Adenocarcinomas are the most commonly diagnosed type of cancer which include the cancer of the lung, breast, pancreas, prostate and colon. Upon diagnosis, surgical removal of the tumor is one of the most important steps in management of patients with adenocarcinomas. Intraoperative diagnosis of surgical margins guides the surgeons regarding the status of the tumor resections and the surrounding tissues for which frozen sections of resected tumors are usually used for analysing the margin status by hematoxylin and eosin staining as the reports need to be sent back to the surgeon within 30 minutes1,2. The results are then confirmed by immunohistochemistry of formalin-fixed tumor sections by using specific antibodies which may take up to a few hours to days. This current intraoperative diagnostic procedure results in the false negative rates up to 38- 54 % without the use of frozen sections and up to 19-20 % with the frozen section analysis3. Thus, there is an urgent unmet medical need for the development of an alternative molecular probe-based method of diagnosis to minimize the extensive false negative rates.
We are developing a nucleic acid-based detection system employing aptamers against epithelial tumor markers, such as EpCAM and cytokeratins as molecular probes and HRP-mimicking DNAzymes as the reporter molecule for accomplishing rapid intraoperative diagnosis of surgical margins and evaluation of lymph nodes.
This nucleic-acid based detection method will enable us to obtain accurate results within 30 minutes and result in a highly sensitive system with a much lowered false-negative rate, leading to improved outcome of patient care. Our novel approach aims to revolutionize the way intraoperative pathology is carried out and once established, it can be adopted by all the hospitals performing cancer surgery throughout the world.