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Updated: Dec 18, 2025
Murine Model for Non-invasive Imaging to Detect and Monitor Ovarian Cancer Recurrence
Published on: November 2, 2014
Novel Molecular Targets for Tumor-Specific Imaging of Epithelial Ovarian Cancer Metastases
Lysanne D A N de Muynck1, Katja N Gaarenstroom2, Cornelis F M Sier1
1Department of Surgery, Leiden University Medical Center, 2333 ZA Leiden, The Netherlands.
Abstract:
In epithelial ovarian cancer (EOC), the strongest prognostic factor is the completeness of surgery. Intraoperative molecular imaging that targets cell-surface proteins on tumor cells may guide surgeons to detect metastases otherwise not visible to the naked eye. Previously, we identified 29% more metastatic lesions during cytoreductive surgery using OTL-38, a fluorescent tracer targeting folate receptor-a (FRa). Unfortunately, eleven out of thirteen fluorescent lymph nodes were tumor negative. The current study evaluates the suitability of five biomarkers (EGFR, VEGF-A, L1CAM, integrin avb6 and EpCAM) as alternative targets for molecular imaging of EOC metastases and included FRa as a reference. Immunohistochemistry was performed on paraffin-embedded tissue sections of primary ovarian tumors, omental, peritoneal and lymph node metastases from 84 EOC patients. Tumor-negative tissue specimens from these patients were included as controls. EGFR, VEGF-A and L1CAM were highly expressed in tumor-negative tissue, whereas avb6 showed heterogeneous expression in metastases. The expression of EpCAM was most comparable to FRa in metastatic lesions and completely absent in the lymph nodes that were false-positively illuminated with OTL-38 in our previous study. Hence, EpCAM seems to be a promising novel target for intraoperative imaging and may contribute to a more reliable detection of true metastatic EOC lesions.
Insights
EpCAM shows promise as a novel target for intraoperative molecular imaging in epithelial ovarian cancer (EOC). This biomarker could improve the detection of true metastatic lesions, overcoming limitations of previous tracers.
Area of Science:
- Oncology
- Surgical Oncology
- Molecular Imaging
Background:
- Complete surgical resection is crucial for epithelial ovarian cancer (EOC) prognosis.
- Intraoperative molecular imaging aids in detecting EOC metastases invisible to the naked eye.
- Previous imaging with OTL-38 targeting folate receptor-alpha (FRa) showed high false-positive rates in lymph nodes.
Purpose of the Study:
- To evaluate five biomarkers (EGFR, VEGF-A, L1CAM, integrin avb6, EpCAM) as alternative targets for EOC intraoperative imaging.
- To compare the expression of these biomarkers with FRa in EOC metastases.
- To identify a reliable target for accurate detection of EOC metastatic lesions.
Main Methods:
- Immunohistochemistry was performed on paraffin-embedded tissues from 84 EOC patients.
- Tissues included primary tumors, omental, peritoneal, and lymph node metastases, plus tumor-negative controls.
- Expression levels of EGFR, VEGF-A, L1CAM, avb6, EpCAM, and FRa were analyzed.
Main Results:
- EGFR, VEGF-A, and L1CAM were highly expressed in tumor-negative tissues.
- Integrin avb6 displayed heterogeneous expression in metastases.
- EpCAM expression in metastases was comparable to FRa and absent in previously identified false-positive lymph nodes.
Conclusions:
- EpCAM is a promising biomarker for intraoperative molecular imaging of EOC.
- Targeting EpCAM may enhance the reliability of detecting true metastatic EOC lesions.
- This approach could improve surgical guidance and patient outcomes in EOC treatment.
