Survival Outcome and Prognostic Factors for Pancreatic Acinar Cell Carcinoma: Retrospective Analysis from the German Cancer Registry Group

Perspective on an Innovative Curative Strategy for Peritoneal Metastasis Involving Peritonectomy, Hyperthermic Intraperitoneal Chemotherapy, and Adjuvant Chemotherapy Identified as Effective in the Histoculture Drug Response Assay (HDRA)

Background/Aim

Peritoneal carcinomatosis is the end stage for patients with gastrointestinal cancer, with survival ranging between 2 and 9 months. Pancreatic acinar cell carcinoma (PACC) is rare and can result in peritoneal metastases. The efficacy of chemotherapy for patients with PACC is unknown, and a systemic treatment strategy has not been established. The aim of the present perspective is to discuss a potential curative strategy combining surgery, heated intraperitoneal chemotherapy (HIPEC), and the histoculture drug response assay (HDRA) to identify effective adjuvant chemotherapy for PACC with peritoneal metastases, based on a published case report.

Case Report

A 31-year-old man with a 20 cm epigastric mass, diagnosed as PACC, had curative-intent resection of a tumor on the distal stomach and pancreas tail. The patient recurred after four courses of adjuvant oral S-1 treatment. Laparotomy demonstrated peritoneal metastases with a peritoneal cancer index of 18. Ascites or other cancer cells in the peritoneal wash were not found. Peritonectomy, combined with HIPEC with gemcitabine and docetaxel, was performed intraoperatively. Postoperative 3-dimensional histoculture of fragments of the resected tumor with drug response testing with the histoculture drug response assay (HDRA) showed gemcitabine had the highest tumor inhibitory rate (70%) among six drugs tested. Based on the HDRA results, the patient was treated with adjuvant systemic gemcitabine chemotherapy. The patient did not have a recurrence within 18 months after surgery.

Conclusion

The present innovative treatment of PACC with peritoneal metastases used laparotomy to determine the extent of peritoneal metastases, peritonectomy to attempt to completely remove the tumor, HIPEC for intraoperative hyperthermic-chemotherapy, and the HDRA to determine the most effective drug for adjuvant chemotherapy. These procedures can be individualized for each patient's cancer, and the HDRA is most critical for individualization.

Pancreatic Acinar Cell Carcinoma: Demographics, Treatment, and Survival Outcomes, A Retrospective Population-Based Study

PURPOSE

Pancreatic acinar cell carcinoma accounts for 1-2% of pancreatic tumors, with increasing frequency in recent years, and still represents a poor prognosis. This study aims to expand and update existing literature by analyzing national data gathered over almost two decades.

METHODS

Data from 488 patients diagnosed with PACC in the Surveillance, Epidemiology, and End Results database were analyzed. This study employed the Cox regression method to compute hazard ratios and identify independent factors influencing survival. Additionally, Kaplan-Meier survival curves were utilized alongside the log-rank test.

RESULTS

The median age was 64.7 years with male predilection (70.5%). "Poorly differentiated carcinoma" was the most common subtype (45.8%). The liver was the most common site of metastases (31.3%). The 5-year observed overall survival (OS) rate was 19.2% (95% CI, 14.9-23.8). The 5-year cause-specific survival (CSS) rate was 22.4% (95% CI, 17.7-27.5). Male gender has a 5-year OS of 19.2% (95% CI, 14.0-25.1) compared to female OS of 30.2% (95% CI, 20.7-40.1). Patients treated with multimodal therapy (surgery with chemoradiation) over only surgery or chemotherapy had better 5-year OS, 53.5% (95% CI, 31.8-71.0). Age > 60 and distant stage were independent factors associated with increased mortality.

CONCLUSION

Pancreatic acinar cell carcinoma is a rare, aggressive form of pancreatic cancer that primarily affects older adults. Our findings offer valuable insights to guide future clinical guidelines and tailored treatment strategies.

Pediatric pancreatic acinar cell carcinoma with a non-canonical BRAF-KMT2C fusion and a classic SND1-BRAF fusion: a case report and literature review

BACKGROUND

Pediatric pancreatic acinar cell carcinoma (PACC) is an exceptionally rare and poorly understood malignancy with a challenging prognosis. Its clinical presentation is often atypical, and standardized treatment guidelines are currently unavailable. While genetic alterations in adult PACC have been studied to some extent, knowledge of genetic abnormalities in pediatric cases remains limited.

CASE PRESENTATION

We report a case of pediatric PACC in a 7-year-old male presenting with a large, non-tender abdominal mass (11 cm x 11 cm) on the right side. Pathological and imaging evidence confirmed the diagnosis of PACC, with no lymph node infiltration or distant metastasis. Comprehensive genomic profiling by next-generation sequencing identified a non-canonical BRAF fusion with KMT2C at the DNA level and a classic SND1-BRAF fusion at the RNA level. The patient underwent surgical resection through a Whipple operation followed by six cycles of mFOLIRINOX chemotherapy and radiation therapy, achieving a favorable outcome up to now.

CONCLUSIONS

Next-generation sequencing has demonstrated significant value in identifying genetic fusions in pediatric PACC. In our case report, we identified both the classical SND1-BRAF fusion, commonly associated with PACC, and a previously unreported nonclassical BRAF-KMT2C fusion. These findings underscore the critical role of BRAF alterations as key drivers of oncogenesis in PACC. A multidisciplinary treatment strategy integrating surgery, chemotherapy, and radiation therapy offers a promising precedent for improving therapeutic outcomes and prolonging survival in pediatric PACC cases.

Clinical Outcomes and Molecular Profiling of Pancreatic Acinar Cell Carcinoma: A Retrospective Study

PURPOSE

Pancreatic acinar cell carcinoma (PACC) is a rare and aggressive form of pancreatic cancer that originates in the acinar cells of the exocrine pancreas. In this study, we aimed to investigate the clinical and molecular characteristics of patients with PACC at our institution.

METHODS

This was a retrospective study of patients with PACC seen at Mayo Clinic between 2002 and 2023. Baseline patient characteristics, tumor pathology, treatment strategies used, and survival outcomes were analyzed. Kaplan-Meier curves were estimated using newsurv macros in SAS.

RESULTS

The study included a total of 65 patients with PACC. The median age at diagnosis was 66 years. Almost half of the patients (48%) presented with resectable/borderline-resectable disease (n = 28). Five-year overall survival (OS) for resectable/borderline-resectable, locally advanced/unresectable, and metastatic disease were 72.0%, 21.6%, and 20.9%, respectively. Somatic and germline next-generation sequencing identified numerous potentially actionable targets including homologous recombination (43% somatic, 33% germline), RAF alterations (29% somatic), and mismatch repair (14% somatic).

CONCLUSION

Our findings underscore the heterogeneity and aggressive nature of PACC. Despite the improved prognosis for patients with resectable/borderline-resectable disease, OS remains poor, particularly for those with locally advanced or metastatic disease. The identification of actionable molecular targets in a significant proportion of patients highlights the potential for personalized therapeutic approaches. Future research should focus on tailored treatment strategies to exploit these molecular vulnerabilities, which may offer new options for improving outcomes in this rare malignancy.

Long-term survival after systemic chemotherapy, chemoradiotherapy, and maintenance therapy for an older adult patient with recurrent pancreatic acinar cell carcinoma

Pancreatic acinar cell carcinoma (PACC) is a rare cancer with no specific treatment. The treatment and chemotherapy for PACC are selected according to pancreatic ductal adenocarcinoma (PDAC). Herein, we describe a recurrent PACC case of an older adult patient. The patient was treated with systemic chemotherapy, chemoradiotherapy, and maintenance therapy based on the pathologic germline BRCA2 variant, resulting in long-term survival. The pathogenic BRCA variant is detected more frequently in patients with PACC than in those with PDAC. The BRCA variant significantly impacts treatment selection and prognosis; therefore, early genomic analysis is recommended when treating PACC.

Rare tumours of the pancreas: monocentric study

PURPOSE

The biology of rare pancreatic tumours, which differs from that of ductal pancreatic cancer, requires increased attention. Although the majority of rare pancreatic tumours are benign, it is difficult to decide whether an invasive component exists without complete removal of the lesion, despite considerable progress in diagnosis. We are investigating a large cohort of patients with histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas.

METHODS

Here we analyze long-term survival from patients, who underwent resection of histologically confirmed epithelial non-ductal non-neuroendocrine neoplasms of the pancreas. At our department between Jan 1st, 1999, and Dec 31st, 2019. The median follow-up was 61 (range 0-168) month. All statistical analyses were performed using SPSS 26.0 (IBM, Chicago, IL, USA) software.

RESULTS

46 patients (48%) were followed up for more than 5 years, 18 patients (19%) for more than 10 years. The 5-year and 10-year survival rates for rare non-invasive pancreatic tumours were 72% and 55% respectively. The proportion of rare tumour entities (non-ductal and non-neuroendocrine) increased continuously and statistically significantly (p = 0.004) from 4.2 to 12.3% in our clinic between 1999 and 2019. If there is no invasive growth yet, there is a varying risk of malignant degeneration in the course of the disease. Therefore, the indication for pancreatic resection is still the subject of discussion.

CONCLUSION

The long-term prognosis of rare epithelial pancreatic tumours after R0 resection-even if they are already malignant-is much better than that of ductal pancreatic cancer.

Comprehensive review of pancreatic acinar cell carcinoma: epidemiology, diagnosis, molecular features and treatment

Pancreatic acinar cell carcinoma is a rare form (0.2-4.3%) of pancreatic neoplasm with unique clinical and molecular characteristics, which largely differ from pancreatic ductal adenocarcinoma. Pancreatic acinar cell carcinoma occurs more frequently in males and can occur in children. Serum lipase is elevated in 24-58% of patients with pancreatic acinar cell carcinoma. Pancreatic acinar cell carcinomas tend to be large at diagnosis (median tumour size: ~5 cm) and are frequently located in the pancreas head. Radiologically, pancreatic acinar cell carcinoma generally exhibits a solid appearance; however, necrosis, cystic changes and intratumoral haemorrhage can occur in larger lesions. Immunostaining is essential for the definitive diagnosis of pancreatic acinar cell carcinoma. Compared with pancreatic ductal adenocarcinoma, pancreatic acinar cell carcinoma has a more favourable prognosis. Although radical surgery is recommended for patients with pancreatic acinar cell carcinoma who do not have distant metastases, the recurrence rate is high. The effectiveness of adjuvant therapy for pancreatic acinar cell carcinoma is unclear. The response to FOLFIRINOX is generally favourable, and some patients achieve a complete response. Pancreatic acinar cell carcinoma has a different genomic profile compared with pancreatic ductal adenocarcinoma. Although genomic analyses have shown that pancreatic acinar cell carcinoma rarely has KRAS, TP53 and CDKN2A mutations, it has a higher prevalence of homologous recombination-related genes, including BRCA1/2 and ATM, than pancreatic ductal adenocarcinoma, suggesting high sensitivity to platinum-containing regimens and PARP inhibitors. Targeted therapies for genomic alternations are beneficial. Therefore, genetic testing is important for patients with pancreatic acinar cell carcinoma to choose the optimal therapeutic strategy.

Near complete remission of an inoperable pancreatic acinar cell carcinoma after BRAF-/MEK-inhibitor treatment-A case report and review of the literature

INTRODUCTION

Pancreatic acinar cell carcinomas are rare malignant neoplasms. High-quality evidence about the best treatment strategy is lacking. We present the case of a 52-year-old male with a BRAFV600E -mutated PACC who experienced a complete remission after chemotherapy with BRAF-/MEK-inhibitors.

CASE

The patient presented with upper abdomen pain, night sweat, and weight loss. CT scan showed a pancreatic tumor extending from the pancreas head to body. Histological workup identified an acinar cell carcinoma. As the tumor was inoperable, chemotherapy with FOFIRNIOX was initiated and initially showed a slight regression of disease. The regimen had to be discontinued due to severe side effects. Molecular analysis identified a BRAFV600E mutation, so the patient was started on BRAF- and MEK-inhibitors (dabrafenib/trametinib). After 16 months, CT scans showed a near complete remission with a markedly improved overall health.

DISCUSSION

Studies suggest that up to one-fourth of PACCs carry a BRAF mutation and might therefore be susceptible to a BRAF-/MEK-inhibitor therapy. This offers a new therapeutic pathway to treat this rare but malignant neoplasm.

Treatment characteristics and outcomes of pure Acinar cell carcinoma of the pancreas - A multicentric European study on radically resected patients

BACKGROUND

Acinar cell carcinomas (ACC) belong to the exocrine pancreatic malignancies. Due to their rarity, there is no consensus regarding treatment strategies for resectable ACC.

METHODS

This is a retrospective multicentric study of radically resected pure pancreatic ACC. Primary endpoints were overall survival (OS) and disease-free survival (DFS). Further endpoints were oncologic outcomes related to tumor stage and therapeutic protocols.

RESULTS

59 patients (44 men) with a median age of 64 years were included. The median tumor size was 45.0 mm. 61.0% were pT3 (n = 36), nodal positivity rate was 37.3% (n = 22), and synchronous distant metastases were present in 10.1% of the patients (n = 6). 5-Years OS was 60.9% and median DFS 30 months. 24 out of 31 recurred systemically (n = 18 only systemic, n = 6 local and systemic). Regarding TNM-staging, only the N2-stage negatively influenced OS and DFS (p = 0.004, p = 0.001). Adjuvant treatment protocols (performed in 62.7%) did neither improve OS (p = 0.542) nor DFS (p = 0.159). In 9 cases, radical resection was achieved following neoadjuvant therapy.

DISCUSSION

Radical surgery is currently the mainstay for resectable ACC, even for limited metastatic disease. Novel (neo)adjuvant treatment strategies are needed, since current systemic therapies do not result in a clear survival benefit in the perioperative setting.

New treatment insights into pancreatic acinar cell carcinoma: case report and literature review

Pancreatic acinar cell carcinoma (PACC) is a rare pancreatic malignancy with unique clinical, molecular, and morphologic features. The long-term survival of patients with PACC is substantially better than that of patients with ductal adenocarcinoma of the pancreas. Surgical resection is considered the first choice for treatment; however, there is no standard treatment option for patients with inoperable disease. The patient with metastatic PACC reported herein survived for more than 5 years with various treatments including chemotherapy, radiotherapy, antiangiogenic therapy and combined immunotherapy.

Acinar cell carcinoma of gastric ectopic pancreas origin: a case report and literature review

BACKGROUND

Primary pancreatic-type acinar cell carcinoma of the stomach is extremely rare, often misdiagnosed, and of unclear origin.

CASE PRESENTATION

We report the case of a primary pure pancreatic-type acinar cell carcinoma of the stomach in a 58-year-old woman. This is the first reported case to exhibit residual ectopic pancreatic tissue adjacent to the tumor serving as evidence for the origin of the carcinoma. Furthermore, we summarized the clinicopathological features of pancreatic-type acinar cell carcinoma of the stomach in order to further understand this solid tumor.

CONCLUSIONS

Primary pancreatic-type acinar cell carcinoma of the stomach is rare. Data on tumors of this histological type are still relatively scarce, and more in-depth research is needed to elucidate their molecular biological characteristics and prognosis.

Integrated Genomic and Clinicopathologic Approach Distinguishes Pancreatic Grade 3 Neuroendocrine Tumor From Neuroendocrine Carcinoma and Identifies a Subset With Molecular Overlap

Distinguishing grade 3 pancreatic neuroendocrine tumor (G3 PanNET) from neuroendocrine carcinoma (PanNEC) is a known diagnostic challenge, and accurate classification is critical because clinical behavior and therapies differ. Although current recommendations suggest that immunohistochemistry for p53, Rb, ATRX, and DAXX can distinguish most cases, some cases remain difficult to classify using this approach. In this study, we reviewed 47 high-grade neoplasms originally diagnosed as pancreatic neuroendocrine neoplasms. In addition to the currently recommended stains, we performed capture-based sequencing of approximately 500 cancer genes and immunohistochemistry for p16 and trypsin or chymotrypsin. Using an integrated molecular and clinicopathologic approach, 42 (89%) of 47 cases had a clear final diagnosis of either G3 PanNET (n = 17), PanNEC (n = 17), or mixed acinar-NEC (n = 8). The 17 G3 PanNETs demonstrated frequent alterations in MEN1 (71%), DAXX (47%), ATRX (24%), TSC2 (35%), SETD2 (42%), and CDKN2A (41%). Contrary to prior reports, TP53 alterations were also common in G3 PanNETs (35%) but were always mutually exclusive with CDKN2A alterations in this group. The 17 PanNECs demonstrated frequent alterations in TP53 (88%), cell cycle genes RB1 (47%), CCNE1/CCND1 (12%), CDKN2A (29%), and in KRAS (53%) and SMAD4 (41%); TP53 was coaltered with a cell cycle gene in 76% of PanNECs. Diffuse strong p16 staining was observed in 69% of PanNECs in contrast to 0% of G3 PanNETs. The 8 acinar-NECs had recurrent alterations in ATM (25%), APC (25%), and STK11 (25%). Five cases remained difficult to classify, 3 of which exhibited overlapping molecular features with alterations in MEN1 with or without ATRX, and RB1 with or without TP53, making it unclear whether to classify as PanNET or PanNEC. Our data demonstrate that molecular profiling and immunohistochemistry for p16 greatly improve the diagnostic accuracy of high-grade pancreatic neuroendocrine neoplasms and identify a subset of rare cases with overlapping features of both PanNET and PanNEC.

Curative remnant total pancreatectomy for recurrent pancreatic acinar cell carcinoma: A case report

Introduction and importance

Acinar cell carcinoma (ACC) of the pancreas is a rare pancreatic cancer subtype (incidence, 0.5–2%) with unclear epidemiology and prognosis. Sometimes, repeat resection including total pancreatectomy is required for recurrence. We report a case of ACC recurring in the remnant pancreatic head after distal pancreatectomy that was successfully cured by remnant pancreatic resection following combination therapy with nab-paclitaxel (nab-PTX) and gemcitabine (GEM).

Case presentation

A 64-year-old woman was referred for pancreatic tumour treatment. CT revealed a 46-mm tumour in the pancreatic body, and endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) indicated ACC. Distal pancreatectomy was performed, and the final diagnosis was ACC. CT 18 months later showed a 34-mm tumour in the remnant pancreatic head revealed as ACC by EUS-FNA. Portal vein invasion was apparent, so neoadjuvant chemotherapy with nab-PTX and GEM was administered, and remnant pancreatic resection (total pancreatectomy) was performed. No recurrence or distant metastasis was present more than 6 months later.

Clinical discussion

Mean survival time for ACC is 18–47 months, and prognosis is good compared with pancreatic ductal adenocarcinoma (PDAC). ACC tends to extend and grow along the main pancreatic duct, which increases the recurrence rate to 50–60%. EUS and EUS-FNA were useful for evaluating tumour extension and diagnosis. Repeat pancreatic resection that included total pancreatectomy was feasible and could be performed safely.

Conclusion

ACC has a better prognosis than PDAC but with a higher recurrence rate. Aggressive surgical resection that included remnant total pancreatotomy with chemotherapy was useful in treating ACC.

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Acinar cell carcinoma (ACC) of the pancreas is a rare type of pancreatic tumour.

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ACC has good prognosis compared with pancreatic ductal adenocarcinoma, but the recurrence rate is high.

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Surgical resection that includes remnant pancreatic resection is useful for pancreatic tumours.

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Neoadjuvant and adjuvant chemotherapy are useful in treating ACC.