The Mystery of Breast Cancer's Cause

For most of the common cancers, a major cause has been identified: smoking causes 90% of lung cancer worldwide, hepatitis viruses cause most liver cancer, H pylori bacteria causes stomach cancer, human papillomavirus causes almost all cases of cervical cancer, colon cancer is largely explained by physical activity, diet and family history. But for breast cancer, there is no smoking gun. It is almost unique among the common cancers of the world in that there is not a known major cause; the