Immunohistochemical Phenotype of Breast Cancer during 25-Year Follow-up of the Royal Marsden Tamoxifen Prevention Trial.

The randomized, double-blinded Royal Marsden Tamoxifen Breast Cancer Prevention Trial in healthy high-risk women started in 1986 and is still blinded. Eligible participants (n = 2,471) were randomly assigned to tamoxifen (20 mg/d) or placebo for 8 years. Analysis in 2006 showed a 30% risk reduction of estrogen receptor (ER)-positive invasive breast cancer mostly in the posttreatment period. Biomarker analysis in this population may identify any subgroup-specific preventive effects tamoxifen. After a median follow-up of 18.4 years, 242 patients had developed invasive cancer, 134 on placebo and 108 on tamoxifen. From these, 180 tissue blocks were available and ER, progesterone receptor (PgR), Ki67, HER2, and EGFR were immunohistochemically analyzed. A 32% reduction in ER+ and PgR+ invasive cancers resulted after 8 years of treatment. Quantitative levels of ER and PgR were lower in the tamoxifen-treated group, significantly so for ER (P = 0.001). These lower ER levels were restricted to the posttreatment period (P = 0.018). Among the ER+ group, there was a similar proportional decrease in PgR+ and PgR- tumors by tamoxifen. The median levels of Ki67 were similar in both arms. The numbers of HER2-positive and EGFR-positive cancers were higher in the tamoxifen arm but not significantly so. In conclusion, the preventive effects of tamoxifen result in reduced ER-positive but not ER-negative tumors and reduced ER expression in the ER-positive cases largely confined to the posttreatment period. Overall reductions in PgR expression are explained by lower frequency of ER-positive cases. Impact on Ki67, HER2, and EGFR was modest. Cancer Prev Res; 10(3); 171-6. ©2017 AACR.

Impact of a Panel of 88 Single Nucleotide Polymorphisms on the Risk of Breast Cancer in High-Risk Women: Results From Two Randomized Tamoxifen Prevention Trials.

Purpose At least 94 common single nucleotide polymorphisms (SNPs) are associated with breast cancer. The extent to which an SNP panel can refine risk in women who receive preventive therapy has not been directly assessed previously. Materials and Methods A risk score on the basis of 88 SNPs (SNP88) was investigated in a nested case-control study of women enrolled in the International Breast Intervention Study (IBIS-I) or the Royal Marsden study. A total of 359 women who developed cancer were matched to 636 controls by age, trial, follow-up time, and treatment arm. Genotyping was done using the OncoArray. Conditional logistic regression and matched concordance indices (mC) were used to measure the performance of SNP88 alone and with other breast cancer risk factors assessed using the Tyrer-Cuzick (TC) model. Results SNP88 was predictive of breast cancer risk overall (interquartile range odds ratio [IQ-OR], 1.37; 95% CI, 1.14 to 1.66; mC, 0.55), but mainly for estrogen receptor-positive disease (IQ-OR, 1.44; 95% CI, 1.16 to 1.79; P for heterogeneity = .10) versus estrogen receptor-negative disease. However, the observed risk of SNP88 was only 46% (95% CI, 19% to 74%) of expected. No significant interaction was observed with treatment arm (placebo IQ-OR, 1.46; 95% CI, 1.13 to 1.87; tamoxifen IQ-OR, 1.25; 95% CI, 0.96 to 1.64; P for heterogeneity = .5). The predictive power was similar to the TC model (IQ-OR, 1.45; 95% CI, 1.21 to 1.73; mC, 0.55), but SNP88 was independent of TC (Spearman rank-order correlation, 0.012; P = .7), and when combined multiplicatively, a substantial improvement was seen (IQ-OR, 1.64; 95% CI, 1.36 to 1.97; mC, 0.60). Conclusion A polygenic risk score may be used to refine risk from the TC or similar models in women who are at an elevated risk of breast cancer and considering preventive therapy. Recalibration may be necessary for accurate risk assessment.

Relationship of ZNF423 and CTSO with breast cancer risk in two randomised tamoxifen prevention trials.

A case-control study from two randomised breast cancer prevention trials of tamoxifen and raloxifene (P-1 and P-2) identified single-nucleotide polymorphisms (SNPs) in or near genes ZNF423 and CTSO as factors which predict which women will derive most anti-cancer benefit from selective oestrogen receptor modulator (SERM) therapy. In this article, we further examine this question using blood samples from two randomised tamoxifen prevention trials: the International Breast Cancer Intervention Study I (IBIS-I) and the Royal Marsden trial (Marsden). A nested case-control study was designed with 2:1 matching in IBIS-I and 1:1 matching in Marsden. The OncoArray was used for genotyping and included two SNPs previously identified (rs8060157 in ZNF423 and rs10030044 near CTSO), and 102 further SNPs within the same regions. Overall, there were 369 cases and 662 controls, with 148 cases and 268 controls from the tamoxifen arms. Odds ratios were estimated by conditional logistic regression, with Wald 95 % confidence intervals. In the tamoxifen arms, the per-allele odds ratio for rs8060157 was 0.99 (95 %CI 0.73-1.34) and 1.00 (95 %CI 0.76-1.33) for rs10030044. In the placebo arm, the odds ratio was 1.10 (95 %CI 0.87-1.40) for rs8060157 and 1.01 (95 %CI 0.79-1.29) for rs10030044. There was no evidence to suggest that other SNPs in the surrounding regions of these SNPs might predict response to tamoxifen. Results from these two prevention trials do not support the earlier findings. rs8060157 in ZNF423 and rs10030044 near CTSO do not appear to predict response to tamoxifen.

Breast cancer incidence in postmenopausal women with osteoporosis or low bone mass using arzoxifene.

The Generations trial, a multicenter, placebo-controlled, double-blind trial, compared arzoxifene 20 mg/day and placebo in 9,354 postmenopausal women with osteoporosis (N=5,252) or low bone mass (N=4,102). Primary outcomes were vertebral fracture in the osteoporotic population and invasive breast cancer in all study participants. Here, we report the detailed breast cancer findings from the trial. Breast cancers were detected by annual mammograms and clinical examination. After 48 months follow-up, breast cancer incidence was compared between treatment groups by estrogen receptor (ER) and progesterone receptor (PR) status and baseline risk factors. Baseline breast cancer risk factors, including age, estimated Gail risk, and bone mineral density, were well balanced between treatment groups. A total of 75 breast cancers occurred 53 in the placebo group and 22 in the arzoxifene group (HR 0.41, 95% CI 0.25-0.68, P<0.001). There were 62 invasive breast cancers, 39 identified as invasive ER-positive (placebo 30, arzoxifene 9; HR 0.30, 95% CI 0.14-0.63, P=0.001) and 30 identified as invasive PR-positive (placebo 23, arzoxifene 7; HR 0.30, 95% CI 0.13-0.71, P=0.003). Breast cancer risk reduction with arzoxifene was similar between Gail risk groups (P interaction=0.31) and between low bone mass and osteoporosis groups (P interaction=0.35). Although generally well tolerated, there was a significant increase in venous thromboembolism, vasomotor symptoms, muscle cramps, and some gynecological events with arzoxifene. These findings demonstrate that in this study arzoxifene reduced the risk of ER-positive breast cancer in this population of postmenopausal women with low bone mass or osteoporosis, an effect similar to that seen with other SERMs.

Prevention of breast cancer using SERMs.

The development of breast cancer is dependant in part on oestrogen. Suppression of ovarian function or use of anti-oestrogens will reduce the incidence of breast cancer. Many trials have now been done involving tens of thousands of healthy women evaluating the use of selective oestrogen receptor modulators to reduce the risk of breast cancer in healthy women. Tamoxifen will reduce the early incidence of breast cancer in pre and postmenopausal women by about 40% but causes vasomotor symptoms, thromboembolism and gynaecological toxicity including polyps, endometrial atypia and rarely cancer. In long follow up trials the risk reduction for breast cancer extends beyond the treatment period out to at least 15 years appearing to get larger with time indicating a true long term prevention effect. The toxicity of tamoxifen is for the most part confined to the treatment period. Raloxifene also has similar breast cancer risk reduction activity to tamoxifen but has less toxicity with no evidence of an increased risk of endometrial atypia or cancer. Tamoxifen is licensed for breast cancer risk reduction in the USA and raloxifene has also recently been approved by the FDA for such use.

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.

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.

Advances in treating metastatic bone cancer: summary statement for the First Cambridge Conference.

The First Cambridge Conference on Advances in Treating Metastatic Bone Cancer, a symposium held in Cambridge, Massachusetts, October 28 to 29, 2005, was convened to discuss recent advances and research related to the natural history of bone metastases and skeletal complications, bone cancer biology, treatment of myeloma and other solid tumors, and treatment-induced bone loss. The conference format combined brief presentations with extended periods of discussion. The conclusions reached during the 2-day meeting are summarized in this article and presented in more detail in the individual articles and accompanying discussion sessions that comprise the conference proceedings.

The effect of the stromal component of breast tumours on prediction of clinical outcome using gene expression microarray analysis.

INTRODUCTION: The aim of this study was to examine the effect of the cellular composition of biopsies on the error rates of multigene predictors of response of breast tumours to neoadjuvant adriamycin and cyclophosphamide (AC) chemotherapy. MATERIALS AND METHODS: Core biopsies were taken from primary breast tumours of 43 patients prior to AC, and subsequent clinical response was recorded. Post-chemotherapy (day 21) samples were available for 16 of these samples. Frozen sections of each core were used to estimate the proportion of invasive cancer and other tissue components at three levels. Transcriptional profiling was performed using a cDNA array containing 4,600 elements. RESULTS: Twenty-three (53%) patients demonstrated a 'good' and 20 (47%) a 'poor' clinical response. The percentage invasive tumour in core biopsies collected from these patients varied markedly. Despite this, agglomerative clustering of sample expression profiles showed that almost all biopsies from the same tumour aggregated as nearest neighbours. SAM (significance analysis of microarrays) regression analysis identified 144 genes which distinguished high- and low-percentage invasive tumour biopsies at a false discovery rate of not more than 5%. The misclassification error of prediction of clinical response using microarray data from pre-treatment biopsies (on leave-one-out cross-validation) was 28%. When prediction was performed on subsets of samples which were more homogeneous in their proportions of malignant and stromal cells, the misclassification error was considerably lower (8%-13%, p < 0.05 on permutation). CONCLUSION: The non-tumour content of breast cancer samples has a significant effect on gene expression profiles. Consideration of this factor improves accuracy of response prediction by expression array profiling. Future gene expression array prediction studies should be planned taking this into account.

Tamoxifen-induced anorexia is associated with fatty acid synthase inhibition in the ventromedial nucleus of the hypothalamus and accumulation of malonyl-CoA.

Fatty acid metabolism in the hypothalamus has recently been shown to regulate feeding. The selective estrogen receptor modulator tamoxifen (TMX) exerts a potent anorectic effect. Here, we show that the anorectic effect of TMX is associated with the accumulation of malonyl-CoA in the hypothalamus and inhibition of fatty acid synthase (FAS) expression specifically in the ventromedial nucleus of the hypothalamus (VMN). Furthermore, we demonstrate that FAS mRNA expression is physiologically regulated by fasting and refeeding in the VMN but not in other hypothalamic nuclei. Thus, the VMN appears to be the hypothalamic site where regulation of FAS and feeding converge. Supporting the potential clinical relevance of these observations, reanalysis of a primary breast cancer prevention study showed that obese women treated with TMX gained significantly less body weight over a 6-year period than obese women given placebo. The finding that TMX can modulate appetite through alterations in FAS expression and malonyl-CoA levels suggests a link between hypothalamic sex steroid receptors, fatty acid metabolism, and feeding behavior.

American Society of Clinical Oncology technology assessment on the use of aromatase inhibitors as adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer: status report 2004.

PURPOSE: To update the 2003 American Society of Clinical Oncology technology assessment on adjuvant use of aromatase inhibitors. RECOMMENDATIONS: Based on results from multiple large randomized trials, adjuvant therapy for postmenopausal women with hormone receptor-positive breast cancer should include an aromatase inhibitor in order to lower the risk of tumor recurrence. Neither the optimal timing nor duration of aromatase inhibitor therapy is established. Aromatase inhibitors are appropriate as initial treatment for women with contraindications to tamoxifen. For all other postmenopausal women, treatment options include 5 years of aromatase inhibitors treatment or sequential therapy consisting of tamoxifen (for either 2 to 3 years or 5 years) followed by aromatase inhibitors for 2 to 3, or 5 years. Patients intolerant of aromatase inhibitors should receive tamoxifen. There are no data on the use of tamoxifen after an aromatase inhibitor in the adjuvant setting. Women with hormone receptor-negative tumors should not receive adjuvant endocrine therapy. The role of other biomarkers such as progesterone receptor and HER2 status in selecting optimal endocrine therapy remains controversial. Aromatase inhibitors are contraindicated in premenopausal women; there are limited data concerning their role in women with treatment-related amenorrhea. The side effect profiles of tamoxifen and aromatase inhibitors differ. The late consequences of aromatase inhibitor therapy, including osteoporosis, are not well characterized. CONCLUSION: The Panel believes that optimal adjuvant hormonal therapy for a postmenopausal woman with receptor-positive breast cancer includes an aromatase inhibitor as initial therapy or after treatment with tamoxifen. Women with breast cancer and their physicians must weigh the risks and benefits of all therapeutic options.

Continuing outcomes relevant to Evista: breast cancer incidence in postmenopausal osteoporotic women in a randomized trial of raloxifene.

BACKGROUND: The randomized, double-blind Multiple Outcomes of Raloxifene Evaluation (MORE) trial found that 4 years of raloxifene therapy decreased the incidence of invasive breast cancer among postmenopausal women with osteoporosis by 72% compared with placebo. We conducted the Continuing Outcomes Relevant to Evista (CORE) trial to examine the effect of 4 additional years of raloxifene therapy on the incidence of invasive breast cancer in women in MORE who agreed to continue in CORE. METHODS: Women who had been randomly assigned to receive raloxifene (either 60 or 120 mg/day) in MORE were assigned to receive raloxifene (60 mg/day) in CORE (n = 3510), and women who had been assigned to receive placebo in MORE continued on placebo in CORE (n = 1703). Breast cancer incidence was analyzed by a log-rank test, and a Cox proportional hazards model was used to compute hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: During the CORE trial, the 4-year incidences of invasive breast cancer and estrogen receptor (ER)-positive invasive breast cancer were reduced by 59% (HR = 0.41; 95% CI = 0.24 to 0.71) and 66% (HR = 0.34; 95% CI = 0.18 to 0.66), respectively, in the raloxifene group compared with the placebo group. There was no difference between the two groups in incidence of ER-negative invasive breast cancer during CORE (P = .86). Over the 8 years of both trials, the incidences of invasive breast cancer and ER-positive invasive breast cancer were reduced by 66% (HR = 0.34; 95% CI = 0.22 to 0.50) and 76% (HR = 0.24; 95% CI = 0.15 to 0.40), respectively, in the raloxifene group compared with the placebo group. During the CORE trial, the relative risk of thromboembolism in the raloxifene group compared with that in the placebo group was 2.17 (95% CI = 0.83 to 5.70). This increased risk, also observed in the MORE trial, persisted over the 8 years of both trials. CONCLUSIONS: The reduction in invasive breast cancer incidence continues beyond 4 years of raloxifene treatment in postmenopausal women with osteoporosis. No new safety concerns related to raloxifene therapy were identified during CORE.