New insights into one of the world’s most common cancers have been discovered by the Cancer Grand Challenges Mutographs team, an international collaboration led by the Wellcome Sanger Institute.
The study, published in Nature Genetics, includes the surprising finding that the huge variance in oesophageal cancer across the world is not the result of a unique pattern of DNA damage. However, a fault in the APOBEC molecule was found to be a factor in 90 per cent of samples analysed, suggesting some oesophageal tumours may be susceptible to certain types of treatment.
Oesophageal squamous cell carcinoma (ESCC) is the world’s eighth most common cancer and the most common type of oesophageal cancer – a disease that affected more than 600,000 people worldwide last year*. Incidence of the disease varies dramatically around the world and is more than one hundred times more common in some countries than others.
In this study, the Cancer Grand Challenges Mutographs team sought to understand this difference, hoping to find a unique pattern of damage on the DNA of patients from areas of high ESCC incidence – known as a mutational signature. Working backwards from this damage can help to identify unknown causes of cancer.
The team studied more than 550 cancer genomes from people with ESCC from eight countries: Iran, China, Kenya, Tanzania, and Malawi (high incidence rates); Brazil, Japan and the UK (lower incidence rates). Lifestyle and environment vary significantly between these countries, but ESCC patients’ genomes were remarkably similar.
Surprisingly, however, no mutational signature was identified that could account for such high variation in ESCC incidence around the world.
Source: Sanger Institute