair. Six patients showed COSMIC mutational signature 10 because of the altered activity of DNA polymerase epsilon.

CONCLUSIONS

Distinct mutational signatures pathways were found in ACC and targeting them may improve clinical outcome.

Survival Outcomes of Acinar Cell Pancreatic Cancer: A National Cancer Database Analysis

OBJECTIVES

Acinar cell pancreatic carcinomas (ACPCs) are rare neoplasms accounting for 1% to 2% of pancreatic tumors in adults. The objective of this study is to evaluate the benefit of chemotherapy in the adjuvant setting in resected ACPC and in the palliative setting for metastatic ACPC.

METHODS

Data were obtained from all US hospitals that contributed to the National Cancer Database between 2004 and 2014. Cases were identified using the histology code 8550.

RESULTS

A total of 593 patients with ACPC were identified. The mean age was 64.4 years (range, 18-90 years), with a male preponderance (72.8%, n = 432). Localized stage disease comprised 52.3% (n = 310) of patients. Among localized ACPC patients, 88.0% (n = 191) underwent surgery and 50.6% (n = 91) received adjuvant chemotherapy. The 5-year overall survival in those who received adjuvant treatment was slightly higher than those who did not receive adjuvant treatment (46.7% vs 44.8%, P = 0.3271). Among advanced-stage ACPC patients, 67.6% received chemotherapy, which translated into improved 5-year overall survival compared with no chemotherapy (8.1% vs 0%, P < 0.0001).

CONCLUSIONS

Chemotherapy in the palliative setting for advanced-stage ACPC patients was associated with improved survival. Adjuvant therapy did not translate into significant survival benefit.

Metastatic Acinar Cell Carcinoma of the Pancreas: A Retrospective Cohort Study on Systemic Chemotherapy and Review of the Literature

OBJECTIVES

Acinar cell carcinoma of the pancreas (pACC) forms a rare subgroup of pancreatic tumors. We report on our institutional experience with systemic first- and further-line therapy in patients with metastatic pACC and embed our findings in a review of the literature.

METHODS

Patients with stage IV pACC who started systemic treatment between 2008 and 2019 at our institution were identified via our institutional database. Clinical data were extracted from the patients' electronic data records. Survival times were calculated by the Kaplan-Meier method.

RESULTS

Six patients received a fluoropyrimidine- and oxaliplatin-containing first-line treatment, and 4 patients were started on gemcitabine-based protocols. Median progression-free survival was 4.8 months [95% confidence interval (CI), 3.3 to not available (n.a.)], and median overall survival was 15.3 months (95% CI, 10.1 to n.a.). Residual survival for second-line treatment was 2.1 months (95% CI, 1.3 to n.a.), although 1 patient experienced almost complete remission under targeted therapy.

CONCLUSIONS

The most encouraging and deep responses result from poly-chemotherapy with leucovorin, 5-fluorouracil, irinotecan, and oxaliplatin (FOLFIRINOX), which seems to be the appropriate choice in fit patients. Gemcitabine monotherapy seems without substantial activity in pACC. Whenever possible, patients with pACC should be screened for targetable mutations.

Multicenter Retrospective Analysis of Chemotherapy for Advanced Pancreatic Acinar Cell Carcinoma: Potential Efficacy of Platinum- and Irinotecan-Containing Regimens

OBJECTIVES

The aim of this multicenter retrospective study was to identify the optimal chemotherapeutic regimen for advanced pancreatic acinar cell carcinoma (PACC).

METHODS

Fifty-eight patients with histopathologically confirmed advanced PACC who had received chemotherapy between 1996 and 2013 were enrolled. The clinical characteristics of the patients and the treatment efficacy data were collected from the medical records at 16 Japanese institutions, using standardized data collection instrument.

RESULTS

The most commonly selected treatment regimens were gemcitabine-, fluoropyrimidine-, platinum-, and irinotecan-containing regimens. The overall response rate in the patients who received first-line chemotherapy were 7% and 38%, respectively, and the median overall survival was 13.2 months. When the data for all the treatment lines were aggregated, the response rates to gemcitabine-, fluoropyrimidine-, platinum-, and irinotecan-containing regimens were 7%, 18%, 40%, and 29%, respectively. The overall survival tended to be better in patients who had received a platinum-containing regimen (hazard ratio, 0.50; 95% confidence interval, 0.23-1.11; P = 0.08) or irinotecan-containing regimen (hazard ratio, 0.42; 95% confidence interval, 0.15-1.19; P = 0.09) at least once in the treatment course as compared with those who had not.

CONCLUSIONS

Our findings suggested that platinum- and irinotecan-containing regimens exhibited some potential efficacy in patients with advanced PACC.

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.

Robot-assisted combined pancreatectomy/hepatectomy for metastatic pancreatic acinar cell carcinoma: case report and review of the literature

Acinar cell carcinoma (ACC) of the pancreas is a rare neoplasm with less aggressive behavior than ductal carcinoma. As a result, surgical resection for metastatic ACC is a therapeutic option which can result in long-term survival. There is a paucity of data describing institutional approaches to these challenging patients, and therefore, we herein describe our institution's approach to a patient with a distal pancreatic ACC and isolated liver metastasis. The patient underwent neoadjuvant chemotherapy (FOLFIRINOX), followed by a robot-assisted distal pancreatectomy/splenectomy and non-anatomic segment 6 resection. He was discharged to home post-operative day 2. Final pathology revealed complete tumor response of the liver metastasis and a margin negative resection of the primary tumor. He remains disease free and without complications at 3 months. We highlight that combined modality therapy for metastatic ACC can yield long-term survival in selected patients. Similarly, the robotic platform enables performance of complex multivisceral resections with rapid recovery. Future research investigating precision medicine for metastatic ACC is warranted given widely variable tumor biology in this disease.

Long-term survival of two patients with recurrent pancreatic acinar cell carcinoma treated with radiofrequency ablation: A case report

BACKGROUND

Pancreatic acinar cell carcinoma (PACC) is a rare type of malignant pancreatic cancer that represents approximately 1% of all pancreatic neoplasms. Due to its very low incidence, only a few retrospective studies are available. Although surgery is the first choice for treatment, most patients experience recurrence (mainly in the liver) and there are no clear recommendations for patients with advanced disease.

CASE SUMMARY

We report two patients with PACC treated with surgery who experienced tumour recurrence in the liver. Patient 1 carried a germline mutation in the APC gene. Both patients were treated with gemcitabine plus oxaliplatin and gemcitabine plus capecitabine as first- and second-line therapies, respectively. After a favourable response to chemotherapy, the patients underwent radiofrequency ablation of the remaining liver metastases. For patient 1, we documented a relapse in the liver after a disease-free period of 9 mo, and treatment with gemcitabine plus capecitabine was restarted. The patient achieved a complete response, and he remains alive without evidence of disease recurrence after six years. After radiofrequency ablation, patient 2 experienced disease-free survival for 21 mo, when peritoneal relapse was diagnosed and treated with chemotherapy. The patient achieved a stable disease state for nearly two years; nevertheless, further progressive disease was documented, and he died seven years after the first relapse.

CONCLUSION

PACC presents different biological behaviours than pancreatic adenocarcinoma. Multidisciplinary treatment involving local ablative therapies may be considered for PACC.

Pancreatic acinar cell carcinoma is associated with BRCA2 germline mutations: a case report and literature review

Acinar cell carcinoma (ACC) is a rare pancreatic neoplasm with dismal prognosis. Insights into the molecular basis of ACC can pave the way for the application of more effective, personalized therapies and detection of patients with hereditary predisposition.

Molecular analysis revealed a germline BRCA2 (and CHEK2) mutation in a patient with a rare pancreatic ACC with extensive intraductal growth. Somatic loss of the wild-type BRCA2 allele in the tumor indicated the causal relationship of ACC with the germline defect. A thorough literature review identified another nine ACCs associated with germline BRCA2 mutation and two ACCs associated with germline BRCA1 mutation, resulting in a prevalence of BRCA1/2 germline mutations in almost 7% of ACCs. Moreover, somatic BRCA1/2 alterations are reported in 16% of sporadic ACCs. Overall, about one fifth (22%) of all pancreatic ACCs exhibit BRCA1/2 deficiency.

This study underscores the important role of BRCA1/2 mutations in pancreatic ACC. All ACC patients should undergo genetic testing for BRCA1/2 mutations to identify carriers of pathogenic variants. This will allow to select patients that can benefit from targeted therapies directed against BRCA1/2-deficient tumors and is also crucial as a referral to genetic screening for the relatives of affected individuals carrying germline BRCA1/2 alterations.

Abbreviations: ACC: acinar cell carcinoma; HBOC: Hereditary Breast and Ovarian Cancer; LOH: loss of heterozygosity; PARP: poly (ADP-ribose) polymerase; PDAC: pancreatic ductal adenocarcinoma; PP: pancreatic panniculitis; SD: standard deviation; WES: whole-exome sequencing.

A Case Report of a Patient with Advanced Acinar Cell Carcinoma of the Pancreas: Long-Term Survival with Regional, Systemic and Targeted Therapy

Acinar cell carcinoma of the pancreas is an uncommon malignancy for which there are no prospective, randomized data to guide therapy. We describe the clinical course and management of a patient with advanced pancreatic acinar cell carcinoma who is alive seven years after diagnosis using systemic and regional chemotherapies as well as molecularly targeted agents.

Pancreatic acinar cell carcinoma with extensive tumor embolism at the trunk of portal vein and pancreatic intraductal infiltration

A 59-year-old man was admitted to the hospital with acute pancreatitis. The cause was suggested to be a pancreatic tumor based on computed tomography (CT). The pancreatic tumor was 45 mm with an extensive tumor embolism at the trunk of the portal vein and intraductal infiltration of the main pancreatic duct (MPD). The pancreatic tumor was diagnosed as acinar cell carcinoma (ACC) by endoscopic ultrasound guided fine needle aspiration. Therefore, the cause of acute pancreatitis was diagnosed to be intraductal infiltration of ACC in the MPD. Chemotherapy was initially performed because it was difficult to perform surgery due to extensive tumor embolism at the trunk of the portal vein. Degeneration and reduction of ACC and tumor embolism of the portal vein was noted on CT after chemotherapy, and extended distal pancreatectomy with portal vein reconstruction was performed. There has been no relapse for 5 years postoperative follow-up. This is an interesting and rare case because ACC with intraductal infiltration of MPD is low in frequency; most ACCs are asymptomatic when they are found, and many cases tend to have poor prognosis in spite of surgical cases.

Novel patient-derived xenograft mouse model for pancreatic acinar cell carcinoma demonstrates single agent activity of oxaliplatin

BACKGROUND

Pancreatic acinar cell carcinoma (PACC) is a rare malignancy, accounting for <1 % of all pancreatic neoplasms. Very few retrospective studies are available to help guide management. We previously reported the case of a patient with metastatic PACC who achieved prolonged survival following doxorubicin treatment. Personalized treatment was based on molecular and in vitro data collected from primary cells developed from their liver metastasis. We now report the characterization of a patient derived tumor xenograft (PDTX) mouse model that originated from this patient's PACC liver metastasis.

METHODS

Fragments of biopsy tissue (5 mm(3)) from PACC liver metastasis were implanted into athymic nude mice. Tumors were grown and passaged from the host mice into new mice to be tested for therapeutic response. Immuno-histochemical (IHC) biomarkers were used to confirm that the PDTX model represents human PACC. The antitumor activities of multiple drugs (5-FU, irinotecan, oxaliplatin, gemcitabine, bevacizumab, erlotinib, doxorubicin and imatinib) were tested. Tumor size was measured over 74 days or until they reached an endpoint volume of ~800 mm(3). Tests to measure serum lipase levels and histological analyses of tumor tissues were also conducted to assess PACC progression and re-differentiation.

RESULTS

The model presented here expresses the same IHC markers found in human PACC. In the chemotherapy study, oxaliplatin produced a prolonged durable growth response associated with increased apoptosis, decreased serum lipase levels and increased healthy acinar cells. Bevacizumab also produced a significant growth response, but the effect was not prolonged as demonstrated by oxaliplatin treatment. The other chemotherapies had moderate to little effect, particularly after treatment ceased. Mutations in DNA repair genes are common in PACC and increase tumor susceptibility to oxaliplatin. To explore this we performed IHC and found no nuclear expression of BRCA2 in our model, indicating a mutation affecting nuclear localization. Gene sequencing confirms BRCA2 has a homozygous gene deletion on Exon 10, which frequently causes a protein truncation.

CONCLUSIONS

In summary, we report the development and characterization of the first and only preclinical PACC PDTX model. Here we show sustained anti-tumor activity of single agent oxaliplatin, a compound that is more effective in tumors that harbor mutations in DNA repair genes. Our data shows that BRCA2 is mutated in our PACC model, which could contribute to the oxaliplatin sensitivity observed. Further studies on this rare PACC model can serve to elucidate other novel therapies, biomarkers, and molecular mechanisms of signaling and drug resistance.

Pancreatic Acinar Cell Carcinoma

Pancreatic acinar cell carcinoma (ACC) is a rare malignant neoplasm that accounts for 1–2% of all pancreatic neoplasms. Here we report two cases of ACC and describe their clinical features, the therapies used to treat them, and their prognosis. The first patient was a 65-year-old woman who had an abdominal CT scan for a urinary infection. Fortuitously, a rounded and well-delimited corporeal pancreatic tumor was discovered. An endoscopic ultrasound (EUS)-guided fine needle aspiration revealed an ACC. During the puncture, a hypoechoic cavity appeared inside the lesion, corresponding to a probable necrotic area. Treatment consisted of a distal splenopancreatectomy. The second patient was a 75-year-old man who complained of abdominal pain. An abdominal CT scan showed a cephalic pancreatic lesion and two hepatic metastases. An EUS-guided fine needle aspiration showed a pancreatic ACC. The patient received chemotherapy with gemcitabine plus oxaliplatin (GEMOX regimen), which enabled an objective response after 6 cycles.

Dynamic aberrant NF-κB spurs tumorigenesis: a new model encompassing the microenvironment

Recently it was discovered that a transient activation of transcription factor NF-κB can give cells properties essential for invasiveness and cancer initiating potential. In contrast, most oncogenes to date were characterized on the basis of mutations or by their constitutive overexpression. Study of NF-κB actually leads to a far more dynamic perspective on cancer: tumors caused by diverse oncogenes apparently evolve into cancer after loss of feedback regulation for NF-κB. This event alters the cellular phenotype and the expression of hormonal mediators, modifying signals between diverse cell types in a tissue. The result is a disruption of stem cell hierarchy in the tissue, and pervasive changes in the microenvironment and immune response to the malignant cells.

Expression profile and potential roles of EVA1A in normal and neoplastic pancreatic tissues

BACKGROUND

EVA1A (eva-1 homolog A) is a novel gene that regulates programmed cell death through autophagy and apoptosis. Our objective was to investigate the expression profiles and potential role of EVA1A in normal and neoplastic human pancreatic tissues.

MATERIALS AND METHODS

The expression pattern of EVA1A in normal pancreatic tissue was examined by indirect immunofluorescence and confocal microscopy. Protein levels in paraffin-embedded specimens from normal and diseased pancreatic and matched non-tumor tissues were evaluated by immunohistochemistry.

RESULTS

EVA1A colocalized with glucagon but not with insulin, demonstrating production in islet alpha cells. Itwas strongly expressed in chronic pancreatitis, moderately or weakly expressed in the plasma membrane and cytoplasm in pancreatic acinar cell carcinoma, and absent in normal pancreatic acinar cells. Although the tissue architecture was deformed, EVA1A was absent in the alpha cells of pancreatic ductal adenocarcinomas, intraductal papillary mucinous neoplasms, mucinous cystadenomas, solid papillary tumors and pancreatic neuroendocrine tumors.

CONCLUSIONS

EVA1A protein is specifically expressed in islet alpha cells, suggesting it may play an important role in regulating alpha-cell function. The ectopic expression of EVA1A in pancreatic neoplasms may contribute to their pathogenesis and warrants further investigation.

Genome variation and personalized cancer medicine

Genomic variation, through effects on gene structure and expression, plays an important role in understanding disease predisposition, biology and clinical response to therapy. Transforming this knowledge into clinically relevant information that tailors interventions to an individual's specific genetic, physical, social and environmental profile is challenging. To illustrate how research initiatives at preclinical phases of development are attempting to address clinically important issues in oncology, six clinical problems related to cancers of the colon, prostate, breast, pancreas and brain (medulloblastoma) as well as metastatic disease of different origins are described. A unifying theme across applications is that healthy individuals previously indistinguishable in regards to cancer risk and patients with cancer previously categorized as similar with regard to prognosis or drug response are being stratified into more refined subgroups with different clinical profiles. Effective matching of a broad range of tests with more tailored strategies for prevention and/or treatment will require well-designed clinical studies to evaluate benefits and costs.

Personalized chemotherapy profiling using cancer cell lines from selectable mice

PURPOSE

High-throughput chemosensitivity testing of low-passage cancer cell lines can be used to prioritize agents for personalized chemotherapy. However, generating cell lines from primary cancers is difficult because contaminating stromal cells overgrow the malignant cells.

EXPERIMENTAL DESIGN

We produced a series of hypoxanthine phosphoribosyl transferase (hprt)-null immunodeficient mice. During growth of human cancers in these mice, hprt-null murine stromal cells replace their human counterparts.

RESULTS

Pancreatic and ovarian cancers explanted from these mice were grown in selection media to produce pure human cancer cell lines. We screened one cell line with a 3,131-drug panel and identified 77 U.S. Food and Drug Administration (FDA)-approved drugs with activity, and two novel drugs to which the cell line was uniquely sensitive. Xenografts of this carcinoma were selectively responsive to both drugs.

CONCLUSION

Chemotherapy can be personalized using patient-specific cell lines derived in biochemically selectable mice.

Clinicopathologic study of 62 acinar cell carcinomas of the pancreas: insights into the morphology and immunophenotype and search for prognostic markers

Acinar cell carcinoma (ACC) of the pancreas is a very rare tumor that has various morphologic features, which may give rise to diagnostic difficulties. Because of its rarity, many clinicopathologic characteristics remain to be further elucidated, and prognostic factors are yet to be well established. With the aim of better characterizing this carcinoma and searching for prognostic indicators, we collected 62 ACCs and investigated the following parameters: site, size, local infiltration, node and distant metastases, architectural pattern, nuclear atypia, presence of necrosis, lymphovascular and perineural invasion, proliferation, BCL10, trypsin, carboxyl ester lipase, amylase, lipase, PDX1, cytokeratin 19 (CK19), CK7, p53, and β-catenin expression. Twelve cases showing >30% of endocrine cells were reclassified as mixed acinar-neuroendocrine carcinomas, whereas 1 tumor was reclassified as a mixed ductal-acinar carcinoma and was excluded from the statistical prognostic evaluations. BCL10 and trypsin were the most reliable immunohistochemical markers, whereas amylase and lipase were not. Surgery was statistically correlated with a better prognosis (P=0.0008). Among resected tumors there was no difference in survival between ACCs and mixed acinar-neuroendocrine carcinomas, and factors that significantly correlated with poor prognosis were size >6.5 cm (P=0.004), lymph node (P=0.0039) and distant (P=0.008) metastases, and UICC stage (P=0.009). Stage was the only independent prognostic factor at multivariable analysis, and the best prognostic discrimination was observed on grouping together stages I and II and grouping together stages III and IV, suggesting a simplification of the UICC staging for such cancers. In addition, vascular and perineural invasion and CK19 and p53 expression showed a trend for poor prognosis, not reaching statistical significance.

The molecular and cellular heterogeneity of pancreatic ductal adenocarcinoma

Current standard therapies for pancreatic ductal adenocarcinoma have failed to attenuate the aggressiveness of this disease or confer notable improvements in survival. Previous molecular research into pancreatic cancers, along with advances in sequencing technologies, have identified many altered genes in patients with pancreatic cancer and revealed the marked genetic heterogeneity of individual tumors. Thus, the lack of success of conventional empiric therapy can be partly attributed to the underlying heterogeneity of pancreatic tumors. The genetic alterations that have been detected in pancreatic cancer range from simple mutations at the level of base pairs to complex chromosomal structural changes and rearrangements. The identification of molecular changes that are unique to an individual patient's tumors, and the subsequent development of strategies to target the tumors in a personalized approach to therapeutics, is a necessary advance to improve therapy for patients with this disease.