Dr Emma Ramsay

Doctor Ramsay completed her PhD with Professor Hogg at UNSW in 2014. On completion, she moved to UT MD Anderson Center, working on a number of early stage translational projects in pancreatic cancer. In 2017 she began work with The University of Sydney measuring procoagulant platelets in lung cancer.


Procoagulant platlets as a diagnostic predictor of thrombosis in lung cancer patients

Emma Ramsay1, Heather Campbell3, John Simes2, Michael Boyer1,4, Anthony Joshua5,6,7, Venessa Chin6,7, Jane Young8.9.10, Bea Brown1, Vivien Chen3,11, Phillip Hogg1,12

1 Sydney Catalyst Translational Cancer Research Centre, The University of Sydney, Camperdown, NSW Australia
2 NHMRC Clinical Trials Centre, The University of Sydney, Camperdown, NSW Australia
3 ANZAC Research Institute, The University of Sydney, Concord, NSW, Australia
4 Chris O'Brien Lifehouse, Camperdown, NSW Australia
5 St Vincent's Hospital Sydney, Darlinghurst, NSW, Australia
6 The Kinghorn Cancer Centre, Darlinghurst, NSW, Australia
7 Garvan Institute of Medical Research, Darlinghurst, NSW, Australia
8 School of Public Health, The University of Sydney, Camperdown, NSW Australia
9 RPA Institute of Academic Surgery, Sydney Local Health District, Camperdown, NSW Australia
10 Surgical Outcomes Research Centre (SOuRCe), Sydney Local Health District, Camperdown, NSW Australia
11 Department of Haematology, Concord Repatriation General Hospital, Concord West, NSW, Australia
12 Centenary Institute, The University of Sydney, Camperdown, NSW Australia

Thrombotic events are a major cause of morbidity and mortality in cancer. The procoagulant subset of platelets, when activated, trigger coagulation and thrombosis by providing a surface for assembly of coagulation factors. Measurement of procoagulant platelets in cancer could have prognostic significance, guiding clinical decisions and minimising thrombotic events. Using serial, citrated blood samples from a prospective cohort of patients with lung cancer enrolled in the EnRICH (Embedding Research (and Evidence) In Cancer Healthcare) Program, a flagship program of Sydney Catalyst and University of Sydney, this is the first clinical study of this measure in a cancer setting.

1. To investigate correlation between lung cancer and elevated procoagulant platelets in the blood.
2. Identify lung cancer patients at risk of thrombosis from the procoagulant platelet population.

Human studies were approved by Royal Prince Alfred Hospital and University of Sydney ethics committees (X16-0447, 2014/244), and conducted according to the Declaration of Helsinki. All participants gave written informed consent. Whole blood was collected in 3.2% citrate and stimulated with platelet agonists for ten minutes to reveal procoagulant platelets. Samples were labelled and analysed by flow cytometry (see Pasalic et al. JTH 16:1198, 2018).

Eighty unique patients have been analysed to date, with consecutive samples taken from thirty-one patients. Blood from cancer patients at baseline and six months had significantly higher numbers of procoagulant platelets compared to healthy individuals (healthy - 4.28 ± 0.92, baseline - 8.42 ± 0.95, 6 months - 10.67 ± 2.23 procoagulant platelets as percentage of total single platelets; mean ± SEM) when stimulated with collagen and thrombin. In concordance, patients diagnosed with more advanced lung cancer exhibited increased procoagulant platelets.

The increased procoagulant platelet capacity of lung cancer patients may provide insight into the risk of thrombotic events. Further collection of data will help identify factors that increase the risk of thrombosis in lung cancer such as treatment.