Prognostic Significance of 18F-FDG PET/CT Radiomics in Patients With Resectable Pancreatic Ductal Adenocarcinoma Undergoing Curative Surgery.

PURPOSE: This study aimed to investigate the prognostic significance of PET/CT radiomics to predict overall survival (OS) in patients with resectable pancreatic ductal adenocarcinoma (PDAC). METHODS: We enrolled 627 patients with resectable PDAC who underwent preoperative 18F-FDG PET/CT and subsequent curative surgery. Radiomics analysis of the PET/CT images for the primary tumor was performed using the Chang-Gung Image Texture Analysis toolbox. Radiomics features were subjected to least absolute shrinkage and selection operator (LASSO) regression to select the most valuable imaging features of OS. The prognostic significance was evaluated by Cox proportional hazards regression analysis. Conventional PET parameters and LASSO score were assessed as predictive factors for OS by time-dependent receiver operating characteristic curve analysis. RESULTS: During a mean follow-up of 28.8 months, 378 patients (60.3%) died. In the multivariable Cox regression analysis, tumor differentiation, resection margin status, tumor stage, and LASSO score were independent prognostic factors for OS (HR, 1.753, 1.669, 2.655, and 2.946; all P < 0.001, respectively). The time-dependent receiver operating characteristic curve analysis showed that the LASSO score had better predictive performance for OS than conventional PET parameters. CONCLUSION: The LASSO score using the 18F-FDG PET/CT radiomics of the primary tumor was the independent prognostic factor for predicting OS in patients with resectable PDAC and may be helpful in determining therapeutic and follow-up plans for these patients.

Single-cell transcriptome analysis reveals subtype-specific clonal evolution and microenvironmental changes in liver metastasis of pancreatic adenocarcinoma and their clinical implications.

BACKGROUND: Intratumoral heterogeneity (ITH) and tumor microenvironment (TME) of pancreatic ductal adenocarcinoma (PDAC) play important roles in tumor evolution and patient outcomes. However, the precise characterization of diverse cell populations and their crosstalk associated with PDAC progression and metastasis is still challenging. METHODS: We performed single-cell RNA sequencing (scRNA-seq) of treatment-naïve primary PDAC samples with and without paired liver metastasis samples to understand the interplay between ITH and TME in the PDAC evolution and its clinical associations. RESULTS: scRNA-seq analysis revealed that even a small proportion (22%) of basal-like malignant ductal cells could lead to poor chemotherapy response and patient survival and that epithelial-mesenchymal transition programs were largely subtype-specific. The clonal homogeneity significantly increased with more prevalent and pronounced copy number gains of oncogenes, such as KRAS and ETV1, and losses of tumor suppressor genes, such as SMAD2 and MAP2K4, along PDAC progression and metastasis. Moreover, diverse immune cell populations, including naïve SELLhi regulatory T cells (Tregs) and activated TIGIThi Tregs, contributed to shaping immunosuppressive TMEs of PDAC through cellular interactions with malignant ductal cells in PDAC evolution. Importantly, the proportion of basal-like ductal cells negatively correlated with that of immunoreactive cell populations, such as cytotoxic T cells, but positively correlated with that of immunosuppressive cell populations, such as Tregs. CONCLUSION: We uncover that the proportion of basal-like subtype is a key determinant for chemotherapy response and patient outcome, and that PDAC clonally evolves with subtype-specific dosage changes of cancer-associated genes by forming immunosuppressive microenvironments in its progression and metastasis.

Bleeding after endoscopic papillectomy and its risk factors: A single center experience of 196 cases.

BACKGROUND: Endoscopic papillectomy (EP) is an effective method to remove an ampulla of Vater (AoV) adenoma with minimal invasiveness. We reviewed the clinical outcomes and prognosis of patients undergoing EP, including tumor recurrence and adverse events. METHODS: A total of 196 patients who underwent EP from January 2004 to December 2017 were included. Clinical information was collected through electronic medical records, and risk factors to predict post-procedural bleeding were analyzed using a multivariate logistic regression model. RESULTS: A total of 93.9% patients (184/196) underwent complete resection. During the follow-up period, 14.7% patients (27/184) experienced tumor recurrence, and two of seven surgically resected tumors were malignant. A total of 45.4% patients (89/196) experienced adverse events related to EP. Delayed bleeding occurred in 16.3% of the patients (32/196), and they were all successfully treated with endoscopic hemostasis and conservative management. The most frequent site of delayed bleeding was the distal end of the papillary orifice, and 56.2% (18/32) patients of delayed bleeding were classified as having mild severity, the others had moderate severity. Familial adenomatous polyposis (FAP) [odds ratio (OR) = 3.80, 95% confidence interval (CI): 1.01-14.29; P < 0.05] and male sex (OR = 2.82, 95% CI: 1.04-7.63; P = 0.04) showed statistical significance in predicting delayed post-EP bleeding. CONCLUSIONS: EP for AoV adenoma was a highly effective and safe procedure. The risk of post-EP delayed bleeding was increased in patients with FAP syndrome and male patients, and post-EP bleeding occurred most commonly in the distal part of the AoV.

Establishment of a patient-specific avatar organoid model derived from EUS-guided fine-needle biopsy for timely clinical application in pancreatic ductal adenocarcinoma (with video).

BACKGROUND AND AIMS: Pancreatic ductal adenocarcinoma (PDAC) has the worst survival rate among tumors. At the time of diagnosis, more than 80% of PDACs are considered to be surgically unresectable, and there is an unmet need for treatment options in these inoperable PDACs. This study aimed to establish a patient-derived organoid (PDO) platform from EUS-guided fine-needle biopsy (EUS-FNB) collected at diagnosis and to determine its clinical applicability for the timely treatment of unresectable PDAC. METHODS: Patients with suspected PDAC were prospectively enrolled at the Samsung Medical Center from 2015 to 2019. PDAC tissues were acquired by means of EUS-FNB to establish PDAC PDOs, which were comprehensively analyzed for histology, genomic sequencing, and high-throughput screening (HTS) drug sensitivity test. RESULTS: PDAC PDOs were established with a success rate of 83.2% (94/113). It took approximately 3 weeks from acquiring minimal EUS-FNB specimens to generating sufficient PDAC PDOs for the simultaneous HTS drug sensitivity test and genomic sequencing. The high concordance between PDAC tissues and matched PDOs was confirmed, and whole-exome sequencing revealed the increased detection of genetic alterations in PDOs compared with EUS-FNB tissues. The HTS drug sensitivity test showed clinical correlation between the ex vivo PDO response and the actual chemotherapeutic response of the study patients in the real world (13 out of 15 cases). In addition, whole-transcriptome sequencing identified candidate genes associated with nab-paclitaxel resistance, such as ITGB7, ANPEP, and ST3GAL1. CONCLUSIONS: This PDAC PDO platform allows several therapeutic drugs to be tested within a short time window and opens the possibility for timely personalized medicine as a "patient avatar model" in clinical practice.

Impact and optimal timing of local therapy addition in borderline resectable or locally advanced pancreatic cancer after FOLFIRINOX chemotherapy.

Background: To evaluate the efficacy and optimal timing of local treatment in patients with borderline resectable (BR) or locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX. Method: Between 2015 and 2020, 258 patients with pancreatic ductal adenocarcinoma (PDAC) were analysed. Treatment outcomes were compared between systemic treatment group (ST) and multimodality treatment groups (MT) using Kaplan-Meier curves and log-rank test. The MT were stratified as follows: FOLFIRINOX + radiation therapy (RT) (MT1), FOLFIRINOX + surgical resection (MT2), and FOLFIRINOX + RT + surgical resection (MT3). Results: With median follow-up period of 18 months, the 2-year overall survival (OS) for the ST was 22.0%, and it was significantly worse than MT (MT1, 46.3%; MT2, 65.7% and MT3; 90.2%; P < .001). The 2-year locoregional progression free survival (LRPFS) and overall PFS in ST were 10.7% and 7.0%, which were also significantly lower than those of MT (2-year LRPFS: MT1, 31.8%; MT2, 45.3%; MT3, 81.0%; 2-year overall PFS: MT1, 23.3%; MT2, 35.0%; MT3, 66.3%; P < .001). In time-varying multivariate Cox proportional hazard model, local treatment contributed to better treatment outcomes, with adjusted hazard ratios of 0.568 (95% confidence interval [CI], 0.398-0.811), 0.490 (95% CI, 0.331-0.726), and 0.656 (95% CI, 0.458-0.940) for OS, LRPFS, and overall PFS, respectively. The time window of 11-17 months after FOLFIRINOX appeared to demonstrate the maximal efficacy of local treatments in OS. Conclusions: Adding local treatment in BR/LAPC patients treated with upfront FOLFIRINOX seemed to contribute in improved treatment outcomes, and it showed maximal efficacy in OS when applied 11-17 months after the initiation of FOLFIRINOX. We suggest that administration of sufficient period of upfront FOLFIRINOX may intensify the efficacy of local treatments, and well controlled prospective trials are expected.

Prolonged progression-free survival achieved by gemcitabine, cisplatin, and albumin-bound paclitaxel for the treatment of advanced biliary tract cancers.

Background: A regimen of gemcitabine, cisplatin, and nab-paclitaxel (GPA) has shown promising results in patients with advanced biliary tract cancer (aBTC). Objectives: This study aimed to evaluate the benefit of GPA compared to a regimen of gemcitabine plus cisplatin (GP) in patients with aBTC. Design: Retrospective study. Methods: Patients with aBTC who received first-line chemotherapy with GPA or GP regimen at the Samsung Medical Center between July 2020 and June 2022 were included. The primary endpoint was progression-free survival (PFS). Results: In all, 37 patients were treated with GPA and 43 patients with GP. The GPA group showed significantly longer median PFS [12.0 months (95% CI, 7.2-16.8)] compared to the GP group [5.5 months (95% CI, 3.7-7.4; p = 0.007)]. The median overall survival (OS) was also longer in the GPA group [18.7 months (95% CI, 13.7-23.7)] than in the GP group [10.7 months (95% CI, 1.5-19.9); p = 0.021]. First-line chemotherapy with GPA was associated with longer PFS, while metastatic disease at initial diagnosis and post-treatment increase in CA 19-9 level were associated with worse PFS. Conclusion: The GPA regimen improved the PFS of patients with aBTC compared to the GP regimen but showed no significant benefit in terms of OS after adjusting for confounding variables. Further large-scale studies are required to establish optimal indications for GPA.

Comparing new and standard chemotherapy treatments for advanced biliary tract cancer: a study of effectiveness and survival In this study, researchers at Samsung Medical Center investigated the effectiveness of two chemotherapy regimens for advanced biliary tract cancer (aBTC) from July 2020 to June 2022. The study compared a new treatment combination, gemcitabine, cisplatin, and nab-paclitaxel (GPA), against the standard treatment of gemcitabine and cisplatin (GP). The main focus was on progression-free survival (PFS) ­ the time patients lived without their cancer worsening, and overall survival (OS) ­ the total lifespan after treatment. A total of 37 patients received the GPA treatment, while 43 received the GP treatment. The results showed that patients on the GPA regimen had a longer median PFS of 12.0 months, compared to 5.5 months for those on the GP regimen. This significant difference suggested that GPA might be more effective in slowing cancer progression. Moreover, the median OS was also longer for patients treated with GPA (18.7 months) than for those with the GP regimen (10.7 months). These findings indicated that GPA not only delayed the progression of cancer but also potentially increased the overall survival time of patients. However, when accounting for other factors that could influence the results, the advantage of GPA in terms of overall survival became less clear. This suggests that while GPA is effective in delaying disease progression, its impact on extending the overall life expectancy of patients with aBTC is not definitive. Despite these promising findings, the researchers cautioned that the benefits of the GPA regimen in extending overall survival need further investigation. The study underscores the potential of GPA in improving outcomes for aBTC patients but also highlights the necessity for more comprehensive studies. These future studies are needed to confirm the optimal treatment for this challenging cancer type. This research is a step towards better understanding and managing aBTC, a cancer that currently has limited treatment options.