Prognosis of women with pT4b breast cancer: The significance of this category in the TNM system

Abstract 

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 >2cm to 5cm was significantly worse (three-year survival: 82% vs. 51%, p<0.01). For tumors >5cm, 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 >2cm to 5cm. For tumors >5cm, 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.

Keywords: Breast cancer, TNM system, T4b/pT4b category, Prognosis