Targeting the insulin growth factor-1 receptor with fluorescent antibodies enables high resolution imaging of human pancreatic cancer in orthotopic mouse models

The goal of the present study was to determine whether insulin-like growth factor-1 receptor (IGF-1R) antibodies, conjugated with bright fluorophores, could enable visualization of pancreatic cancer in orthotopic nude mouse models. IGF-1R antibody (clone 24-31) was conjugated with 550 nm or 650 nm fluorophores. Western blotting confirmed the expression of IGF-1R in Panc-1, BxPC3, and MIAPaCa-2 human pancreatic cancer cell lines. Labeling with fluorophore-conjugated IGF-1R antibody demonstrated fluorescent foci on the membrane of the pancreatic cancer cells. Subcutaneous Panc-1, BxPC-3, and MIA PaCa-2 tumors became fluorescent after intravenous administration of fluorescent IGF-1R antibodies. Orthotopically-transplanted BxPC-3 tumors became fluorescent with the conjugated IGF-1R antibodies, and were easily visible with intravital imaging. Gross and microscopic ex vivo imaging of resected pancreatic tumor and normal pancreas confirmed that fluorescence indeed came from the membrane of cancer cells, and it was stronger from the tumor than the normal tissue. The present study demonstrates that fluorophore-conjugated IGF-1R antibodies can visualize pancreatic cancer and it can be used with various imaging devices such as endoscopy and laparoscopy for diagnosis and fluorescence-guided surgery.ope

Second Primary Cancer after Treating Gastrointestinal Cancer

Advances in diagnosis and therapeutic technologies have brought increased life expectancy for most cancers, but paradoxically it also has increased the risk of second primary malignancies. Cancer survivors have a higher risk of developing cancer than the general population. This suggests that more studies are needed to develop screen and management programs for cancer survivors, especially patients with gastrointestinal cancers, which are the most common cancers in Korea.ope

Fluorescent-Antibody Targeting of Insulin-Like Growth Factor-1 Receptor Visualizes Metastatic Human Colon Cancer in Orthotopic Mouse Models

Fluorescent-antibody targeting of metastatic cancer has been demonstrated by our laboratory to enable tumor visualization and effective fluorescence-guided surgery. The goal of the present study was to determine whether insulin-like growth factor-1 receptor (IGF-1R) antibodies, conjugated with bright fluorophores, could enable visualization of metastatic colon cancer in orthotopic nude mouse models. IGF-1R antibody (clone 24-31) was conjugated with 550 nm, 650 nm or PEGylated 650 nm fluorophores. Subcutaneous, orthotopic, and liver metastasis models of colon cancer in nude mice were targeted with the fluorescent IGF-1R antibodies. Western blotting confirmed the expression of IGF-1R in HT-29 and HCT 116 human colon cancer cell lines, both expressing green fluorescent protein (GFP). Labeling with fluorophore-conjugated IGF-1R antibody demonstrated fluorescent foci on the membrane of colon cancer cells. Subcutaneously- and orthotopically-transplanted HT-29-GFP and HCT 116-GFP tumors brightly fluoresced at the longer wavelengths after intravenous administration of fluorescent IGF-1R antibodies. Orthotopically-transplanted HCT 116-GFP tumors were brightly labeled by fluorescent IGF-1R antibodies such that they could be imaged non-invasively at the longer wavelengths. In an experimental liver metastasis model, IGF-1R antibodies conjugated with PEGylated 650 nm fluorophores selectively highlighted the liver metastases, which could then be non-invasively imaged. The IGF-1R fluorescent-antibody labeled liver metastases were very bright compared to the normal liver and the fluorescent-antibody label co-located with green fluorescent protein (GFP) expression of the colon cancer cells. The present study thus demonstrates that fluorophore-conjugated IGF-1R antibodies selectively visualize metastatic colon cancer and have clinical potential for improved diagnosis and fluorescence-guided surgery.ope

FOLFIRINOX or Gemcitabine-based Chemotherapy for Borderline Resectable and Locally Advanced Pancreatic Cancer: A Multi-institutional, Patient-Level, Meta-analysis and Systematic Review

Background: Pancreatic cancer often presents as locally advanced (LAPC) or borderline resectable (BRPC). Neoadjuvant systemic therapy is recommended as initial treatment. It is currently unclear what chemotherapy should be preferred for patients with BRPC or LAPC. Methods: We performed a systematic review and multi-institutional meta-analysis of patient-level data regarding the use of initial systemic therapy for BRPC and LAPC. Outcomes were reported separately for tumor entity and by chemotherapy regimen including FOLFIRINOX (FIO) or gemcitabine-based. Results: A total of 23 studies comprising 2930 patients were analyzed for overall survival (OS) calculated from the beginning of systemic treatment. OS for patients with BRPC was 22.0 months with FIO, 16.9 months with gemcitabine/nab-paclitaxel (Gem/nab), 21.6 months with gemcitabine/cisplatin or oxaliplatin or docetaxel or capecitabine (GemX), and 10 months with gemcitabine monotherapy (Gem-mono) (p < 0.0001). In patients with LAPC, OS also was higher with FIO (17.1 months) compared with Gem/nab (12.5 months), GemX (12.3 months), and Gem-mono (9.4 months; p < 0.0001). This difference was driven by the patients who did not undergo surgery, where FIO was superior to other regimens. The resection rates for patients with BRPC were 0.55 for gemcitabine-based chemotherapy and 0.53 with FIO. In patients with LAPC, resection rates were 0.19 with Gemcitabine and 0.28 with FIO. In resected patients, OS for patients with BRPC was 32.9 months with FIO and not different compared to Gem/nab, (28.6 months, p = 0.285), GemX (38.8 months, p = 0.1), or Gem-mono (23.1 months, p = 0.083). A similar trend was observed in resected patients converted from LAPC. Conclusions: In patients with BRPC or LAPC, primary treatment with FOLFIRINOX compared with Gemcitabine-based chemotherapy appears to provide a survival benefit for patients that are ultimately unresectable. For patients that undergo surgical resection, outcomes are similar between GEM+ and FOLFIRINOX when delivered in the neoadjuvant setting.ope

MUC1 selectively targets human pancreatic cancer in orthotopic nude mouse models

The goal of this study was to determine whether MUC1 antibody conjugated with a fluorophore could be used to visualize pancreatic cancer. Anti-MUC1 (CT2) antibody was conjugated with 550 nm or 650 nm fluorophores. Nude mouse were used to make subcutaneous and orthotopic models of pancreatic cancer. Western blot and flow cytometric analysis confirmed the expression of MUC1 in human pancreatic cancer cell lines including BxPC-3 and Panc-1. Immunocytochemistry with fluorophore conjugated anti-MUC1 antibody demonstrated fluorescent areas on the membrane of Panc-1 cancer cells. After injecting the conjugated anti-MUC1 antibodies via the tail vein, subcutaneously transplanted Panc-1 and BxPC-3 tumors emitted strong fluorescent signals. In the subcutaneous tumor models, the fluorescent signal from the conjugated anti-MUC1 antibody was noted around the margin of the tumor and space between the cells. The conjugated anti-MUC1 antibody bound the tumor in orthotopically-transplanted Panc-1 and BxPC-3 models enabling the tumors to be imaged. This study showed that fluorophore conjugated anti-MUC1 antibodies could visualize pancreatic tumors in vitro and in vivo and may help to improve the diagnosis and treatment of pancreatic cancer.ope

Insulin-Like Growth Factor-1 Receptor Targeted Fluorescent Imaging for Gallbladder Cancer in Orthotopic Mouse Models

Background/aims: Gallbladder cancer is fatal, but fluorescent imaging technology can facilitate timely diagnosis and improve patient outcomes. Fluorophore-conjugated insulin-like growth factor-1 receptor (IGF-1R) targeted antibodies were used to visualize gallbladder cancer in orthotopic tumor mouse models. Methods: Western blotting, flow cytometric analysis, and confocal microscopy detected the expression of IGF-1R in SNU-308, SNU-478, and SNU-1196 bile duct cancer cells. In vivo imaging of SNU-478 and SNU-1196 subcutaneous tumors and orthotopic gallbladder tumor models of SNU-478 were performed after injection with DyLight 650-conjugated IGF-1R antibody. Results: Western blotting and flow cytometric analysis showed that IGF-1R was expressed in bile duct cancer cells, and confocal microscopy demonstrated that IGF-1R antibody was able to bind to IGF-1R on the cell membrane. Fluorescent IGF-1R antibody injected into the mouse tail vein made subcutaneous tumors and orthotopic tumors become fluorescent. The intensity of fluorescence from the tumor was stronger than that from surrounding normal tissues. Histochemical examination confirmed that the tumor was located inside the gallbladder and adjacent liver parenchyma of mice. Conclusions: Our study showed that a fluorescent IGF-1R-targeted antibody could help detect gallbladder tumors. Tumor-specific imaging technology can be applied to endoscopy, laparoscopy, and robotic surgery for better management of gallbladder cancer.ope

Analysis of Clinical Predictive Factors Affecting the Outcome of Second-Line Chemotherapy for Gemcitabine-Refractory Advanced Pancreatic Cancer

Background/Aims: The benefit of second-line chemotherapy (SL) after failed first-line chemotherapy (FL) in patients with advanced pancreatic cancer has not yet been established. We evaluated the clinical characteristics affecting the benefits of SL compared to best supportive care (BSC), identified the prognostic factors, and ultimately devised a model of clinical parameters to assist in making decision between SL and BSC after the failure of gemcitabine-based FL. Methods: The records of patients who received gemcitabinebased FL for advanced pancreatic cancer at Yonsei University Hospital between January 2010 and December 2015 were retrospectively reviewed. Significant clinical parameters were assessed for their potential as predictive factors. Results: SL patients received a longer duration of FL compared with BSC patients with median duration being 16.0 weeks (range, 8.0 to 26.0 weeks) and 8.0 weeks (range, 4.0 to 16.0 weeks), respectively (p<0.001). When the SL group was stratified by their modified overall survival (mOS) (longer and shorter than 6 months), we found significant differences for several clinical factors, namely, metastasis to the peritoneum (p<0.001), number of metastases (p<0.001), thrombotic events (p=0.003), and level of carbohydrate antigen 19-9 (CA19- 9; p=0.011). In multivariate analysis, more than one site of metastasis, occurrence of thrombotic event during FL, and a CA19-9 level above 90 U/mL were significant independent prognostic factors for mOS in the SL group (p<0.05). When an attempt was made to devise a prognostic nomogram, Harrell's C-index of the final prognosis prediction model was 0.62. Conclusions: SL may be beneficial for patients without peritoneal metastasis or thrombotic events who have a single metastasis and a level of CA19-9 less than 90 U/mL. This prognostic nomogram can be used to predict mOS before the administration of SL after the failure of gemcitabinebased FL.ope

Laparoscopic pancreaticoduodenectomy with excision of aberrant right hepatic artery after preoperative segmental embolization in mid-bile duct cancer

Laparoscopic pancreaticoduodenectomy has proven to be a safe and effective alternative to open pancreaticoduodenectomy with similar oncologic outcomes. Cases including excision of the hepatic artery with or without reconstruction during pancreaticoduodenectomy have been reported for periampullary cancer. Here we present a case of an 82-year-old patient who underwent laparoscopic pancreaticoduodenectomy following preoperative arterial embolization of an aberrant right hepatic artery arising from the superior mesenteric artery.ope

EGFR-targeted fluorescent imaging using the da Vinci® Firefly™ camera for gallbladder cancer

Background: Fluorescent imaging may aid with the precise diagnosis and treatment of patients with gallbladder cancer. In this study, we sought to demonstrate whether the da Vinci® surgical system and Firefly™ camera could detect EGFR-targeted fluorescent images in orthotopic mouse models of gallbladder cancer. Methods: An orthotopic mouse model of gallbladder cancer was created by injecting NOZ gallbladder cancer cells mixed with Matrigel into the gallbladder. In vivo imaging of subcutaneous and orthotopic gallbladder tumors was performed after the injection of DyLight 650- or 800-conjugated EGFR antibody. Results: Western blotting, flow cytometry, and confocal microscopy showed the presence of EGFR in NOZ cells, but not in HEK293 cells. Subcutaneous NOZ cell tumors fluoresced after injection with fluorescent EGFR antibody, but subcutaneous HEK293 tumors did not. Fluorescent EGFR antibody made orthotopic NOZ tumors fluoresce, with an intensity stronger than that in the surrounding normal tissues. Histochemical examination confirmed the location of the tumors inside the gallbladder and adjacent liver parenchyma. Fluorescent signal was also detected in orthotopic gallbladder tumors with Firefly™ camera. Conclusion: Our study showed that fluorescent EGFR antibodies and the Firefly camera in the da Vinci system can detect fluorescing gallbladder tumors, which demonstrates their potential use for molecular imaging-based prevision surgery in the near future.ope

Long-term outcomes of fully covered self-expandable metal stents versus plastic stents in chronic pancreatitis

Chronic pancreatitis (CP) related main pancreatic duct (MPD) stricture has been a challenge for endoscopists. Fully covered self-expandable metal stents (FC-SEMS) has been tried in CP patients, but the efficacy and safety are still controversial. Thus, we aim to compare the long-term clinical efficacy of FC-SEMS vs. plastic stent placement in persistent MPD strictures secondary to CP. Between 2007 and 2018, 80 chronic pancreatitis patients (58 males, median age 49 years), who underwent endoscopic placement of FC-SEMS (n = 26) and plastic stent (n = 54) for persistent MPD strictures after at least 3 months of initial single plastic stenting, were retrospectively analyzed during a median follow-up duration of 33.7 months. As a result, MPD stricture resolution rate was statistically higher in FC-SEMS group (87.0% vs. 42.0%, p < 0.001). Although immediate complications occurred similarly (38.5% vs. 37.0%, p = 0.902), spontaneous migration (26.9%) and de novo strictures (23.1%) were pronounced delayed complications in FC-SEMS group. Pain relief during follow-up was significantly higher in FC-SEMS group (76.9% vs. 53.7%, p = 0.046). The total procedure cost was similar in both groups ($1,455.6 vs.$1,596.9, p = 0.486). In comparison with plastic stent, FC-SEMS placement for persistent MPD strictures had favorable long-term clinical efficacy, with its typical complications like spontaneous migration and de novo strictures.ope