肺癌(原发性)是肺内最常见的恶性肿癌。近年来,我国肺癌发生率和病死率呈明显上升趋势。据统计,肺癌发病率城市比农村高,大城市比小城市高,市区比郊区高,内地比沿海高,工业发达地区比不发达地区高,原因很简单,是废气和致癌物污染大气造成的。其预防方法主要有:戒烟这一点已是人 Lung cancer (primary) is the most common malignant tumor of the lung. In recent years, the incidence of lung cancer and mortality in China have shown a clear upward trend. According to statistics, the incidence of lung cancer in urban areas is higher than in rural areas. Big cities are taller than small cities, urban areas are higher than suburbs, and the mainland is higher than coastal areas. Industrially developed areas are higher than underdeveloped regions. The reason is simple. It is caused by exhaust gas and carcinogens polluting the atmosphere. of. The main methods of prevention are: quitting smoking is already a human