Letrozole inhibits tumor proliferation more effectively than tamoxifen independent of HER1/2 expression status

BACKGROUND: The biological basis for the superior efficacy of neoadjuvant letrozole versus tamoxifen for postmenopausal women with estrogen receptor (ER)-positive locally advanced breast cancer was investigated by analyzing tumor proliferation and expression of estrogen-regulated genes before and after the initiation of therapy. METHODS: Tumor samples were obtained at baseline and at the end of treatment from 185 patients participating in a double blind randomized Phase III study of neoadjuvant endocrine therapy. These paired specimens were simultaneously analyzed for Ki67, ER, progesterone receptor (PgR), trefoil factor 1 (PS2), HER1 (epidermal growth factor receptor), and HER2 (ErbB2 or neu) by semiquantitative immunohistochemistry. RESULTS: The treatment-induced reduction in geometric mean Ki67 was significantly greater with letrozole (87%) than tamoxifen (75%; analysis of covariance P = 0.0009). Differences in the average Ki67 reduction were particularly marked for ER-positive tumors that overexpressed HER1 and/or HER2 (88 versus 45%, respectively; P = 0.0018). Twenty-three of 92 tumors (25%) on tamoxifen and 14 of 93 on letrozole (15%) showed a paradoxical increase in Ki67 with treatment, and the majority of these cases was HER1/2 negative. Letrozole, but not tamoxifen, significantly reduced expression of the estrogen-regulated proteins PgR and trefoil factor 1, regardless of HER1/2 status (P < 0.0001). ER down-regulation occurred with both agents, although levels decreased more with tamoxifen (P < 0.0001). CONCLUSION: Letrozole inhibited tumor proliferation to a greater extent than tamoxifen. The molecular basis for this advantage appears complex but includes possible tamoxifen agonist effects on the cell cycle in both HER1/2+ and HER1/2- tumors. A pattern of continued proliferation despite appropriate down-regulation of PgR expression with estrogen deprivation or tamoxifen was also documented. This observation suggests the estrogenic regulation of proliferation and PgR expression may be dissociated in endocrine therapy resistant cells.     

Semi-quantitative evaluation of estrogen receptor expression is a strong predictive factor of pathological complete response after anthracycline-based neo-adjuvant chemotherapy in hormonal-sensitive breast cancer

Absence of hormonal receptors (HR) expression is a predictive factor of high pathologic complete response (pCR) rate after neo-adjuvant chemotherapy. However, HR-positive tumors are less chemosensitive. In the present study, we evaluated the predictive value of estrogen (ER) and progesterone (PgR) semi-quantitative expression in patients with HR-positive tumors treated uniformly with antracycline-based neoadjuvant chemotherapy without hormonal treatment. Value of HR expression as a predictive factor was then evaluated in a multivariate analysis with tumor grade, Ki67 index and HER2 expression. From January 2000 and December 2006, 177 patients with HR-positive breast ductal invasive carcinoma ≥2 cm in its largest diameter were treated with six cycles of an anthracycline-based neo-adjuvant chemotherapy. Tumor grade, ER, PgR, HER2 status and Ki67 index were determined on microbiopsy performed before chemotherapy. A semi-quantitative evaluation of ER and PgR expression by IHC was performed using the Barnes’score. pCR rate was significantly different (P < 0.001) according to the ER expression score. pCR rate was 28% for low score, 9% for medium score and 3% for high score. On the contrary, pCR rate was not significantly different (P = 0.49) according to the PgR expression score. In the multivariate analysis, ER expression score (P = 0.0002) and Ki67 index (P = 0.02) were the only predictive factors of response for HR-positive tumors. pCR after anthracycline-based chemotherapy is significantly correlated with the ER expression score.     

Relationship between oestrogen receptor status and proliferation in predicting response and long-term outcome to neoadjuvant chemotherapy for breast cancer

Oestrogen receptor (ER) negative breast cancers are more likely to achieve a pathological complete response (pCR) to neoadjuvant chemotherapy compared to those with ER positive tumours. ER positive tumours exhibit low proliferation and ER negative cancers high proliferation. The aim of this study was to determine to what extent the better response of ER negative cancers correlates with proliferation rate. A retrospective analysis of a prospectively maintained database identified 175 neoadjuvant chemotherapy patients with tissue available for Ki67 analysis. On univariate analysis, pre-therapy Ki67 (P = 0.04), ER status (P = 0.002), HER2 status (P = 0.004) and grade (P = 0.0009) were associated with a pCR. In a multivariate model, HER2 was the only significant predictor of pCR. No significant relationship between pre-therapy Ki67 and relapse-free and overall survival was demonstrated. Ki67 is not an independent predictor of clinical CR or pCR. Aspects of ER status beyond its inverse relationship with proliferation may contribute to its predictive value for pCR.     

Alpha- and beta-adrenergic receptor (AR) protein expression is associated with poor clinical outcome in breast cancer: an immunohistochemical study

Breast cancer mortality is frequently associated with metastatic disease. Metastasis models have shown adrenoceptor (AR) stimulation induces cell migration which is inhibited by adrenoceptor antagonist drugs. We investigated adrenoceptor protein expression in clinical breast tumours and its association with disease progression and prognosis. Immunohistochemistry on tissue microarrays was used to characterise α1b, α2c and β₂2 adrenoceptor protein expression in operable breast tumours. Associations with tumour-relevant biological markers and clinical outcome were statistically assessed. Strong α1b expression occurred in large high grade (P < 0.0001), HER2+ (P < 0.0001) or basal-like (CK5/6, P = 0.0005; CK14, P = 0.0001; EGFR, P = 0.003) cancers, showing increased proliferation (Mib1, P = 0.002), decreased apoptosis (Bcl2, P < 0.0001) and poor NPI membership (P = 0.001). α1b expression correlated with poor cancer-specific survival (LR = 7.628, P = 0.022) and tumour recurrence (LR = 6.128, P = 0.047). Strong α2c was over-expressed in high grade (P = 0.007), HER3+ (P = 0.002) and HER4+ (P < 0.0001) cancers with borderline increase in EGFR, p53 and MIB1 proteins, and inverse association with hormonal (PgR, P = 0.002) phenotype. In contrast, strong β₂ expression occurred in small-size, luminal-like (ER+, P < 0.001) tumours of low grade (P < 0.001) and lymph node stage (P = 0.027) that showed poor prognosis when hormonal treatment was withheld. Adrenoceptors were not found to be independent predictors of clinical outcome. Alpha1b and α2c AR is over-expressed in basal-like breast tumours of poor prognosis. Strong β₂ adrenoceptor expression is seen in patients with a luminal (ER+) tumour phenotype and good prognosis, due to benefits derived from hormonal therapy. These findings suggest a possible role for targeted therapy using adrenoceptor antagonists.     

Shorter survival-times following adjuvant endocrine therapy in oestrogen- and progesterone-receptor positive breast cancer overexpressing HER2 and/or with an increased expression of vascular endothelial growth factor

Purpose: To investigate the possible correlation between expression of HER2 and vascular endothelial growth factor (VEGF), and to determine the predictive value of these factors in patients receiving adjuvant endocrine therapy including the group with a breast cancer (BC) positive for both oestrogen receptor (ER) and progesterone receptor (PgR). Material and methods: By enzyme immuno-sorbent assays (ELISA) tumour levels of HER2 and VEGF proteins were determined in 679 consecutive primary BC patients, median age 63 years, median follow-up time 92 months. A total of 404 patients received adjuvant endocrine therapy, mainly tamoxifen, out of them 295 had an ER and PgR positive BC. In 160 patients, HER2 status was also determined by immunohistochemistry (IHC) using the monoclonal antibody CB11. Results: Overexpression of HER2 by IHC was found in 15% of the patients. Overexpression of HER2 by ELISA correlated with HER2 by IHC (P < 0.001) and a higher VEGF expression (P = 0.004). Patients receiving adjuvant endocrine therapy with high VEGF (RFS P = 0.0087, BCCS P = 0.0012) or over-expressing HER2 (RFS P = 0.0116, BCCS P = 0.0036) had significantly shorter survival. Factors retaining statistical significance in multivariate analyses for recurrence-free survival (RFS) were nodal status (P < 0.001), tumour size (P = 0.005) and VEGF (P = 0.032) and for breast cancer corrected survival (BCCS) nodal status (P < 0.001), tumour size (P = 0.001), ER status (P = 0.022), and VEGF (P = 0.016). Both factors were significantly correlated with survival in the group with a BC positive for both ER and PgR; VEGF (RFS P = 0.0177, BCCS P = 0.0321) and HER2 (RFS P = 0.0143, BCCS P = 0.0311). In multivariate analyses, nodal status (P < 0.001) and VEGF (P = 0.021) were independent factors for RFS. Nodal status (P < 0.001) and tumour size (P = 0.016) retained independent factors for BCCS. Combined analysis identified a high-risk group (HER2 positive and high VEGF) with significantly reduced survival. Conclusion: The results from this retrospective analysis suggest that overexpression of HER2 and higher VEGF expression may add information on patient’s outcome after adjuvant endocrine therapy in ER and PgR positive BC.     

A meta-analysis of oestrogen receptor,progesterone receptor and human epidermal growth factor receptor 2 discordance between primary breast cancer and metastases

BackgroundThe discordance in oestrogen receptor (ER), progesterone receptor (PgR) and human epidermal growth factor receptor 2 (HER2) status between primary and recurrent breast cancer is being intensively investigated and a large amount of data have been produced. However, results from different studies are heterogeneous and often conflicting. To highlight this issue, a meta-analysis of published data was performed.MethodsA literature search was performed using Medline, and all the studies published from 1983 to 2011 comparing changes in ER, PgR and/or HER2 status in patients with matched breast primary and recurrent tumours were included. We used random-effects models to estimate pooled discordance proportions.ResultsWe selected 48 articles, mostly reporting retrospective studies. Thirty-three, 24 and 31 articles were focused on ER, PgR and HER2 changes, respectively. A total of 4200, 2739 and 2987 tumours were evaluated for ER, PgR and HER2 discordance, respectively. The heterogeneity between study-specific discordance proportions was high for ER (I² = 91%, p < 0.0001), PgR (I² = 79%, p < 0.0001) and HER2 (I² = 77%, p < 0.0001). Pooled discordance proportions were 20% (95% confidence interval (CI): 16–35%) for ER, 33% (95% CI: 29–38%) for PgR and 8% (95% CI: 6–10%) for HER2. Pooled proportions of tumours shifting from positive to negative and from negative to positive were 24% and 14% for ER (p = 0.0183), respectively. The same figures were 46% and 15% for PgR (p < 0.0001), and 13% and 5% for HER2 (p = 0.0004).ConclusionOur findings strengthen the concept that changes in receptor expression may occur during the natural history of breast cancer, suggesting clinical implications and a possible impact on treatment choice.     

Breast cancer subtype approximations and loco-regional recurrence after immediate breast reconstruction

Background

A small but significant proportion of patients with breast cancer (BC) will develop loco-regional recurrence (LRR) after immediate breast reconstruction (IBR). The LRR also varies according to breast cancer subtypes and clinicopathological features.

Methods

We studied 1742 consecutive BC patients with IBR between 1997 and 2006. According to St Gallen conference consensus 2011, its BC approximations were applied to classify BC into five subtypes: estrogen receptor (ER) and/or progesterone receptor (PgR) positive, HER2 negative, and low Ki67 (<14%) [luminal A]; ER and/or PgR positive, HER2 negative and high Ki67(≥14%) [luminal B/HER2 negative]; ER and/or PgR positive, any Ki67 and HER2 positive [luminal B/HER2 positive]; ER negative, PgR negative and HER2 positive [HER2 positive/nonluminal]; and ER negative, PgR negative and HER2 negative [triple negative]. Cumulative incidences of LRR were compared across different subgroups by means of the Gray test. Multivariable Cox regression models were applied.

Results

Median follow up time was 74 months (range 3–165). The cumulative incidence of LRR was 5.5% (121 events). The 5-year cumulative incidence of LRR was 2.5% for luminal A; 5.0% for luminal B/HER2 negative; 9.8% for luminal B/HER2 positive; 3.8% for HER2 non luminal; and 10.9% for triple negative. On multivariable analysis, tumor size (pT) >2 cm, body mass index (BMI) ≥25, triple negative and luminal B/HER2 positive subtypes were associated with increased risk of LRR.

Conclusion

Luminal B/HER2 positive, triple negative subtypes and BMI ≥25 are independent prognostic factors for risk of LRR after IBR.     

Proliferation, steroid receptors and clinical/pathological response in breast cancer treated with letrozole

Sixty-three postmenopausal women with large primary breast cancers were treated with neoadjuvant letrozole (2.5 mg daily) for 3 months. Tumour samples were taken at diagnosis and after 10-14 days and 3 months treatment. Immunohistochemical staining for Ki67, oestrogen receptor (ER) and progesterone receptor (PgR) was performed and related to clinical (ClinR) and pathological responses (PathR) after 3 months treatment. ClinR was observed in 48 of 63 cases (76.2%) and PathR in 47 of 62 (75.8%). Pretreatment Ki67 scores were similar in responders (R) and non-responders (NR). Highly significant Ki67 decreases occurred in all tumour subgroups at 10-14 days (P<0.005). A significant difference in Ki67 scores at 10-14 days (P<0.007) was found between PathR and PathNR but not between ClinR and ClinNR. At 3 months, decreases from pretreatment Ki67 scores were highly significant in all tumour subgroups irrespective of response status. However, whereas Ki67 scores were significantly different between pathological R and NR (P = 0.009), the corresponding comparison of ClinR status was not. Significant decreases between 10-14 days and 3 months were found only in ClinR and PathR (P = 0.02 and 0.045, respectively). Treatment significantly reduced PgR expression at 14 days and 3 months (both P<0.0001), but the level of changes was not different between response status groups. In summary, letrozole produces rapid and profound decreases in expression of Ki67 and PgR but changes do not always correlate with clinical and pathological responses.     

Analysis of Ki‐67 expression with neoadjuvant anastrozole or tamoxifen in patients receiving goserelin for premenopausal breast cancer

BACKGROUND:

The increasing costs associated with large‐scale adjuvant trials mean that the prognostic value of biologic markers is increasingly important. The expression of nuclear antigen Ki‐67, a marker of cell proliferation, has been correlated with treatment efficacy and is being investigated for its value as a predictive marker of therapeutic response. In the current study, the authors explored correlations between Ki‐67 expression and tumor response, estrogen receptor (ER) status, progesterone receptor (PgR) status, and histopathologic response from the STAGE study (S_ tudy of T_ amoxifen or A_ rimidex, combined with G_ oserelin acetate to compare E_ fficacy and safety).

METHODS:

In a phase 3, double‐blind, randomized trial (National Clinical Trials identifier NCT00605267), premenopausal women with ER‐positive, early stage breast cancer received either anastrozole plus goserelin or tamoxifen plus goserelin for 24 weeks before surgery. The Ki‐67 index, hormone receptor (ER and PgR) status, and histopathologic responses were determined from histopathologic samples that were obtained from core‐needle biopsies at baseline and at surgery. Tumor response was determined by using magnetic resonance imaging or computed tomography.

RESULTS:

In total, 197 patients were randomized to receive either anastrozole plus goserelin (n = 98) or tamoxifen plus goserelin (n = 99). The best overall tumor response was better for the anastrozole group compared with the tamoxifen group both among patients who had a baseline Ki‐67 index ≥20% and among those who had a baseline Ki‐67 index <20%. There was no apparent correlation between baseline ER status and the Ki‐67 index in either group. Positive PgR status was reduced from baseline to week 24 in the anastrozole group.

CONCLUSIONS:

In premenopausal women with ER‐positive breast cancer, anastrozole produced a greater best overall tumor response compared with tamoxifen regardless of the baseline Ki‐67 index. Cancer 2013. © 2012 American Cancer Society.     

A randomized trial to assess the biological activity of short-term (pre-surgical) fulvestrant 500 mg plus anastrozole versus fulvestrant 500 mg alone or anastrozole alone on primary breast cancer

Introduction

Fulvestrant shows dose-dependent biological activity. Greater estrogen-receptor (ER) blockade may feasibly be achieved by combining fulvestrant with anastrozole. This pre-surgical study compared fulvestrant plus anastrozole versus either agent alone in patients with ER-positive breast cancer.

Methods

In this double-blind, multicenter trial, 121 patients received fulvestrant 500 mg on Day 1 plus anastrozole 1 mg/day for 14 to 21 days (F + A); fulvestrant plus anastrozole placebo (F); or fulvestrant placebo plus anastrozole (A), 2 to 3 weeks before surgery. ER, progesterone-receptor (PgR) and Ki67 expression were determined from tumor biopsies before treatment and at surgery.

Results

A total of 103 paired samples were available (F, n = 35; F+A, n = 31; A, n = 37). All treatments significantly reduced mean ER expression from baseline (F: -41%, P = 0.0001; F + A: -39%, P = 0.0001; A: -13%, P = 0.0034). F and F + A led to greater reductions in ER versus A (both P = 0.0001); F + A did not lead to additional reductions versus F. PgR and Ki67 expression were significantly reduced with all treatments (means were -34% to -45%, and -75% to -85%, respectively; all P = 0.0001), with no differences between groups.

Conclusions

In this short-term study, all treatments reduced ER expression, although F and F + A showed greater reductions than A. No significant differences were detected between the treatment groups in terms of PgR and Ki67 expression. No additional reduction in tumor biomarkers with combination treatment was observed, suggesting that F + A is unlikely to have further clinical benefit over F alone.

Trial registration

Clinicaltrials.gov NCT00259090.     

Letrozole in the neoadjuvant setting: the P024 trial

Neoadjuvant chemotherapy trials have consistently reported lower response rates in hormone receptor-positive (HR+) breast cancer when compared with HR? cases. Preoperative endocrine therapy has therefore become a logical alternative and has gained considerable momentum from the finding that aromatase inhibitors (AIs) are more effective than tamoxifen for HR+ breast cancer in both the neoadjuvant and adjuvant settings. The most convincing neoadjuvant trial to demonstrate the superiority of an AI versus tamoxifen was the P024 study, a large multinational double-blind trial in postmenopausal women with HR+ breast cancer ineligible for breast-conserving surgery. The overall response rate (ORR) was 55% for letrozole and 36% for tamoxifen (P < 0.001). Significantly more letrozole-treated patients underwent breast-conserving surgery (45 vs. 35%, respectively; P = 0.022). In addition, ORR was significantly higher with letrozole than tamoxifen in the human epidermal growth factor receptor HER1/HER2+ subgroup (P = 0.0004). The clinical efficacy of letrozole in HER2+ breast cancer was confirmed by fluorescent in situ hybridization analysis and was found to be comparable to that of HER2? cases (ORR 71% in both subsets). Biomarker studies confirmed the superiority of letrozole in centrally assessed estrogen receptor-positive (ER+) tumors and found a strong relationship with the degree of ER positivity for both agents. Interestingly, letrozole was effective even in marginally ER+ tumors and, unlike tamoxifen, consistently reduced the expression from estrogen-regulated genes (progesterone receptor and trefoil factor 1). Furthermore, when analyzed by Ki67 immunohistochemistry, letrozole was significantly more effective than tamoxifen in reducing tumor proliferation (P = 0.0009). Thus, neoadjuvant letrozole is safe and superior to tamoxifen in the treatment of postmenopausal women with HR+ locally advanced breast cancer.     

Survival Outcomes in Breast Cancer Patients With Low Estrogen/Progesterone Receptor Expression

IntroductionThe prognostic value of low estrogen and progesterone receptors expression (ER/PgR 1%-10%) in early breast cancer patients is still unclear.Patients and MethodsWe retrospectively analyzed 1424 consecutive patients with HER2/neu-negative and low endocrine receptors expression early breast cancer, submitted to surgery at the European Institute of Oncology between January 1995 and December 2009. Patients were classified according to the percentage of ER/PgR expression using immunohistochemistry. Group 1 with ER/PgR < 1%, and group 2 with ER/PgR 1% to 10%.ResultsGroup 1 (ER/PgR < 1%) included 1300 patients, and group 2 (ER/PgR 1%-10%) 124 patients. Median follow-up time was 74 months (range, 3-192 months). The 5-year disease-free survival (DFS) rate was 74% (95% confidence interval [CI], 72%-77%) for group 1, and 79% (95% CI, 70%-86%) for group 2 (P = .16). The 5-year overall survival (OS) rate was 86% (95% CI, 84%-88%) in group 1 and 90% (95% CI, 83%-95%) in group 2 (P = .13). In patients without lymph node involvement, the 5-year OS rate was 92% (95% CI, 89.5%-93.6%) for group 1 and 98% (95% CI, 90.2%-99.8%) for group 2 (P = .061). One hundred ten patients received endocrine therapy with no significant effect on DFS (P = .36) and OS (P = .30).ConclusionThe ER/PgR 1%-10% group had a slight, but not statistically significant, better prognosis than the ER/PgR <1% group. Further studies are needed to identify the appropriate clinical approach in this subset of patients with low ER/PgR expression (ER/PgR 1%-10%), HER2-negative early breast cancer.     

p53 accumulation is a strong predictor of recurrence in estrogen receptor‐positive breast cancer patients treated with aromatase inhibitors

Aromatase inhibitors have played a central role in endocrine therapy for estrogen receptor (ER)‐positive breast cancer in postmenopausal women. However, factors predictive of the efficacy of aromatase inhibitors, and prognostic factors, both for early and late recurrence in women treated with adjuvant aromatase inhibitors have not been identified. Whole genome analysis identified that a TP53 gene mutation exists in ER‐positive breast cancers, although the frequency of TP53 gene mutation in luminal tumors is lower compared with basal‐like or human epidermal growth factor receptor type 2 (HER2)‐positive breast cancers. We examined expression of p53, as well as ER, progesterone receptor, HER2 and Ki‐67 using immunohistochemistry in postmenopausal ER‐positive breast cancer patients who were treated with aromatase inhibitors as adjuvant endocrine therapy. There were 53 (21%) tumors that contained 10% or more p53‐positive cells. High p53 expression was positively correlated with tumor grade, HER2 score and Ki‐67 expression. Significant association was observed between disease‐free survival and high p53 expression in multivariate analysis (P < 0.0001). Compared with women without recurrence, women with early recurrence had significantly higher p53 expression (P < 0.0001), as did women with late recurrence (P = 0.037). The present study demonstrates that p53 accumulation is a strong predictor of both early and late recurrence in ER‐positive breast cancer patients treated with aromatase inhibitors as adjuvant endocrine therapy. TP53 gene alteration might be a key biological characteristic of ER‐positive breast cancer.     

Cyclin D1 expression is associated with poor prognostic features in estrogen receptor positive breast cancer

Cyclins D1 and E play an important role in breast carcinogenesis. High cyclin E expression is common in hormone receptor negative and high grade aggressive breast cancer, whereas cyclin D1 in hormone receptor positive and low grade breast cancer. Experimental data has suggested that cyclin D1 and E mediate cell proliferation by different mechanisms in estrogen receptor (ER) positive and negative breast cancer. To test this hypotheses in large breast cancer material and to clarify the histopathological correlations of cyclin E and D1, especially the association with proliferation, we analyzed cyclin E and D1 immunohistochemical expression on breast tumour microarrays consisting of 1348 invasive breast cancers. High cyclin D1 expression was associated with high grade (P < 0.0005), high cyclin A (P < 0.0005) and Ki67 (P < 0.0005) expression among ER positive but with low grade (P = 0.05) and low Ki67 (P = 0.01) expression among ER negative breast cancers. Cyclin E and D1 expression correlated positively in ER positive (P < 0.0005) but had a negative correlation in ER negative tumours (P = 0.004). Cyclin E associated with high grade among all tumours (P < 0.0005). In conclusion, the findings of this study show that cyclin D1 has separate roles, and proliferation is driven by different mechanisms in ER positive and negative breast cancers.     

Is triple negative a prognostic factor in breast cancer?

Background  Breast cancer is characterized by hormone dependency, and endocrine therapy is a key treatment in breast cancer. Recently, targeted therapies such as Trastuzumab treatment for HER2-positive breast cancer has been important. Triple-negative (TN) breast cancer is characterized by lack of expression of estrogen receptor (ER) and progesterone receptor (PgR), and the absence of HER2 protein overexpression, and so there is no targeted therapy for this subtype. In this study, we examined the biological and prognostic characteristics in TN breast cancer. Patients and methods  Between January 1998 and September 2006, 1,552 patients with primary breast cancer were investigated retrospectively in this study and ER, PgR and HER2 status were evaluated in all cases. Furthermore, p53 overexpression and Ki67 values were examined immunohistochemically. Results  Patient distribution according to ER, PgR or HER2 status was as follows: ER and PgR positive: 57.9%, and ER and PgR negative: 25.1%. With regards to the HER2 status, HER2 positive was 23.3%, and triple negative (TN) was 14.0%. TN breast cancer has a high proliferation rate, high nuclear grade and frequent p53 overexpression. Patients with TN tumors had a significantly poorer disease-free survival (DFS) than those with non-TN tumors. After recurrence the overall survival (OS) rate in TN cases was significantly lower than that of the non-TN cases. Multivariate analysis revealed that TN was a significant factor for DFS and OS after recurrence. Conclusion  TN breast cancer is a rare subtype with a high proliferation rate and a high nuclear grade, p53 overexpression, and lower DFS/OS. To improve the prognosis of TN breast cancer, a new effective strategy needs to be developed.     

Aromatase expression and outcomes in the P024 neoadjuvant endocrine therapy trial

Background Expression of aromatase by malignant breast epithelial cells and/or the surrounding stroma implies local estrogen production that could influence the outcome of endocrine therapy for breast cancer. Methods A validated immunohistochemical assay for aromatase was applied to samples from the P024 neoadjuvant endocrine therapy trial that compared tamoxifen and letrozole. The presence of aromatase expression by tumor or stromal cells was correlated with tumor response, treatment induced changes in proliferation index (Ki67), relapse-free survival (RFS) and breast cancer-specific survival (BCSS). Results Tumor and stromal aromatase expression were highly correlated (P = 0.0001). Tumor cell aromatase, as a semi-continuous score, also correlated with smaller tumor size at presentation (P = 0.01) higher baseline ER Allred score (P = 0.006) and lower Ki67 levels (P = 0.003). There was no significant relationship with clinical response or treatment-induced changes in Ki67. However, in a Cox multivariable model that incorporated a post-treatment tumor profile (pathological T stage, N stage, Ki67 and ER status of the surgical specimen), the presence of tumor aromatase expression at baseline sample remained a favorable independent prognostic biomarker for both RFS (P = 0.01, HR 2.3, 95% CI 1.2–4.6 for absent expression) and BCSS (P = 0.008, HR 3.76, 95% CI 1.4–10.0). Conclusions Autocrine estrogen synthesis may be most characteristic of smaller, more indolent and ER-rich breast cancers with lower baseline growth rates. However, response to endocrine treatment may not depend on whether the estrogenic stimulus has a local versus systemic source.     

Preoperative treatment of postmenopausal breast cancer patients with letrozole: A randomized double-blind multicenter study

Background:A randomized, double-blind, multicenter studywas conducted to compare the anti-tumor activity of letrozole vs.tamoxifen in postmenopausal women with ER and/or PgR positive primaryuntreated breast cancer. Patients and methods:Threehundred thirty-seven postmenopausal women with ER and/or PgR positiveprimary untreated breast cancer were randomly assigned once dailytreatment with either letrozole 2.5 mg or tamoxifen 20 mg for fourmonths. At baseline none of the patients were considered to becandidates for breast-conserving surgery (BCS) and 14% ofthe patients were considered inoperable. The primary endpoint was tocompare overall objective response (CR + PR) determined by clinicalpalpation. Secondary endpoints included overall objective response onultrasound and mammography and the number of patients who qualified forBCS. Results:Overall objective response rate (clinicalpalpation) was statistically significantly superior in the letrozolegroup, 55% compared to tamoxifen, 36% (P<0.001). Secondary endpoints of ultrasound response, 35% vs.25% (P= 0.042), mammographic response, 34% vs.16% (P< 0.001), and BCS, 45% vs. 35%(P= 0.022) between the letrozole and tamoxifen groups,respectively, showed letrozole to be significantly superior. Bothtreatments were well tolerated. Conclusions:This studyshows that letrozole is more effective than tamoxifen as preoperativetherapy in postmenopausal patients with ER and/or PgR positive primaryuntreated breast cancer and is at least as well tolerated.     

Gene expression of topoisomerase II alpha (TOP2A) by microarray analysis is highly prognostic in estrogen receptor (ER) positive breast cancer

Introduction Overexpression of Topoisomerase II alpha (TOP2A) has been implicated with gene amplification of the 17q21 amplicon and consecutively with ErbB2 overexpression and amplification. However, gene amplification does not necessarily correlate with RNA and protein expression. There is growing evidence that TOP2A protein expression is a strong prognostic and TOP2A gene amplification might be a predictive marker (particularly for the use of anthracyclines). Methods Large scale analysis was performed using Affymetrix microarray data from n = 1,681 breast cancer patients to evaluate TOP2A expression. Results TOP2A expression showed a strong correlation with tumor size (χ²-test, P < 0.001), grading (P < 0.001), ErbB2 (P < 0.001) and Ki67 expression (P < 0.001) as well as nodal status (P = 0.042). Survival analysis revealed a significant prognostic value in ER positive (n = 994; log rank P < 0.001), but not in ER negative breast cancer patients (n = 369, P = 0.35). The prognostic impact of TOP2A expression was independent of Ki67 expression in ER positive tumors (P = 0.002 and P = 0.007 for high and low Ki67, respectively). Moreover a worse prognosis of high TOP2A expressing tumors was found in the subgroup of ErbB2 negative tumors (P < 0.001) and a trend among ErbB2 positive tumors (P = 0.11). The prognostic value of TOP2A was independent of whether the patients were untreated or had received adjuvant therapy. In multivariate Cox regression analysis including standard parameters TOP2A emerged to be the top prognostic marker (HR 2.40, 95% CI 1.68–3.43, P < 0.001). Conclusion TOP2A expression is an independent prognostic factor in ER positive breast cancer and could be helpful for risk assessment in ER positive breast cancer patients. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users. A. Rody and T. Karn contributed equally to this work.     

Effect of a switch of aromatase inhibitors on musculoskeletal symptoms in postmenopausal women with hormone-receptor-positive breast cancer: the ATOLL (articular tolerance of letrozole) study

The objective of the present study was to evaluate the effect of the switch of aromatase inhibitors (AIs) on musculoskeletal symptoms in postmenopausal women with hormone-receptor-positive breast cancer. This was a 6-month, prospective, non-randomized, multicenter study. Patients who had discontinued anastrozole due to musculoskeletal symptoms were eligible to participate in this study, and received letrozole, which was initiated 1 month after anastrozole discontinuation. Musculoskeletal symptoms were systematically assessed for severity, location of the symptoms, presence of swelling and of morning stiffness by the oncologist patients when patients stopped taking their anastrozole, 1 month after the discontinuation of anastrozole, and 1, 3, and 6 months after initiating the letrozole therapy. The primary endpoint was the percentage of patients who discontinued letrozole due to the severe musculoskeletal symptoms. After switching from anastrozole therapy, and at the end of the 6-month letrozole treatment, 128 (71.5%) out of 179 patients (61.3 ± 8.4 years) continued with letrozole. Fifty-one patients (28.5%) discontinued treatment due to severe joint pain. At the end of the 6-month, 116 patients (73.9%) had arthralgia, 33 (21.0%) myalgia, 25 (15.9%) arthritis, 22 (14.0%) tendinitis, and 20 (12.7%) polyalgic syndrome. Bivariate analysis of the factors associated with letrozole discontinuation showed that the duration of a prior anastrozole treatment was a significant predictor (P = 0.04). This study shows that in patients intolerant to one AI, switching to another agent allows a higher proportion of patients to continue the therapy and maximize hormonal adjuvant therapy and disease outcome benefits.