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Mitch Dowsett

Publications and source records attributed to Mitch Dowsett.

At least 19 recordsLinked to original sources
PubMed2007

Prognostic value of Ki67 expression after short-term presurgical endocrine therapy for primary breast cancer.

Tumor expression of the proliferation antigen Ki67 is widely used to assess the prognosis of cancer patients. A change in the expression of Ki67 after short-term exposure of patients to therapeutic agents is frequently used as a pharmacodynamic marker of efficacy, particularly among breast cancer patients before undergoing surgery. To determine the clinical significance of the level of tumor cell proliferation during endocrine therapy for breast cancer, we measured the expression of Ki67 in tumor biopsy samples taken before and after 2 weeks of presurgical treatment with anastrozole or tamoxifen or the combination of anastrozole plus tamoxifen in 158 patients with hormone receptor-positive primary disease. In a multivariable analysis, we found that higher Ki67 expression after 2 weeks of endocrine therapy was statistically significantly associated with lower recurrence-free survival (P = .004) whereas higher Ki67 expression at baseline was not. Larger baseline tumor size and lower estrogen receptor level after 2 weeks of treatment were also statistically significantly associated with poorer recurrence-free survival (P < .001 and P = .04, respectively). Our data indicate that measurements of tumor Ki67 level after short-term endocrine treatment may improve the prediction of recurrence-free survival by integrating the prognostic value of Ki67 level at baseline with changes in Ki67 level that are associated with treatment benefit.

Adult↗
PubMed2007

2-year follow-up of trastuzumab after adjuvant chemotherapy in HER2-positive breast cancer: a randomised controlled trial.

BACKGROUND: Trastuzumab--a humanised monoclonal antibody against HER2--has been shown to improve disease-free survival after chemotherapy in women with HER2-positive early breast cancer. We investigated the drug's effect on overall survival after a median follow-up of 2 years in the Herceptin Adjuvant (HERA) study. METHODS: HERA is an international multicentre randomised trial that compared 1 or 2 years of trastuzumab treatment with observation alone after standard neoadjuvant or adjuvant chemotherapy in women with HER2-positive node positive or high-risk node negative breast cancer. 5102 women participated in the trial; we analysed data from 1703 women who had been randomised for treatment with trastuzumab for 1 year and 1698 women from the control group, with median follow-up of 23.5 months (range 0-48 months). The primary endpoint of the trial was disease-free survival. Here, we assess overall survival, a secondary endpoint. Analyses were done on an intent-to-treat basis. This trial is registered with the European Clinical Trials Database, number 2005-002385-11. FINDINGS: 97 (5.7%) patients randomised to observation alone and 58 (3.4%) patients randomised to 1 year of treatment with trastuzumab were lost to follow-up. 172 women stopped trastuzumab prematurely. 59 deaths were reported for trastuzumab and 90 in the control group. The unadjusted hazard ratio (HR) for the risk of death with trastuzumab compared with observation alone was 0.66 (95% CI 0.47-0.91; p=0.0115). 218 disease-free survival events were reported with trastuzumab compared with 321 in the control group. The unadjusted HR for the risk of an event with trastuzumab compared with observation alone was 0.64 (0.54-0.76; p<0.0001). INTERPRETATION: Our results show that 1 year of treatment with trastuzumab after adjuvant chemotherapy has a significant overall survival benefit after a median follow-up of 2 years. The emergence of this benefit after only 2 years reinforces the importance of trastuzumab in the treatment of women with HER2-positive early breast cancer.

Adult↗
PubMed2007

Evaluation of Phi29-based whole-genome amplification for microarray-based comparative genomic hybridisation.

For the optimal performance of high throughput genomic technologies sufficient yields of high-quality DNA are crucial. Following microdissection, most samples fail to produce sufficient quantities of DNA for genome-wide experiments. Various PCR-based amplification methods have been used, but these usually produce nonuniform representations of the genome. Bacteriophage Phi29 DNA polymerase random-primed DNA amplification is based on isothermal multiple displacement amplification. We sought to define the genome representation of this method in a bacterial artificial chromosome microarray comparative genomic hybridisation (aCGH) platform. Test genomic female DNA was amplified using Phi29 amplification at four different starting concentrations (0.5, 5, 10 and 50 ng). These products were combined with unamplified and amplified genomic female DNA as reference. In addition, 50 ng of DNA from five microdissected breast cancer frozen samples, were amplified using the same method. Three combinations were performed: unamplified test with unamplified reference, amplified test with unamplified reference and both amplified tumour and reference DNA. aCGH was performed with an in-house 16 K BAC platform (a resolution of approximately 100 Kb). Pearson's correlation tests and hierarchical clustering were performed to compare the profiles obtained. aCGH profiles obtained with amplified test and unamplified reference female genomic DNA showed copy number biases throughout the genome. These biases were more conspicuous with smaller amounts of starting material and mapped to regions of known copy number polymorphisms. When similar concentrations of test and reference DNA were amplified, the biases were significantly reduced, rendering accurate profiles. For the tumours, representative profiles were obtained when both test and reference DNA were amplified. Phi29 amplification induces copy number biases and unamplified material remains the gold standard for copy number analysis. For accurate results using Phi29 amplification, samples subjected to aCGH analysis should be combined with reference DNA amplified with the same method, using similar amounts of starting template.

Breast Neoplasms↗
PubMed2006

Influences on circulating oestrogens in postmenopausal women: relationship with breast cancer.

Sex hormones are intrinsically linked to the development and treatment of the majority of breast cancers. High oestradiol levels are associated with elevated breast cancer risk in the postmenopausal setting and are given increasing importance in determining chemoprevention target groups. This review aims to evaluate the impact of various lifestyle factors including body mass index, diet, smoking, and alcohol on normal physiological sex hormone profiles. The role of genetic polymorphisms is also discussed, and all are placed within the context of designing future epidemiological studies and breast cancer risk algorithms.

Breast Neoplasms↗
PubMed2006

The relationship between factors affecting endogenous oestradiol levels in postmenopausal women and breast cancer.

Breast cancer accounts for 1 in 4 of all female cancers worldwide; approaching 13,000 women dying per year in the UK alone. Seventy five per cent of all diagnosed breast cancers are oestrogen receptor (ER) positive. Ovarian synthesis of oestrogens ceases at menopause and as breast cancer is more prevalent in postmenopausal women the non-ovarian sources of oestrogen are important in disease progression. There is now considerable evidence that associates increased breast cancer risk with prolonged exposure to oestrogens hence greater attention is now being given to determining whether the measurement of plasma oestrogen may assist in identifying chemoprevention target groups. Studies suggest that in most postmenopausal patients the intra-tumoural concentrations of oestrogens are up to 20-fold higher than those present in the plasma however, while the extent of biosynthesis of oestrogens within breast tissue is a major determinant of local exposure, plasma levels are a useful indicator of overall metabolism in peripheral tissues. As such it is important to understand factors that influence these measurements. This review summarises the impact of lifestyle such as body mass index, together with the role of genetic polymorphisms placed within the context of designing future epidemiological studies and breast cancer risk algorithms.

Animals↗
PubMed2006

Endogenous steroid hormone concentrations and risk of breast cancer among premenopausal women.

BACKGROUND: Higher levels of endogenous sex steroid hormones are associated with increased risks of breast cancer in postmenopausal women. Data for premenopausal women are sparse, in part because of the complexity of measuring hormone levels that vary cyclically. We prospectively evaluated associations between plasma sex hormone levels and breast cancer risk among premenopausal women in a case-control study nested within the Nurses' Health Study II. METHODS: From 1996 to 1999, blood samples were collected from 18,521 premenopausal women during the early follicular and midluteal phases of their menstrual cycles. A total of 197 cases of breast cancer were diagnosed among these women after blood collection and before June 1, 2003; these case subjects were matched to 394 control subjects. Logistic regression models, controlling for breast cancer risk factors, were used to calculate relative risks (RRs) and 95% confidence intervals (CIs). All statistical tests were two-sided. RESULTS: Women in the highest (versus the lowest) quartiles of follicular total and free estradiol levels had statistically significantly increased risks of breast cancer (RR = 2.1 [95% CI = 1.1 to 4.1], P(trend) = .08, and RR = 2.4 [95% CI = 1.3 to 4.5], P(trend) = .01, respectively); the associations were stronger for invasive breast cancer and for estrogen and progesterone receptor-positive (ER+/PR+) tumors. Luteal estradiol levels were not associated with breast cancer risk. Higher levels of total and free testosterone and androstenedione in both menstrual cycle phases were associated with modest, non-statistically significant increases in overall risk of breast cancer and with stronger, statistically significant increases in risks of invasive and ER+/PR+ cancers (e.g., RR of invasive cancers for the top [versus bottom] quartile of luteal total testosterone levels = 2.0 [95% CI = 1.1 to 3.6], P(trend) = .05, and RR of ER+/PR+ cancers = 2.9 [95% CI = 1.4 to 6.0], P(trend) = .02). Levels of estrone, estrone sulfate, progesterone, and sex hormone-binding globulin were not associated with breast cancer risk. The absolute number of cases observed over 3 years were 30 among women in the lowest 25% of follicular total estradiol levels and 50 among women in the highest 25%. CONCLUSIONS: Levels of circulating estrogens and androgens may be important in the etiology of premenopausal breast cancer.

Adult↗
PubMed2006

Implications of gene-environment interaction in studies of gene variants in breast cancer: an example of dietary isoflavones and the D356N polymorphism in the sex hormone-binding globulin gene.

Studies to identify common genetic variants contributing to breast cancer risk often yield inconsistent results. Breast cancer is a complex disease involving both genetic and environmental determinants. Dietary isoflavones are thought to reduce breast cancer risk by stimulating circulating sex hormone-binding globulin (SHBG) levels. The SHBG gene contains a D356N polymorphism and the N variant is associated with reduced SHBG clearance compared with the D variant. In this study, we show a significant gene-environment interaction between SHBG D356N polymorphism and dietary isoflavone exposure on circulating SHBG levels in 1,988 postmenopausal women. SHBG levels were positively associated with isoflavones in women carrying the N variant (etap2 = 1.9%; P = 0.006) but not in women carrying only the D variant (etap2 = 0.0%; P = 0.999; P(interaction) = 0.019). This finding shows that the subtle effects of some genetic variants may be magnified and only become detectable in the presence of certain exposures. This gene-environment interaction might explain heterogeneity in studies associating SHBG gene variants and soy consumption with breast cancer risk in Far East population exposed to high isoflavone levels compared with populations with lower levels.

Aromatase↗
PubMed2006

Comparison of methods to measure low serum estradiol levels in postmenopausal women.

CONTEXT: Accurate measurement of low serum estradiol (E(2) < 30 pg/ml or < 110 pmol/liter) is needed to study relationships between endogenous E(2) and risks of diseases in older women. OBJECTIVE: The objective of this study was to determine whether an extraction-based (indirect) assay or a non-extraction-based (direct) assay correlates better with mass spectrometry and body mass index (BMI). DESIGN/SETTING: In a pilot study of 40 postmenopausal women, endogenous E(2) measurements from three indirect and four direct assay methods and gas chromatography-tandem mass spectrometry (GC-MS/MS) were compared. A confirmatory study compared an indirect and a direct assay, selected among those in the pilot study, to GC-MS/MS; this study was conducted in 374 postmenopausal women not taking hormone therapy from the Ultra Low-dose TRansdermal estrogen Assessment (ULTRA) trial. MAIN OUTCOMES: Pearson correlation coefficients among E(2) measurements by assay methods and BMI, and their confidence intervals, by bias-corrected bootstrap method, were used. RESULTS: In the pilot study, E(2) by three indirect assays correlated better (P < 0.03) with GC-MS/MS and with BMI than measurements by four direct assays. In the confirmatory study, the indirect assay correlated better (P < 0.01) with GC-MS/MS and BMI than the direct assay. Measurements by the indirect and direct assays were overestimated, but deviations in direct assay measurements were less precise. Mean E(2) by the indirect and direct assays were higher (by 14 and 68%, respectively) and less reproducible than by GC-MS/MS. CONCLUSION: Until mass spectrometry is practical for wide use, extraction-based indirect assays may be preferable for measuring low postmenopausal serum E(2).

Aged↗
PubMed2006

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.

Adult↗
PubMed2006

Evaluation of Ki-67 proliferation and apoptotic index before, during and after neoadjuvant chemotherapy for primary breast cancer.

INTRODUCTION: Biological markers that reliably predict clinical or pathological response to primary systemic therapy early during a course of chemotherapy may have considerable clinical potential. This study evaluated changes in Ki-67 labeling index and apoptotic index (AI) before, during, and after neoadjuvant anthracycline chemotherapy. METHODS: Twenty-seven patients receiving neoadjuvant FEC (5-fluorouracil, epirubicin, and cyclophosphamide) chemotherapy for operable breast cancer underwent repeat core biopsy after 21 days of treatment. Tissue from pre-treatment biopsy, day 21 and surgery was analysed for Ki-67 index and AI. RESULTS: The objective clinical response rate was 56%. Eight patients (31%) achieved a pathological response by histological criteria; two patients had a near-complete pathological response. A reduction in Ki-67 index was observed in 68% of patients at day 21 and 72% at surgery; Ki-67 index increased between day 21 and surgery in 54%. AI decreased in 50% of tumours by day 21, increased in 45% and was unchanged in one patient; 56% demonstrated rebound increases in AI by the time of surgery. Neither pre-treatment nor post-chemotherapy median Ki-67 index nor median AI at all three time points or relative changes at day 21 and surgery differed significantly between clinical or pathological responders and non-responders. Clinical responders had lower median Ki-67 indices at day 21 (11.4% versus 27.0%, p = 0.02) and significantly greater percentage reductions in Ki-67 at day 21 than did non-responders (-50.6% versus -5.3%, p = 0.04). The median day-21 Ki-67 was higher in pathological responders (30.3% versus 14.1%, p = 0.046). A trend toward increased AI at day 21 in pathological responders was observed (5.30 versus 1.68, p = 0.12). Increased day-21 AI was a statistically significant predictor of pathological response (p = 0.049). A strong trend for predicting pathological response was seen with higher Ki-67 indices at day 21 and AI at surgery (p = 0.06 and 0.06, respectively). CONCLUSION: The clinical utility of early changes in biological marker expression during chemotherapy remains unclear. Until further prospectively validated evidence confirming the reliability of predictive markers is available, clinical decision-making should not be based upon individual biological tumour marker profiles.

Adult↗
PubMed2006

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.

Breast Neoplasms↗
PubMed2006

Estrogen-independent proliferation is present in estrogen-receptor HER2-positive primary breast cancer after neoadjuvant letrozole.

PURPOSE: To investigate the impact of human epidermal growth factor receptor (HER) 1 and HER2 gene amplification on endocrine therapy responsiveness, a fluorescence in situ hybridization (FISH) study was conducted on tumor samples from 305 postmenopausal patients with stage II and III estrogen receptor (ER) -positive (ER > or = 10%) breast cancers treated on two independent neoadjuvant endocrine therapy trials. PATIENTS AND METHODS: FISH analysis focused on HER1 and/or HER2 immunohistochemistry (IHC) -positive patients and a random selection of HER1/2 IHC-negative patients. HER2 FISH status was correlated with response and changes in the proliferation marker Ki67. RESULTS: HER1 was rarely amplified (< 1%), and HER2 amplification was observed in 9.2% of patients. Letrozole response by clinical measurement (71% HER2 FISH positive v 71% HER2 FISH negative), mammogram (44% HER2 FISH positive v 47% HER2 FISH negative), or ultrasound (47% HER2 FISH positive v 54% HER2 FISH negative) was not impaired by HER2 FISH-positive status. In contrast, HER2 FISH-positive tumors showed higher histologic grade (P = .009), higher pretreatment Ki67 (P = .005), and less Ki67 suppression after letrozole when compared with HER2 FISH-negative tumors (P = .0001). Similar observations regarding Ki67 were made in a smaller cohort of tamoxifen-treated tumors. CONCLUSION: Neoadjuvant letrozole is clinically effective in ER-positive HER2 FISH-positive tumors, indicating sensitivity to short-term estrogen deprivation. However, continued proliferation despite ongoing letrozole or tamoxifen treatment in the majority of ER-positive HER2 FISH-positive samples (88%) could imply therapeutic resistance that may manifest later in the clinical course of the disease. Discordance between clinical and biomarker findings in this study serves to emphasize the need for surrogate end point validation in neoadjuvant endocrine trials through correlation with information on long-term outcomes.

Aged↗
PubMed2006

Paracrine-stimulated gene expression profile favors estradiol production in breast tumors.

Paracrine interactions between adipose fibroblasts and malignant epithelial cells are essential for structural and hormonal support of breast tumors. Factors derived from malignant epithelial cells inhibit adipogenic differentiation of fibroblasts and upregulate expression of aromatase, which stimulates estrogen synthesis and creates a localized, growth-stimulatory environment. Here, we characterized the gene expression profile of breast adipose fibroblasts in an in vitro model of malignancy to identify other paracrine interactions that support tumor growth. Primary breast adipose fibroblasts from cancer-free women were treated with conditioned media from malignant breast epithelial cells or normal breast epithelial cells, and differences in gene expression were identified by microarray. A total of 79 differentially regulated genes encoding cytokines, enzymes, angiogenic factors, cytoskeletal proteins, extra-cellular matrix remodeling proteins, signal transduction proteins and cell surface receptors were identified, and 6 of these were verified by real-time PCR. Among these, the expression of aldo-keto reductase family 1, member C3 (AKR1C3) was upregulated. AKR1C3 has multiple enzymatic properties, including conversion of estrone to estradiol and androstenedione to testosterone. Immunoreactive AKR1C3 was detected in epithelial and stromal components of benign lesions and ductal carcinomas in situ, and in 59.8% of epithelial and 69.6% of stromal cells in invasive breast carcinomas. AKR1C3 expression was significantly higher in myoepithelial cells surrounding the neoplastic epithelium of ductal carcinoma in situ compared with those surrounding benign epithelial lesions. Importantly, AKR1C3 and aromatase mRNA levels correlated positively in 61 malignant breast tumors (R=0.3967, p=0.00156). Malignant epithelial cell-conditioned medium significantly increased formation of testosterone and estradiol from androstenedione in breast adipose fibroblasts. In conclusion, malignant epithelial cell-derived factors significantly upregulate the enzymes AKR1C3 and aromatase that catalyze a series of complementary reactions to convert the circulating precursor androstenedione to biologically active estradiol in vitro in the stromal fibroblasts, and in vivo, in stromal component of breast tumors.

3-Hydroxysteroid Dehydrogenases↗
PubMed2006

Adjuvant aromatase inhibitors for early breast cancer after chemotherapy-induced amenorrhoea: caution and suggested guidelines.

PURPOSE: Aromatase inhibitors (AIs) are now established as adjuvant therapy for early hormone receptor-positive breast cancer in postmenopausal women. Their use is sometimes extended to younger women after chemotherapy-induced amenorrhoea; we have audited this in one institution's breast unit, and we propose guidelines for use in such circumstances. PATIENTS AND METHODS: The use of aromatase inhibitors as adjuvant therapy in younger women age > or = 40 with hormone receptor-positive early breast cancer and chemotherapy-induced amenorrhea has been audited clinically and biochemically. Results A total of 45 such women were identified in the audit, with a median age of 47 years (range, 39 to 52 years). Twelve women (27%) showed a return of ovarian function (10 renewed menses, one pregnancy, one biochemically premenopausal) after starting an AI. Median age at restart of ovarian function was 44 years (range, 40 to 50 years). CONCLUSION: AIs may promote recovery of ovarian function in some women with chemotherapy-induced amenorrhea and should be used with caution. Biochemical monitoring of ovarian function requires highly sensitive immunoassays. Guidelines for the selection and delivery of adjuvant endocrine therapy in such patients are proposed.

Adult↗
PubMed2006

Cyclin D1 protein overexpression and CCND1 amplification in breast carcinomas: an immunohistochemical and chromogenic in situ hybridisation analysis.

Conflicting results on the prevalence of cyclin D1 ovexpression and its correlation with CCND1 amplification and outcome of breast cancer patients have been reported. Owing to limited sensitivity and specificity of most antibodies against cyclin D1, evaluation of cyclin D1 immunoexpression is reported to be problematic. The aims of this study were to assess the prevalence of cyclin D1 expression in breast carcinomas using the SP4 rabbit monoclonal antibody; to correlate cyclin D1 expression with amplification, assessed using chromogenic in situ hybridisation (CISH); and to analyse the relationship between CCND1 amplification and overexpression with clinicopathological parameters and outcome in a tissue microarray containing replicate tumour samples from 245 breast cancer patients. Immunohistochemistry for cyclin D1 was performed using the SP4 and the results were scored according to the Allred scoring system. CISH was carried out using the Zymed CCND1 SpotLight probe. CISH signals were counted in 60 morphologically unequivocal neoplastic cells. Amplification was defined as >5 signals per nucleus in more than 50% of cancer cells, or when large gene copy clusters were seen. Strong cyclin D1 expression and CCND1 amplification were found in 67.4 and 14.5% of the cases, respectively. A strong correlation between cyclin D1 overexpression and CCND1 amplification was demonstrated (P<0.0001). Cyclin D1 expression showed a positive correlation with hormone receptor expression (both ER and PgR, P<0.0001). An inverse correlation was observed between an immunohistochemical panel of 'basal-like' markers and both cyclin D1 overexpression (P<0.0001) and CCND1 amplification (P<0.0001). On univariate analysis cyclin D1 expression showed a correlation with longer overall survival (OS). Neither cyclin D1 nor CCND1 were independent prognostic factors for disease-free survival or OS. The results of this study confirm the association between cyclin D1 overexpression and positivity for hormone receptors and the lack of CCND1 amplification in basal-like breast carcinomas.

Antibodies, Monoclonal↗
PubMed2006

Proliferation and apoptosis as markers of benefit in neoadjuvant endocrine therapy of breast cancer.

The study of changes in proliferation as a marker of treatment benefit during presurgical endocrine treatment of breast cancer has become increasingly popular, particularly using the nuclear marker Ki67, and holds the potential for prioritizing new treatments for full clinical development. There are weakly significant relationships between Ki67 change and clinical response that differ according to data handling. In the neoadjuvant Immediate Preoperative Anastrozole, Tamoxifen, or Combined with Tamoxifen trial, suppression of Ki67 at both 2 and 12 weeks was greater with the aromatase inhibitor anastrozole than with either tamoxifen or the combination of anastrozole and tamoxifen. We report here that absolute values of Ki67 after 2 weeks were also significantly lower with anastrozole than with tamoxifen and the combination. This indicates that it may be possible to make such comparisons using surgical samples only. We argue that these changes in proliferation and concurrent changes in apoptosis may be expected to be more predictive of adjuvant benefit from endocrine therapy than clinical response.

Anastrozole↗