Search

Pancreatic ductal adenocarcinoma (PDAC) is a fatal malignancy due to the difficulty in diagnosis and poor prognosis because of the high recurrence rate, necessitating reliable biomarkers to improve the diagnosis and prognosis. However, the existing markers have limitations. We previously identified extracellular vesicles (EVs) recognized by O‐glycan‐binding lectins (Amaranthus caudatus agglutinin [ACA]) as a novel diagnostic biomarker for PDAC using an EV‐counting system (ExoCounter). This retrospective study analyzed changes in ACA‐positive EVs in perioperative PDAC serum and its association with prognosis using ExoCounter. Absolute EV levels in the pre‐ and postoperative sera of 44 patients who underwent curative pancreatectomy for PDAC were quantified using ExoCounter. The carbohydrate antigen 19‐9 levels declined in most samples postoperatively, and presented no correlation with poor prognosis. In contrast, ACA‐positive EVs increased in serum at 7 days postoperatively in 27 of 44 patients (61.4%). We therefore divided participants with ACA‐positive EVs before and after surgery into elevation and decline groups. The overall survival (OS) and recurrence‐free survival (RFS) of patients with higher ACA‐positive EVs were significantly shorter than those with lower ACA‐positive EVs (26.1 months vs. not reached, P = 0.018; 11.9 vs. 38.6 months, P = 0.013). Multivariable analysis revealed that ACA‐positive EV elevation in postoperative serum was an independent prognostic factor for poor OS (hazard ratio [HR] = 3.891, P = 0.023) and RFS (HR = 2.650, P = 0.024). The detection of ACA‐positive EVs in perioperative serum may be used to predict the prognosis of PDAC in the early postoperative period. [ABSTRACT FROM AUTHOR]

Background: Postoperative pancreatic fistula (POPF) is a major complication of distal pancreatectomy (DP). Although the visceral fat area (VFA) is a risk factor for POPF in DP, its measurement is complicated. This study aimed to identify a simple marker as a predictive indicator of POPF. Methods: We included 210 patients who underwent resection at our institution between 2020 and 2023. The patients' characteristics, preoperative laboratory data, and radiographic findings (e.g., portal vein distance and VFA) and their association with pancreatic fistula after DP were analyzed. POPF was defined as Grade B or C pancreatic fistula on the basis of the International Study Group of Pancreatic Surgery 2016 consensus. Results: POPF developed in 82 (39.0%) patients. Univariate analysis showed that female sex, pancreatic thickness of the cutting line, operative time, blood loss, C‐reactive protein (CRP) level on postoperative day (POD) 3, drain amylase level on POD 3, VFA, and the peritoneum to portal vein distance (PPD) were associated with POPF. Receiver operating characteristic curve analysis of PPD showed a higher area under the curve than VFA (cutoff for PPD: 68 mm). Multivariate analysis showed that CRP (odds ratio [OR]: 2.214), drain amylase (OR: 2.875), and PPD (OR: 15.538) were independent risk factors. When we compared the DP fistula risk score and PPD, receiver operating characteristic analysis showed areas under the curve of 0.650 and 0.803, respectively. Conclusions: A PPD of ≥68 mm is a useful risk predictor of POPF. Determining this distance is simple and easily applicable in the clinical setting. [ABSTRACT FROM AUTHOR]

Alterations in KRAS, CDKN2A (p16), TP53, and SMAD4 genes have been major drivers of pancreatic carcinogenesis. The clinical course of patients with pancreatic cancer in relation to these driver alterations has not been fully characterised in large populations. We hypothesised that pancreatic carcinomas with different combinations of KRAS mutation and aberrant expression of CDKN2A, p53, and SMAD4 might show distinctive recurrence patterns and post‐operative survival outcomes. To test this hypothesis, we utilised a multi‐institutional cohort of 1,146 resected pancreatic carcinomas and assessed KRAS mutations by droplet digital polymerase chain reaction and CDKN2A, p53, and SMAD4 expression by immunohistochemistry. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease‐free survival (DFS) and overall survival (OS) were computed according to each molecular alteration and the number of altered genes using the Cox regression models. Multivariable competing risks regression analyses were conducted to assess the associations of the number of altered genes with specific patterns of recurrence. Loss of SMAD4 expression was associated with short DFS (multivariable HR, 1.24; 95% CI, 1.09–1.43) and OS times (multivariable HR, 1.27; 95% CI, 1.10–1.46). Compared to cases with 0–2 altered genes, cases with three and four altered genes had multivariable HRs for OS of 1.28 (95% CI, 1.09–1.51) and 1.47 (95% CI, 1.22–1.78), respectively (ptrend < 0.001). Patients with an increasing number of altered genes were more likely to have short DFS time (ptrend = 0.003) and to develop liver metastasis (ptrend = 0.006) rather than recurrence at local or other distant sites. In conclusion, loss of SMAD4 expression and an increasing number of altered genes were associated with unfavourable outcomes in pancreatic cancer patients. This study suggests that the accumulation of the four major driver alterations can confer a high metastatic potential to the liver, thereby impairing post‐operative survival among patients with pancreatic cancer. [ABSTRACT FROM AUTHOR]

KRAS mutation is a major driver of pancreatic carcinogenesis and will likely be a therapeutic target. Due to lack of sensitive assays for clinical samples of pancreatic cancer with low cellularity, KRAS mutations and their prognostic association have not been fully examined in large populations. In a multi‐institutional cohort of 1162 pancreatic cancer patients with formalin‐fixed paraffin‐embedded tumor samples, we undertook droplet digital PCR (ddPCR) for KRAS codons 12/13/61. We examined detection rates of KRAS mutations by clinicopathological parameters and survival associations of KRAS mutation status. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease‐free survival (DFS) and overall survival (OS) were computed using the Cox regression model with adjustment for potential confounders. KRAS mutations were detected in 1139 (98%) patients. The detection rate did not differ by age of tissue blocks, tumor cellularity, or receipt of neoadjuvant chemotherapy. KRAS mutations were not associated with DFS or OS (multivariable HR comparing KRAS‐mutant to KRAS‐wild‐type tumors, 1.04 [95% CI, 0.62–1.75] and 1.05 [95% CI, 0.60–1.84], respectively). Among KRAS‐mutant tumors, KRAS variant allele frequency (VAF) was inversely associated with DFS and OS with HRs per 20% VAF increase of 1.27 (95% CI, 1.13–1.42; ptrend <0.001) and 1.31 (95% CI, 1.16–1.48; ptrend <0.001), respectively. In summary, ddPCR detected KRAS mutations in clinical specimens of pancreatic cancer with high sensitivity irrespective of parameters potentially affecting mutation detections. KRAS VAF, but not mutation positivity, was associated with survival of pancreatic cancer patients. [ABSTRACT FROM AUTHOR]

We introduce a Xilinx RF System-on-Chip (RFSoC)-based qubit controller (called the Quantum Instrumentation Control Kit, or QICK for short), which supports the direct synthesis of control pulses with carrier frequencies of up to 6 GHz. The QICK can control multiple qubits or other quantum devices. The QICK consists of a digital board hosting an RFSoC field-programmable gate array, custom firmware, and software and an optional companion custom-designed analog front-end board. We characterize the analog performance of the system as well as its digital latency, important for quantum error correction and feedback protocols. We benchmark the controller by performing standard characterizations of a transmon qubit. We achieve an average gate fidelity of F a v g = 99.93 %. All of the schematics, firmware, and software are open-source. [ABSTRACT FROM AUTHOR]