Breast carcinoma growth rate described by mammographic doubling time and S-phase fraction. Correlations to clinical and histopathologic factors in a screened population.

Abstract

In a retrospective study, correlations among mammographic doubling times (DT), clinicopathologic prognostic factors, and cytometric predictors were examined. One hundred fifty-eight patients with the possibility to calculate mammographic tumor DT were selected and the tumors were histologically reexamined and flow cytometric analysis for ploidy and S-phase fraction (SPF) was performed. The tumors were Stage I in 68%, and 45% were detected by mammographic screening. DT ranged from 0.6 months to an indefinite time (median, 9.0 months). Short DT was significantly correlated to large tumor size (P = 0.01) and advanced pathologic tumor stage (P = 0.016), but there was no correlation between DT and histologic grade. Ploidy analysis indicated that there were 57% aneuploid and 7% tetraploid tumors. There was a significant overrepresentation of euploid tumors among tumors smaller than 10 mm (P = 0.02). Ploidy was correlated to histologic grade (P less than 0.001) and DT (P = 0.009). SPF was calculated in 122 cases. SPF correlated significantly with pathologic stage (P = 0.002), tumor size (P = 0.037), histologic grade (P = 0.001), the presence of axillary lymph node metastases (P = 0.046), DT (P = 0.02), and DNA ploidy (P less than 0.001). Compared with interval carcinoma, screening-detected carcinoma showed favorable characteristics concerning size, stage, DT, ploidy, and SPF but not regarding histologic grade and axillary lymph node metastases. DT shows great variations. Factors related to tumor biology (i.e., DT, DNA ploidy, and SPF) are strongly correlated with one another, but they have no correlation with axillary lymph node metastases. Cancer detected by screening is discovered at an early stage and shows favorable characteristics concerning DT, ploidy, and SPF.