Image-Guided Coring for Large-Scale Projects in Molecular Oncologic Pathology
Gabrielle M Baker, Laleh Montaser, Nicholas Knoblauch, Stephen Christensen, Aditi Hazra, Rulla Tamimi, Laura C Collins, Andrew H Beck. Beth Israel Deaconess Medical Center & Harvard Medical School, Boston, MA; Brigham and Women's Hospital, Harvard Medical School, Boston, MA
Background: Recent advances in molecular pathology permit a wide range of DNA- and RNA-based assays to be performed on archival formalin-fixed paraffin-embedded tissue (FFPE). Three commonly used techniques are laser-capture microdissection (LCM), macro-dissection from unstained slides, and direct coring of a block via a needle. While precise, LCM is extremely labor intensive making it impractical for most large-scale projects. Also labor intensive, macro-dissection requires manually scraping tissue from multiple slides per case. Although coring is by far the least labor intensive method, it is also potentially the least accurate and most error-prone method as the standard approach involves manual alignment of an annotated glass slide with an FFPE block followed by the attempt to manually sample designated regions of interest on the FFPE block. This traditional coring approach is especially problematic for small lesions. To overcome these limitations we have implemented an image-guided coring (IGC) procedure for molecular analyses.
Design: Whole slide digital scans of H&E-stained slides are acquired using the Panoramic SCAN (3D-Histech) and a pathologist selects regions of interest from these digital images using the PannoramicViewer Software package (3D-Histech). This annotated image is overlaid onto a digital image of the FFPE block using TMA-Master software (3D-Histech) and a computer-guided robotic arm is prompted to accurately sample the selected regions of the FFPE block. This selectively acquired tissue can then be used in downstream molecular analyses.
Results: IGC was performed on 300 breast cancer cases from the Nurses' Health Study with subsequent RNA extraction from both invasive cancer and normal terminal duct lobular units for downstream molecular analysis. A high success rate of adequate RNA (ng/mL) extraction from tumor and normal tissue via IGC has been obtained (88% and 64.79%, respectively).
Conclusions: IGC is an effective new approach for sampling FFPE tissue blocks, thereby serving as a valuable tool to link molecular assays to cancer morphology. Furthermore, IGC provides an ideal balance between precision and efficiency for large-scale projects in molecular oncologic pathology.
Monday, March 4, 2013 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 303, Monday Morning