Rethinking TNM: breast cancer TNM classification for treatment decision-making and research.

Current classification for solid tumors is based upon characteristics of their extent. Size of the primary tumor, presence of metastatic regional lymph nodes and/or of distant metastases are the key elements for their categorization. Treatment decision-making may depend upon defined extent of disease, but it requires the knowledge of several other factors. Furthermore, effective therapeutics is less dependent upon extent of disease, biological features being increasingly instrumental for treatment choice. A new classification that integrates both requisites is proposed. The scope of this proposal is to transform the current rigid and gross categorization into a more analytical and fine tuned listing including biological variables, making staging allocation more flexible and functional for proper clinical and research needs in the present and for the future. The significant changes we propose are: