Scientists find virus strains linked to 'Cantonese cancer'

Scientists in Singapore have identified new variants of a virus that are associated with various cancers - including one that affects Cantonese people more than others.

This could make it easier to identify individuals at high risk of developing the cancers and get them to undergo intervention programmes early.

The scientists discovered that the two new Epstein-Barr virus (EBV) variants are associated with the most common head and neck cancer in Singapore - nasopharyngeal carcinoma - as well as gastric cancer and several kinds of lymphoma.

Nasopharyngeal carcinoma is also called Cantonese cancer as individuals from the Cantonese dialect group who are infected with the EBV are 20 times more at risk of developing the cancer than those from other regions or populations.

In the latest study published in scientific journal Nature Genetics on Monday, the scientists discovered a unique EBV strain associated with an increased risk of developing Cantonese cancer.

Individuals with the strain are 11 times more likely to develop the cancer than non-carriers.

This EBV strain appears to have originated in Asia. Currently, more than 40 per cent of individuals in southern China are infected by this strain. About 80 per cent of cancer cases among individuals from the Cantonese dialect group are caused by this strain.

The scientists are from the Agency for Science, Technology and Research's Genome Institute of Singapore (GIS) and several other research institutes, including the Sun Yat-Sen University Cancer Centre and the Institute of Zoology of the Chinese Academy of Sciences.

GIS deputy executive director Liu Jian Jun, who is the lead author, said the importance of EBV viral variants in the development of Cantonese cancer and its widespread occurrence among the Cantonese group have been poorly explored in the past, and his study "provided novel insights into the (Cantonese cancer) endemic".

He added that the findings could provide the basis for implementing effective intervention programmes to reduce the number of cases of the cancer.

GIS executive director Ng Huck Hui said: "The discovery of these high-risk EBV viral variants has important implications for public health efforts to reduce the burden of (Cantonese cancer), particularly among (the Cantonese)."

Professor Ng said that testing for such variants will enable the identification of individuals who are at high risk and the early detection of the cancer.

The development of vaccines against the EBV strains is expected to "greatly reduce" the cancer's incidence rate, he added.