Biomarkers and outcome after tamoxifen treatment in node-positive breast cancers from elderly women

The predictive role of tumour proliferative rate and expression of p53, bcl -2 and bar proteins, alone and in association with tumour size, nodal invol vement and oestrogen receptors (ER), was analysed on 145 elderly patients ( greater than or equal to 70 years of age) with histologically assessed node -positive breast cancers treated with radical or conservative surgery plus radiotherapy followed by adjuvant tamoxifen fort least 1 year. The 7-year p robability of relapse was significantly higher for patients with tumours ra pidly proliferating (hazard ratio (HR) = 2.0, P = 0.01), overexpressing p53 (HR = 4.4, P = 0.0001), weakly or not exhibiting bcl-2(HR = 1.9, P = 0.02) , without ERs (HR = 3.4, P = 0.0001) or with greater than or equal to 4 pos itive lymph nodes (HR = 2.3, P = 0.003) than for patients with tumours expr essing the opposite patho-biological profile; Conversely, tumour size and b ar expression failed to influence relapse-free survival. Adjustment for the duration of tamoxifen treatment did not change these findings. Oestrogen r eceptors; cell proliferation, p53 accumulation and bcl-2 expression were al so predictive for overall survival. Within ER-positive tumours, cell prolif eration, p53 accumulation, bcl-2 expression and lymph node involvement prov ided significant and independent information for relapse and, in associatio n, identified subgroups of patients with relapse probabilities of 20% (low- risk group, exhibiting only one unfavourable factor) to 90% (high-risk grou p, exhibiting three unfavourable factors). Such data could represent the in itial framework for a biologically tailored therapy even for elderly patien ts and highlight the importance of a patho-biological characterization of t heir breast cancers. (C) 2000 Cancer Research Campaign.