1980TiP - Homogenisation of leftover surgical tissue across multiple cancer types: A feasibility study (HoLST-F)

Abstract

BackgroundIntratumour heterogeneity is recognised across different tumour types and has implications for therapeutic resistance. At present, clinical practice often relies upon molecular information derived from a single biopsy of a primary or metastatic tumour. This information guides treatment choice but may not be representative of the diversity of the tumour. It is currently difficult to evaluate how effectively a single region guides treatment decisions because the formalin-fixed residual surgical sample that is not paraffin embedded for diagnostic purposes is typically thrown away. Retention and homogenisation – ‘blending’- of this residual formalin-fixed leftover tumour tissue creates a more representative sample for analysis. DNA may be extracted from this sample for sequencing. Pilot data in kidney cancer has demonstrated the potential of this methodology for robust mutational calling, accurate determination of cancer cell fraction and the ability to discern clonal from subclonal variants. Such information may be clinically relevant; for example, discerning resistant subclones prior to treatment, or identifying clonal neoantigens worth targeting with immunotherapy. Trial designIn order to establish the feasibility of homogenization as a potential companion diagnostic tool, our study aims to 1) identify the proportion of primary tumour cases that have left over tissue amenable to homogenization across multiple tumour types and 2) pilot homogenization across multiple tumour types. The molecular profile of the homogenate will be compared to that obtained from the diagnostic specimen using next generation sequencing techniques. This is a prospective non-interventional study (NCT03832062). Patients undergoing surgical intervention at The Royal Marsden Hospital (NHS Foundation Trust) with leftover tumour tissue from primary breast, colorectal, gastric, pancreatic, ovarian, renal cancer and sarcoma surgeries, as well as melanoma lymph node dissections will be included in the feasibility assessment. We plan to homogenise 500 cases across different tumour types. The study opened in September 2018 and is expected to run for 2 years. Clinical trial identificationNCT03832062; Release date: February 2019. Legal entity responsible for the studyRoyal Marsden NHS Foundation Trust. FundingVentana Medical Systems (a subsidiary of Roche). DisclosureL. Gallegos: Full / Part-time employment: Roche. S. Hill: Full / Part-time employment: Roche. A. Barhoumi: Full / Part-time employment: Roche. S. Stanislaw: Full / Part-time employment: Roche. M. Mendoza: Full / Part-time employment: Roche. J.M.G. Larkin: Research grant / Funding (institution): Roche; Advisory / Consultancy: Roche. N. Alexander: Full / Part-time employment: Roche; Shareholder / Stockholder / Stock options: Roche. S. Turajlic: Research grant / Funding (institution): Ventana Medical Systems (subsidiary of Roche). All other authors have declared no conflicts of interest.