People in Southern China, North Africans and Eskimos are more prone to develop cancer of the nose and throat than other races, possibly because they all eat a lot of salted or preserved fish, University of Hong Kong researchers said yesterday. The incidence of nasopharyngeal cancer among people in southern China areas such as Guangdong and Guangxi is 25 to 30 per 100,000 per year and 10 per 100,000 for North African and Eskimo - compared to only one per 100,000 for caucasians in Europe and North America. Presenting these findings, Jonathan Sham Shun-tong, head of department of clinical oncology at the University of Hong Kong, said doctors believed both genetic factors and diet played a role in causing cancer. Professor Sham said preserved fish was common in the diet of people from the three high risk groups. He said the cancer rate of Chinese people from the North, where preserved fish was not popular, was only 10 per 100,000 people about one-third of the rate of Chinese people in the south. The findings also show nearly three times more men than women suffer from nasopharyngeal cancer. Professor Sham cited recent research from the Pamela Youde Nethersole Eastern Hospital showing the incidence of nasopharyngeal cancer in Hong Kong had dropped by 10 per cent for every 10 years over the past two decades. The oncology professor said the drop could be caused by the growing health consciousness among local people, which included measures such as cutting down the amount of preserved fish in the diet. Another reason could be people seeking treatment on the mainland.