Biomarker Development in Endometrial Cancer: Circulating Tumour Cells, Tissue Methylation and Genotyping Studies

Endometrial cancer (EC) is the most common gynaecological malignancy in the developed world and 4th most common women’s cancer in the UK. Although approximately 75% of women present with surgically resectable disease, 20% of these will relapse and 25% of initial diagnoses occur with metastatic disease. There are currently no validated biomarkers to assess treatment response or target molecular therapies, despite evidence for targetable aberrations in the literature. The PI3K pathway in particular is commonly mutated in EC and stathmin is a recently identified phosphoprotein associated with PI3K pathway activation and with prognostic significance in EC. I investigated biomarker development and novel pathways in EC in two ways: firstly, through a feasibility study of circulating tumour cell (CTC) enumeration and molecular profiling (MP) in patients with advanced endometrioid and non-endometrioid EC (EEC and NEEC); and secondly, through methylation and copy number variation (CNV) studies on formalin-fixed paraffin-embedded (FFPE) and fresh frozen (FF) EEC. CTCs have prognostic and predictive significance in a number of cancers, with increasing evidence on CTC MP. CTC enumeration and assessment of stathmin overexpression was performed on the validated Veridex CellSearch platform and shown to be feasible. In addition, CTC positivity was associated with worse survival and there was a subset of patients for whom a positive CTC count was predictive of outcome on chemotherapy. The second component focused on methylation and CNV analysis in the different phases of endometrial carcinogenesis from normal endometrium to atypical endometrial hyperplasia (AEH) and EEC. By extracting DNA from FFPE and FF EEC and using the Illumina Infinium HumanMethylation450 BeadChip, I was able to demonstrate these methods were feasible and that differential methylation and CNV was evident in the transition from normal endometrium through to AEH and EEC. This research provides a basis for further biomarker development and novel target selection in EC

Enumeration and Molecular Characterisation of Circulating Tumour Cells in Endometrial Cancer

BACKGROUND: This is a feasibility study to determine whether circulating tumour cells (CTCs) are detectable and suitable for molecular profiling in advanced endometrial cancer (aEC). METHOD: Between October 2012 and February 2014, 30 patients with aEC had baseline and up to 3 follow-up samples. CTCs and stathmin expression were evaluated using the CellSearch platform. Epithelial cell adhesion molecule (EpCAM) and stathmin immunohistochemistry were performed on FFPE tumour tissue. RESULTS: Eighteen from 30 (60%) patients had detectable CTCs during study [1 CTC (n = 7), 2 (n = 4), 3 (n = 1), 4 (n = 2), 7 (n = 1), 8 (n = 1), 22 (n = 1), 172 (n = 1) in 7.5 ml blood]. Ten from 18 patients had between 50 and 100% of detectable CTCs that were stathmin positive. More CTC-positive than CTC-negative patients had non-endometrioid versus endometrioid histology, tumour size ≥5 versus 0.05, 95% confidence interval 0.7-16.2]. Twenty-one tumour blocks were tested for EpCAM and stathmin immunohistochemistry (IHC). Stathmin tumour immunostaining scores (TIS) on IHC were higher in CTC-positive patients. CONCLUSION: CTC enumeration and molecular profiling with stathmin on the CellSearch platform is feasible in aEC. Stathmin TIS on IHC, a known prognostic marker in EC, was associated with CTC positivity

Treatment of breast cancer 2 (BRCA2)-mutant follicular dendritic cell sarcoma with a poly ADP-ribose polymerase (PARP) inhibitor: A case report

Background: Follicular dendritic cell sarcoma is a rare tumour with clinical behaviour covering a spectrum from indolent to aggressive disease. Treatment recommendations are currently based on case reports and small series describing combinations of surgery, chemotherapy and radiotherapy providing the best patient outcomes. Recent knowledge on molecular aberrations in this disease have not yet impacted on therapeutic decisions. Case presentation: We describe a case of progressive follicular dendritic cell sarcoma of the lung and pleura, treated based on knowledge of the tumour's molecular aberrations. The patient was initially treated with surgery, chemotherapy and radiotherapy and developed disease progression. Mutation testing by Caris molecular intelligence demonstrated a breast cancer 2 gene mutation and further treatment with carboplatin and veliparib achieved disease stabilisation. Conclusion: Understanding of the molecular profile of rare tumours is key to improve therapeutic decision making and patient outcomes