Reappraising imaging features of pancreatic acinar cystic transformation: be aware of differential diagnoses.

OBJECTIVES: Imaging features of pancreatic acinar cystic transformation (ACT) have been published. We aimed to describe the clinical and radiological characteristics of patients with a presumed pancreatic ACT diagnosis, reappraising the value of these published imaging criteria. MATERIALS AND METHODS: Single-center retrospective study (2003-2021) of consecutive patients with a presumed diagnosis of ACT as suggested by the local expert multidisciplinary case review board. Patients without available imaging (CT or MRI) for review were excluded. Patients were classified into "certain" ACT (if ≥ 2 imaging criteria and no differential diagnosis) or "uncertain" ACT (if ≥ 1 imaging criteria and suggested differential diagnoses). RESULTS: Sixty-four patients (35 males, [55%]) were included. ACT was considered "certain" for 34 patients (53%) and "uncertain" for 30 patients (47%). The number of ACT criteria did not differ between groups, with 91.2% of patients with ≥ 3 ACT imaging criteria in the "certain" group vs 93.3% in the "uncertain" group (p = 0.88). In the "uncertain" group, the main suggested differentials were branch-duct intraductal papillary mucinous neoplasm (18/30 patients, 60%), calcifying chronic pancreatitis (8/30 patients, 27%), both (three patients, 10%) and serous cystadenoma (one patient, 3%). Calcifications were significantly more frequent in the "uncertain" group (89% vs 63% in the "certain" group, p = 0.02). CONCLUSION: Published ACT imaging criteria are frequently associated with features suggesting differential diagnoses. They appear insufficient to reach a final diagnosis in a subset of patients. CLINICAL RELEVANCE STATEMENT: ACT displays a heterogeneous morphological imaging presentation challenging the non-invasive diagnostic work-up. Physicians' and radiologists' awareness of this entity is important to better understand its natural history and improve non-invasive diagnostic criteria. KEY POINTS: The criteria to help diagnose ACT are frequently associated with features suggestive of differentials. The main alternatives suggested when ACT diagnosis was "uncertain" were branch-duct intraductal papillary mucinous neoplasm and calcifying chronic pancreatitis. Published ACT diagnostic imaging criteria can be insufficient for a definite non-invasive diagnosis.

Pancreatic Acinar Cystic Transformation: Familial Forms Do Exist.

ABSTRACT: Pancreatic acinar cystic transformation (ACT) is a recently described entity of the pancreatic cysts' spectrum. It is a nonneoplastic pancreatic lesion, mostly asymptomatic, and is considered a rare disease, with less than 100 reported cases. Its benign nature and the absence of reported cases of malignant transformation or invasive lesions were a plea for a conservative approach. As a consequence, little is known about the pathogenesis of this lesion. No familial history of ACT has been previously described. Here, we report a familial case of 2 siblings with typical ACT imaging lesions giving evidence for familial aggregation. No obvious environmental exposure was identified as a potential risk factor for ACT development. No physiological data exist to suggest a congenital nature of these lesions, but for the first patient, the calcifications seem to have appeared with time. Further research, with high throughput sequencing technologies, may elucidate genetic polymorphisms explaining potential ACT familial phenotype. In practice, careful family history collection must be performed to identify a possible familial form of ACT when this diagnosis is proposed.

Efficacy and tolerance of LV5FU2-carboplatin chemotherapy in patients with advanced pancreatic ductal adenocarcinoma after failure of standard regimens.

Background: Chemotherapy options in patients with advanced pancreatic ductal adenocarcinoma (PDAC) after failure of standard chemotherapies are limited. Objectives: We aimed to report the efficacy and safety of the leucovorin and 5-fluorouracil (LV5FU2) and carboplatin combination in this setting. Design: We performed a retrospective study including consecutive patients with advanced PDAC who received LV5FU2-carboplatin between 2009 and 2021 in an expert center. Methods: We measured overall survival (OS) and progression-free survival (PFS), and explored associated factors using Cox proportional hazard models. Results: In all, 91 patients were included (55% male, median age 62), with a performance status of 0/1 in 74% of cases. LV5FU2-carboplatin was mainly used in third (59.3%) or fourth line (23.1%), with three (interquartile range: 2.0-6.0) cycles administered on average. The clinical benefit rate was 25.2%. Median PFS was 2.7 months (95% CI: 2.4-3.0). At multivariable analysis, no extrahepatic metastases (p = 0.083), no ascites or opioid-requiring pain (p = 0.023), <2 prior treatment lines (p < 0.001), full dose of carboplatin (p = 0.004), and treatment initiation >18 months after initial diagnosis (p < 0.001) were associated with longer PFS. Median OS was 4.2 months (95% CI: 3.48-4.92) and was influenced by the presence of extrahepatic metastases (p = 0.058), opioid-requiring pain or ascites (p = 0.039), and number of prior treatment lines (0.065). Prior tumor response under oxaliplatin did not impact either PFS or OS. Worsening of preexisting residual neurotoxicity was infrequent (13.2%). The most common grade 3-4 adverse events were neutropenia (24.7%) and thrombocytopenia (11.8%). Conclusion: Although the efficacy of LV5FU2-carboplatin appears limited in patients with pretreated advanced PDAC, it may be beneficial in selected patients.

The PRSS3P2 and TRY7 deletion copy number variant modifies risk for chronic pancreatitis.

BACKGROUND: PRSS1 and PRSS2 constitute the only functional copies of a tandemly-arranged five-trypsinogen-gene cluster (i.e., PRSS1, PRSS3P1, PRSS3P2, TRY7 and PRSS2) on chromosome 7q35. Variants in PRSS1 and PRSS2, including missense and copy number variants (CNVs), have been reported to predispose to or protect against chronic pancreatitis (CP). We wondered whether a common trypsinogen pseudogene deletion CNV (that removes two of the three trypsinogen pseudogenes, PRSS3P2 and TRY7) might be associated with CP causation/predisposition. METHODS: We analyzed the common PRSS3P2 and TRY7 deletion CNV in a total of 1536 CP patients and 3506 controls from France, Germany, India and Japan by means of quantitative fluorescent multiplex polymerase chain reaction. RESULTS: We demonstrated that the deletion CNV variant was associated with a protective effect against CP in the French, German and Japanese cohorts whilst a trend toward the same association was noted in the Indian cohort. Meta-analysis under a dominant model yielded a pooled odds ratio (OR) of 0.68 (95% confidence interval (CI) 0.52-0.89; p = 0.005) whereas an allele-based meta-analysis yielded a pooled OR of 0.84 (95% CI 0.77-0.92; p = 0.0001). This protective effect is explicable by reference to the recent finding that the still functional PRSS3P2/TRY7 pseudogene enhancers upregulate pancreatic PRSS2 expression. CONCLUSIONS: The common PRSS3P2 and TRY7 deletion CNV was associated with a reduced risk for CP. This finding provides additional support for the emerging view that dysregulated PRSS2 expression represents a discrete mechanism underlying CP predisposition or protection.

MRI is useful to suggest and exclude malignancy in mucinous cystic neoplasms of the pancreas.

OBJECTIVES: To evaluate the value of MRI in differentiating benign (b-MCN) and malignant (m-MCN) MCN. European guidelines suggest that certain mucinous cystic neoplasms (MCN) of the pancreas can be conservatively managed. METHODS: A retrospective single-center study of consecutive patients with resected MCN. MRIs were independently reviewed by two readers blinded to the pathological results. The authors compared b-MCN (i.e., mucinous-cystadenoma comprising high-grade dysplasia (HGD)) and m-MCN (i.e., cystadenocarcinoma). RESULTS: Sixty-three patients (62 women [98%]) with 63 MCN (6 m-MCN, 2 HGD) were included. m-MCN tumors had a tendency to be larger than b-MCN (median 86 [25-103] vs. 45 [17-130] mm, p = .055). The combination of signal heterogeneity on T2-weighted imaging, wall thickness ≥ 5 mm, the presence of mural nodules ≥ 9 mm, and enhancing septa had an area under the ROC curve of 0.97 (95% CI 0.91-1.00) for the diagnosis of m-MCN. A total of 24 (37%), 20 (32%), 10 (16%), 5 (8%), and 4 (6%) out of 63 MCNs showed 0, 1, 2, 3, and 4 of these features, respectively. The corresponding rate of m-MCN was 0%, 0%, 10%, 20%, and 100%, respectively, with a good-to-excellent inter-reader agreement. Patterns with a high NPV for m-MCN included an absence of enhancing septa or walls (NPV 97% and 100%, respectively), wall thickness < 3 mm (NPV 100%), and no mural nodules (NPV 100%). CONCLUSIONS: A combination of 4 imaging features suggests malignant MCN on MRI. On the other hand, visualization of a thin non-enhancing wall with no mural nodules suggests benign MCN. KEY POINTS: • A heterogenous signal on T2-weighted MRI, a ≥ 5-mm-thick wall, mural nodules ≥ 9 mm, and/or enhancing septa suggest malignant MCNs. • A thin non-enhancing wall with no mural nodules suggests benign MCNs. • MRI should be performed in the pre-therapeutic evaluation of MCN to help determine the therapeutic strategy in these patients.

Gastrointestinal bleeding in patients with pancreatic cancer: Causes and haemostatic treatments.

BACKGROUND: Gastrointestinal bleeding is a rare but severe complication of pancreatic ductal adenocarcinoma. OBJECTIVE: The purpose of this study was to describe the causes and treatments of non-postoperative gastrointestinal bleeding in patients with pancreatic ductal adenocarcinoma, and explore the parameters associated with therapeutic effectiveness. METHODS: This was a single-centre observational retrospective study (2000-2017) with data collected from the prospectively coded diagnostic hospital's database system including patients with pancreatic ductal adenocarcinoma who had a gastrointestinal bleeding episode. Effectiveness of haemostatic treatment was assessed according to transfusion requirements and immediate and long-term haemostatic efficacy; the latter defined as no bleeding recurrence. RESULTS: The population included 72 patients with pancreatic ductal adenocarcinoma who had 94 episodes of gastrointestinal bleeding. The main causes of gastrointestinal bleeding were gastroduodenal tumour invasion (56.4%) and oesophageal variceal bleeding due to left-sided portal hypertension (19.1%). In cases of gastrointestinal bleeding caused by tumour invasion, the main treatment was therapeutic endoscopy (41.5%). Among patients who had gastrointestinal bleeding by tumour invasion treated by endoscopy or radiation therapy, haemostatic immediate efficacy rates were 70.6% and 100%, respectively. Bleeding recurrence rates were 35.3% and 25.0%, for patients treated by endoscopy or radiation therapy, respectively, for a first episode of gastrointestinal bleeding by tumour invasion. Transfusion requirements, before and after treatment, were not different in patients treated by haemostatic radiation therapy for gastrointestinal bleeding by tumour invasion compared to other treatments (odds ratio 0.3, 95% CI (0.06-1.59); p = 0.16). The median survival after all-cause gastrointestinal bleeding was 2.72 months (1.43-4.01). CONCLUSION: Gastroduodenal tumour invasion was the main cause of gastrointestinal bleeding in patients with pancreatic ductal adenocarcinoma; haemostatic radiation therapy is a potential interesting option for gastrointestinal bleeding treatment in this context.