肺癌、乳腺癌、前列腺癌和结直肠癌是人类最常见的癌症。但是随着治疗技术的完善、早期诊断方式的改进和生活方式的改变,癌症患者90％以上都可以存活5年。而且,从上个世纪90年代起,这些癌症的死亡率基本上都在以每年2％的比率递减。 Lung cancer, breast cancer, prostate cancer and colorectal cancer are the most common cancers in humans. However, with the improvement of treatment technology, improvement of early diagnosis methods and lifestyle changes, more than 90% of cancer patients can survive for 5 years. Moreover, since the 1990s, the mortality rate of these cancers has been decreasing at a rate of 2% per year.