Twenty-year follow-up of the Royal Marsden randomized, double-blinded tamoxifen breast cancer prevention trial.

Background: Several clinical trials have reported an early reduction in breast cancer incidence in healthy women using tamoxifen to reduce their risk of breast cancer but have not reported longer follow-up data for the evaluation of breast cancer prevention. We report the blinded 20-year follow-up (median follow-up = 13 years) of the Royal Marsden trial to identify any long-term prevention of breast cancer associated with tamoxifen treatment.

Methods: We randomly assigned 2494 healthy women to oral tamoxifen (20 mg/day) or placebo for 8 years.

Prevention of breast cancer using selective oestrogen receptor modulators (SERMs).

Placebo controlled trials in over 25,000 women showed that tamoxifen reduced breast cancer risk by about 40% and osteoporotic fracture risk by about 32%. Similarly placebo controlled trials in nearly 18,000 women showed that raloxifene reduced breast cancer risk by 44-72% and osteoporotic fractures risk by 30-50%. A direct comparison of tamoxifen with raloxifene showed similar risk reduction for breast cancer and osteoporotic fractures with less toxicity for raloxifene.

Reduction in bone relapse and improved survival with oral clodronate for adjuvant treatment of operable breast cancer [ISRCTN83688026].

Introduction: Experimental and clinical data show that the oral bisphosphonate clodronate (Bonefos) can inhibit tumor-induced osteoclastic bone resorption. This randomized, double-blind, placebo-controlled, multicenter trial was designed to determine if the addition of oral clodronate to standard treatment for primary operable breast cancer could reduce the subsequent occurrence of bone metastases and thereby improve overall survival.

Methods: 1,069 patients with primary operable stage I-III breast cancer were randomized to receive oral clodronate (1,600 mg/day) or placebo for 2 years, in conjunction with standard treatment for primary breast cancer including surgery, radiotherapy, adjuvant chemotherapy, and/or tamoxifen.