BRAF-mutant microsatellite-stable rectal cancer with acquired KRAS mutation leading to drug resistance in liver metastasis.

BRAF-mutant microsatellite-stable colorectal cancer (CRC), metastasized to distant sites, is associated with a poor prognosis. However, the BEACON CRC regimen, comprising a BRAF inhibitor, MEK inhibitor, and anti-EGFR antibody, offered a prolonged prognosis. Nonetheless, resistance to this regimen may occur, as observed in our reported case of CRC, where a KRAS mutation was identified in addition to the BRAF V600E mutation. Here, we present a case of 74-year-old woman with rectal cancer (pT4bN1bM0 Stage IIIc) harboring the BRAF V600E mutation. After resection of the primary tumor and during adjuvant chemotherapy using CAPOX (capecitabine and oxaliplatin), liver and lung metastases became apparent, and a companion diagnosis test revealed the presence of a BRAF V600E mutation. The new lesions were deemed resistant to the CAPOX regimen, and we decided to introduce encorafenib and cetuximab. After resection of liver metastases, encorafenib and cetuximab were reintroduced, but a new lesion appeared in hepatic S7, indicating resistance to the encorafenib and cetuximab regimen. The resistant liver metastasis was subsequently resected. To elucidate the resistance mechanism, we conducted a comprehensive analysis using the FoundationOne CDx cancer gene panel test, revealing the presence of a KRAS Q61H mutation alongside the BRAF V600E mutation. Subsequent liquid biopsy after liver recurrence confirmed the persistence of the KRAS Q61H mutation. Our results highlight the significance of cancer genome profiling tests (CGP tests) and liquid biopsies in guiding treatment strategies for BRAF-mutant colorectal cancer. Therefore, CGP testing offers valuable information for treatment, even if it does not lead to new drug administrations.

Role of robotic surgery as an element of Enhanced Recovery After Surgery protocol in patients undergoing pancreatoduodenectomy.

BACKGROUND: Although the current trend in pancreatoduodenectomy (PD) has shifted from open surgery to minimally invasive surgery (MIS), evidence on the role of MIS as an element of Enhanced Recovery After Surgery (ERAS) in PD is limited. This study aimed to investigate the effect of robotic surgery using the ERAS protocol on the outcomes of patients undergoing PD. METHODS: This retrospective study included 252 patients who underwent open PD (OPD) or robotic PD (RPD) managed using the ERAS protocol between January 2017 and March 2023. Outcomes stratified by the surgical approach were compared. Multivariable analyses were performed to evaluate the effect of ERAS items, including robotic surgery, on outcomes after PD. RESULTS: Of 252 patients, 202 (80.2%) underwent OPD, and 50 (19.2%) underwent RPD. Multivariable analyses demonstrated that perioperative management center support (odds ratio [OR], 2.85; 95% CI, 1.14-7.72; P = .025), robotic surgery (OR, 6.40; 95% CI, 1.94-26.1; P = .002), early solid intake (OR, 2.84; 95% CI, 1.46-5.63; P = .002), and early drain removal (OR, 3.77; 95% CI, 2.04-7.06; P < .001) were significant ERAS items related to early discharge after PD. CONCLUSION: Our study demonstrated that employing the ERAS protocol for OPD and RPD is feasible and safe. Moreover, our results suggested the role of robotic surgery as an element of the ERAS protocol for PD. A combination of ERAS protocols and MIS may be safe and feasible for accelerating postoperative recovery after PD.

Long-term activation of anti-tumor immunity in pancreatic cancer by a p53-expressing telomerase-specific oncolytic adenovirus.

BACKGROUND: Pancreatic cancer is an aggressive, immunologically "cold" tumor. Oncolytic virotherapy is a promising treatment to overcome this problem. We developed a telomerase-specific oncolytic adenovirus armed with p53 gene (OBP-702). METHODS: We investigated the efficacy of OBP-702 for pancreatic cancer, focusing on its long-term effects via long-lived memory CD8 + T cells including tissue-resident memory T cells (TRMs) and effector memory T cells (TEMs) differentiated from effector memory precursor cells (TEMps). RESULTS: First, in vitro, OBP-702 significantly induced adenosine triphosphate (ATP), which is important for memory T cell establishment. Next, in vivo, OBP-702 local treatment to murine pancreatic PAN02 tumors increased TEMps via ATP induction from tumors and IL-15Rα induction from macrophages, leading to TRM and TEM induction. Activation of these memory T cells by OBP-702 was also maintained in combination with gemcitabine+nab-paclitaxel (GN) in a PAN02 bilateral tumor model, and GN + OBP-702 showed significant anti-tumor effects and increased TRMs in OBP-702-uninjected tumors. Finally, in a neoadjuvant model, in which PAN02 cells were re-inoculated after resection of treated-PAN02 tumors, GN + OBP-702 provided long-term anti-tumor effects even after tumor resection. CONCLUSION: OBP-702 can be a long-term immunostimulant with sustained anti-tumor effects on immunologically cold pancreatic cancer.

Circulating cell-free DNA methylation patterns as non-invasive biomarkers to monitor colorectal cancer treatment efficacy without referencing primary site mutation profiles.

This study investigates methylation patterns in circulating cell-free DNA (ccfDNA) for their potential role in colorectal cancer (CRC) detection and the monitoring of treatment response. Through methylation microarrays and quantitative PCR assays, we analyzed 440 samples from The Cancer Genome Atlas (TCGA) and an additional 949 CRC samples. We detected partial or extensive methylation in over 85% of cases within three biomarkers: EFEMP1, SFRP2, and UNC5C. A methylation score for at least one of the six candidate regions within these genes' promoters was present in over 95% of CRC cases, suggesting a viable detection method. In evaluating ccfDNA from 97 CRC patients and 62 control subjects, a difference in methylation and recovery signatures was observed. The combined score, integrating both methylation and recovery metrics, showed high diagnostic accuracy, evidenced by an area under the ROC curve of 0.90 (95% CI = 0.86 to 0.94). While correlating with tumor burden, this score gave early insight into disease progression in a small patient cohort. Our results suggest that DNA methylation in ccfDNA could serve as a sensitive biomarker for CRC, offering a less invasive and potentially more cost-effective approach to augment existing cancer detection and monitoring modalities, possibly supporting comprehensive genetic mutation profiling.

Robotic Pancreatoduodenectomy in Portal Annular Pancreas Using a Hanging Maneuver with Indocyanine Green Fluorescence Imaging.

BACKGROUND: Sufficient knowledge and surgical management of portal annular pancreas (PAP) are essential for pancreatic surgery. As PAP is a relatively rare pancreatic anomaly, few studies have described surgical techniques for patients with PAP undergoing robotic pancreatoduodenectomy (RPD). PATIENTS AND METHODS: An 82-year-old female patient who underwent RPD presented with distal cholangiocarcinoma and type III PAP (the fusion of the uncinate process with the anteportal main pancreatic duct). After the Kocher maneuver and stomach transection, the pancreas was transected into the neck of the anteportal portion. The retroportal portion was dissected, encircled with hanging tape, and compressed. Blood supply from the mesenteric vessels was confirmed using indocyanine green (ICG) fluorescence imaging. Subsequently, the retroportal portion was stapled. CONCLUSIONS: This study demonstrates a unique surgical technique for type III PAP using the hanging maneuver with ICG fluorescence imaging. Surgeons should decide on the surgical strategy on the basis of the fusion and ductal anatomy of the pancreas.

Innovative suture technique for robotic hepaticojejunostomy: double-layer interrupted sutures.

PURPOSE: Biliary reconstruction remains a technically demanding and complicated procedure in minimally invasive hepatopancreatobiliary surgeries. No optimal hepaticojejunostomy (HJ) technique has been demonstrated to be superior for preventing biliary complications. This study aimed to investigate the feasibility of our unique technique of posterior double-layer interrupted sutures in robotic HJ. METHODS: We performed a retrospective analysis of a prospectively collected database. Forty-two patients who underwent robotic pancreatoduodenectomy using this technique between September 2020 and November 2022 at our center were reviewed. In the posterior double-layer interrupted technique, sutures were placed to bite the bile duct, posterior seromuscular layer of the jejunum, and full thickness of the jejunum. RESULTS: The median operative time was 410 (interquartile range [IQR], 388-478) min, and the median HJ time was 30 (IQR, 28-39) min. The median bile duct diameter was 7 (IQR, 6-10) mm. Of the 42 patients, one patient (2.4%) had grade B bile leakage. During the median follow-up of 12.6 months, one patient (2.4%) with bile leakage developed anastomotic stenosis. Perioperative mortality was not observed. A surgical video showing the posterior double-layer interrupted sutures in the robotic HJ is included. CONCLUSIONS: Posterior double-layer interrupted sutures in robotic HJ provided a simple and feasible method for biliary reconstruction with a low risk of biliary complications.

Impact of cancer-associated fibroblasts on survival of patients with ampullary carcinoma.

Background: Cancer-associated fibroblasts (CAFs) reportedly enhance the progression of gastrointestinal surgery; however, the role of CAFs in ampullary carcinomas remains poorly examined. This study aimed to investigate the effect of CAFs on the survival of patients with ampullary carcinoma. Materials and methods: A retrospective analysis of 67 patients who underwent pancreatoduodenectomy between January 2000 and December 2021 was performed. CAFs were defined as spindle-shaped cells that expressed α-smooth muscle actin (α-SMA) and fibroblast activation protein (FAP). The impact of CAFs on survival, including recurrence-free (RFS) and disease-specific survival (DSS), as well as prognostic factors associated with survival, was analyzed. Results: The high-α-SMA group had significantly worse 5-year RFS (47.6% vs. 82.2%, p = 0.003) and 5-year DSS (67.5% vs. 93.3%, p = 0.01) than the low-α-SMA group. RFS (p = 0.04) and DSS (p = 0.02) in the high-FAP group were significantly worse than those in the low-FAP group. Multivariable analyses found that high α-SMA expression was an independent predictor of RFS [hazard ratio (HR): 3.68; 95% confidence intervals (CI): 1.21-12.4; p = 0.02] and DSS (HR: 8.54; 95% CI: 1.21-170; p = 0.03). Conclusions: CAFs, particularly α-SMA, can be useful predictors of survival in patients undergoing radical resection for ampullary carcinomas.

Impact of educational video on performance in robotic simulation training (TAKUMI-1): a randomized controlled trial.

The use of virtual reality for simulations plays an important role in the initial training for robotic surgery. This randomized controlled trial aimed to investigate the impact of educational video on the performance of robotic simulation. Participants were randomized into the intervention (video) group that received an educational video and robotic simulation training or the control group that received only simulation training. The da Vinci® Skills Simulator was used for the basic course, including nine drills. The primary endpoint was the overall score of nine drills in cycles 1-10. Secondary endpoints included overall, efficiency, and penalty scores in each cycle, as well as the learning curves evaluated by the cumulative sum (CUSUM) analysis. Between September 2021 and May 2022, 20 participants were assigned to the video (n = 10) and control (n = 10) groups. The video group had significantly higher overall scores than the control group (90.8 vs. 72.4, P < 0.001). Significantly higher overall scores and lower penalty scores were confirmed, mainly in cycles 1-5. CUSUM analysis revealed a shorter learning curve in the video group. The present study demonstrated that educational video training can be effective in improving the performance of robotic simulation training and shortening the learning curve.

Role of the Pfannenstiel Incision in Robotic Hepato-Pancreato-Biliary Surgery.

Studies remain limited on the role of the Pfannenstiel incision in minimally invasive hepato-pancreato-biliary (HPB) surgery, especially robotic surgery. The role of various extraction sites in robotic HPB surgery should be understood. Herein, we describe the surgical techniques, outcomes, advantages, and disadvantages of the Pfannenstiel incision in robotic pancreatic surgery. Seventy patients underwent robotic pancreatectomy at our institution between September 2020 and October 2022. The Pfannenstiel incision was used for specimen retrieval in 55 patients. Advantages of the Pfannenstiel incision include less pain, cosmetic benefits, and a lower incidence of complications. Moreover, the specimen could be removed using the robotic system docked. However, all complex reconstructions should be performed intra-abdominally during robotic pancreatoduodenectomies. The incidence of mortality and postoperative pancreatic fistula (grade B) was 0% and 9.1%, respectively. During the median follow-up (11.2 months) after surgery, complications at the Pfannenstiel incision site included surgical site infection (n = 1, 1.8%) and incisional hernia (n = 1, 1.8%). The Pfannenstiel incision can be a useful option for specimen retrieval in minimally invasive HPB surgery, according to the surgeon's preferences and the patient's condition.

ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer.

Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy.

Robotic surgery for congenital biliary dilatation using the scope switch technique (with video).

TECHNIQUE: Minimally invasive congenital biliary dilatation (CBD) surgery is technically demanding. However, few studies have reported surgical approaches of robotic surgery for CBD. This report presents robotic CBD surgery using a scope-switch technique. Our robotic surgery technique for CBD consisted of four steps: step 1, Kocher's maneuver; step 2, dissection of the hepatoduodenal ligament using the scope switch technique; step 3, preparation for the Roux-en-Y loop; and step 4, hepaticojejunostomy. RESULTS: The scope switch technique can provide different surgical approaches for dissecting the bile duct, including anterior approach by the standard position and right approach by the scope switch position. When approaching the ventral and left side of the bile duct, anterior approach with the standard position is suitable. In contrast, the lateral view by the scope switch position is preferable for approaching the bile duct laterally and dorsally. Using this technique, the dilated bile duct can be dissected circumferentially from four directions: anterior, medial, lateral, and posterior. Thereafter, complete resection of the choledochal cyst can be achieved. CONCLUSIONS: The scope switch technique in robotic surgery for CBD can be useful for dissecting around the bile duct with different surgical views, leading to the complete resection of the choledochal cyst.

Role of Surgery for Pancreatic Ductal Adenocarcinoma in the Era of Multidisciplinary Treatment.

The incidence and mortality rates of pancreatic ductal adenocarcinoma (PDAC) have increased in recent years worldwide [...].

Surgical Techniques of Gastrojejunostomy in Robotic Pancreatoduodenectomy: Robot-Sewn versus Stapled Gastrojejunostomy Anastomosis.

Background: Delayed gastric emptying (DGE) is a major complication of pancreatoduodenectomy (PD). Several efforts have been made to decrease the incidence of DGE. However, the optimal anastomotic method for gastro/duodenojejunostomy (GJ) remains debatable. Moreover, few studies have reported the impact of GJ surgical techniques on outcomes following robotic pancreatoduodenectomy (RPD). This study aimed to investigate the surgical outcomes of robot-sewn and stapled GJ anastomoses in RPD. Methods: Forty patients who underwent RPD at the Okayama University Hospital between September 2020 and October 2022 were included. The outcomes between robot-sewn and stapled anastomoses were compared. Results: The mean [standard deviation (SD)] operative and GJ time were 428 (63.5) and 34.0 (15.0) minutes, respectively. Postoperative outcomes included an overall incidence of DGE of 15.0%, and the mean postoperative hospital stays were 11.6 (5.3) days in length. The stapled group (n = 21) had significantly shorter GJ time than the robot-sewn group (n = 19) (22.7 min versus 46.5 min, p < 0.001). Moreover, stapled GJ cases were significantly associated with a lower incidence of DGE (0% versus 21%, p = 0.01). Although not significant, the stapled group tended to have shorter postoperative hospital stays (9.9 days versus 13.5 days, p = 0.08). Conclusions: Our findings suggest that stapled GJ anastomosis might decrease anastomotic GJ time and incidence of DGE after RPD. Surgeons should select a suitable method for GJ anastomosis based on their experiences with RPD.

Genomically Stable Gastric Cancer Characterized by Hypomethylation in Wnt Signal Cascade.

INTRODUCTION: Gastric cancer is divided into four subtypes by their molecular features linked with genetic alterations, e.g., Epstein-Barr virus (EBV), microsatellite instability-high (MSI-high), chromosomal instability (CIN), and genomically stable (GS), called as TCGA classification. In this study, we tried to clarify the epigenetic features of the four GC subtypes according to aberrant methylation status in 23 loci. METHODS: A total of 98 gastric cancers and their normal gastric mucosa samples were included in this study. We divided gastric cancers into TCGA subtypes which were determined in line with MSI-high, EBV, CIN, to GS by their molecular features. The 13 loci of polymorphic microsatellite sequences were used to determine loss of heterogeneity for the detection of CIN. The MSI status was determined by three mononucleotide repeat markers. Infection of EBV was determined by recovering EBV BNRF1 sequence from genomic DNA collected from gastric cancers. Methylation status of 23 loci was investigated by the combined bisulfite restriction analysis. Status of other findings, e.g., KRAS mutations, HER2 expression status, and infection of helicobacter pylori were confirmed. RESULTS: Gastric cancers were divided into MSI (13%), EBV (7%), CIN (53%), and GS (27%). By histological classification, poorly differentiated adenocarcinoma was more in tumors categorized in MSI-high, and GS and signet-ring cell carcinoma (sig) were more in GS. Among the 23 loci investigated their methylation status, 18 loci were significantly hypermethylated in caner tissues. An unsupervised clustering divided gastric cancers into two clusters and revealed that most GS tumors clustered together in a cluster that exhibited lower methylation levels, distinct from the other subtypes. The inter-variable clustering revealed that a cluster contained the three loci (SFRP2-region 1/2 and APC) belonging to the Wnt signal cascade (Wnt-associated loci). The mean methylation score of Wnt-associated loci was the lowest in GS tumors (MSI-high: 2.7 [95% confidence interval, 2.3-2.9]; EBV: 2.1 [1.2-3.1]; CIN: 2.4 [2.2-2.7]; GS: 1.3 [0.8-0.7]). In contrast, the mean methylation score of the other 15 loci was significantly higher in MSI-high, while that in GS was as same as that in EBV or CIN (MSI-high: 10.4 [8.3-12.4]; EBV: 5.7 [1.7-9.7]; CIN: 4.4 [3.6-5.1]; GS: 3.4 [2.2-4.6]). Additionally, the lower methylation score of Wnt-associated loci was observed only in sig tumors. CONCLUSIONS: GS subtype tumors have the potential to possess distinct signatures in DNA hypomethylation profiles in Wnt signaling pathway, especially in sig.

Surgical Strategies to Dissect around the Superior Mesenteric Artery in Robotic Pancreatoduodenectomy.

The concept of the superior mesenteric artery (SMA)-first approach has been widely accepted in pancreatoduodenectomy. However, few studies have reported surgical approaches to the SMA in robotic pancreatoduodenectomy (RPD). Herein, we present our surgical strategies to dissect around the SMA in RPD. Among the various approaches, our standard protocol for RPD included the right approach to the SMA, which can result in complete tumor resection in most cases. In patients with malignant diseases requiring lymphadenectomy around the SMA, we developed a novel approach by combining the left and right approaches in RPD. Using this approach, circumferential dissection around the SMA can be achieved through both the left and right sides. This approach can also be helpful in patients with obesity or intra-abdominal adhesions. The present study summarizes the advantages and disadvantages of both the approaches during RPD. To perform RPD safely, surgeons should understand the different surgical approaches and select the best approach or a combination of different approaches, depending on demographic, anatomical, and oncological factors.

Neonatal hemochromatosis with εγδß-thalassemia: a case report and analysis of serum iron regulators.

BACKGROUND: Neonatal hemochromatosis causes acute liver failure during the neonatal period, mostly due to gestational alloimmune liver disease (GALD). Thalassemia causes hemolytic anemia and ineffective erythropoiesis due to mutations in the globin gene. Although neonatal hemochromatosis and thalassemia have completely different causes, the coexistence of these diseases can synergistically exacerbate iron overload. We report that a newborn with εγδß-thalassemia developed neonatal hemochromatosis, which did not respond to iron chelators and rapidly worsened, requiring living-donor liver transplantation. CASE PRESENTATION: A 1-day-old Japanese boy with hemolytic anemia and targeted red blood cells was diagnosed with εγδß-thalassemia by genetic testing, and required frequent red blood cell transfusions. At 2 months after birth, exacerbation of jaundice, grayish-white stool, and high serum ferritin levels were observed, and liver biopsy showed iron deposition in hepatocytes and Kupffer cells. Magnetic resonance imaging scans showed findings suggestive of iron deposits in the liver, spleen, pancreas, and bone marrow. The total amount of red blood cell transfusions administered did not meet the criteria for post-transfusion iron overload. Administration of an iron-chelating agent was initiated, but iron overload rapidly progressed to liver failure without improvement in jaundice and liver damage. He underwent living-donor liver transplantation from his mother, after which iron overload disappeared, and no recurrence of iron overload was observed. Immunohistochemical staining for C5b-9 in the liver was positive. Serum hepcidin levels were low and serum growth differentiation factor-15 levels were high prior to living-donor liver transplantation. CONCLUSIONS: We reported that an infant with εγδß-thalassemia developed NH due to GALD, and that coexistence of ineffective erythropoiesis in addition to erythrocyte transfusions may have exacerbated iron overload. Low serum hepcidin levels, in this case, might have been caused by decreased hepcidin production arising from fetal liver damage due to neonatal hemochromatosis and increased hepcidin-inhibiting hematopoietic mediators due to the ineffective hematopoiesis observed in thalassemia.

Robotic Spleen-Preserving Distal Pancreatectomy with Preservation of Splenic Vessels Using the Gastrohepatic Ligament Approach: The Superior Window Approach in the Kimura Technique.

Minimally invasive spleen-preserving distal pancreatectomy (SPDP) is technically challenging, and only a few reports have described surgical approaches for minimally invasive SPDP. This report demonstrates our novel gastrohepatic ligament approach in robotic SPDP with preservation of the splenic vessels (the superior window approach in the Kimura technique). Our gastrohepatic ligament approach for robotic SPDP included four steps. First, the gastrohepatic ligament was divided extensively, and the pancreas was confirmed (step 1). In this step, we did not lift the stomach, nor did we divide the gastrocolic ligament. Next, the superior and inferior borders of the pancreas were dissected, and the tunneling of the pancreas on the superior mesenteric vein was performed (step 2). Following the division of the pancreas (step 3), the pancreatic body and tail were dissected from the medial to the lateral side with preservation of the splenic vessels (step 4). Using this approach, the pancreas can be directly accessed via the gastrohepatic ligament route and dissected without division of the gastrocolic ligament or retraction of the stomach. The present approach for robotic SPDP preserves splenic vessels, facilitating easy access to the pancreas with minimal dissection, and may be optional in selected patients, including those with low body mass index.