Hepatocellular carcinoma

An update on the management of Hepatocellular carcinoma (HCC) is provided in the present article for those interested in the UEMS/EBSQ exam in Surgical Oncology. The most recent publications in HCC, including surveillance, guidelines, and indications for liver resection, liver transplantation, and locoregional or systemic therapies, are summarised. The objective is to yield a set of main points regarding HCC that are required in the core curriculum of hepatobiliary oncological surgery.

Fluorescence-guided surgery: comprehensive review

BACKGROUND

Despite significant improvements in preoperative workup and surgical planning, surgeons often rely on their eyes and hands during surgery. Although this can be sufficient in some patients, intraoperative guidance is highly desirable. Near-infrared fluorescence has been advocated as a potential technique to guide surgeons during surgery.

METHODS

A literature search was conducted to identify relevant articles for fluorescence-guided surgery. The literature search was performed using Medical Subject Headings on PubMed for articles in English until November 2022 and a narrative review undertaken.

RESULTS

The use of invisible light, enabling real-time imaging, superior penetration depth, and the possibility to use targeted imaging agents, makes this optical imaging technique increasingly popular. Four main indications are described in this review: tissue perfusion, lymph node assessment, anatomy of vital structures, and tumour tissue imaging. Furthermore, this review provides an overview of future opportunities in the field of fluorescence-guided surgery.

CONCLUSION

Fluorescence-guided surgery has proven to be a widely innovative technique applicable in many fields of surgery. The potential indications for its use are diverse and can be combined. The big challenge for the future will be in bringing experimental fluorophores and conjugates through trials and into clinical practice, as well as validation of computer visualization with large data sets. This will require collaborative surgical groups focusing on utility, efficacy, and outcomes for these techniques.

Development of biotissue training models for anastomotic suturing in pancreatic surgery

BACKGROUND

Anastomotic suturing is the Achilles heel of pancreatic surgery. Especially in laparoscopic and robotically assisted surgery, the pancreatic anastomosis should first be trained outside the operating room. Realistic training models are therefore needed.

METHODS

Models of the pancreas, small bowel, stomach, bile duct, and a realistic training torso were developed for training of anastomoses in pancreatic surgery. Pancreas models with soft and hard textures, small and large ducts were incrementally developed and evaluated. Experienced pancreatic surgeons (n = 44) evaluated haptic realism, rigidity, fragility of tissues, and realism of suturing and knot tying.

RESULTS

In the iterative development process the pancreas models showed high haptic realism and highest realism in suturing (4.6 ± 0.7 and 4.9 ± 0.5 on 1-5 Likert scale, soft pancreas). The small bowel model showed highest haptic realism (4.8 ± 0.4) and optimal wall thickness (0.1 ± 0.4 on -2 to +2 Likert scale) and suturing behavior (0.1 ± 0.4). The bile duct models showed optimal wall thickness (0.3 ± 0.8 and 0.4 ± 0.8 on -2 to +2 Likert scale) and optimal tissue fragility (0 ± 0.9 and 0.3 ± 0.7).

CONCLUSION

The biotissue training models showed high haptic realism and realistic suturing behavior. They are suitable for realistic training of anastomoses in pancreatic surgery which may improve patient outcomes.

Pancreatic cancer

The need for a common education and training track in surgical oncology across Europe has been emphasized. ESSO provides several hands-on courses for skills training and face-to-face discussions. The core curriculum provides a framework for the overall theoretical requirements in surgical oncology. The UEMS/EBSQ fellowship exam is designed to test core competencies in the candidate's core knowledge in their prespecified area of expertise. A core set of points for each cancer type is lacking. Hence, a condensed outline of themed expected to be covered in the curriculum and relevant to an optimal practice in surgical oncology is provided. This article outlines pancreatic cancer.

Impact of complications after surgery for colorectal liver metastasis on patient survival

BACKGROUND

In some patients with colorectal liver metastases it is not clear whether liver resection or isolated liver perfusion is the best treatment option. For instance, the risk of complications after surgery may be so substantial and affect subsequent survival. Aim of the present study is to compare complication occurrence and its effect on survival after liver resection and perfusion.

METHODS

Patient records of all 225 patients with colorectal liver metastases treated with liver resection (n = 121) or liver perfusion (n = 104) in the period 1997-2006 were reviewed for complications during the initial hospitalisation until 30 d after discharge, and to assess patient survival until the last hospital visit. Median duration of follow-up was 38 mo for overall survival and 22 mo for survival after surgery.

RESULTS

Complications occurred less often in patients undergoing resection than perfusion (29.8% versus 49.0%, X(2) = 8.77, P < 0.01). Postoperative mortality rates were similar in both groups (4.1% and 4.8%, respectively). As expected, long term survival after liver surgery was better in the resection group: at 3 y, 60% of patients survived in the resection group, compared with 22% after liver perfusion (log rank X(2) = 35.29 P < 0.001). However, liver resection patients with postoperative complications, had similar survival as perfusion patients without complications (log rank X(2) = 2.45, p = 0.12). This remained after adjustment for differences between the patient groups at time of surgery.

CONCLUSION

Liver resection has superior long-term survival, but survival is significantly reduced by the occurrence of post-surgical complications. When complications occur after liver resection, survival is comparable to patients who underwent uncomplicated liver perfusion.

Image-Guided Surgery: Breast Cancer Detection Using Monoclonal Antibodies Conjugated to a Near-Infrared Fluorescent Dye in a Syngeneic Rat Model

Background: Incomplete tumor resections occur frequently in patients undergoing breast-conserving surgery. As the surgeon can only rely on palpation and visual inspection, real-time visualization of cancer cells during surgery is needed to increase the number of complete tumor resections. Near-infrared fluorescence (NIRF) imaging using an intra-operative camera system is a novel technique to assess the extent of disease during surgery. Advantages of NIRF light (700-900 nm) include high tissue penetration up to several centimeters deep and low autofluorescence providing sufficient signal-to-noise ratio. Currently, several NIRF dyes are available for chemical conjugation to molecules that can target tumors, e.g. antibodies. This study aimed to investigate whether monoclonal antibodies conjugated to a NIRF dye could detect primary breast carcinomas in a syngeneic rat model.Methods: The hormone-dependent syngeneic breast cancer rat model EMR86 and its derived cell line MCR86 were used. Tumors were induced by orthotopic implantation of fresh EMR86 tumor fragments of 1 mm3 into the flanks at four sites in female WAG/Rij rats (Harlan, the Netherlands). The mouse monoclonal antibody MG1 was used for tumor cell detection. MG1 (IgG2a) recognizes a membrane epitope of rat cancer cells of epithelial origin and is developed by our research group. MG1 was conjugated to the NIRF dye CW-800 (LI-COR, USA) and dye/protein ratio was determined using absorbance measurements (UltroSpec, Amersham, UK). Fluorescence imaging of cells, animals and organs was performed using IVIS Spectrum (Caliper, USA) and Odyssey (LI-COR, USA) equipment.Results: Conjugated antibodies MG1-CW800 bound specifically to cultured MCR86 cells. The signal intensity was linearly correlated with the number of cells and concentration of MG1-CW800 (R2=0.99, p&lt;0.00001). Addition of unconjugated MG1 lowered the fluorescent signal in a competitive binding assay, showing that labeling did not influence binding properties. Intravenous injection of unconjugated MG1 (200 μg/rat) in 3 Wag/Rij rats and subsequent immunohistochemical analysis of tissue sections revealed a specific and exclusive binding of MG1 to the EMR86 tumors and no difference in staining intensity between 24 and 48hrs after injection. Intravenous injection of conjugated MG1-CW800 (200 μg/rat) demonstrated a clear fluorescent demarcation of EMR86 tumors and the surrounding tissue after spectral unmixing (paired t-test 8.17, p&lt;0.00001). Mean fluorescence did not differ between 24 and 48hrs after injection (t=1.85, p=0.11). However, a two-fold increase of the dye/protein ratio led to a two-fold increase of the in vivo fluorescence (t=-6.40, p=0.0001).Conclusion: Intravenous injection of monoclonal antibodies MG1 conjugated to the NIRF dye CW800 enabled detection of primary breast carcinomas in the syngeneic hormone-dependent EMR86 rat model. This study demonstrates proof-of-concept for future labeling of clinically relevant antibodies (e.g. HER2/neu, EGF, VEGF). Translation of this technique to breast cancer patients can lead to intra-operative identification of optimal resection margins in order to increase the comple tumor resection rate.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5006.

Intra-Operative Imaging of the Invasive Tumor Border by a Cathepsin-Sensing Near-Infrared Fluorescence Probe in a Syngeneic Breast Cancer Rat Model

Background: An incomplete tumor resection occurs in 5-45% of the patients undergoing breast-conserving surgery. As the surgeon can only rely on palpation and visual inspection, real-time visualization of cancer cells at the time of surgery is needed to increase the number of complete tumor resections. Near-infrared fluorescence (NIRF) imaging is a promising technique to assess the extent of disease during surgery. This study aimed to validate NIRF imaging in a breast cancer rat model.Methods: The hormone-dependent syngeneic breast cancer rat model EMR86 and its derived cell line MCR86 were used. Tumor cells were detected with the cathepsin-activatable (mainly cathepsin-B) NIRF probe ProSense® (VisEn Medical, USA). Fluorescence imaging of the animals, organs and tissue sections was performed using IVIS Spectrum (Caliper, USA), Odyssey (LI-COR, USA) and SP5 microscope (Leica, Germany). Intra-operative fluorescence imaging was performed using the Fluobeam700 system equipped with a 690 nm class 3B laser and a CCD camera (Fluoptics, France).Results: ProSense was activated by cleavage in MCR86 cells. The signal intensity was linearly correlated with the number of cells, the concentration of ProSense and the incubation time (all R2&gt;0.93, p&lt;0.0001). The influence of ProSense concentration and tumor volume on fluorescent intensity was confirmed in nine rats each bearing four tumors (mean volume=0.38 ±0.36 cm3). In contrast to the in vitro data, no difference in fluorescence intensity was found between 24hr and 48hr after injection of ProSense (paired t=-0.27, p=0.80). Therefore, subsequent experiments were conducted 24hr after injection. Calibration of the intra-operative camera system demonstrated a strong correlation of fluorescence intensity and activated ProSense concentration (R2=0.9903). Using the intra-operative NIRF camera, all 64 mammary tumors (0.01-1.8 cm3) were successfully detected. Histological assessment of residual fluorescent hotspots confirmed the presence of breast cancer cells indicating incomplete resections of the primary tumor (margin positivity). The signal intensity of the tumor was 60-fold higher than the surrounding tissue (p&lt;0.0001). Fluorescence scanning microscopy of 2-mm thick tumor sections revealed a significantly two-fold higher signal intensity at the tumor border compared to the tumor center (t=-8.12, p&lt;0.00001). Fluorescent microscopy of 10 um frozen tissue sections confirmed the higher intensity at the border, which was mainly located in the tumor-associated stroma.Conclusion: We demonstrated that it is possible to detect and resect sub-mm breast tumor depositions under fluorescent guidance in a syngeneic rat model. The higher fluorescent signal at the tumor border likely reflects the extra-cellular matrix degradation induced by increased cathepsin-B activity. Intra-operative imaging of cathepsin activity at the invasive border facilitates clear demarcation of tumor margins. Clinical introduction of this technique has the potential to substantially improve breast-conserving surgery.Acknowledgement: We want to thank Fluoptics for providing us with the Fluobeam700 system to perform the above described experiments.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 5007.