乳腺癌是女性最常见的恶性肿瘤,2002年全球乳腺癌以115万新发病例居恶性肿瘤发病数第2位,病死率居第5位[1]。乳腺癌的发生与发展是机体内外多种因素共同作用的结果。尽管乳腺癌流行病学研究已深入开展,但其病因学及发生发展的机理尚未确定,因此许多不同的危险因素被假定。现就 Breast cancer is the most common malignant tumor in women. In 2002, the number of newly diagnosed breast cancer in the world was 2.15 million, and the case fatality rate was the fifth (1). The occurrence and development of breast cancer is the result of many factors inside and outside the body. Although the epidemiological study of breast cancer has been carried out in depth, but its etiology and mechanism of occurrence and development has not been established, so many different risk factors are assumed. Now