Preoperative diagnosis of adhesion severity between the abdominal wall and intestinal tract with novel abdominal ultrasound methodology to enhance surgical safety.

BACKGROUND: Adhesions between the abdominal wall and intestinal tract from previous surgeries can complicate reoperations; however, predicting the extent of adhesions preoperatively is difficult. This study aimed to develop a straightforward approach for predicting adhesion severity using a novel abdominal ultrasound technique that quantifies the displacement of motion vectors of two organs to enhance surgical safety. The efficacy of this methodology was assessed experimentally and clinically. METHODS: Using Aplio500T, a system we developed, we measured the displacement of the upper peritoneum and intestinal tract as a vector difference and computed the motion difference ratio. Twenty-five rats were randomized into surgery and nonsurgery groups. The motion difference ratio was assessed 7 days after laparotomy to classify adhesions. In a clinical trial, 51 patients undergoing hepatobiliary pancreatic surgery were evaluated for the motion difference ratio within 3 days preoperatively. Intraoperatively, adhesion severity was rated and compared with the motion difference ratio. A receiver operating characteristic curve was used to appraise the diagnostic value of the motion difference ratio. RESULTS: In the animal experiment, the adhesion group exhibited a significantly higher motion difference ratio than the no-adhesion group (0.006 ± 0.141 vs 0.435 ± 0.220, P < .001). In the clinical trial, the no-adhesion or no-laparotomy group had a motion difference ratio of 0.128 ± 0.074; mild-adhesion group, 0.143 ± 0.170; moderate-adhesion group, 0.326 ± 0.153; and high-adhesion group, 0.427 ± 0.152. The motion difference ratio receiver operating characteristic curve to diagnose the adhesion level (≥moderate) was 0.938, indicating its high diagnostic value (cut-off 0.204). CONCLUSION: This methodology may preoperatively predict moderate-to-high adhesions.

High expression of autotaxin is associated with poor recurrence-free survival in cholangiocarcinoma.

BACKGROUND AND AIM: Autotaxin (ATX) is an extracellular lysophospholipase D that catalyzes the hydrolysis of lysophosphatidylcholine into lysophosphatidic acid (LPA). Recent accumulating evidence indicates the biological roles of ATX in malignant tumors. However, the expression and clinical implications of ATX in human cholangiocarcinoma (CCA) remain elusive. METHODS: In this study, the expression of ATX in 97 human CCA tissues was evaluated by immunohistochemistry. Serum ATX levels were determined in CCA patients (n = 26) and healthy subjects (n = 8). Autotaxin expression in cell types within the tumor microenvironment was characterized by immunofluorescence staining. RESULTS: High ATX expression in CCA tissue was significantly associated with a higher frequency of lymph node metastasis (p = 0.050). High ATX expression was correlated with shorter overall survival (p = 0.032) and recurrence-free survival (RFS) (p = 0.001) than low ATX expression. In multivariate Cox analysis, high ATX expression (p = 0.019) was an independent factor for shorter RFS. Compared with low ATX expression, high ATX expression was significantly associated with higher Ki-67-positive cell counts (p < 0.001). Serum ATX levels were significantly higher in male CCA patients than in healthy male subjects (p = 0.030). In the tumor microenvironment of CCA, ATX protein was predominantly expressed in tumor cells, cancer-associated fibroblasts, plasma cells, and biliary epithelial cells. CONCLUSIONS: Our study highlights the clinical evidence and independent prognostic value of ATX in human CCA.

Ferroptosis-related gene glutathione peroxidase 4 promotes reprogramming of glucose metabolism via Akt-mTOR axis in intrahepatic cholangiocarcinoma.

The role of the ferroptosis-related gene glutathione peroxidase 4 (GPX4) in oncology has been extensively investigated. However, the clinical implications of GPX4 in patients with intrahepatic cholangiocarcinoma (ICC) remain unknown. This study aimed to evaluate the prognostic impact of GPX4 and its underlying molecular mechanisms in patients with ICC. Fifty-seven patients who underwent surgical resection for ICC between 2010 and 2017 were retrospectively analyzed. Based on the immunohistochemistry, patients were divided into GPX4 high (n = 15) and low (n = 42) groups, and clinical outcomes were assessed. Furthermore, the roles of GPX4 in cell proliferation, migration and gene expression were analyzed in ICC cell lines in vitro and in vivo. The results from clinical study showed that GPX4 high group showed significant associations with high SUVmax on 18F-fluorodeoxyglucose-positron emission tomography (≥8.0, P = 0.017), multiple tumors (P = 0.004), and showed glucose transporter 1 (GLUT1) high expression with a trend toward significance (P = 0.053). Overall and recurrence-free survival in the GPX4 high expression group were significantly worse than those in the GPX4 low expression group (P = 0.038 and P < 0.001, respectively). In the experimental study, inhibition of GPX4 attenuated cell proliferation and migration in ICC cell lines. Inhibition of GPX4 also decreased the expression of glucose metabolism-related genes, such as GLUT1 or HIF1α. Mechanistically, these molecular changes are regulated in Akt-mechanistic targets of rapamycin axis. In conclusion, this study suggested the pivotal value of GPX4 serving as a prognostic marker for patients with ICC. Furthermore, GPX4 can mediate glucose metabolism of ICC.

Completion of adjuvant S-1 chemotherapy after surgical resection for biliary tract cancer: A single center experience.

BACKGROUNDS: A recent randomized control trial (JCOG1202; ASCOT trial) demonstrated the efficacy of adjuvant S-1 chemotherapy (ASC) for biliary tract cancer (BTC) after surgical resection; however, the significance of the completion of ASC in the real-world setting remains unknown. METHODS: Data of consecutive patients who underwent surgical resection for biliary tract cancer (BTC) from 2011 to 2021 were retrospectively reviewed. Of these, patients who underwent ASC were enrolled in this study. Patients were divided into two groups according to whether ASC was completed: the completion group and the non-completion group. Clinicopathological features and survival outcomes were assessed. RESULTS: Of the 223 patients with BTC who underwent surgical resection, 75 patients who underwent ASC were included for analysis. Among them, 48 (64.0 %) completed the intended ASC course, while 27 cases (36.0 %) discontinued the treatment. The most common reason for the discontinuation was adverse event (n = 16, 59.3 %), followed by disease recurrence (n = 9, 33.3 %). Patients in the completion group showed significantly better overall survival (OS) (p < 0.001) and recurrence-free survival (RFS) (p < 0.001) compared to the non-completion group. Further, after excluding the patients in the non-completion group who discontinued ASC due to disease recurrence, the significance of ASC completion was retained for both OS and RFS. CONCLUSION: The completion of ASC was associated with improved prognosis in patients with BTC after surgical resection. The achievement of ASC should be the goal after surgical resection, while further study may be warranted regarding the resistance of ASC.

PEGylated Fluorescent Anti-carcinoembryonic Antigen Antibody Labels Colorectal Cancer Tumors in Orthotopic Mouse Models.

INTRODUCTION: Colorectal cancer (CRC) patients often develop liver metastasis. However, curative resection of liver metastasis is not always possible due to poor visualization of tumor margins. The present study reports the characterization of a humanized anti-carcinoembryonic antigen monoclonal antibody conjugated to a PEGylated near-infrared dye, that targets and brightly labels human CRC tumors in metastatic orthotopic mouse models. METHODS: The hT84.66-M5A (M5A) monoclonal antibody was conjugated with a polyethylene glycol (PEG) chain that incorporated a near infrared (NIR) IR800 dye to establish M5A-IR800 Sidewinder (M5A-IR800-SW). Nude mice with CRC orthotopic primary tumors and liver metastasis both developed from a human CRC cell line, were injected with M5A-IR800-SW and imaged with the Pearl Trilogy Imaging System. RESULTS: M5A-IR800-SW targeted and brightly labeled CRC tumors, both in primary-tumor and liver-metastasis models. M5A-IR800-SW at 75 µg exhibited highly-specific tumor labeling in a primary-tumor orthotopic model with a median tumor-to-background ratio of 9.77 and in a liver-metastasis orthotopic model with a median tumor-to-background ratio of 7.23 at 96 h. The precise labeling of the liver metastasis was due to lack of hepatic accumulation of M5A-IR800-SW in the liver. CONCLUSIONS: M5A-IR800-SW provided bright and targeted NIR images of human CRC in orthotopic primary-tumor and liver-metastasis mouse models. The results of the present study suggest the clinical potential of M5A-IR800-SW for fluorescence-guided surgery including metastasectomies for CRC. The lack of hepatic NIR signal is of critical importance to allow for precise labeling of liver tumors.

Acinar cystic transformation in the pancreatic tail.

Pancreatic acinar cystic transformation (ACT) is a rare non-neoplastic cystic lesion that is predominantly located at the pancreatic head in females. Preoperative definitive diagnosis of ACT remains challenging despite advances in radiologic imaging methods. A 25-year-old male patient presented with abdominal discomfort and a 50-mm cystic lesion in the pancreatic tail. The patient underwent laparoscopic distal pancreatectomy, because branch duct intraductal papillary mucinous neoplasm cannot be ruled out and the presence of abdominal symptoms. The resected specimen revealed a collection of small and large cysts lined by a single cuboidal epithelium layer with scattered pancreatic tissue exhibiting fibrosis in the septal wall. The cystic lesion was epithelial, trypsin-positive, B cell lymphoma 10-positive, cytokeratin 19-positive, mucin 1-positive, and MUC6-negative with a differentiated lobular central conduit causing to an adeno-cystic cell, thereby supporting the ACT diagnosis. Distinguishing ACT from other pancreatic cystic tumors remains a diagnostic challenge despite improvements in radiologic imaging methods. Surgical resection may be justified when other cystic neoplasms cannot be excluded because of its heterogeneous nature, although the ACT is a non-neoplastic lesion, and cases of malignant transformation have never been reported to date.

Long-term outcomes and salvageability in patients undergoing liver resection for intermediate- and advanced-stage hepatocellular carcinoma.

BACKGROUNDS: The prognosis of intermediate- and advanced-stage hepatocellular carcinoma after liver resection should be comprehensively analyzed due to the high incidence of tumor recurrence and the availability of salvage therapy. This study evaluated the long-term outcome and salvageability in these patients after liver resection. METHODS: Data from consecutive patients with intermediate- and advanced-stage hepatocellular carcinoma who underwent initial liver resection from 2000 to 2016 were retrospectively reviewed. Analyses were performed in the setting of the initial liver resection and the recurrence(s). Active salvage therapy for recurrence was defined as the implementation of each therapy with curative intent-repeat surgery, ablative therapy, and liver transplantation. RESULTS: Among the 1,013 liver resections for hepatocellular carcinoma, a total of 270 patients were eligible for this study (intermediate hepatocellular carcinoma, n = 134; advanced hepatocellular carcinoma, n = 136). The 5-year overall survival rates for intermediate and advanced-stage hepatocellular carcinoma were 49.7% and 36.8%, respectively; meanwhile, the actual recurrence rates excluding patients who died without recurrence were 94.7% and 90.7%, respectively. Active salvage therapy was performed in 43 (39.8%) patients with intermediate-stage hepatocellular carcinoma and 25 (23.4%) patients with advanced-stage hepatocellular carcinoma. Overall survival after initial liver resection, first active salvage therapy, and second/more active salvage therapy were comparable in both stages. CONCLUSIONS: This study suggests that although liver resection alone may not yield remission in most patients with intermediate and advanced-stage hepatocellular carcinoma, active salvage therapy can potentially prolong survival. Further study to identify approaches to decrease recurrence rates and increase salvageability for these patients would be warranted.

Highly Selective Targeting of Pancreatic Cancer in the Liver with a Near-Infrared Anti-MUC5AC Probe in a PDOX Mouse Model: A Proof-of-Concept Study.

Accurately identifying metastatic disease is critical to directing the appropriate treatment in pancreatic cancer. Mucin 5AC is overexpressed in pancreatic cancer but absent in normal pancreas tissue. The present proof-of-concept study demonstrates the efficacy of an anti-mucin 5AC antibody conjugated to an IR800 dye (MUC5AC-IR800) to preferentially label a liver metastasis of pancreatic cancer (Panc Met) in a unique patient-derived orthotopic xenograft (PDOX) model. In orthotopic models, the mean tumor to background ratio was 1.787 (SD ± 0.336), and immunohistochemistry confirmed the expression of MUC5AC within tumor cells. MUC5AC-IR800 provides distinct visualization of pancreatic cancer liver metastasis in a PDOX mouse model, demonstrating its potential utility in staging laparoscopy and fluorescence-guided surgery.

Impact of liver volumetric regeneration on survival outcomes in patients with hepatocellular carcinoma after major hepatectomy.

PURPOSE: Prognostic value of liver volumetric regeneration (LVR) in patients with hepatocellular carcinoma (HCC) who undergo major hepatectomy remains unknown. The aim of this study was to investigate the impact of LVR on long-term outcomes in these patients. METHODS: Data of 399 consecutive patients with HCC who underwent major hepatectomy between 2000 to 2018 were retrieved from a prospectively maintained institutional database. The LVR-index was defined as the relative increase in liver volume from 7 days to 3 months (RLV3m/RLV7d, where RLV3m and RLV7d is the remnant liver volume around 3 months and postoperative 7 days after surgery). The optimal cut-off value was determined using the median value of LVR-index. RESULTS: A total of 131 patients were eligible in this study. The optimal cut off value of LVR-index was 1.194. The 1-, 3-, 5- and 10-year overall survival (OS) rate of patients in the high LVR-index group were significantly better compared to those in the low LVR-index group (95.5%, 84.8%, 75.4% and 49.1% vs. 95.4%, 70.2%, 56.4%, and 19.9%, p = 0.002). Meanwhile, there was no significant difference with regards to time to recurrence between the two groups (p = 0.607). Significance of LVR-index for OS was retained after adjusting for known prognostic factors (p = 0.002). CONCLUSION: In patients with HCC undergoing major hepatectomy, LVR-index may serve as a prognostic indicator for OS.

Benchmarks and Geographic Differences in Gallbladder Cancer Surgery: An International Multicenter Study.

BACKGROUND: High-quality surgery plays a central role in the delivery of excellent oncologic care. Benchmark values indicate the best achievable results. We aimed to define benchmark values for gallbladder cancer (GBC) surgery across an international population. PATIENTS AND METHODS: This study included consecutive patients with GBC who underwent curative-intent surgery during 2000-2021 at 13 centers, across seven countries and four continents. Patients operated on at high-volume centers without the need for vascular and/or bile duct reconstruction and without significant comorbidities were chosen as the benchmark group. RESULTS: Of 906 patients who underwent curative-intent GBC surgery during the study period, 245 (27%) were included in the benchmark group. These were predominantly women (n = 174, 71%) and had a median age of 64 years (interquartile range 57-70 years). In the benchmark group, 50 patients (20%) experienced complications within 90 days after surgery, with 20 patients (8%) developing major complications (Clavien-Dindo grade ≥ IIIa). Median length of postoperative hospital stay was 6 days (interquartile range 4-8 days). Benchmark values included ≥ 4 lymph nodes retrieved, estimated intraoperative blood loss ≤ 350 mL, perioperative blood transfusion rate ≤ 13%, operative time ≤ 332 min, length of hospital stay ≤ 8 days, R1 margin rate ≤ 7%, complication rate ≤ 22%, and rate of grade ≥ IIIa complications ≤ 11%. CONCLUSIONS: Surgery for GBC remains associated with significant morbidity. The availability of benchmark values may facilitate comparisons in future analyses among GBC patients, GBC surgical approaches, and centers performing GBC surgery.

Specific Targeting and Labeling of Colonic Polyps in CPC-APC Mice with Mucin 5AC Fluorescent Antibodies: A Model for Detection of Early Colon Cancer.

Poor visualization of polyps can limit colorectal cancer screening. Fluorescent antibodies to mucin5AC (MUC5AC), a glycoprotein upregulated in adenomas and colorectal cancer, could improve screening colonoscopy polyp detection rate. Adenomatous polyposis coli flox mice with a Cdx2-Cre transgene (CPC-APC) develop colonic polyps that contain both dysplastic and malignant tissue. Mice received MUC5AC-IR800 or IRdye800 as a control IV and were sacrificed after 48 h for near-infrared imaging of their colons. A polyp-to-background ratio (PBR) was calculated for each polyp by dividing the mean fluorescence intensity of the polyp by the mean fluorescence intensity of the background tissue. The mean 25 µg PBR was 1.70 (±0.56); the mean 50 µg PBR was 2.64 (±0.97); the mean 100 µg PBR was 3.32 (±1.33); and the mean 150 µg PBR was 3.38 (±0.87). The mean PBR of the dye-only control was 2.22 (±1.02), significantly less than the 150 µg arm (p-value 0.008). The present study demonstrates the ability of fluorescent anti-MUC5AC antibodies to specifically target and label colonic polyps containing high-grade dysplasia and intramucosal adenocarcinoma in CPC-APC mice. This technology can potentially improve the detection rate and decrease the miss rate of advanced colonic neoplasia and early cancer at colonoscopy.

Primary hepatic extranodal marginal zone B-cell mucosa-associated lymphoid tissue lymphoma treated by laparoscopic partial hepatectomy: a case report.

BACKGROUND: Primary hepatic extranodal marginal zone B-cell mucosa-associated lymphoid tissue (MALT) lymphoma is very rare, so it is difficult to diagnose preoperatively. And there is no established treatment for hepatic MALT lymphoma. We report herein a case of primary hepatic MALT lymphoma treated by laparoscopic partial hepatectomy, and discuss the usefulness of laparoscopic hepatectomy for a rare liver tumor. CASE PRESENTATION: This patient was a woman in her 60s, who was diagnosed preoperatively as having synchronous liver metastasis from sigmoid colon cancer; therefore, laparoscopic partial hepatectomy was performed. She had a good course after the operation and was discharged on postoperative day 12. However, she was diagnosed pathologically as having primary hepatic MALT lymphoma. A bone marrow biopsy was also performed, and then she was finally diagnosed as having limited-stage primary hepatic MALT lymphoma. She received no postoperative treatment and showed no recurrence for 4 years postoperatively. CONCLUSIONS: We experienced the good result of the patient with limited-stage primary MALT lymphoma treated by laparoscopic partial hepatectomy. Liver tumors are sometimes misdiagnosed by imaging examinations alone. Laparoscopic hepatectomy has been widespread recently as a minimally invasive procedure, and it may be useful for both diagnosis and treatment.

Clinically relevant model of oxaliplatin-induced sinusoidal obstruction syndrome.

AIM: Sinusoidal obstruction syndrome (SOS) induced by oxaliplatin-including chemotherapies (OXCx) is associated with impaired hepatic reserve and higher morbidity after hepatic resection. However, in the absence of an appropriate animal experimental model, little is known about its pathophysiology. This study aimed to establish a clinically relevant reproducible model of FOLFOX-induced SOS and to compare the clinical/histopathological features between the clinical and animal SOS settings. METHODS: We performed clinical/pathological analyses of colorectal liver metastasis (CRLM) patients who underwent hepatectomy with/without preoperative treatment of FOLFOX (n = 22/18). Male micro-minipigs were treated with 50% of the standard human dosage of the FOLFOX regimen. RESULTS: In contrast to the monocrotaline-induced SOS model in rats, hepatomegaly, ascites, congestion, and coagulative necrosis of hepatocytes were absent in patients with CRLM with OXCx pretreatment and OXCx-treated micro-minipigs. In parallel to CRLM cases with OXCx pretreatment, OXCx-challenged micro-minipigs exhibited deteriorated indocyanine green clearance, morphological alteration of liver sinusoidal endothelial cells, and upregulated matrix metalloproteinase-9. Using our novel porcine SOS model, we identified the hepatoprotective influence of recombinant human soluble thrombomodulin in OXCx-SOS. CONCLUSIONS: With distinct differences between monocrotaline-induced rat SOS and human/pig OXCx-SOS, our pig OXCx-SOS model serves as a preclinical platform for future investigations to dissect the pathophysiology of OXCx-SOS and seek preventive strategies.

Proof of Principle of Combining Fluorescence-Guided Surgery with Photoimmunotherapy to Improve the Outcome of Pancreatic Cancer Therapy in an Orthotopic Mouse Model.

BACKGROUND: Pancreatic cancer is a recalcitrant disease in which R0 resection is often not achieved owing to difficulty in visualization of the tumor margins and proximity of adjacent vessels. To improve outcomes, we have developed fluorescence-guided surgery (FGS) and photoimmunotherapy (PIT) using a fluorescent tumor-specific antibody. METHODS: Nude mice received surgical orthotopic implantation (SOI) of the human pancreatic cancer cell line BxPC-3 expressing green fluorescent protein. An anti-carcinoembryonic antigen-related cell adhesion molecule (CEACAM) monoclonal antibody (6G5j) was conjugated to the 700-nm fluorescent dye IR700DyeDX (6G5j-IR700DX). Three weeks after SOI, 16 mice received 50 µg 6G5j-IR700DX via the tail vein 24 h before surgery and were randomized to two groups: FGS-only (n = 8) and FGS + PIT (n = 8). All tumors were imaged with the Pearl Trilogy imaging system and resected under the guidance of the FLARE imaging system. The FGS + PIT group received PIT of the post-surgical bed at an intensity of 150 mW/cm2 for 30 min. Mice were sacrificed 4 weeks after initial surgery, and tumors were imaged with a Dino-Lite digital microscope, excised, and weighed. RESULTS: The 6G5j-IR700DX dye illuminated the orthotopic pancreatic tumors for FGS and PIT. The metastatic recurrence rate was 100.0% for FGS-only and 25.0% for FGS + PIT (p = 0.007). The average total recurrent tumor weight was 2370.3 ± 1907.8 mg for FGS-only and 705.5 ± 1200.0 mg for FGS + PIT (p = 0.039). CONCLUSIONS: FGS and adjuvant PIT can be combined by using a single antibody-fluorophore conjugate to significantly reduce the frequency of pancreatic cancer recurrence.

Assessing the development status of intraoperative fluorescence imaging for anatomy visualisation, using the IDEAL framework.

Objectives: Intraoperative fluorescence imaging is currently used in a variety of surgical fields for four main purposes: visualising anatomy, assessing tissue perfusion, identifying/localising cancer and mapping lymphatic systems. To establish evidence-based guidance for research and practice, understanding the state of research on fluorescence imaging in different surgical fields is needed. We evaluated the evidence on fluorescence imaging used to visualise anatomical structures using the IDEAL framework, a framework designed to describe the stages of innovation in surgery and other interventional procedures. Design: IDEAL staging based on a thorough literature review. Setting: All publications on intraoperative fluorescence imaging for visualising anatomical structures reported in PubMed through 2020 were identified for five surgical procedures: cholangiography, hepatic segmentation, lung segmentation, ureterography and parathyroid identification. Main outcome measures: The IDEAL stage of research evidence was determined for each of the five procedures using a previously described approach. Results: 225 articles (8427 cases) were selected for analysis. Current status of research evidence on fluorescence imaging was rated IDEAL stage 2a for ureterography and lung segmentation, IDEAL 2b for hepatic segmentation and IDEAL stage 3 for cholangiography and parathyroid identification. Enhanced tissue identification rates using fluorescence imaging relative to conventional white-light imaging have been documented for all five procedures by comparative studies including randomised controlled trials for cholangiography and parathyroid identification. Advantages of anatomy visualisation with fluorescence imaging for improving short-term and long-term postoperative outcomes also were demonstrated, especially for hepatobiliary surgery and (para)thyroidectomy. No adverse reactions associated with fluorescent agents were reported. Conclusions: Intraoperative fluorescence imaging can be used safely to enhance the identification of anatomical structures, which may lead to improved postoperative outcomes. Overviewing current research knowledge using the IDEAL framework aids in designing further studies to develop fluorescence imaging techniques into an essential intraoperative navigation tool in each surgical field.

Proof of concept of improved fluorescence-guided surgery of colon cancer liver metastasis using color-coded imaging of a tumor-labeling fluorescent antibody and indocyanine green restricted to the adjacent liver segment.

BACKGROUND: Indocyanine green has been used for fluorescence-guided surgery of liver metastasis and labeling of liver segments. However, indocyanine green is nonspecific, and indocyanine green labeling does not always clearly outline tumor margins. In addition, it is difficult to distinguish between a tumor and its adjacent liver segment colored with indocyanine green alone. In the present study, we performed fluorescence-guided surgery in an orthotopic colon-cancer liver metastasis mouse model by labeling the metastatic liver tumor with an anti-carcinoembryonic antigen fluorescent antibody and with indocyanine green restricted to the adjacent liver segment. METHODS: A liver metastasis model was established with human LS174T colon cancer tumor fragments. To label the tumor, mice received SGM-101, an anti-carcinoembryonic antigen antibody conjugated to a near-infrared fluorophore (700 nm), currently in clinical trials, 3 days before surgery. Indocyanine green (800 nm) was injected after ligation of the tumor-bearing Glissonean pedicle with fluorescence labeling restricted to the liver segment adjacent to the tumor. Bright-light surgery and fluorescence-guided surgery were performed to resect the liver metastasis. To assess recurrence, mice underwent necropsy 3 weeks after surgery and the tumor was weighed. RESULTS: Fluorescence-guided anatomic left lateral lobectomy and fluorescence-guided partial liver resection were both performed with color-coded double labeled imaging. Tumor weight 3 weeks after surgery was significantly lower with fluorescence-guided surgery compared to bright-light surgery (38 ± 57 mg vs 836 ± 668 mg, P = .011) for partial liver resection. CONCLUSION: The present study provides a proof-of-concept that color-coded and double labeling of the tumor and adjacent liver segment has the potential to improve liver metastasectomy.

Anti-mucin 4 fluorescent antibody brightly targets colon cancer in patient-derived orthotopic xenograft mouse models: A proof-of-concept study for future clinical applications.

BACKGROUND: There is a high rate of positive surgical margins with resection of liver metastases in colorectal cancer (CRC). The present study reports using a fluorescent anti-mucin 4 (MUC4) antibodies to label primary CRC and liver metastases to better visualize tumor margins in mouse models. METHODS: Western blotting for MUC4 protein expression of normal colon and CRC tumor lysates was performed. Orthotopic primary and liver metastatic CRC mouse models received anti-MUC4 antibody conjugated to IR800 (MUC4-IR800). Mice were sacrificed and imaged after 48 hours. RESULTS: Western blotting demonstrated increased MUC4 expression in a human CRC cell line and patient-derived primary and liver-metastatic CRCs. The LS174T orthotopic primary CRC model tumor to background ratio (TBR) was 2.04 (±0.35). The patient-derived orthotopic xenograft (PDOX) primary CRC model TBR was 2.17 (±0.35). The PDOX liver metastasis model TBR was 1.56 (±0.53). CONCLUSION: MUC4-IR800 provided bright labeling of primary and liver tumors in CRC orthotopic mouse models, demonstrating their future clinical potential for margin visualization in fluorescence guided surgery.

Fluorescent Anti-CEA Nanobody for Rapid Tumor-Targeting and Imaging in Mouse Models of Pancreatic Cancer.

Tumor-specific targeting with fluorescent probes can enhance contrast for identification of cancer during surgical resection and visualize otherwise invisible tumor margins. Nanobodies are the smallest naturally-occurring antigen-binding molecules with rapid pharmacokinetics. The present work demonstrates the efficacy of a fluorescent anti-CEA nanobody conjugated to an IR800 dye to target and label patient derived pancreatic cancer xenografts. After intravenous administration, the probe rapidly localized to the pancreatic cancer tumors within an hour and had a tumor-to-background ratio of 2.0 by 3 h. The fluorescence signal was durable over a prolonged period of time. With the rapid kinetics afforded by fluorescent nanobodies, both targeting and imaging can be performed on the same day as surgery.