Prognostic factors in primary breast cancer

Approximately 25% of women with node-negative breast cancer treated with surgery alone eventually experience a relapse of their disease. Survival in this group of patients correlates with the level of estrogen-receptors and inversely with the size of the primary tumor. Moreover, the rate of tumor growth, as determined either clinically or by using in vitro techniques, such as thymidine-labeling and flow cytometric measurements of DNA content, can be used to identify patients with node-negative breast cancer who have a high probability of recurrence. Based on such an analysis, the subset of patients with slow growing cancers may be spared adjuvant cytotoxic therapy. On the other hand, a rapid tumor growth rate predicts for a higher than usual chance of relapse among patients with node-positive breast cancer. Therefore, this subset of women may benefit from more prolonged and/or intensive adjuvant chemotherapy than is currently recommended. Finally, ongoing studies of structural or functional disturbances of proto-oncogenes in breast cancer can be expected to provide practitioners with additional prognostic indicators that will lead to further improvements in the management of this group of diseases in the near future.