THE number of people falling victim to lung cancer is declining in Hong Kong, medical experts said. Doctors who have collated and analysed figures for the Cancer Registry are hailing the trend as a turning point in curbing the disease. 'This is definitely something major,' said Dr William Foo, consultant in radiotherapy and oncology at Queen Elizabeth Hospital. Although there were still more than 3,000 new cases of lung cancer a year, the rate was declining, he said. He refused to divulge exact figures, saying the data needed to be refined and further analysed. Dr Foo will brief health authorities on the trend in April. He is preparing a report to update the data at the registry, where figures lag a few years behind current information because of difficulties collating the data. He said there had been a clear drop in the number of new cases in the few years to 1994. Lung cancer is the most common cancer in Hong Kong, killing 2,966 people in 1996. Dr Foo said the reason for the drop in the number of cases was not yet clear. 'The same thing has been happening in the United States,' he said. 'We don't know why it's happening in Hong Kong, but in the US, I think it's a change in smoking habits.' Community medicine expert Dr Linda Koo Chih-ling said she believed there was a dietary link. 'On one hand, the amount of smoking in the male population has declined since the mid-80s, but there's also dietary effects - more than half of women with lung cancer have never smoked,' she said. Dr Koo's research at Hong Kong University indicates that the chances of getting lung cancer are increasingly related to what people eat. Diets had shifted from rice and small amounts of meat, fish and vegetables to larger portions of meat, poultry, fish and processed foods, she explained. Dr Koo agreed that the rate of lung cancer had reached a plateau and was now on the decline. But she believed that a significant drop in the number cases could still be a decade or more away.