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

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

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

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

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

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.

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 Rare Pathological Subtype of Pancreatic Cancer

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

Efficacy of chemotherapy for patients with metastatic or recurrent pancreatic adenosquamous carcinoma: A multicenter retrospective analysis

BACKGROUND/OBJECTIVES

Pancreatic adenosquamous carcinoma (PASC) is a rare variant of pancreatic ductal adenocarcinoma (PDAC). The usual treatment for metastatic or recurrent PASC is systemic chemotherapy in accordance with the PDAC treatment strategy. This study aimed to investigate the efficacy of chemotherapy, especially the benefit of recent combination therapies, in patients with metastatic or recurrent PASC.

METHODS

We conducted a multicenter retrospective analysis of 116 patients with metastatic or recurrent PASC treated with first-line chemotherapy between April 2001 and December 2017 at 24 Japanese institutions.

RESULTS

Combination chemotherapies included gemcitabine + nab-paclitaxel (GnP, n = 28), fluorouracil/leucovorin + irinotecan + oxaliplatin (FFX, n = 10), gemcitabine + S-1 (GS, n = 10), and others (n = 9). Monotherapies included gemcitabine (n = 51) and S-1 (n = 8). The median overall survival (OS) was 6.5, 7.3, and 4.3 months for the whole cohort, the combination therapy group, and the monotherapy group, respectively. Multivariate analysis indicated that combination therapy showed a better trend in OS than monotherapy (hazard ratio = 0.68; 95% confidence interval, 0.38-1.20). GnP or FFX were selected in 58.7% of patients after FFX was approved in Japan, and revealed a median OS, median progression-free survival, and objective response rate of 7.3 months, 2.8 months, and 26.9% in GnP and 7.2 months, 2.3 months, and 20.0% in FFX respectively.

CONCLUSIONS

This study suggests that combination therapy may be more effective than monotherapy. GnP and FFX showed similar and clinically meaningful efficacy for patients with metastatic or recurrent PASC.

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.

Optimizing Chemotherapy of Pancreatic Acinar Cell Carcinoma: Our Experiences and Pooled Analysis of Literature

Background:

Pancreatic acinar cell carcinoma (PACC) is rare, and its appropriate treatment remains unknown. We aim to explore the characteristics and optimal treatment of it.

Methods:

The data on clinicopathologic characteristics, molecular alteration, treatment, and survival of patients diagnosed with PACC at the Sun Yat-sen University Cancer Center from 2005 to 2020 were collected. The optimal treatment was explored by co-analyzing our results and published literatures.

Results:

Twenty-two PACC patients were enrolled. Eight of 17 non-metastatic patients received adjuvant chemotherapy. The patients receiving fluoropyrimidine-based regimen (n = 3) had a better median disease-free survival (mDFS) than those with gemcitabine-based regimen (n = 5) (unreached vs 27 months). Eight metastatic patients received first-line chemotherapy. Four patients received second-line chemotherapy. The objective response rate (ORR) of the fluoropyrimidine-based regimen was 85.7% (6/7), much better than that of the gemcitabine-based regimen (0/5). One patient who had responded to the first-line FOLFIRINOX (5-fluorouracil + oxaliplatin + leucovorin + irinotecan) regimen received olaparib as maintenance treatment for 5 months with good tolerance. Thirty-one published literatures, with a total of 86 cases, were included in the co-analysis. The ORR of the first-line fluoropyrimidine-based regimen (n = 47) was higher than that of gemcitabine-based regimen (n = 39) (59.6% vs 15.3%, P < .001). Eight of 11 patients treated with the FOLFIRINOX regimen achieved partial response (PR).

Conclusions:

For patients with metastasis, a fluorouracil-based regimen such as FOLFIRINOX may be preferred, and maintenance treatment of poly ADP-ribose polymerase (PARP) inhibitors after effective platinum-containing treatment for breast cancer susceptibility gene (BRCA) mutation patients must be assessed.

Long Non-Coding RNAs in Epithelial-Mesenchymal Transition of Pancreatic Cancer

Non-coding RNAs (ncRNAs), or RNA molecules that do not code for proteins, are generally categorized as either small or long ncRNA (lncRNA) and are involved in the pathogenesis of several diseases including many cancers. Identification of a large number of ncRNAs could help to elucidate previously unknown mechanisms in phenotype regulation. Some ncRNAs are encapsulated by extracellular vesicles (EVs) and transferred to recipient cells to regulate cellular processes, including epigenetic and post-transcriptional regulations. Recent studies have uncovered novel molecular mechanisms and functions of lncRNAs in pancreatic ductal adenocarcinoma (PDAC), one of the most intractable cancers that is highly invasive and metastatic. As the epithelial-mesenchymal transition (EMT) triggers tumor cell invasion and migration, clarification of the roles of lncRNA in EMT and tumor cell stemness would be critical for improving diagnostic and therapeutic approaches in metastatic cancers. This review provides an overview of relevant studies on lncRNA and its involvement with EMT in PDAC. Emerging knowledge offers evidence for the dysregulated expression of lncRNAs and essential insights into the potential contribution of both lncRNAs and EVs in the pathogenesis of PDAC. Future directions and new clinical applications for PDAC are also discussed.

BRCA-mutant pancreatic ductal adenocarcinoma

Despite continued research, pancreatic ductal adenocarcinoma (PDAC) remains one of the main causes of cancer death. Interest is growing in the role of the tumour suppressors breast cancer 1 (BRCA1) and BRCA2-typically associated with breast and ovarian cancer-in the pathogenesis of PDAC. Indeed, both germline and sporadic mutations in BRCA1/2 have been found to play a role in the development of PDAC. However, data regarding BRCA1/2-mutant PDAC are lacking. In this review, we aim to outline the specific landscape of BRCA-mutant PDAC, focusing on heritability, clinical features, differences between BRCA1 and 2 mutations and between germline and sporadic alterations, as well as established therapeutic strategies and those that are still under evaluation.

PD-L1 and Notch as novel biomarkers in pancreatic sarcomatoid carcinoma: a pilot study

BACKGROUND

The improved immunological understanding revealed the tumor microenvironment as an appealing driver to restore the immune response against cancer cells resulting in a paradigm shift in the oncology field. However, the complexity of the tumor milieu suggests the role of several pathways linking in immunomodulation mechanisms. Pancreatic cancer represents a model of the intricate relationship between malignant cells and their surrounding neighborhood.

RESEARCH DESIGN AND METHODS

In this study, we analyzed, retrospectively, six cases of rare pancreatic sarcomatoid carcinoma (PSC) and evaluated the expression of PD-L1 and Notch, aiming to explore new attributes in immunophenotype.

RESULTS

PD-L1 CPS ≥ 1was common in PSCs (83%) with half samples expressing PD-L1 CPS ≥ 50. Notch1 and Notch3 demonstrated a high range of expression. A direct significant correlation between PD-L1 and Notch3 overexpression (r = 0.7; p = 0.036) has been observed. Immunofluorescence studies revealed a co-localization of Notch3 and PD-L1 when both proteins were over-expressed within cytoplasmic or membranous compartments of the same cells.

CONCLUSIONS

Our data identify a unique biological characterization of this rare pancreatic histotype. These findings provide a rationale for future studies evaluating the potential crosstalk between PD-L1/PD-1 axis and Notch pathways and prompting the development of novel therapeutics strategy.

Dramatic Response to Carboplatin Plus Paclitaxel in Pancreatic Mucinous Cystadenocarcinoma with Liver Metastasis

Mucinous cystic neoplasm (MCN) of the pancreas is a rare cystic tumor occurring in the pancreatic body and tail in young to middle-aged women that is pathologically characterized by an ovarian-like stroma. Chemotherapy for recurrent/advanced pancreatic MCN has been based on chemotherapy regimens for pancreatic ductal adenocarcinoma, but the prognosis is poor. We herein report a 37-year-old woman with pancreatic mucinous cystadenocarcinoma with liver metastasis that responded dramatically to carboplatin plus paclitaxel therapy (CBDCA+PTX). CBDCA+PTX may be a treatment option for recurrent/advanced pancreatic MCN with an ovarian-like stroma.

Multiple-line Chemotherapy for a Patient with Unresectable Mucinous Cystic Neoplasm of the Pancreas

A 74-year-old woman with a cyst in her pancreatic tail was referred to our hospital. Computed tomography confirmed a large cystic lesion with irregular wall thickening, abdominal lymph node swelling, and ascites. We diagnosed her with an unresectable mucinous cystic neoplasm, since ascites cytology revealed adenocarcinoma. The patient received chemotherapy up to the fifth line for 55.2 months. Gemcitabine plus nab-paclitaxel and modified FOLFIRINOX achieved a partial response with a progression-free survival time of 12.1 and 20.4 months, respectively. The overall survival time from the beginning of first-line chemotherapy was 69.4 months.

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.

The contemporary trend in worsening prognosis of pancreatic acinar cell carcinoma: A population-based study

BACKGROUND

Primary acinar cell carcinoma (ACC) is a rare exocrine tumor of the pancreas with unclear clinical characteristics. Our goal was to determine the incidence and update the clinical characteristics and outcomes of ACC.

METHODS

Through the Surveillance, Epidemiology, and End Results (SEER) database, we identified 252 patients with the latest diagnosis of ACC (2004-2016). The age-adjusted incidence (AAI) was calculated using the SEER*Stat Software version 8.3.6. The Kaplan-Meier method was used to draw survival curves and differences among them were compared by the log-rank test. Cox proportional hazards models were used to evaluate factors that had independent predictive effects on the overall survival.

RESULTS

The AAI of pancreatic ACC was on the rise with the mean age at diagnosis of 63.79±14.79 years. Most patients (15.9%) had poorer differentiated tumors. The patients presented with distant stage were 54.4% compared with 53.1% between 1988 and 2003. The 1-, 2-, and 5-years survival rates for pancreatic ACC patients were 53.5%, 34.6%,17.5%, respectively (compared with 78.5%, 67.0%, and 42.8%, between 1988 and 2003). The multivariate COX analysis showed that the patient's age, surgery, chemotherapy, and summary stage, but not marital status were independent prognosis factors for ACC.

CONCLUSIONS

Pancreatic ACC is a highly malignant tumor with an increasing incidence in recent years. The rate of distant metastasis is increasing and the survival rate is worse than in the past, suggesting that it may require more aggressive treatment and follow-up. Surgery, radiotherapy, and chemotherapy are all effective treatments, but prospective studies are still needed to verify them.

Pancreatic mucinous cystadenocarcinoma in a patient harbouring BRCA1 germline mutation effectively treated with olaparib: A case report

BACKGROUND

Pancreatic mucinous cystadenocarcinoma (MCAC) is a rare malignancy with a poor prognosis when it presents metastases at diagnosis. Due to its very low incidence, there are no clear recommendations for the treatment of advanced disease. Olaparib (an oral PARP inhibitor) has been approved for the maintenance treatment of patients with metastatic pancreatic adenocarcinoma harbouring germline BRCA1/2 mutations. Herein, we report the first case of a germline BRCA1 mutated unresectable MCAC which was effectively treated with olaparib.

CASE SUMMARY

A 41-year-old woman, without personal or family history of cancer, was diagnosed with ovarian and peritoneal metastases of MCAC. She underwent 12 cycles of gemcitabine plus oxaliplatin (GEMOX) obtaining a partial response and allowing radical surgery. One year later, local recurrence was documented, and other 12 cycles of GEMOX were administered obtaining a complete response. Seven years later, another local recurrence, not amenable to surgical resection, was diagnosed. She started FOLFIRINOX (oxaliplatin, irinotecan, leucovorin and fluorouracil), obtaining a partial response after 8 cycles. Given the excellent response to platinum-based chemotherapy, BRCA testing was performed, and a BRCA1 germline mutation was detected. She was switched to maintenance olaparib due to chemotherapy-related toxicities and achieved an almost complete metabolic response, with a reduction in the diameter of the lesion, after three months of therapy.

CONCLUSION

The current case suggests the beneficial effect of olaparib in BRCA mutated MCAC. However, further studies are required.

Successful BRAF/MEK inhibition in a patient with BRAF V600E-mutated extrapancreatic acinar cell carcinoma

Pancreatic acinar cell carcinoma (PAC) is a rare disease with a poor prognosis. Treatment options for metastatic PAC are limited and often follow chemotherapeutic regimens for pancreatic ductal adenocarcinoma. Although recurrent genomic alterations, such as BRAF fusions and defects in genes involved in homologous recombination DNA repair, have been described in PAC, data on the clinical efficacy of molecularly guided, targeted treatment are scarce. Here we describe the case of a 27-yr-old patient with BRAF^V600E-mutated PAC who was successfully treated with a combination of BRAF and MEK inhibitors. The patient presented to our clinic with abdominal pain and weight loss. Imaging showed extensive retroperitoneal disease as well as mediastinal lymphadenopathy. Because of elevated α-fetoprotein (AFP) levels and inconclusive histologic findings, a germ cell tumor was suspected; however, PEI chemotherapy was unsuccessful. A repeat biopsy yielded the diagnosis of PAC and treatment with FOLFIRINOX was initiated. Comprehensive molecular profiling within the MASTER (Molecularly Aided Stratification for Tumor Eradication Research) precision oncology program revealed a somatic BRAF^V600E mutation and a germline PALB2 stop-gain mutation. Therapy was therefore switched to BRAF/MEK inhibition, resulting in almost complete remission and disease control for 12 mo and a remarkable improvement in the patient's general condition. These results indicate that BRAF alterations are a valid therapeutic target in PAC that should be routinely assessed in this patient population.

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.

Patients With Acinar Cell Carcinoma of the Pancreas After 2005: A Large Population Study

OBJECTIVES

Acinar cell carcinoma of the pancreas is a rare tumor with limited data. We aim to evaluate the characteristics, treatments, and outcomes of pancreatic acinar cell carcinoma after 2005.

METHODS

We retrospectively reviewed patients with pancreatic acinar cell carcinoma treated in Peking University Cancer Hospital and Institute (2005-2018) and identified cases from Surveillance, Epidemiology, and End Results database (2005-2015).

RESULTS

A total of 306 cases in our institute (n = 11) and Surveillance, Epidemiology, and End Results database (n = 295) were identified. The median age was 67 years, and 73.5% were male. The 5-year survival was 36.8% for all patients (median, 27 months). About 37% underwent surgical resection. The 5-year survival was 65.6% for resected patients as compared with 16.9% for unresected ones (P < 0.0001). Among locoregional and metastatic diseases, surgery significantly prolonged survival as well (P = 0.0003). Stage IV patients who received chemotherapy had a better survival than those without it (median, 16 vs 3 months; P = 0.0019). Aging, stage IV, and no surgery were independent predictors of poor overall survival.

CONCLUSIONS

For pancreatic acinar cell carcinoma, surgery is a potentially curative treatment contributing to long-term survival and suggested even in advanced diseases. Chemotherapy improved survival for metastatic patients.

Lipase hypersecretion syndrome: A rare cutaneous manifestation of advanced pancreatic acinar cell carcinoma

Careful recognition of cutaneous lesions in patients with malignancies may aid in avoiding additional morbidity during end of life care.

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.

Diagnosis and Surgical Treatment and Pathological Findings of Solid Pseudopapillary Tumor of the Pancreas: A Single-Institution Experience

Purpose

To investigate the diagnosis, surgical treatment, and pathology of solid pseudopapillary tumors of the pancreas in our institution.

Patients and Methods

We retrospectively analyzed the demographic details, clinical features, imaging findings, and pathological findings of 87 patients with a confirmed diagnosis of solid pseudopapillary tumors of the pancreas (SPTP) and underwent surgery in Tongji Hospital of Tongji Medical College, over a period of 8 years from 2011 to 2018.

Results

Our study involved a total of 87 patients (16 males and 71 females) with a mean age of 31.3±13.1 years (range: 10–61 years). The main compliant was abdominal pain or discomfort (n=49) and the median tumor size was 58.6±31.7 mm (range: 16–156mm). Tumors were located in the head (27 patients, 31%), the neck (13 patients, 15%), and the body and tail (47 patients, 54%). There were no significant differences between the patients in terms of sex, age, or tumor location. Partial pancreatectomy was performed in 79 patients, enucleation in six patients, and total pancreatectomy in two patients. R0 resection was achieved in 86 patients. The postoperative morbidity was 36.8%, and the main complication was pancreatic fistula. Pathological examination and immunohistochemical markers were used to provide a final diagnosis. The main follow-up period was 46 months (range: 13–97 months). At the end of the follow-up period, 86 patients were alive and had not experienced recurrence; one patient was lost to follow-up.

Conclusion

The accurate diagnosis of SPTP is vital. Our data showed that surgical resection is safe and associated with low morbidity and mortality rates. Pathological findings can play an important role in diagnosis and long-term survival.

The Italian Rare Pancreatic Exocrine Cancer Initiative

INTRODUCTION

Exocrine pancreatic cancers include common type pancreatic ductal adenocarcinoma and cystic neoplasms, which account for 85% and 10% of cases, respectively. The remaining 5% are rare histotypes, comprising adenosquamous carcinoma, acinar cell carcinoma, signet ring cell carcinoma, medullary carcinoma, pancreatoblastoma, hepatoid carcinoma, undifferentiated carcinoma and its variant with osteoclast-like giant cells, solid pseudopapillary carcinoma, and carcinosarcoma. Due to their low incidence, little knowledge is available on their clinical and molecular features as well as on treatment choices. The national initiative presented here aims at the molecular characterization of series of rare histotypes for which therapeutic and follow-up data are available.

METHODS

A nationwide Italian Rare Pancreatic Cancer (IRaPaCa) task force whose first initiative is a multicentric retrospective study involving 21 Italian cancer centers to retrieve histologic material and clinical and treatment data of at least 100 patients with rare exocrine pancreatic cancers has been created. After histologic revision by a panel of expert pathologists, DNA and RNA from paraffin tissues will be investigated by next-generation sequencing using molecular pathway-oriented and immune-oriented mutational and expression profiling panels constructed availing of the information from the International Cancer Genome Consortium. Bioinformatic analysis of data will drive validation studies by immunohistochemistry and in situ hybridization, as well as nanostring assays.

CONCLUSIONS

We expect to gather novel data on rare pancreatic cancer types that will be useful to inform the design of therapeutic choices.