From the stars to cancer: astronomy helps predict response to treatment
Using tools designed to reconstruct the structure of the universe to develop increasingly accurate biomarkers: the AstroPath project
Tools developed in the field of astronomy can help to analyse the tumour microenvironment with greater precision and, in the long term, to better predict the response to immunotherapy. This is the principle behind AstroPath, the platform presented by Janis Taube during the 11th Annual Meeting of the Alliance Against Cancer in Naples.
Professor of Dermatology, Oncology and Pathology and Director of the Division of Dermatopathology at Johns Hopkins, Taube began by noting that the most widely used biomarkers today, such as PD-L1 expression, provide important information, but are not always sufficient to identify patients who will respond to drugs targeting immune checkpoints. The reason is that it is not just a question of which cells or molecules are present in the tumour: their location, the distance between them and the way they interact are also important.
The AstroPath platform
AstroPath combines multi-colour immunofluorescence – a technique that allows several proteins within a tissue to be observed simultaneously – with advanced image analysis systems borrowed from astronomy. The principle is the same as that used to create maps of the sky: thousands of images are aligned and integrated into a single representation. Instead of stars and galaxies, however, cancer cells and immune system cells are identified, whilst retaining information on the position and characteristics of each.
The result is an extremely detailed map of the tumour microenvironment, down to single-cell resolution: it is no longer just a question of measuring the level of a particular biomarker; it is now possible to observe on which cells it is expressed, which other cells are in the vicinity, and which spatial configurations are associated with response to or resistance against treatment.
Melanoma: the first testing ground
Significant results have already emerged in advanced melanoma: studies published in *Science* have shown that AstroPath can recognise, in samples taken prior to treatment, specific combinations of immune cells and expression levels of PD-1 and PD-L1. Using a panel of six markers, a signature associated with response and survival following treatment with anti-PD-1 drugs was identified and subsequently verified in a second group of patients.
