Cancer of unknown primary (CUP) is a term that is used to describe cancer where the original (first) tumour, called the primary, cannot be found and only the metastatic tumours – the tumours that grow as the cancer spreads through the body – are detectable. It might not be possible to identify the primary as:
1) it may be too small to see on a scan, 2) it might have been attacked and killed by the immune system or 3) it might have “sloughed” off (as can happen in gut tumours), or 4) the types of cells found in the secondary tumours don’t look like they’ve come from any obvious primary site.
Despite an improvement in diagnostic techniques there has only been a small decline in mortality from CUP over the last six years, and only about 1 in 3 patients diagnosed with CUP will survive beyond a year.
The Cancer of Unknown Primary GeCIP Domain will use the data from the 100,000 Genomes Project to define the changes in the tumour DNA, and try to identify factors that can be used to more accurately diagnose and understand CUP biology.