Surgical outcome of adenosquamous carcinoma of the pancreas

Adenosquamous carcinoma is rare,accounting for 3%-4% of all pancreatic carcinoma cases. These tumors are characterized by the presence of variable proportions of mucin-producing glandular elements and squamous components,the latter of which should account for at least 30% of the tumor tissue. Recently,several reports have described cases of adenosquamous carcinoma of the pancreas. However,as the number of patients who undergo resection at a single institute is limited,large studies describing the clinicopathological features,therapeutic management,and surgical outcome for adenosquamous carcinoma of the pancreas are lacking. We performed a literature review of English articles retrieved from Medline using the keywords 'pancreas' and 'adenosquamous carcinoma'. Additional articles were obtained from references within the papers identif ied by the Medline search. Our subsequent review of the literature revealed that optimal adjuvant chemotherapy and/or radiotherapy regimens for adenosquamous carcinoma of the pancreas have not been established,and that curative surgical resection offers the only chance for long-term survival. Unfortunately,the prognosis of the 39 patients who underwent pancreatic resection for adenosquamous carcinoma was very poor,with a 3-year overall survival rate of 14.0% and a median survival time of 6.8 mo. Since the postoperative prognosis of adenosquamous carcinoma of the pancreas is currently worse than that of pancreatic adenocarcinoma,new adjuvant chemotherapies and/or radiation techniques should be investigated as they may prove indispensible to the improvement of surgical outcomes.

Large-duct pattern invasive adenocarcinoma of the pancreas–a variant mimicking pancreatic cystic neoplasms: A minireview

Pancreatic cancer currently has no subtypes that inform clinical decisions;hence,there exists an opportunity to rearrange the morphological and molecular taxonomy that guides a better understanding of tumor characteristics.Nonetheless,accumulating studies to date have revealed the large-duct type variant,a unique subtype of pancreatic ductal adenocarcinoma(PDA)with cystic features.This subtype often radiographically mimics intraductal papillary mucinous neoplasms(IPMNs)and involves multiple small cysts occasionally associated with solid masses.The“bunch-of-grapes”sign,an imaging characteristic of IPMNs,is absent in large-duct PDA.Large-duct PDA defines the mucin profile,and genetic alterations are useful in distinguishing large-duct PDA from IPMNs.Histologically,neoplastic ducts measure over 0.5 mm,forming large ductal elements.Similar to classic PDAs,this subtype is frequently accompanied by perineural invasion and abundant desmoplastic reactions,and KRAS mutations in codon 12 are nearly ubiquitous.Despite such morphological similarities with IPMNs,the prognosis of large-duct PDA is equivalent to that of classic PDA.Differential diagnosis is therefore essential.

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.

Two rare cancers of the exocrine pancreas: to treat or not to treat like ductal adenocarcinoma?

Pancreatic cancer is an aggressive malignancy with increasing incidence.Pancreatic ductal adenocarcinoma(PDAC)accounts for>90%of pancreatic cancer diagnoses,while other exocrine tumors are much rarer.In this review,we have focused on two rare cancers of the exocrine pancreas:adenosquamous carcinoma of the pancreas(ASCP)and pancreatic acinar cell carcinoma(PACC).The latest findings regarding their cellular and molecular pathology,clinical characteristics,prognosis,and clinical management are discussed.New genetic and transcriptomic data suggest that ASCP is related to or overlaps with the basal transcriptomic subtype of PDAC.These tumors are highly aggressive and driven by activated KRAS and MYC expression.Clinical outcomes remain poor and effective treatments are limited.PACC has no morphologic or genetic resemblance to PDAC and more favorable outcomes.Early stage PACC patients have improved survival with surgical resection and patients with advanced disease benefit most from platinum-or fluoropyrimidine-containing chemotherapy.Frequency of actionable genetic mutations is high in this disease and case reports suggest good outcomes when matched therapy is given.Dedicated clinical studies examining ASCP and PACC are limited and difficult to accrue.Further research is needed to define optimal clinical management for these rare diseases.