Biomarker prediction of clinical outcome in operable breast cancer patients treated with tamoxifen

The predictivity of tumour size, oestrogen (ER) and progesterone (PgR) rece ptors, H-3-thymidine labelling index (TLI), c-erbB-2 and p27(kip1) expressi on on clinical outcome was analysed on a consecutive series of 118 postmeno pausal patients with ER-positive, node-positive tumours. All patients were treated with surgery +/- radiotherapy and adjuvant tamoxifen (30 mg/day) fo r at least 2 years. TLI, ER, c-erbB-2 and p27(kip1) were generally unrelate d to each other. PgR was directly related to ER and inversely to c-erbB-2. Tumour size was inversely related to both c-erbB-2 and p27(kip1) expression . At a median follow-up of 75 months, 5-year relapse-free survival was sign ificantly lower for patients with very rapidly proliferating (HR = 2.61, 95 % CI = 1.34-5.08), PgR negative (HR = 2.76, 95% CI = 1.43-5.33) or relative ly low ER content (HR = 2.20, 95% CI = 1.14-4.25) tumours than for patients with tumours expressing the opposite biological profiles. Overall survival was also significantly different as a function of TLI (HR = 3.47, 95% CI = 1.52-7.93) and PgR (HR = 2.27, 95% CI = 1.00-5.15). TLI and PgR maintained an independent relevance in multivariate analysis and together were capabl e of identifying subgroups of patients at significantly different risk of r elapse and death.