Proliferation, lymph vessel invasion and histologic type as prognostic factors in lymph node negative breast cancer

Breast cancer is a leading cause of cancer mortality among women in the western world, second only to lung cancer. Since the mammography screening program in Norway started in 1995, 70% and more of all new breast cancers diagnosed are small tumors 2cm in diameter without signs of regional or distant metastasis. Not surprisingly, the five year relative survival is very good (87.8%). Their improvement of absolute 10% survival with adjuvant systemic chemotherapy is less substantial than that for lymph node-positive patients. Both 7 the benefits and disadvantages of this 10% survival improvement must be considered when deliberating adjuvant systemic therapy (1, 2) and prognostic/predictive features are important in these decisions. Often, a combination of features is used in the decision making process for adjuvant systemic therapy, where tumour diameter, oestrogen receptor, grade and also age play a major role (3, 4). These guidelines identify 80% or more of all node-negative patients as high risk, although only ~15% of these patients die from metastatic disease without adjuvant treatment. This means that 65% of these patients are over-treated. On a world-wide basis, a more sensitive and specific prognosticator could therefore prevent enormous unnecessary suffering