Screening and increased use of adjuvants are responsible—adjuvants more so

The survival of women who will be diagnosed with breast cancer in the United Kingdom and Europe in 2005 is significantly better than that for their counterparts diagnosed in the 1970s and ‘80s, although five year survival remains lower in Europe than in the United States (79% v 89%).1 What is known about the reasons for these differences, and what could increase survival still more?

Any improvement in survival is unlikely to be attributable to a change in the biological behaviour of breast cancer. It must reflect improvement, therefore, in diagnosing and managing breast cancer, leading to fewer distant relapses and deaths. This could be a consequence of early detection through screening or improved systemic treatment with adjuvants after surgery to eliminate micrometastases and prevent recurrence. However, screening amounts to secondary prevention rather than primary prevention. Delay in diagnosing symptomatic breast cancer is associated with inferior survival,2 but as no absolute correlation exists between the chronology and biological behaviour of breast cancer, the term early can be misleading. Even patients with small tumours which are node …