Chronic pancreatitis and resectable synchronous pancreatic carcinoma: A survival analysis

Development and Validation of a Model for Postpancreatectomy Hemorrhage Risk

Importance

Postpancreatectomy hemorrhage (PPH) due to postoperative pancreatic fistula (POPF) is a life-threatening complication after pancreatoduodenectomy. However, there is no prediction tool for early identification of patients at high risk of late PPH.

Objective

To develop and validate a prediction model for PPH.

Design, Setting, and Participants

This retrospective prognostic study included consecutive patients with clinically relevant POPF who underwent pancreatoduodenectomy from January 1, 2009, to May 20, 2023, at the University Hospital Mannheim (derivation cohort), and from January 1, 2012, to May 31, 2022, at the University Hospital Dresden (validation cohort). Data analysis was performed from May 30 to July 29, 2023.

Exposure

Clinical and radiologic features of PPH.

Main Outcomes and Measures

Accuracy of a predictive risk score of PPH. A multivariate prediction model-the hemorrhage risk score (HRS)-was established in the derivation cohort (n = 139) and validated in the validation cohort (n = 154).

Results

A total of 293 patients (187 [64%] men; median age, 69 [IQR, 60-76] years) were included. The HRS comprised 4 variables with associations: sentinel bleeding (odds ratio [OR], 35.10; 95% CI, 5.58-221.00; P < .001), drain fluid culture positive for Candida species (OR, 14.40; 95% CI, 2.24-92.20; P < .001), and radiologic proof of rim enhancement of (OR, 12.00; 95% CI, 2.08-69.50; P = .006) or gas within (OR, 12.10; 95% CI, 2.22-65.50; P = .004) a peripancreatic fluid collection. Two risk categories were identified with patients at low risk (0-1 points) and high risk (≥2 points) to develop PPH. Patients with PPH were predicted accurately in the derivation cohort (C index, 0.97) and validation cohort (C index 0.83). The need for more invasive PPH management (74% vs 34%; P < .001) and severe complications (49% vs 23%; P < .001) were more frequent in high-risk patients compared with low-risk patients.

Conclusions and Relevance

In this retrospective prognostic study, a robust prediction model for PPH was developed and validated. This tool may facilitate early identification of patients at high risk for PPH.

Multitasking dynamic contrast enhanced magnetic resonance imaging can accurately differentiate chronic pancreatitis from pancreatic ductal adenocarcinoma

Background and aims

Accurate differentiation of chronic pancreatitis (CP) and pancreatic ductal adenocarcinoma (PDAC) is an area of unmet clinical need. In this study, a novel Multitasking dynamic contrast enhanced (DCE) magnetic resonance imaging (MRI) technique was used to quantitatively evaluate the microcirculation properties of pancreas in CP and PDAC and differentiate between them.

Methods

The Multitasking DCE technique was able to acquire one 3D image per second during the passage of MRI contrast agent, allowing the quantitative estimation of microcirculation properties of tissue, including blood flow F_p, plasma volume fraction v_p, transfer constant K^trans, and extravascular extracellular volume fraction v_e. Receiver operating characteristic (ROC) analysis was performed to differentiate the CP pancreas, PDAC pancreas, normal control pancreas, PDAC tumor, PDAC upstream, and PDAC downstream. ROCs from quantitative analysis and conventional analysis were compared.

Results

Fourteen PDAC patients, 8 CP patients and 20 healthy subjects were prospectively recruited. The combination of F_p, v_p, K^trans, and v_e can differentiate CP versus PDAC pancreas with good AUC (AUC [95% CI] = 0.821 [0.654 - 0.988]), CP versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), PDAC pancreas versus normal pancreas with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC tumor with excellent AUC (1.000 [1.000 - 1.000]), CP versus PDAC downstream with excellent AUC (0.917 [0.795 - 1.000]), and CP versus PDAC upstream with fair AUC (0.722 [0.465 - 0.980]). This quantitative analysis outperformed conventional analysis in differentiation of each pair.

Conclusion

Multitasking DCE MRI is a promising clinical tool that is capable of unbiased quantitative differentiation between CP from PDAC.

Impact of spleen preservation on the incidence of postoperative pancreatic fistula after distal pancreatectomy: Is less more?

BACKGROUND

Postoperative pancreatic fistula (POPF) remains a major complication after distal pancreatectomy (DP) with a significant impact on patients' quality of life. There is limited evidence that preservation of the spleen reduces the risk of POPF. Therefore, we aimed to investigate the impact of splenectomy on perioperative outcome.

METHODS

Data from patients who underwent DP for malignant and benign disease at our institution between 2004 and 2021 were reviewed. Patients were grouped according to spleen preservation (SP-DP) and splenectomy (DPS). Intraoperative parameters and postoperative outcomes were compared between groups. Univariable and multivariable analyses were used to investigate factors that influence the occurrence of clinically relevant (cr)POPF.

RESULTS

A total of 199 patients were included, of whom 61 (30.7%) patients underwent SP-DP. Patients who underwent SP-DP had a significantly lower rate of crPOPF (p = 0.022), shorter hospital stay (p = 0.003), and less readmissions (p = 0.012). On multivariate analysis, obesity (OR 2.88, p = 0.021), benign lesions (OR 2.35, p = 0.018), postoperative acute pancreatitis (OR 2.53, p = 0.028), and splenectomy (OR 2.83, p = 0.011) were independent risk factors associated with the onset of crPOPF.

DISCUSSION

Preservation of the spleen reduces the risk of crPOPF in patients undergoing distal pancreatectomy for benign and malignant disease.

Interpreting Sequence Variation in PDAC-Predisposing Genes Using a Multi-Tier Annotation Approach Performed at the Gene, Patient, and Cohort Level

We investigated germline variation in pancreatic ductal adenocarcinoma (PDAC) predisposition genes in 535 patients, using a custom-built panel and a new complementary bioinformatic approach. Our panel assessed genes belonging to DNA repair, cell cycle checkpoints, migration, and preneoplastic pancreatic conditions. Our bioinformatics approach integrated annotations of variants by using data derived from both germline and somatic references. This integrated approach with expanded evidence enabled us to consider patterns even among private mutations, supporting a functional role for certain alleles, which we believe enhances individualized medicine beyond classic gene-centric approaches. Concurrent evaluation of three levels of evidence, at the gene, sample, and cohort level, has not been previously done. Overall, we identified in PDAC patient germline samples, 12% with mutations previously observed in pancreatic cancers, 23% with mutations previously discovered by sequencing other human tumors, and 46% with mutations with germline associations to cancer. Non-polymorphic protein-coding pathogenic variants were found in 18.4% of patient samples. Moreover, among patients with metastatic PDAC, 16% carried at least one pathogenic variant, and this subgroup was found to have an improved overall survival (22.0 months versus 9.8; p=0.008) despite a higher pre-treatment CA19-9 level (p=0.02). Genetic alterations in DNA damage repair genes were associated with longer overall survival among patients who underwent resection surgery (92 months vs. 46; p=0.06). ATM alterations were associated with more frequent metastatic stage (p = 0.04) while patients with BRCA1 or BRCA2 alterations had improved overall survival (79 months vs. 39; p=0.05). We found that mutations in genes associated with chronic pancreatitis were more common in non-white patients (p<0.001) and associated with longer overall survival (52 months vs. 26; p=0.004), indicating the need for greater study of the relationship among these factors. More than 90% of patients were found to have variants of uncertain significance, which is higher than previously reported. Furthermore, we generated 3D models for selected mutant proteins, which suggested distinct mechanisms underlying their dysfunction, likely caused by genetic alterations. Notably, this type of information is not predictable from sequence alone, underscoring the value of structural bioinformatics to improve genomic interpretation. In conclusion, the variation in PDAC predisposition genes appears to be more extensive than anticipated. This information adds to the growing body of literature on the genomic landscape of PDAC and brings us closer to a more widespread use of precision medicine for this challenging disease.

Impact of intraoperative margin clearance on survival following pancreatoduodenectomy for pancreatic cancer: a systematic review and meta-analysis

The use of intraoperative margin revision to achieve margin clearance in patients undergoing pancreatoduodenectomy for pancreatic cancer is controversial. We performed a systematic review and meta-analysis to summarize the evidence of intraoperative margin revisions of the pancreatic neck and its impact on overall survival (OS). Nine studies with 4501 patients were included. Patient cohort was stratified in an R0R0-group (negative margin on frozen and permanent section), R1R0-group (revised positive margin on frozen section which turned negative on permanent section), and R1R1-group (positive margin on frozen and permanent section despite margin revision). OS was higher in the R1R0-group (HR 0.83, 95% CI 0.72-0.96, P = 0.01) compared to the R1R1-group but lower compared to the R0R0-group (HR 1.20; 95% CI 1.05-1.37, P = 0.008), respectively. Subgroup analyses on the use of different margin clearance definitions confirmed an OS benefit in the R1R0-group compared to the R1R1-group (HR 0.81; 95% CI 0.65-0.99, P = 0.04). In conclusion, intraoperative margin clearance of the pancreatic neck margin is associated with improved OS while residual tumor indicates aggressive tumor biology. Consensus definitions on margin terminologies, clearance, and surgical techniques are required.

Obesity and Pancreatic Cancer: A Matched-Pair Survival Analysis

BACKGROUND

Morbid obesity is a risk factor for pancreatic ductal adenocarcinoma (PDAC). However, the impact of obesity on postoperative outcomes and overall survival in patients with PDAC remains a controversial topic.

METHODS

Patients who underwent pancreatic surgery for PDAC between 1997 and 2018 were included in this study. Matched pairs (1:1) were generated according to age, gender and American Society of Anesthesiologists status. Obesity was defined according to the WHO definition as BMI ≥ 30 kg/m². The primary endpoint was the difference in overall survival between patients with and without obesity.

RESULTS

Out of 553 patients, a total of 76 fully matched pairs were generated. Obese patients had a mean BMI-level of 33 compared to 25 kg/m² in patients without obesity (p = 0.001). The frequency of arterial hypertension (p = 0.002), intraoperative blood loss (p = 0.039), and perineural invasion (p = 0.033) were also higher in obese patients. Clinically relevant postoperative complications (p = 0.163) and overall survival rates (p = 0.885) were comparable in both study groups. Grade II and III obesity resulted in an impaired overall survival, although this was not statistically significant. Subgroup survival analyses revealed no significant differences for completion of adjuvant chemotherapy and curative-intent surgery.

CONCLUSIONS

Obesity did not affect overall survival and postoperative complications in these patients with PDAC. Therefore, pancreatic surgery should not be withheld from obese patients.

Mass-forming pancreatitis versus pancreatic ductal adenocarcinoma: CT and MR imaging for differentiation

Various inflammatory abnormalities of the pancreas can mimic pancreatic ductal adenocarcinoma (PDAC) at cross-sectional imaging. Misdiagnosis of PDAC at imaging may lead to unnecessary surgery. On the other hand, chronic pancreatitis (CP) bears a greater risk of developing PDAC during the course of the disease. Thus, differentiation between mass-forming chronic pancreatitis (MFCP) and PDAC is important to avoid unnecessary surgery and not to delay surgery of synchronous PDAC in CP.

Imaging features such as the morphology of the mass including displacement of calcifications, presence of duct penetrating, sign appearance of duct stricturing, presence or absence of vessel encasement, apparent diffusion coefficient (ADC) value and intravoxel incoherent motion (IVIM) at diffusion-weighted imaging (DWI), fluorodeoxyglucose (FDG) uptake in PET/CT, and mass perfusion parameters can help to differentiate between PDAC and MFCP. Correct interpretation of imaging features can appropriately guide biopsy and surgery, if necessary. This review summarizes the relevant computed tomography (CT) and magnetic resonance imaging (MRI) features that can help the radiologist to come to a confident diagnosis and to guide further management in equivocal cases.

Evaluation of Texture Analysis for the Differential Diagnosis of Mass-Forming Pancreatitis From Pancreatic Ductal Adenocarcinoma on Contrast-Enhanced CT Images

Purpose: To investigate the potential of computed tomography (CT) imaging features and texture analysis to differentiate between mass-forming pancreatitis (MFP) and pancreatic ductal adenocarcinoma (PDAC).

Materials and Methods: Thirty patients with pathologically proved MFP and 79 patients with PDAC were included in this study. Clinical data and CT imaging features of the two lesions were evaluated. Texture features were extracted from arterial and portal phase CT images using commercially available software (AnalysisKit). Multivariate logistic regression analyses were used to identify relevant CT imaging and texture parameters to discriminate MFP from PDAC. Receiver operating characteristic curves were performed to determine the diagnostic performance of predictions.

Results: MFP showed a larger size compared to PDAC (p = 0.009). Cystic degeneration, pancreatic ductal dilatation, vascular invasion, and pancreatic sinistral portal hypertension were more frequent and duct penetrating sign was less frequent in PDAC compared to MFP. Arterial CT attenuation, arterial, and portal enhancement ratios of MFP were higher than PDAC (p < 0.05). In multivariate analysis, arterial CT attenuation and pancreatic duct penetrating sign were independent predictors. Texture features in arterial phase including SurfaceArea, Percentile40, InverseDifferenceMoment_angle90_offset4, LongRunEmphasis_angle45_offset4, and uniformity were independent predictors. Texture features in portal phase including LongRunEmphasis_angle135_offset7, VoxelValueSum, LongRunEmphasis_angle135_offset4, and GLCMEntropy_angle45_offset1 were independent predictors. Areas under the curve of imaging feature-based, texture feature-based in arterial and portal phases, and the combined models were 0.84, 0.96, 0.93, and 0.98, respectively.

Conclusions: CT texture analysis demonstrates great potential to differentiate MFP from PDAC.

Early postoperative pancreatitis following pancreaticoduodenectomy: what is clinically relevant postoperative pancreatitis?

BACKGROUND/OBJECTIVES

Postoperative pancreatitis (POP) has recently been shown to be the cause of pancreatic fistula (POPF) following pancreaticoduodenectomy (PD). The aim of the present study was to document the perioperative outcome associated with POP and determine potential risk factors for POP.

METHODS

Patients undergoing PD between 2009 and 2015 were identified from the prospective data base at a single center. The previous suggested definition of POP by Connor was used. Complications were graded according to the Clavien-Dindo classification and by the grading proposed for POP. Risk factors for POP were analyzed by univariate and multivariate analysis.

RESULTS

Of 190 patients, a total of 100 patients (53%) developed POP of whom 22 (12%) and 13 (7%) had grade B and grade C complications, respectively. Elevated serum CRP-levels on postoperative day (POD) 2 and elevated serum lipase on POD 1 were associated with onset of cr-POP.

CONCLUSION

The proposed definition of POP constitutes a valuable tool to assess a serious pancreatic-surgery associated complication. Routine serum CRP and serum lipase levels on the first two postoperative days enable sufficient discrimination of clinically relevant POP.