Investigation of primary tamoxifen therapy for elderly patients with operable breast cancer

Tamoxifen therapy in elderly patients (> 70 years) with operable breast cancer has been investigated by two trials in our unit. The first compared tamoxifen with surgery alone: 62% patients eventually failed tamoxifen, 47% required surgery. But 37% had control of the primary tumour with tamoxifen alone for over 5 years. To identify those with a long-term response to tamoxifen a second trial included cases with high oestrogen receptor (ER) content. Patients were randomized to tamoxifen 20 mg daily (n = 94) or mastectomy and adjuvant tamoxifen (n = 53). Only 3% of patients initially progressed on tamoxifen, compared to 26% in the first trial. In the second trial at a median followup of 3 years, 32% of patients receiving tamoxifen had developed local relapse, but only 16% needed surgery. Patients with static disease after 6 months on tamoxifen had a significantly shorter duration of control and were more likely to require mastectomy compared to partial or complete responders. To select patients with long-term control of the primary tumour with tamoxifen we propose a two stage selection where cases with low ER are excluded, and those with static response of the primary tumour at 6 months have the tumour removed.