Aims: The T4b/pT4b category of the TNM System for breast cancer is discussed controversially. For a more detailed analysis, we explored the prognosis of patients with breast cancer strictly fulfilling the criteria for T4b/pT4b tumors according to the TNM System.
Methods: Retrospectively analysed data from patients with pT4b breast tumors diagnosed between January 1994 and December 2004 were collected. Reclassification was undertaken according to the TNM System criteria establishing a study group including only "correctly" classified T4b/pT4b tumors. A control group with pT1-3 carcinomas was used for analysing the prognostic value of criteria for T4b/pT4b tumors.
Results: Eighty-six patients with pT4b carcinomas were found. After reclassification, 65 remained as pT4b fulfilling the strict criteria. The study group showed a 60% three-year Disease Specific Survival (DSS). Age (p<0.01) and regional lymph node status (p<0.01) were significantly related to prognosis. Compared to the control group, the DSS in the study group of patients with a tumor size >2 cm to 5 cm was significantly worse (three-year survival: 82% vs. 51%, p<0.01). For tumors >5 cm, the DSS was not significantly different between both groups (three-year survival: 68% vs. 72%, p=0.7).
Conclusions: The criteria for T4b/pT4b breast cancer are associated with a poorer prognosis in patients with a tumor size >2 cm to 5 cm. For tumors >5 cm, prognosis is independent of T4b/pT4b criteria. These findings do not justify the demanded deletion of the T4b/pT4b category. The missing uniformity in applying the correct criteria of T4b/pT4b tumors queries the practicability of this category.