The leading cause of lung cancer among women in the city was cooking oil fumes while men are more likely to develop the disease from smoking, said medical experts after a five-year research study.

　　Doctors announced the results yesterday with analysis on some new tendencies in lung cancer. They said patients are younger, especially women.

　　According to the Shanghai Tumor Research Institute, more local residents die of lung cancer in the city than anything else. Following breast cancer, it has the second-highest incidence rate.

　　"An unhealthy lifestyle is a very important reason for lung cancer," said Dr He Yumin from Shanghai Minshen Traditional Chinese Medicine Tumor Diagnosis and Treatment Center.

　　He followed 2,276 lung cancer patients for five years. Among them, 1,483 were male.

　　Smoking causes 70 percent of cases among men while only 18 percent of female patients developed cancer from smoking or inhaling second-hand smoke, according to the report.

　　However, more than 60 percent of women with the disease had long term, close contact with strong oil fumes from cooking and complained about irritated eyes and throat.

　　About 32 percent fried foods in boiling oil in unventilated kitchens. About 25 percent of women's bedrooms were adjacent to the kitchen.

　　However, local women were surprised to learn cooking oil fumes could lead to cancer. Some claimed they may change food preparation methods.

　　"Unless my family and I don't eat at home every day, I must stay in the kitchen to cook," said Xu Li, a 45-year-old local woman. "I know the fumes are bad for the skin, but it is the first time I heard that it can result in lung cancer. I have already started frying less."

　　Doctors said women's lung cancer had few links to personal health and physical condition, but was closely related to family cancer history, unhealthy dietary habits and weak immune systems.

　　Other experts agreed with He.

　　"Smoking is by far the biggest cause of lung cancer for men," said Dr Tan Binyong, honorary president of the Respiratory Disease Institute at Fudan University's Medical College. "It's true that second-hand smoke and cooking fumes are the main causes among women."

　　He's research also warned people not to stand near of stalls selling fried foods due to the poor quality of oils used.

　　The chance of catching lung cancer is three times higher if exposed to the fume for a long time, experts said.