Background: Because of the considerable heterogeneity in breast carcinoma with noninflammatory skin involvement (T4b/Stage IIIB), a revision was proposed of the TNM staging system that would classify these tumors exclusively based on their tumor size and lymph node status. In the current study, the authors evaluated how implementation of this proposal will affect Stage III noninflammatory breast cancer.
Methods: Two hundred seven patients who were classified with noninflammatory Stage III breast cancer were treated consecutively between 1990 and 1999 at the University Hospital Basel, Switzerland. To assess the extent of T4b/Stage IIIB tumors independent of the clinicopathologic feature of skin involvement, the reclassification was undertaken.
Results: Of 68 patients who had nonmetastatic T4b breast cancer, 37 patients (54.4%) had a tumor extent in accordance with Stage I/II and had improved disease-specific survival (DSS) compared with patients who had Stage III breast cancer (P = .008). Excluding those patients from Stage III led to a 17.9% reduction of the number of patients in this group (n = 170 patients). The 10-year DSS declined from 48.5% to 42.9%.
Conclusions: Considerable numbers of patients who are classified with noninflammatory Stage IIIB breast cancer show only a limited disease extent. Through a revision of the T4 category, these low-risk patients were excluded from the highest nonmetastatic TNM stage, and overstaging could be avoided. This procedure decreased the degree of heterogeneity of the entire Stage III group and may result in a more precise assessment of this disease entity.
Copyright 2006 American Cancer Society.