Red clover isoflavones are safe and well tolerated in women with a family history of breast cancer.

OBJECTIVE: To assess the safety and tolerability of a standardized 40 mg red clover isoflavone dietary supplement (Promensil, Novogen) in women with a family history of breast cancer to evaluate the feasibility of using the supplement for prevention of breast cancer in healthy women. STUDY DESIGN: Healthy women aged 35-70 years (n = 401) with at least one first-degree relative with breast cancer received red clover isoflavones or placebo for three years in a randomized, double-blind, placebo-controlled pilot trial. Participants were assessed clinically and blood samples taken for biochemical analysis every six months. In addition, study participants underwent mammography, bone density and transvaginal ultrasound (postmenopausal women only) once per year. RESULTS: No significant differences in breast density, endometrial thickness, serum cholesterol, follicle stimulating hormone levels and bone mineral density were detected between those taking red clover isoflavones and placebo. In postmenopausal women, some significant differences in bone marker levels were seen between active and placebo groups, at six months and at 12 months. The adverse event profile was similar across all red clover isoflavone and placebo groups. CONCLUSION: This three-year study supports the growing body of evidence that treatment with red clover isoflavones is safe and well tolerated in healthy women. Supplements containing red clover isoflavones did not adversely affect breast density, skeletal strength or cardiovascular status. In postmenopausal women, endometrial status was not adversely affected. The adverse event profile was similar between red clover isoflavones, and placebo and endocrine status did not differ.

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. The primary outcome was occurrence of invasive breast cancer. A secondary planned analysis of estrogen receptor (ER)-positive invasive breast cancer was also done. Survival was assessed by use of a Cox proportional hazards model in both univariate and multivariable analyses. The durability of the treatment effect was assessed by use of a Cox regression analysis. All statistical tests were two-sided. RESULTS: Among the 2471 eligible participants (1238 participants in the tamoxifen arm and 1233 participants in the placebo arm), 186 developed invasive breast cancer (82 on tamoxifen and 104 on placebo; hazard ratio [HR] = 0.78, 95% confidence interval [CI] = 0.58 to 1.04; P = .1). Of these 186 cancers, 139 were ER positive (53 on tamoxifen and 86 on placebo; HR = 0.61, 95% CI = 0.43 to 0.86; P = .005). The risk of ER-positive breast cancer was not statistically significantly lower in the tamoxifen arm than in the placebo arm during the 8-year treatment period (30 cancers in the tamoxifen arm and 39 in the placebo arm; HR = 0.77, 95% CI = 0.48 to 1.23; P = .3) but was statistically significantly lower in the posttreatment period (23 in the tamoxifen arm and 47 in the placebo arm; HR = 0.48, 95% CI = 0.29 to 0.79; P = .004). Fifty-four participants in each arm have died from any cause (HR = 0.99, 95% CI = 0.68 to 1.44; P = .95). The adverse event profiles for both arms were similar to those previously reported and occurred predominantly during the treatment period. CONCLUSIONS: A statistically significant reduction in the incidence of ER-positive breast cancer was observed in the tamoxifen arm that occurred predominantly during the post treatment follow-up, indicating long-term prevention of estrogen-dependent breast cancer by tamoxifen.

BRCA1/BRCA2 mutation status and analysis of cancer family history in participants of the Royal Marsden Hospital tamoxifen chemoprevention trial.

We have analysed the pedigrees of all 70 women who developed cancer in the Royal Marsden Hospital (RMH) tamoxifen chemoprevention trial, using the Claus model, to assess breast cancer susceptibility heterozygote risk (HR) and screened the entire coding regions of BRCA1 and 2 genes in 62 of these cases. We found a reduced incidence of breast cancers developing on tamoxifen in women who have a lower HR, but not in women with higher HR. There were too few BRCA1/2 mutations (4 cases) to be able to determine the efficacy of tamoxifen by BRCA status. Immunohistochemical analysis showed a significantly lower frequency of median ER (p=0.03) in the cancers developing in tamoxifen-treated patients. These results suggest that tamoxifen is less likely to be effective at reducing breast cancers which are ER negative and also in some individuals at higher HR.

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. All patients were assessed for bone metastases at two and five years and additionally when clinically indicated. Survival status was determined as of the close of the study on 30 June 2000 with a median follow up of 5.6 years. The treatment arms were compared using the unstratified log-rank test. Hazard ratios (HRs) with 95% confidence intervals were calculated. RESULTS: Oral clodronate significantly reduced the risk of bone metastases in all patients over the 5 year study period (51 patients versus 73 patients with placebo; HR = 0.692, P = 0.043); the difference was also statistically significant over the 2 year medication period (19 patients versus 35 patients with placebo; HR = 0.546, P = 0.031). These differences were most pronounced in patients with stage II/III disease (39 patients versus 64 patients with placebo, HR = 0.592, P = 0.009 over 5 years; 16 patients versus 32 patients with placebo, HR= 0.496, P = 0.020 over 2 years). Survival data also favoured the clodronate arm (HR for all patients = 0.768, P = 0.048; HR for stage II/III disease = 0.743, P = 0.041), although this was not significant due to multiple analyses. Oral clodronate was well tolerated, with mild-to-moderate diarrhoea being the most frequently reported adverse event. CONCLUSION: These results confirm that oral clodronate will significantly improve the 5 year bone relapse free survival when used as a supplementary adjuvant treatment for patients receiving standard treatment for primary operable breast cancer.

Randomized, placebo-controlled trial of clodronate in patients with primary operable breast cancer.

PURPOSE: The development of bone metastases depends on tumor-induced osteoclastic resorption of bone, which may be inhibited by the antiosteolytic bisphosphonate clodronate. Given to patients with primary breast cancer, clodronate might reduce the subsequent incidence of bone metastases. PATIENTS AND METHODS: This double-blind, multicenter trial accrued 1,069 assessable patients with operable breast cancer between 1989 and 1995. All patients received surgery, radiotherapy, chemotherapy, and tamoxifen as required. Patients were randomized to receive oral clodronate 1,600 mg/d or a placebo for 2 years starting within 6 months of primary treatment. The primary end point was relapse in bone, analyzed on an intent-to-treat basis, during the medication period and during the total follow-up period (median follow-up, 2,007 days). Secondary end points were relapse in other sites, mortality, and toxicity. RESULTS: During the total follow-up period, there was a nonsignificant reduction in occurrence of bone metastases (clodronate, n = 63; placebo, n = 80; hazards ratio [HR], 0.77; 95% confidence interval [CI], 0.56 to 1.08; P =.127). During the medication period there was a significant reduction in the occurrence of bone metastases (clodronate, n = 12; placebo, n = 28; HR, 0.44; 95% CI, 0.22 to 0.86; P =.016). The occurrence of nonosseous metastases was similar (clodronate, n = 112; placebo, n = 128; P =.257), but there was a significant reduction in mortality (clodronate, n = 98; placebo, n = 129; P =.047) during the total follow-up period. CONCLUSION: Clodronate, given to patients with primary operable breast cancer, may reduce the occurrence of bone metastases, although this reduction was only significant during this medication period. There was a significant reduction in mortality.