Recurrence-risk stratification using the Beppu score and selection of perioperative chemotherapy for colorectal liver metastases.

The annual postoperative disease-free survival for colorectal liver metastases can be easily estimated by weighting six preoperative clinical parameters (Beppu score). We identified three recurrence-risk stratification groups: the low (≤6 points), moderate (7-10 points), and high-risk (≥11 points). For low-, moderate-, and high-risk patients, hepatectomy alone, hepatectomy with adjuvant chemotherapy, and hepatectomy with preoperative chemotherapy are recommended, respectively. The Beppu score enables the decision on the necessity and timing of perioperative chemotherapy.

Perioperative disabilities in activities of daily living are associated with worse prognosis after hepatectomy for colorectal liver metastasis.

BACKGROUND: The number of vulnerable patients with colorectal liver metastasis (CRLM) has increased. This study aimed to clarify the relationship between perioperative activities of daily living (ADL) and clinical outcomes after hepatectomy for CRLM. METHODS: Consecutive patients undergoing resection of CRLM from 2004 to 2020 were included. Pre- or postoperative ADL was evaluated according to Barthel index (BI) scores, which range from 0 to 100. Higher scores represent greater level of independence in ADL. Pre- or postoperative BI scores of ≤85 were defined as perioperative disabilities in ADL. Multivariable Cox proportional hazard regression models were utilised to estimate adjusted hazard ratios (HRs) and confidence interval (CI). RESULTS: A total of 218 patients were included, 16 (7.3%) revealed preoperative BI scores of ≤85, and 32 (15%) revealed postoperative BI scores of ≤85. In multivariate analyses, the perioperative disabilities in ADL were independently associated with shorter overall survival (HR, 1.96; 95% CI, 1.10-3.31; P = 0.023) and cancer-specific survival (HR, 2.31; 95% CI, 1.29-3.92; P = 0.006). CONCLUSION: Perioperative disabilities in ADL were associated with poor prognosis following hepatectomy for CRLM. Improving preoperative vulnerability and preventing functional decline after surgery may provide a favourable prognosis for patients with CRLM.

RAS mutation status in combination with the JSHBPS nomogram may be useful for preoperative identification of colorectal liver metastases with high risk of recurrence and mortality after hepatectomy.

PURPOSE: To investigate the prognostic impact of RAS mutations on the Japanese Society of Hepatobiliary and Pancreatic Surgeons (JSHBPS) nomogram score in patients with colorectal cancer liver metastasis (CRLM) following hepatectomy. METHODS: We included 218 consecutive patients undergoing hepatectomy for CRLM between 2004 and 2020. The JSHBPS nomogram score was calculated using six preoperative clinical factors. The score ranged from 0 to 25, and higher scores indicated greater tumor burden. Associations of RAS mutations with disease-free survival (DFS) and overall survival (OS) by the JSHBPS nomogram score were examined. Multivariable Cox proportional hazard regression models were used to estimate adjusted hazard ratios (HRs) and confidence intervals (CIs). RESULTS: RAS mutations were detected in 72 (33%) of the 218 patients. Multivariate analyses revealed that RAS mutations were independently associated with poor DFS (HR, 1.93; 95% CI: 1.20-3.10; p = .007) and OS (HR, 2.65; 95% CI: 1.59-4.71; p = .001) compared with wild-type RAS with JSHBPS nomogram scores ≤ 10. However, in patients with scores ≥ 11, the association of RAS mutations with DFS or OS was not statistically significant (p > .08). CONCLUSION: RAS mutation status in combination with the JSHBPS nomogram may be useful for preoperatively identifying CRLM with high risk of recurrence and mortality after hepatectomy.

Surgery for Hepatocellular Carcinoma With Macroscopic Vascular Invasion in the Era of Modern Molecular Therapy.

It has been reported that patients with macroscopic vascular invasion accompanying hepatocellular carcinoma have a poor prognosis. Modern molecular therapy with multitargeted tyrosine kinase inhibitors and immune checkpoint inhibitors has shown promising results in patients with metastatic hepatocellular carcinoma; however, molecular therapy is limited to patients with Child-Pugh class A disease. This review summarizes the present status of surgical therapies, including conversion hepatectomy, for patients with MVI in the developing era of novel molecular therapy. Phase III studies showed patients with macroscopic vascular invasion had significant survival benefits from sorafenib [hazard ratio (HR)=0.68] and regorafenib (HR=0.67) versus placebo, and nivolumab (HR=0.74) versus sorafenib. Lenvatinib and atezolizumab plus bevacizumab showed marginal effects. It is currently widely assumed that molecular therapy alone will not cure the disease but that additional conversion hepatectomy will be required. A response other than progressive disease is essential but a pathological complete response is not always required. A significant randomized controlled trial has already started in China to assess the necessity for conversion hepatectomy after effective atezolizumab plus bevacizumab treatment, and the results are still awaited. According to Japanese national data, upfront hepatectomy can be recommended for patients with initially resectable disease and macroscopic vascular invasion other than for those with tumors in the main portal vein and the inferior vena cava. In addition, adequate adjuvant therapies with hepatic arterial chemotherapy and transarterial chemoembolization may be beneficial but an effective adjuvant molecular therapy is currently unavailable. In conclusion, novel molecular therapies with higher response rates customized to the oncologic characteristics of each hepatocellular carcinoma with macroscopic vascular invasion are needed to increase the likelihood of conversion surgery and improve long-term outcomes.

Cancer-associated fibroblasts reuse cancer-derived lactate to maintain a fibrotic and immunosuppressive microenvironment in pancreatic cancer.

Glycolysis is highly enhanced in pancreatic ductal adenocarcinoma (PDAC) cells; thus, glucose restrictions are imposed on nontumor cells in the PDAC tumor microenvironment (TME). However, little is known about how such glucose competition alters metabolism and confers phenotypic changes in stromal cells in the TME. Here, we report that cancer-associated fibroblasts (CAFs) with restricted glucose availability utilize lactate from glycolysis-enhanced cancer cells as a fuel and exert immunosuppressive activity in the PDAC TME. The expression of lactate dehydrogenase A (LDHA), which regulates lactate production, was a poor prognostic factor for patients with PDAC, and LDHA depletion suppressed tumor growth in a CAF-rich murine PDAC model. Coculture of CAFs with PDAC cells revealed that most of the glucose was taken up by the tumor cells and that CAFs consumed lactate via monocarboxylate transporter 1 to enhance proliferation through the TCA cycle. Moreover, lactate-stimulated CAFs upregulated IL-6 expression and suppressed cytotoxic immune cell activity synergistically with lactate. Finally, the LDHA inhibitor FX11 reduced tumor growth and improved antitumor immunity in CAF-rich PDAC tumors. Our study provides insight regarding the crosstalk among tumor cells, CAFs, and immune cells mediated by lactate and offers therapeutic strategies for targeting LDHA enzymatic activity in PDAC cells.

Precision anatomy for minimally invasive spleen-preserving distal pancreatectomy in children: A case report of solid-pseudopapillary neoplasm in a 12-year-old girl.

INTRODUCTION: Solid pseudopapillary neoplasm (SPN) is a rare and low malignant tumor found mainly in young females. There is no standardized procedure for SPN of the pancreatic body and tail in children. In adults, an international consensus on precision anatomy for minimally invasive distal pancreatectomy (MIDP) was established recently (PAM-HBP Surgery Project). The aim of this study is to demonstrate that precision anatomy can also be safely and effectively implemented in the pediatric population. PRESENTATION OF CASE: A 12-year-old girl with an incidentally found SPN located in the pancreatic tail was referred to our hospital. She successfully underwent an R0 resection by laparoscopic spleen-preserving distal pancreatectomy (LSPDP) under the concept of precision anatomy. The patient recovered uneventfully and was discharged on day 7. DISCUSSION: This is the first successful report of LSPDP under the concept of precision anatomy in children. In accordance with the recommendations from the international consensus, the "anterior approach" was selected to dissect and encircle the splenic artery based on the vascular anatomy identified by preoperative imaging. The dorsal dissection border of the pancreas along the anterior layer above the Gerota's fascia was carefully maintained and the splenic vessels were preserved taking into consideration the low malignant potential of SPN and to decrease the risk of complications associated with splenectomy, which were also the essential issues of the consensus. CONCLUSION: The implementation of precision anatomy for pediatric pancreas surgery should facilitate the safe diffusion of MIDP for SPN and other benign or low-malignant tumors in children.

The Prognostic Role of Serine Racemase in Patients With Pancreatic Cancer: A New Marker in Cancer Metabolism.

OBJECTIVES: Serine racemase (SRR) participates in serine metabolism in central nervous systems. Serine racemase is only studied in colorectal cancer, and its role in pancreatic cancer (PC) is unknown. This study aims to investigate the role of SRR in PC. METHODS: Totally 182 patients with PC were enrolled in this study. Slices from patients were stained for SRR and CD8+ T cells. Kaplan-Meier methods were used to do survival analysis according to SRR expression from immunohistochemical staining. Univariate and multivariate Cox regression analysis was performed to clarify the independent prognostic value of SRR. Bioinformatic tools were used to explore and validate the expression, prognostic value, possible mechanism, and immune interaction of SRR in PC. RESULTS: The expression of SRR was lower in tumor tissue than normal tissue, also potentially decreased with the increasing tumor grade. Low SRR expression was an independent risk factor for overall survival (hazards ratio, 1.875; 95% confidence interval, 1.175-2.990; P = 0.008) in patients with PC. Serine racemase was positively correlated with CD8+ T cells infiltration and possibly associated with CCL14 and CXCL12 expression. CONCLUSIONS: Serine racemase plays a prognostic role in PC and may be a potentially therapeutic target.

A surgical resection of hepatic granuloma mimicking intrahepatic cholangiocarcinoma: a case report.

Hepatic granuloma is relatively rare, and benign tumor of the liver. Herein, we report an unusual case of hepatic granuloma mimicking intrahepatic cholangiocarcinoma (ICC). An 82-year-old woman with a history of viral hepatitis B was admitted for investigation of liver mass in the left lobe. Dynamic computed tomography revealed a mostly hypo-enhancing main tumor with a peripheral ring enhancement, and positron emission tomography demonstrated localized an abnormal accumulation of fludeoxyglucose. Considering the possibility of malignant disease, extended left hepatectomy was performed. The resected tumor was macroscopically a periductal infiltrating nodular type, 4.5 × 3.6 cm in diameter. The pathological findings showed that granuloma and coagulative necrosis were present, and diagnosis of hepatic granuloma was confirmed. Pathological studies demonstrated that periodic acid-Schiff stain, Grocott-Gomori stain and Ziehl-Neelsen stain were all negative in the lesion.

Hyperglycaemia induces metabolic reprogramming into a glycolytic phenotype and promotes epithelial-mesenchymal transitions via YAP/TAZ-Hedgehog signalling axis in pancreatic cancer.

BACKGROUND: Hyperglycaemia is a well-known initial symptom in patients with pancreatic ductal adenocarcinoma (PDAC). Metabolic reprogramming in cancer, described as the Warburg effect, can induce epithelial-mesenchymal transition (EMT). METHODS: The biological impact of hyperglycaemia on malignant behaviour in PDAC was examined by in vitro and in vivo experiments. RESULTS: Hyperglycaemia promoted EMT by inducing metabolic reprogramming into a glycolytic phenotype via yes-associated protein (YAP)/PDZ-binding motif (TAZ) overexpression, accompanied by GLUT1 overexpression and enhanced phosphorylation Akt in PDAC. In addition, hyperglycaemia enhanced chemoresistance by upregulating ABCB1 expression and triggered PDAC switch into pure basal-like subtype with activated Hedgehog pathway (GLI1 high, GATA6 low expression) through YAP/TAZ overexpression. PDAC is characterised by abundant stroma that harbours tumour-promoting properties and chemoresistance. Hyperglycaemia promotes the production of collagen fibre-related proteins (fibronectin, fibroblast activation protein, COL1A1 and COL11A1) by stimulating YAP/TAZ expression in cancer-associated fibroblasts (CAFs). Knockdown of YAP and/or TAZ or treatment with YAP/TAZ inhibitor (K975) abolished EMT, chemoresistance and a favourable tumour microenvironment even under hyperglycemic conditions in vitro and in vivo. CONCLUSION: Hyperglycaemia induces metabolic reprogramming into glycolytic phenotype and promotes EMT via YAP/TAZ-Hedgehog signalling axis, and YAP/TAZ could be a novel therapeutic target in PDAC.

Thrombospondin-1 overexpression stimulates loss of Smad4 and accelerates malignant behavior via TGF-ß signal activation in pancreatic ductal adenocarcinoma.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is characterized by abundant stroma and cancer-associated fibroblasts (CAFs) provide a favorable tumor microenvironment. Smad4 is known as tumor suppressor in several types of cancers including PDAC, and loss of Smad4 triggers accelerated cell invasiveness and metastatic potential. The thrombospondin-1 (TSP-1) can act as a major activator of latent transforming growth factor-ß (TGF-ß) in vivo. However, the roles of TSP-1 and the mediator of Smad4 loss and TGF-ß signal activation during PDAC progression have not yet been addressed. The aim is to elucidate the biological role of TSP-1 in PDAC progression. METHODS AND RESULTS: High substrate stiffness stimulated TSP-1 expression in CAFs, and TSP-1 knockdown inhibited cell proliferation with suppressed profibrogenic and activated stroma-related gene expressions in CAFs. Paracrine TSP-1 treatment for PDAC cells promoted cell proliferation and epithelial mesenchymal transition (EMT) with activated TGF-ß signals such as phosphorylated Akt and Smad2/3 expressions. Surprisingly, knockdown of DPC4 (Smad4 gene) induced TSP-1 overexpression with TGF-ß signal activation in PDAC cells. Interestingly, TSP-1 overexpression also induced downregulation of Smad4 expression and enhanced cell proliferation in vitro and in vivo. Treatment with LSKL peptide, which antagonizes TSP-1-mediated latent TGF-ß activation, attenuated cell proliferation, migration and chemoresistance with enhanced apoptosis in PDAC cells. CONCLUSIONS: TSP-1 derived from CAFs stimulates loss of Smad4 expression in cancer cells and accelerates malignant behavior by TGF-ß signal activation in PDAC. TSP-1 could be a novel therapeutic target, not only for CAFs in stiff stroma, but also for cancer cells in the PDAC microenvironment.

Risk factors for lymph node metastasis in patients with pancreatic neuroendocrine neoplasms.

BACKGROUND: Although PNENs generally have a better prognosis than pancreatic cancers, some PNENs display malignant behavior including lymph node (LN) metastasis. Complete tumor resection can be the only potentially curative treatment for patients with resectable PNENs. However, the indications for LN dissection are still controversial. Over the last decade, minimally invasive surgery such as laparoscopic pancreatic surgery (LPS) has been increasingly performed for pancreatic tumors including PNENs. AIM: To investigate the risk factors for LN metastasis in PNENs and to select appropriate patients for limited surgery by LPS. METHODS: From April 2001 to December 2019, 92 patients underwent pancreatic resection for PNENs at Kumamoto University Hospital. Finally, 82 patients were enrolled in this study. Using perioperative factors, we examined the predictive factors for LN metastasis in PNENs. RESULTS: Among the 82 patients, the percentage of LN metastasis according to the pathological findings was 12% (10/82 cases). The median tumor size was 12 mm (range: 5-90 mm). The median tumor size in the LN-positive group (37 mm) was significantly larger than that in the LN-negative group (12 mm) (P = 0.0001). Multivariate analyses revealed that larger tumor size (≥ 20 mm) was an independent risk factor for LN metastasis (odds ratio 16.8, P = 0.0062). In patients with small tumors (≤ 10 mm), LN metastasis was not found. CONCLUSION: Larger tumor size (≥ 20 mm) is an independent risk factor for LN metastasis in PNENs. In smaller PNENs (≤ 10 mm), we may be able to choose limited surgery without LN dissection.

Multimodal therapy with aggressive hepatectomy, everolimus, and octreotide for metastatic pancreatic neuroendocrine neoplasm enables 10-year survival.

The presence of neuroendocrine liver metastases is one of the poorest prognostic factors in patients with pancreatic neuroendocrine neoplasms, and surgical resection of neuroendocrine liver metastases is the only curable treatment. A 38-year-old man had a pancreatic neuroendocrine neoplasm with synchronous multiple liver metastases, and two surgeries and continuous everolimus and octreotide achieved R0 resection. However, multiple neuroendocrine liver metastases developed twice after more than 5 years of recurrence-free survival. Aggressive repeat hepatectomy was performed and he has survived for more than 10 years after the initial surgery. This report highlights that patients with pancreatic neuroendocrine neoplasms have a potential risk of recurrence even after 5 years of recurrence-free survival. In addition, combined aggressive hepatectomy and continuous medication can contribute dramatically to long-term survival even for late-stage recurrence of liver metastases.

Impairment of perioperative activities of daily living is associated with poor prognosis following hepatectomy for hepatocellular carcinoma.

BACKGROUND: The number of cancer patients with impairment of activities of daily living (ADLs) has increased. This study aimed to examine associations of perioperative Barthel index score, a validated measure of ADLs, with survival outcomes following hepatectomy for hepatocellular carcinoma (HCC). METHODS: We analyzed data of 492 consecutive patients who underwent hepatectomy for HCC between 2010 and 2018. Pre- and postoperative ADLs were assessed using the Barthel index (range, 0-100; higher scores indicate greater independence). Preoperative Barthel index score ≤85 or postoperative Barthel index score ≤85 was defined as impairment of perioperative ADLs. Cox proportional hazards regression was used to calculate hazard ratios (HRs) after adjusting for potential confounders. RESULTS: Among the 492 patients, 26 (5.2%) had a preoperative Barthel index score ≤85 and 95 (19%) had a postoperative Barthel index score ≤85. Impairment of perioperative ADLs was independently associated with shorter overall survival (multivariable HR: 1.75, 95% confidence interval [CI]: 1.06-2.81, p = 0.028). The association of impairment of perioperative ADLs with recurrence-free survival was not statistically significant. CONCLUSION: Impairment of perioperative ADLs is associated with poor prognosis following hepatectomy for HCC. Maintenance and improvement of perioperative ADLs would be important to provide favorable long-term outcomes in patients with HCC.

Using Artificial Intelligence to Find the Optimal Margin Width in Hepatectomy for Colorectal Cancer Liver Metastases.

Importance: In patients with resectable colorectal cancer liver metastases (CRLM), the choice of surgical technique and resection margin are the only variables that are under the surgeon's direct control and may influence oncologic outcomes. There is currently no consensus on the optimal margin width. Objective: To determine the optimal margin width in CRLM by using artificial intelligence-based techniques developed by the Massachusetts Institute of Technology and to assess whether optimal margin width should be individualized based on patient characteristics. Design, Setting, and Participants: The internal cohort of the study included patients who underwent curative-intent surgery for KRAS-variant CRLM between January 1, 2000, and December 31, 2017, at Johns Hopkins Hospital, Baltimore, Maryland, Memorial Sloan Kettering Cancer Center, New York, New York, and Charité-University of Berlin, Berlin, Germany. Patients from institutions in France, Norway, the US, Austria, Argentina, and Japan were retrospectively identified from institutional databases and formed the external cohort of the study. Data were analyzed from April 15, 2019, to November 11, 2021. Exposures: Hepatectomy. Main Outcomes and Measures: Patients with KRAS-variant CRLM who underwent surgery between 2000 and 2017 at 3 tertiary centers formed the internal cohort (training and testing). In the training cohort, an artificial intelligence-based technique called optimal policy trees (OPTs) was used by building on random forest (RF) predictive models to infer the margin width associated with the maximal decrease in death probability for a given patient (ie, optimal margin width). The RF component was validated by calculating its area under the curve (AUC) in the testing cohort, whereas the OPT component was validated by a game theory-based approach called Shapley additive explanations (SHAP). Patients from international institutions formed an external validation cohort, and a new RF model was trained to externally validate the OPT-based optimal margin values. Results: This cohort study included a total of 1843 patients (internal cohort, 965; external cohort, 878). The internal cohort included 386 patients (median [IQR] age, 58.3 [49.0-68.7] years; 200 men [51.8%]) with KRAS-variant tumors. The AUC of the RF counterfactual model was 0.76 in both the internal training and testing cohorts, which is the highest ever reported. The recommended optimal margin widths for patient subgroups A, B, C, and D were 6, 7, 12, and 7 mm, respectively. The SHAP analysis largely confirmed this by suggesting 6 to 7 mm for subgroup A, 7 mm for subgroup B, 7 to 8 mm for subgroup C, and 7 mm for subgroup D. The external cohort included 375 patients (median [IQR] age, 61.0 [53.0-70.0] years; 218 men [58.1%]) with KRAS-variant tumors. The new RF model had an AUC of 0.78, which allowed for a reliable external validation of the OPT-based optimal margin. The external validation was successful as it confirmed the association of the optimal margin width of 7 mm with a considerable prolongation of survival in the external cohort. Conclusions and Relevance: This cohort study used artificial intelligence-based methodologies to provide a possible resolution to the long-standing debate on optimal margin width in CRLM.

Survival impact of immune cells infiltrating peritumoral area of hepatocellular carcinoma.

Inflammatory and immune cells in the tumor microenvironment are reported to be associated with tumor progression in several cancers. In total, 225 patients who underwent initial and curative hepatectomy for hepatocellular carcinoma (HCC) from 2004 to 2013 were enrolled in this study. Tumor-associated neutrophils (TANs), M2 macrophages (TAMs; tumor-associated macrophages), CD8+ T cells, and regulatory T cells (Tregs) were evaluated by immunohistochemistry (IHC), and their relationships with patient clinicopathological characteristics and prognosis were evaluated. IHC was performed focusing on TANs first. We could not find a relationship between intratumoral and peritumoral TANs and clinicopathological features except for the fibrous capsule and infiltration of tumors into capsule. Next, TAMs, CD8+ cells and Tregs were evaluated by IHC. At the peritumoral area, TANs and TAMs (r = 0.36, p = 0.001) or Tregs (r = 0.16, p = 0.008) showed a positive correlation, whereas TANs and CD8+ cells showed a negative correlation (r = -0.16, p = 0.02). As for survival outcomes, at the peritumoral area, high TANs (p = 0.0398), low CD8+ cells (p = 0.0275), and high TAMs (p = 0.001) were significantly associated with worse overall survival (OS). In addition, high TANs (p = 0.010), and high TAMs (p = 0.00125) were significantly associated with worse disease-free survival (DFS). Finally, we established a risk signature model by combining the expression patterns of these cells. The high-risk signature group had significantly worse OS (p = 0.0277) and DFS (p = 0.0219) compared with those in the low-risk signature group. Our risk signature based on immune cells at the peritumoral area of the HCC can predict patient prognosis of HCC after curative hepatectomy.

The efficacy of anatomic resection for hepatocellular carcinoma within Milan criteria: A retrospective single-institution case-matched study.

INTRODUCTION: Still now, the efficacy of anatomic resection (AR) for hepatocellular carcinoma (HCC) is controversial. The aim of this study is to examine it in our cohort and detect an optimal indicator for AR. METHODS: The present study included 656 patients with primary HCC within Milan criteria who underwent hepatectomy from 2000 to 2019. Our cohort was divided into AR (n = 378) and non-anatomic resection (NAR) (n = 278) groups, and 1:1 propensity score matching (PSM) was performed to minimize the effect of potential confounders. Recurrence-free survival (RFS), overall survival (OS), and a preoperative indicator for AR were examined. RESULTS: 210 patients from each group were well-matched, and preoperative confounding factors were balanced between the two groups. There was no significant difference in RFS and OS between the two groups before (RFS; HR = 0.89 P = 0.25, OS; HR = 1.08 P = 0.64) and after PSM (RFS; HR = 0.93 P = 0.60, OS; HR = 1.07 P = 0.75). Subgroup analysis showed that the survival improvement effect of AR was observed in cases with a fucosylated fraction of alfa-fetoprotein (AFP-L3) > 10% and poorly differentiation (P for interaction <0.05). Moreover, the logistic regression analysis showed that preoperative AFP-L3 > 10% was an independent predictor for poorly differentiation (OR = 2.58, P = 0.03). CONCLUSION: The efficacy of AR for patients with primary HCC within Milan criteria was not shown. But it was suggested that AFP-L3 > 10% might be a preoperative indicator of AR for HCC within Milan criteria.

Survival Impact of Perioperative Red Blood Cell Transfusion During Pancreatectomy in Patients With Pancreatic Ductal Adenocarcinoma: A Propensity Score Matching Analysis.

OBJECTIVES: The aim of this study was to show the real impact of perioperative red blood cell transfusion (PBT) on prognosis in patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma. METHODS: Patients who underwent pancreatectomy between 2004 and 2018 were enrolled. Short- and long-term outcomes in patients who received PBT (PBT group) were compared with those who did not (non-PBT group). RESULTS: From a total of 197 patients, 55 (27.9%) received PBT, and 142 (72.1%) did not. The PBT group displayed a higher level of carbohydrate antigen 19-9 (P = 0.02), larger tumor size (P < 0.001), and a higher rate of lymph node metastasis (P = 0.02), and underwent more frequent pancreaticoduodenectomy (P < 0.001) and portal vein resection (P < 0.001). Before matching, recurrence-free survival (RFS) and overall survival (OS) in the PBT group were significantly worse than the non-PBT group (RFS: hazard ratio [HR], 1.73 [P = 0.002]; OS: HR, 2.06 [P < 0.001]). After matching, RFS and OS in the PBT group were not significantly different from the non-PBT group (RFS: HR, 1.44 [P = 0.15]; OS: HR, 1.53 [P = 0.11]). CONCLUSIONS: Our results show that PBT has no survival impact in patients who underwent pancreatectomy for pancreatic ductal adenocarcinoma.