Breast cancer is up 31 percent in the financial hub of Shanghai over the past decade, and 23 percent in the capital, Beijing, according to data from the Beijing Center for Disease Control and Prevention cited by the China Daily.
"Unhealthy lifestyles are mostly to blame for the growing numbers," the paper quoted Qiao Youlin, a cancer researcher at the Chinese Academy of Medical Sciences, as saying.
"Chinese women, especially those living in cities, should pay extra attention to their health and examine their breasts for any suspicious lumps on a monthly basis," he said.
Breast cancer now affects about 45 women out of every 100,000 in Beijing and about 55 out of 100,000 in Shanghai.
Those numbers still remain far lower than in industrialised countries such as the United States.
Qiao advised women to avoid known risk factors such as smoking, drinking alcohol, using cosmetics that contain estrogen and consumption of oily food, and urged them to get more exercise.
Although nutrition for millions of Chinese has improved as incomes have risen, diet-related health problems also have spiked due to increasingly sedentary lifestyles and growing consumption of western-style fatty foods.