Their new method can classify the disease, which could lead to new targeted therapies.
Researchers have discovered and identified sub-types of ovarian cancer cells, which can then be used to accurately identify which ovarian cancer subtypes are likely to lead to more severe cancer outcomes - an approach which has been dubbed the 'Oxford Classification of Carcinoma of the Ovary' or 'Oxford Classic' for short.
The new, Oxford-developed method has been validated in a recent collaboration between the University of Oxford and Imperial College London.
The Oxford Classic will provide much more accurate predictions for disease outcome in patients, as well as helping researchers to develop targeted therapies for each type of cancer.
A study published today in Clinical Cancer Research, has demonstrated its powerful prognostic usage in a new independent set of samples from a group of ovarian cancer patients.
Serous ovarian cancer (SOC) is the most common ovarian cancer type but is challenging to classify and predict its prognosis.
Using the Oxford Classic, researchers found that a specific SOC subtype, known as "EMT-high subtype", were associated with a lower survival rate.
EMT stands for epithelial-mesenchymal transition, the process by which epithelial cells change and become more mobile. This mobility provides the cells with the opportunity to spread, leading to cancer progression. EMT-high subtypes are tumours that have a high number of cancer cells with greater mobility.
Researchers also found that EMT-high subtypes were associated with abundance of a type of immune cells called M2 macrophage. M2 macrophages possess immunosuppressive properties, and can lead to poorer treatment responses if they are found in high quantities within a tumour.
It has previously been observed that patients with high-EMT tumours had a poor immune response. The study confirms that the EMT-high subtype is associated with an immunosuppressive environment (and so poor patient responses to treatment) due to their association with more M2 macrophages - a link that has not previously been identified.
Professor Ahmed Ahmed from the Nuffield Department of Women's and Reproductive Health and originator of the Oxford Classic, said, "Our group is very excited that we were able to confirm that the Oxford Classic can predict which patients are likely to have poor outcome.
"It is now important to identify new personalised therapies for the Oxford Classic-defined EMT-high ovarian cancer subtype. The finding that there is a strong connection with abundant M2 Macrophages already offers a good hint as to where we could find good treatment options for patients with this type."
Classifying the EMT status of a tumour, using the Oxford Classic, could potentially become a valuable part of future cancer stratification methods. This will ensure that appropriate treatment methods and attention are given to patients with a poorer overall prognosis.
Cary Wakefield, CEO of Ovarian Cancer Action, said, "While other cancers have achieved major improvements in treatment outcomes, ovarian cancer continues to go unrecognised, underfunded, and misdiagnosed. The Oxford classic is an exciting breakthrough that will help to identify new treatment options for ovarian cancers that have a lower chance of survival.
"Funding important research like this will bring us closer towards a shared goal of more women surviving ovarian cancer."