Prediction of Axillary Lymph Node Metastases in a Screened Breast Cancer Population

To define a subgroup of patients, in whom axillary dissection could be omitted, we analysed the frequency of pathologically confirmed lymph node metastases depending on tumour size, hormonal receptors, DNA ploidy, S-phase fraction (SPF), and clincial nodal status among 1 145 patients with stage I-II breast cancer from an area with ongoing screening. Clinical nodal status and tumour size were strongly correlated to pathological nodal status. Also SPF > 10% was strongly correlated to node positivity in univariate analysis. In multivariate analysis there was still a significant correlation among cases with tumour size ≤ 20 mm. In conclusion, patients with clincially negative nodal status, and tumour size ≤ 20 mm and ≤ 10 mm had pathologically positive nodes in 25% and 15% of cases respectively. The addition of SPF did not lower these figures significantly since small tumours with high SPF are few.