Receptor-positive Breast Cancer Patients Research Articles

Group medical appointments: A novel approach in patient education for adjuvant endocrine therapy.

133 Background: Group medical appointments (GMA) are currently practiced for a wide range of medical conditions such as diabetes, hypertension, asthma, and cardiovascular disease. Previously, postmenopausal estrogen receptor positive breast cancer patients (ERBCP) attended individual physician clinic appointments to learn about their options for adjuvant endocrine therapy. This resulted in variable education provided, lengthy medical oncologist (MO) clinic visits and significant wait-lists to attend clinic. Accordingly, we embarked on a pilot program to determine the feasibility and acceptability of GMA in this patient population. Methods: Since 2010, ERBCP requiring endocrine therapy were referred and scheduled in the biweekly GMA program. Education regarding choices, risks, benefits and side effects of endocrine therapy were provided by a nurse practitioner (NP) and/or pharmacist (RX). After questions were solicited from the group, individual ERBCP were provided with prescriptions and scheduled for guideline-based follow-up. Results: Approximately 900 ERBCP have attended GMA, with 100% of MOs referring eligible patients. Surveys indicate high levels of satisfaction with the information provided and the GMA format. Conclusions: GMA provided by NP and/or RX is feasible and acceptable to both ERBCP and MOs. Health system benefits include increased efficiency and reduced cost, with MO clinic reserved for complex patient needs. Patient benefits include timely access to care and high levels of reported satisfaction. Future work will examine the effects of GMA on patient compliance and medication reconciliation with endocrine therapy.

Serum concentrations of tamoxifen and its metabolites increase with age during steady-state treatment

It has been suggested that the concentrations of tamoxifen and its demethylated metabolites increase with age. We measured the serum concentrations of the active tamoxifen metabolites, 4OHtamoxifen (4OHtam), 4-hydroxy-N-desmethyltamoxifen (4OHNDtam, Endoxifen), tamoxifen and its demethylated metabolites. Their relations to age were examined. One hundred fifty-one estrogen receptor and/or progesterone receptor positive breast cancer patients were included. Their median (range) age was 57 (32–85) years. Due to the long half-life of tamoxifen, only patients treated with tamoxifen for at least 80 days were included in the study in order to insure that the patients had reached steady-state drug levels. Tamoxifen and its metabolites were measured by liquid chromatography-tandem mass spectrometry. Their serum concentrations were related to the age of the patients. To circumvent effects of cytochrome (CYP) 2D6 polymorphisms we also examined these correlations exclusively in homozygous extensive metabolizers. The concentrations of 4OHNDtam, tamoxifen, NDtam (N-desmethyltamoxifen), and NDDtam (N-desdimethyltamoxifen) were positively correlated to age (n = 151, p = 0.017, 0.045, 0.011, and 0.001 respectively). When exclusively studying the CYP2D6 homozygous extensive metabolizers (n = 86) the correlation between 4OHNDtam and age increased (p = 0.008). Up to tenfold inter-patient variation in the serum concentrations was observed. The median (inter-patient range) concentration of 4OHNDtam in the age groups 30–49, 50–69, and >69 years were 65 (24–89), 116 (25–141), and 159 (26–185) ng/ml, respectively. We conclude that the serum concentrations of 4OHNDtam (endoxifen), tamoxifen, and its demethylated metabolites increase with age during steady-state tamoxifen treatment. This may represent an additional explanation why studies on the effects of CYP2D6 polymorphisms on outcome in tamoxifen-treated breast cancer patients have been inconsistent. The observed high inter-patient range in serum concentrations of tamoxifen and its metabolites, especially in the highest age group, suggest that use of therapeutic monitoring of tamoxifen and its metabolites is warranted.

Breast Cancer Index Identifies Early-Stage Estrogen Receptor–Positive Breast Cancer Patients at Risk for Early- and Late-Distant Recurrence

Residual risk of relapse remains a substantial concern for patients with hormone receptor-positive breast cancer, with approximately half of all disease recurrences occurring after five years of adjuvant antiestrogen therapy. The objective of this study was to examine the prognostic performance of an optimized model of Breast Cancer Index (BCI), an algorithmic gene expression-based signature, for prediction of early (0-5 years) and late (>5 years) risk of distant recurrence in patients with estrogen receptor-positive (ER(+)), lymph node-negative (LN(-)) tumors. The BCI model was validated by retrospective analyses of tumor samples from tamoxifen-treated patients from a randomized prospective trial (Stockholm TAM, n = 317) and a multi-institutional cohort (n = 358). Within the Stockholm TAM cohort, BCI risk groups stratified the majority (∼65%) of patients as low risk with less than 3% distant recurrence rate for 0 to 5 years and 5 to 10 years. In the multi-institutional cohort, which had larger tumors, 55% of patients were classified as BCI low risk with less than 5% distant recurrence rate for 0 to 5 years and 5 to 10 years. For both cohorts, continuous BCI was the most significant prognostic factor beyond standard clinicopathologic factors for 0 to 5 years and more than five years. The prognostic sustainability of BCI to assess early- and late-distant recurrence risk at diagnosis has clinical use for decisions of chemotherapy at diagnosis and for decisions for extended adjuvant endocrine therapy beyond five years.

Anti-cancer Effects of Costunolide in Estrogen Receptor Positive MCF-7 Breast Cancer Cells

Costunolide (C<SUB>15</SUB>H<SUB>20</SUB>O<SUB>2</SUB>) is a sesquiterpene lactone that was isolated from many herbal medicines and it has diverse effects (anti-viral, anti-fungal, and anti-inflammatory) according to previous reports. However, the anti-cancer effects of Costunolide and its mechanism of actions are not well known in estrogen receptor positive breast cancer. In this study, we observed that costunolide suppresses cell growth in estrogen receptor positive MCF-7 breast cancer cells as shown by MTT assay and soft agar colony formation assay. To examine the mechanism by which costunolide inhibits MCF-7 cell growth, we performed FACS analysis. We found that costunolide induced G2/M and S cell cycle arrest, and regulated cycle-related protein expression. In addition, costunolide inhibited ERK signaling pathway and induced autophagy. Therefore, costunolide might be a good and useful chemotherapy agent for estrogen receptor positive breast cancer patients.

Ki-67 level in hormone reptor positive breast cancer patients: A retrospective review of 9,061 Korean women.

551 Background: Although young age breast cancer represents poor prognosis, no definitive explanation could have been made for the phenomenon. A tumor proliferation marker Ki67 is known to be a marker for both prognosis and prediction for chemotherapy responsiveness, and its level varies widely depending on the breast cancer subtype. This study was aimed to analyze Ki67 in relationship with age in hormone receptor positive breast cancer patients. Methods: We retrospectively reviewed 9061 consecutive cases of hormone receptor positive invasive breast cancer from data base at Seoul National University Hospital (SNUH) (between 2000 and 2012), Samsung Medical Center (SMC) (between 2004 and 2010), and National Cancer Center (NCC) (between 2001 and 2010) in Korea. Patients with estrogen receptor (ER) or progesterone receptor (PR) positive tumors were included irrespective of HER2 amplification. A multicenter data of Ki67 level identified by immunohistochemistry (IHC) and age at diagnosis were analyzed. Patients who underwent neoadjuvant systemic therapy were excluded. Results: Total 6222 cases from SNUH, 976 from SMC and 1863 from NCC were included. The three datasets were analyzed separately due to variable IHC methods in each institute. Mean ages were 49.30 years (range 20-86), 47.75 years (range 22-81) and 45.31 years (range 25-59), and mean Ki67 levels were 4.66% (range 1-100), 22.98% (range 1-97) and 14.58% (range 1-90), at SNUH, SMC, NCC respectively. Ki67 level was inversely proportional with age at diagnosis in all three datasets, and the level was significantly higher for patients &lt;40 years compared to ≥40 years (mean Ki67: 5.97 vs 4.41, p&lt;0.001; 28.60 vs 21.88, p&lt;0.001; 17.01 vs 14.03, p&lt;0.001, respectively). There was an inverse relation with age as well when Ki67 level was categorized into ‘&lt;10% vs ≥10% (p&lt;0.001)’, ‘&lt;20% vs ≥20% (p=0.03)’ and ‘&lt;14% vs ≥14% (p&lt;0.001)’ respectively. Conclusions: Despite the variability of assessing Ki67 expression, Ki67 level was significantly higher in young age hormone receptor positive breast cancer from all three analyses. This could partly explain the poor prognosis and substantial responsiveness to chemotherapy in this age group of patients.

Efficacy of zoledronic acid in postmenopausal Japanese women with early breast cancer receiving adjuvant letrozole: 36-month results.

e20510 Background: We reported 12-month results of upfront zoledronic acid (ZOL) therapy, which prevented bone loss in postmenopausal Japanese women who were receiving adjuvant letrozole, confirming the Z-FAST and ZO-FAST studies results. But the examination in the long term of aromatase inhibitor-associated bone loss has not been proved in the Japanese or Asia women. Methods: Postmenopausal women with hormone receptor positive early breast cancer (BC) patients receiving adjuvant letrozole were randomly assigned to receive either upfront or delayed-start ZOL (4mg intravenously every 6 months) for 5 years. The delayed group received ZOL when lumbar spine (L2-L4) BMD decreased to less than young adult mean (YAM) – 2.0 S.D or when a nontraumatic fractured occurred. The primary endpoint of this study was to compare the changes in L1-L4 BMD at month 12 between the groups. Secondary endpoints, measured at other predetermined timepoints, included comparing changes in L1-L4, L2-L4and total hip (TH) BMD and markers of bone turnover, fracture incidence, and time to disease recurrence. We report the results of 36-month interim analysis. Results: At 36 months, mean change in L1-L4 BMD was 10.7% higher in the upfront group than in the delayed group ( 95% CI, 9.2% to 12.1%; p&lt; 0.001 ), L2-L4BMD was 10.9% higher ( 95% CI, 9.3% to 12.5%; p&lt; 0.001 ), and TH BMD was 6.7% higher ( 95% CI, 5.3% to 8.1%; p&lt; 0.001 ). The incidence of fracture was not significantly different between each group (upfront, 1(1.0%) vs. delayed, 4(4.1%)). Disease recurrence was reported in 3 upfront (3.1%) and 1 delayed (1.0%) patients. By month 36, 11 patients (11.3%) in the delayed group initiated ZOL therapy. There was no significant difference of adverse events other than fever with ZOL at the first treatment between the two groups. Conclusions: Upfront ZOL seems to be the preferred treatment strategy versus delayed administration, as it significantly and progressively increases BMD in postmenopausal Japanese women with early BC who were receiving adjuvant letrozole for 36 months. Clinical trial information: UMIN000001104.

Comparison of the efficacy of adjuvant letrozole and anastrozole in hormone-receptor positive postmenopausal breast cancer patients.

e11554 Background: In the adjuvant hormonal treatment of postmenopausal breast cancer patients, most of the trials have showed the superiority of aromatase inhibitors over tamoxifen. However, there are limited data in the literature comparing the efficacy of aromatase inhibitors in postmenopausal women. Thus, the aim of this study is to compare the efficacy of letrozole and anastrozole in hormone-receptor positive postmenopausal breast cancer patients. Methods: Newly diagnosed breast cancer patients from 2001 to 2012 in our clinic were retrospectively analyzed. A total 566 hormone receptor-positive postmenopausal breast cancer patients were analyzed. The patients were divided into two group; anastrozole group (n=235) and letrozole patients (n=331). Kaplan–Meier survival analysis was carried out for disease free survival (DFS) and overall survival (OS). The log-rank test was used to examine the statistical significance of the differences observed between the groups. Results: The mean age was 59.2±8.5 in anastrozole group, and 60.1±8.4 in letrozole arm (P = 0.19). The mean BMI was 29.4±5.1 kg/m2 and 29.3±5.3 kg/m2 of anastrozole and letrozole arm, respectively (P =0.84). The median follow-up time for this analysis was 25.1 months. The histology of the primary tumor and type of surgery was similar and not statistically significant in both groups. Also in both arms the incidence of lymphovascular invasion, perineural invasion, HER2 positivity and histological grade were similar and not statistically significant. There were no apparent differences in baseline nodal status (P = 0.43), tumor size (P = 0.58) and tumor stage (P = 0.15) between two treatment arms. In anastrozole arm DFS rate was 93.7%, 81.3% and 66.0% whereas in letrozole arm DFS rate was 90.6%, 78.7% and 68.5% in the first, third and fifth years respectively. Median OS could not be obtained due to low events in both groups. Three year survival rate in anastrozole group was 98.8%, whereas in letrozole arm was 96.7% (P=0.84). Conclusions: In this retrospective study, the efficacy of letrozole and anastrozole was similar in hormone-receptor positive postmenopausal breast cancer patients.

The role of chemotherapy in hormone receptor-positive and HER2-positive breast cancer patients over age 70.

e12511 Background: Standard adjuvant therapy for HER2 positive female breast cancer patients that are estrogen receptor (ER) positive is chemotherapy, trastuzumab, and endocrine therapy. For patients older than 70 years of age, the combination of chemotherapy and trastuzumab may increase the toxicity profile. The purpose of this study was to evaluate the role of chemotherapy in for the ER+/PR+/HER- and ER+/PR+/HER+ subtypes in patients over age 70. These subtypes differ only by HER2 status. Methods: We identified 13,167 cases of patients over age 70 with stages 1-3 first primary invasive breast cancer from the California Cancer Registry diagnosed between January 1, 2000 and December 31, 2010. Of these, 9,710 were ER+/PR+/HER- and 988 were ER+/PR+/HER+. Cox regression analysis adjusted for race/ethnicity, socioeconomic status, grade, and year of diagnosis was used to compare risk of mortality for combination endocrine and chemotherapy versus endocrine therapy alone. Analyses were conducted separately for each stage. Results: For the ER+/PR+/HER- subtype, there was no difference in the risk of mortality for patients given endocrine and chemotherapy versus endocrine therapy alone for stages 1 and 2. For stage 3, there was a 57% reduced risk of mortality (HR = 0.43; 95%CI: 0.27-0.69) for patients given combination chemo and endocrine therapy. For the ER+/PR+/HER+ subtype, there were no differences in risk of mortality in any stage due to treatment. Conclusions: With the exception of stage 3 patients with the ER+/PR+/HER- subtype, chemotherapy appears to add little or no benefit to risk of mortality for patients over 70 years of age. These results support the use of endocrine therapy and anti-HER2 therapy without chemotherapy in elderly patients with early stage, estrogen receptor positive, HER2 positive breast cancer.

Equol enhances tamoxifen’s anti-tumor activity by induction of caspase-mediated apoptosis in MCF-7 breast cancer cells

BackgroundSoy phytoestrogens, such as daidzein and its metabolite equol, have been proposed to be responsible for the low breast cancer rate in Asian women. Since the majority of estrogen receptor positive breast cancer patients are treated with tamoxifen, the basic objective of this study is to determine whether equol enhances tamoxifen’s anti-tumor effect, and to identify the molecular mechanisms involved.MethodsFor this purpose, we examined the individual and combined effects of equol and tamoxifen on the estrogen-dependent MCF-7 breast cancer cells using viability assays, annexin-V/PI staining, cell cycle and western blot analysis.ResultsWe found that equol (>50 μM) and 4-hydroxy-tamoxifen (4-OHT; >100 nM) significantly reduced the MCF-7 cell viability. Furthermore, the combination of equol (100 μM) and 4-OHT (10 μM) induced apoptosis more effectively than each compound alone. Subsequent treatment of MCF-7 cells with the pan-caspase inhibitor Z-VAD-FMK inhibited equol- and 4-OHT-mediated apoptosis, which was accompanied by PARP and α-fodrin cleavage, indicating that apoptosis is mainly caspase-mediated. These compounds also induced a marked reduction in the bcl-2:bax ratio, which was accompanied by caspase-9 and caspase-7 activation and cytochrome-c release to the cytosol. Taken together, these data support the notion that the combination of equol and tamoxifen activates the intrinsic apoptotic pathway more efficiently than each compound alone.ConclusionsConsequently, equol may be used therapeutically in combination treatments and clinical studies to enhance tamoxifen’s effect by providing additional protection against estrogen-responsive breast cancers.

Abstract 2615: 19-Nor-2α-(3-hydroxypropyl)-1α,25-dihydroxy vitaminD3 (MART-10) is a potent cell growth regulator and tumor metastasis inhibitor in MCF-7 cells: a new emerging strategy against ER+ breast cancer.

Abstract Aims: For estrogen receptor positive (ER+) breast cancer patients, hormone antagonist therapy is currently a standard regimen with a successful rate of 50 % to prevent cancer recurrence post radical surgery and radiation therapy. Recently, the active form of vitamin D3, 1α,25-dihydroxyvitamin D3 [1α,25(OH)2D3], has received much attention due to its potent antitumor effects in pre-clinical studies, yet its clinical application has been hampered by its hypercalcemia side effect. In this study, we investigated the in vitro effects of a new class of less-calcemic vitamin D analog, 19-nor-2α-(3-hydroxypropyl)-1α,25-dihydroxyvitamin D3 (MART-10), on ER+MCF-7 cells. Materials and Methods: Cell number counting was used to evaluate the antiproliferative effect of 1α,25(OH)2D3 and MART-10 on MCF-7 and MDA-MB-231 cells. Flow cytometry, western blot, q-RT/PCR, and cellular invasion and migration assays were conducted to compare the effects of 1α,25(OH)2D3 and MART-10 on cell cycle progression, apoptosis induction, protein and mRNA expression, and cancer cell metastasis of MCF-7 cells, respectively. Results: We demonstrate that in MCF-7 cells: (1) MART-10 is 500- to 1000-fold more potent than 1α,25(OH)2D3 in inhibiting cell growth and arresting them at G0/G1 phase, mediated by a greater induction of p21 and p27 expression. (2) MART-10 is more active than 1α,25(OH)2D3 in causing cell apoptosis through higher BAX/Bcl expression ratio and the subsequent cytochrome C release from mitochondria to cytosol without involving caspases. (3) MART-10 is more active than 1α,25(OH)2D3 in preventing cell invasion and migration with a greater upregulation of E-cadherin expression. No effects on MMP-2 and -9 were observed. (4) MART-10 upregulated CYP24A1 expression to a greater extent and for a longer period of time than 1α,25(OH)2D3, suggesting it can exert a greater vitamin D receptor (VDR) transactivation and is more resistant to CYP24A1-mediated degradation. (5) VDR is highly expressed in MCF-7 cells, but not in MDA-MB-231 cells, that may explain the greater 1α,25(OH)2D3 and MART-10 effects observed in MCF-7 cells. (6) MART-10 is more potent than 1α,25(OH)2D3 in suppressing ER expression. Conclusion: Based on our results, MART-10 is a promising vitamin D analog for the potential treatment of ER+ breast cancer. Further in vivo animal study is warranted. Citation Format: Shin-Cheh Chen, Kun-Chun Chiang, Horng-Heng Juang, Ling-Ling Hsieh. 19-Nor-2α-(3-hydroxypropyl)-1α,25-dihydroxy vitaminD3 (MART-10) is a potent cell growth regulator and tumor metastasis inhibitor in MCF-7 cells: a new emerging strategy against ER+ breast cancer. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2615. doi:10.1158/1538-7445.AM2013-2615

G Protein–Coupled Estrogen Receptor Is Apoptotic and Correlates with Increased Distant Disease-Free Survival of Estrogen Receptor–Positive Breast Cancer Patients

G protein-coupled estrogen receptor 1 (GPER1), previously named GPR30, is a membrane receptor reported to mediate nongenomic estrogen responses. We investigated if GPER1 expression correlates with any clinicopathologic variables and distant disease-free survival (DDFS) in patients with breast cancer, if any prognostic impact of the receptor is dependent on estrogen receptor-α (ER-α) status, and if the receptor impacts apoptotic signaling in ER-positive breast cancer cells. GPER1 expression was analyzed by immunohistochemistry in breast tumors from 273 pre- and postmenopausal stage II patients, all treated with adjuvant tamoxifen for 2 years (cohort I) and from 208 premenopausal lymph node-negative patients, of which 87% were not subjected to any adjuvant systemic treatment (cohort II). GPER1-dependent proapoptotic signaling was analyzed in MCF7 cells with and without GPER1 knockdown, T47D cells, HEK293 cells (HEK), and HEK stably expressing GPER1 (HEK-R). GPER1 positively correlates with ER and progesterone receptor expression. Multivariate analysis showed that GPER1 is an independent prognostic marker of increased 10-year DDFS in the ER-positive subgroup. HEK-R has higher basal proapoptotic signaling compared with HEK including increased cytochrome C release, caspase-3 cleavage, PARP cleavage, and decreased cell viability. Treating HEK-R with the proteasome inhibitor epoxomicin, to decrease GPER1 degradation, further increases receptor-dependent proapoptotic signaling. Also, GPER1 knockdown decreases basal and agonist-stimulated proapoptotic receptor signaling in MCF7 cells. GPER1 is a prognostic indicator for increased DDFS in ER-positive breast cancer, which may be associated with constitutive GPER1-dependent proapoptotic signaling in ER-positive breast cancer cells.

Overview of the use of Oncotype DX® as an additional treatment decision tool in early breast cancer

Oncotype DX® is a multigene assay that provides prognostic information in terms of 10-year distant recurrence and predicts the likelihood of adjuvant chemotherapy benefit in estrogen receptor positive breast cancer patients, based on the expression of a panel of 21 genes (16 cancer-related and five reference genes) from a tumor specimen (core biopsy or surgical resection). It has been validated using multiple prospectively designed studies of archived tumor specimens from well-controlled clinical studies. In different countries with varying therapeutic approaches, using Oncotype DX has consistently resulted in a significant reduction in the number of patients who are prescribed chemotherapy, and in addition, it can identify a smaller subset of patients who would benefit from chemotherapy among patients who would otherwise receive endocrine therapy alone.

Abstract P6-07-17: Proteomic screening of FFPE tissue identifies FKBP4 as an independent prognostic factor in hormone receptor positive breast cancers

Abstract Background: Adjuvant endocrine therapy reduces the risk of recurrence and death in hormone receptor positive breast cancer patients; however, 40–50% of estrogen receptor (ER) positive tumors are resistant to endocrine therapy. Identifying prognostic and predictive biomarkers to detect these non-responsive breast cancers at time of diagnosis may allow for improved clinical outcome for these patients. FKBP4 (FKBP52) is a co-chaperone protein that has been shown to regulate progesterone but not estrogen receptor activity, and was recently found to be highly expressed in early stage breast cancer compared to benign breast tissue. This evidence suggests that FKBP4 may play an important role in endocrine-responsive breast cancers. Methods: Global proteomic screening for biomarkers of aggressive breast cancer was performed on tissue samples from 24 patients with lymph node negative (LN−) disease and 24 patients with lymph node positive (LN+) disease randomly selected from the Calgary Tamoxifen Cohort, a retrospective cohort of breast cancer patients treated with adjuvant tamoxifen [n=511] from 1985–2000 at the Tom Baker Cancer Centre (Calgary, Canada). Liquid tissue lysates from FFPE tissue were analyzed by mass spectrometry and differentially expressed proteins were identified by the semi-quantitative spectral count method. FKBP4 was identified as an upregulated target in LN+ patients. The mRNA expression database of Kao et al. (BMC Cancer, 2011) was used to assess the prognostic potential of targets identified in the proteomic screen. FKBP4 protein expression was evaluated in tissue microarrays built from FFPE samples from the Calgary Tamoxifen Cohort using quantitative fluorescence immunohistochemistry and HistoRx AQUA analysis. Ten-year overall survival (OS) or five-year disease free survival (DFS) were the primary outcomes. Continuous variable FKBP4 data was dichotomized at the top quartile for both mRNA and protein expression analysis. Results: Univariate analysis demonstrated a significant association between high levels of FKBP4 mRNA and worse OS in ER+HER2− patients [n=182, HR=2.118 (1.070–4.192), p = 0.031] within the Kao et al database. Similarly, univariate analysis demonstrated that high levels of FKBP4 protein expression was associated with significantly worse DFS in ER+ HER2− patients [n=358, HR=1.632 (1.001–2.659), p = 0.049] in the Calgary Tamoxifen Cohort. FKBP4 was found to be an independent prognostic factor in both mRNA and protein expression cohorts using multivariate analysis adjusted for age, T stage, and lymph node status [OS: HR=2.786 (1.394–5.570), p = 0.004], or age, tumor size, tumor grade, and lymph node status [DFS: HR=1.875 (1.021–3.442), p = 0.043], respectively. Conclusions: Proteomic screening from FFPE tissue can identify new breast cancer biomarker candidates. Using this technique we have identified FKBP4 as an independent prognostic factor in ER+HER2− breast cancers, measured either by mRNA expression analysis or by quantitative protein expression analysis. Further studies are required to determine if FKBP4 may also be a predictive biomarker for tamoxifen response in ER+HER2− patients. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P6-07-17.

Abstract P1-09-01: Long-term effect of tamoxifen use on the risk of contralateral breast cancer

Abstract Background: Tamoxifen has been used widely in the treatment of breast cancer due to its beneficial effects on recurrences and mortality. Both randomized trials and observational studies give evidence that tamoxifen also reduces the incidence of contralateral breast cancer. The effect of tamoxifen seems to be present not only during treatment but also after termination of treatment, but the question is how long this effect lasts. Few studies have presented long-term follow-up data on risk of contralateral breast cancer after tamoxifen treatment. Material and Methods: In the Danish Breast Cancer Cooperative Group (DBCG) Database, we identified 50,323 women who had undergone surgery for invasive breast cancer and who had received treatment according to DBCG guidelines during 1978–2007. Among these women, 16,319 were users of tamoxifen while 34,004 were non-users. Contralateral breast cancer cases were identified in the Danish Cancer Registry and in the DBCG Database through 2009. The incidence of contralateral breast cancer among users of tamoxifen was compared to that of non-users by estimating incidence rate ratios (IRRs) in Cox regression analyses with adjustment for age at first breast cancer diagnosis, calendar period at first breast cancer diagnosis, histology of first breast cancer, radiotherapy, chemotherapy and other endocrine treatments besides tamoxifen. Results: During follow-up, 295 cases of contralateral breast cancer were observed among users of tamoxifen while 1,485 cases were observed among non-users resulting in an IRR of 0.82 (95% CI = 0.71–0.94) after adjustments. Further analyses will include calculation of IRRs for contralateral breast cancer by time since breast cancer diagnosis, duration of tamoxifen and time since cessation of tamoxifen as well as calculation of IRRs after restriction to estrogen receptor positive breast cancer patients. Results of these analyses will be presented. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P1-09-01.

Abstract S1-9: Comparative Performance of Breast Cancer Index (BCI) vs. Oncotype Dx and IHC4 in the Prediction of Late Recurrence in Hormonal Receptor-Positive Lymph Node-Negative Breast Cancer Patients: A TransATAC Study

Abstract Background: Patients with estrogen receptor positive (ER+) early breast cancer have a continuous yearly recurrence rate extending out to 15 years after having received adjuvant endocrine therapy for five years. More than half of the recurrences (i.e. late recurrences) in this group will occur beyond five years from diagnosis. Thus, residual risk of recurrence remains a substantial concern for ER+ breast cancer patients. Current multi-gene signatures have significant prognostic performance in predicting early recurrence (0–5 years post-diagnosis), however, such signatures have limited performance in predicting the risk of late recurrence (&amp;gt; 5 years) (Albain et al. Lancet Oncol 2010; 11: 55–65; Buyse et al. JNCI 2006; 98: 1183–1192). The comparative prognostic performance of Breast Cancer Index (BCI), Recurrence Score (RS) and IHC4 for predicting early and late recurrence was examined in the translational arm of Arimidex, Tamoxifen, Alone or in Combination trial (TransATAC). Methods: RNA extracted from 1102 formalin-fixed paraffin-embedded blocks of primary tumor samples previously collected for the TransATAC study was used to perform real-time RT-PCR for BCI analyses. BCI was calculated and risk groups were determined using pre-specified cut points. RS and IHC4 values were previously generated. The prognostic value of each signature beyond standard clinical variables (Clinical Treatment Score (CTS) was assessed using likelihood ratio chi-square (LR-χ2) and calculated by Cox proportional hazards models. Prognostic evaluation for early recurrences (0–5 years) was performed by censoring survival time to 5 years, and for late recurrences (5–10 years) by analyzing those patients who had remained recurrence-free for at least 5 years. Clinical endpoints examined were distant recurrence, any recurrence, breast cancer death and overall survival. Results: Of 1102 tumor specimens assayed, 29 failed quality control and 915 samples were matched for reportable values of BCI, IHC4 and RS. Here, only node-negative patients were evaluated (N = 665). All 3 signatures had significant prognostic performance for early distant recurrence (0–5 years), and overall (0–10 years) each provided prognostic information beyond CTS with LR-χ2 values of 22.7, 22.9 and 13.8 for BCI, IHC4 and RS, respectively. Notably, only BCI was significant beyond CTS for late distant recurrence (5–10 years) (LR-χ2: 7.97, p = 0.005) versus RS (LR-χ2: 0.51, p = 0.5) and IHC4 (LR-χ2: 1.63, p = 0.2). Similar comparative results of BCI, RS and IHC4 for late recurrence were observed for the other clinical endpoints. Discussion: This is the first large-scale clinical study to compare several multi-gene signatures for their prognostic strength to quantify late residual risk of recurrence after endocrine therapy. BCI, unlike IHC4 and RS, is a significant prognostic factor for late recurrence and enables the assessment of individual recurrence risk for ER+ patients recurrence-free after 5 years of endocrine therapy. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S1-9.

Abstract OT3-4-06: Circulating tumor cells to guide the choice between chemotherapy and hormone therapy as first line treatment for hormone receptors positive metastatic breast cancer patients: the STIC CTC METABREAST trial

Abstract Background: Baseline CTC count already demonstrated its accuracy as an independent prognostic marker in metastatic breast cancer (MBC), before the start of any treatment (Cristofanilli, NEJM 2004; Pierga Ann Oncol 2011) for progression free survival and overall survival. Multivariate analyses performed in both a pooled analysis (Liu, ASCO 2011) and in the IC 2006–04 study showed that the other independent prognostic factors were the performance status and hormone-receptor (HR) status. Oppositely, the other criteria that are frequently used to choose between hormone therapy and chemotherapy for the treatment of first line hormone receptor-positive MBC patients (e.g. number of metastatic sites, visceral disease, metastasis-free interval…) were not independent prognostic factors. As CTC count is highly correlated to PFS, we designed a large pivotal phase III trial to evaluate the use of CTC to determine the disease aggressiveness and the choice of first line treatment in potentially hormonosensitive MBC. Trial design: First line metastatic breast cancer patients will be randomized between the clinician choice and CTC count-driven choice. In the CTC arm, patients with ≥5 CTC/7.5ml will receive chemotherapy whereas patients with &amp;lt;5 CTC/7.5ml will receive endocrine therapy as first line treatment. Eligibility criteria: Main inclusion criteria include hormone receptor-positive metastatic breast cancer patients with no previous treatment for the metastatic disease, and who can receive either hormone therapy or chemotherapy as first line treatment. Statistical methods: As every patient will receive a treatment, this pivotal trial has been designed to show a non-inferiority of the CTC arm for PFS (primary clinical endpoint) and a superiority of the CTC arm for the medico-economics study (co-primary endpoint). Present accrual and target accrual: This trial began in March 2012 and more than 15 French cancer centers participate to this study. The accrual of 996 metastatic breast cancer patients should be completed in 2 to 3 years. 20 patients have been included in 2 months in the first opened center. Contact information for people with a specific interest in the trial The STIC CTC METABREAST trial has been funded by the French Ministry of Health (STIC program) and Veridex. The promoter is the Institut Curie (Paris). Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr OT3-4-06.

WS9-3 - The Clinical Significance of Pathologic Complete Response (PCR) after Neoadjuvant Chemotherapy and Treatment Strategy in HER2 and Hormonal Receptor Positive (HR+) Breast Cancer Patients

ABSTRACT Background For patients with HER2+ breast cancer, the achievement of pCR after neoadjuvant chemotherapy is regarded as a surrogate end point of prognosis, however, which is not clear among HER2 + HR+ patients. Methods We retrospectively investigated 163 HER2+ patients who received neoadjuvant chemotherapy in Hyogo Cancer Center between 2003 and 2010. HR+ was defined as estrogen or progesterone receptor positive, and pCR was no evidence of invasive carcinoma in the breast and axillary lymph nodes at surgery. Logistic regression analysis and logrank test were carried out to identify predictive factors of pCR and its prognostic significance on recurrence-free survival. Results The median age was 55 years (range, 25–84) and the median follow-up was 59 months (range 12–104). Stages I, IIA, IIB, and III were 4, 57, 56, 46 patients, HER2 + HR+ and HER2 + HR- were 89 and 74 patients, respectively. The rates of patients receiving anthracycline, taxane and trastuzumab (T) were 66, 82 and 51%, respectively. After surgery, 98% of HER2 + HR+ patients received hormonal therapy. Multivariate analysis revealed that HER2 + HR+ (OR, 0.46; P = .047) and inclusion of T (OR, 2.87; P = .01) were significant predictors of pCR. Although 5 years recurrence-free survival rate was significantly higher in HER2 + HR- patients with pCR compared with non-pCR (88% versus 64%; P = .03), which was not in HER2 + HR+ patients (94% versus 84%; P = .49). Conclusions HER2 + HR+ breast cancer patients had significantly lower achievement rate of pCR, which was less prognostic compared with that in HER2 + HR- patients. On the other hand, HER2 + HR+ patients had better prognosis; therefore, the reduction in side-effects by replacing cytotoxic drugs with anti-HER2 agents and hormonal therapy might be be more beneficial than the improvement of pCR in neoadjuvant settings. The predictive factors of response to achieve the replacement would be needed.

299 - Association of alpha2a and beta2 Adrenoceptors Expression With Clinical Outcome in Breast Cancer

ABSTRACT Disclosure All authors have declared no conflicts of interest. Previous studies have shown that alpha2-adrenoceptor antagonists can inhibit the growth of breast cancer cells. The action of beta2 adrenoceptors on cell proliferation is still controversial. In this study, we investigated the association of alpha2a and beta2 adrenoceptors expression with tumor-relevant biological markers and clinical outcome. Immunohistochemistry assay was performed on paraffin-embedded tumors to detect alpha2a and beta2 adrenoceptor expression in 220 operable breast tumors. We initially demonstrated that alpha2a expression was associated with Her-2 status (P = 0.048) and a marginal significance was observed between alpha2a expression and ER (P = 0.061). We also find that beta2 expression was not associated with any tumor-relevant biological markers. Kaplan-Meier models trended to show associations between different beta2 expression and DFS (P = 0.092). Further analysis was made and we found in hormone receptor positive breast cancer patients, strong beta2 expression correlated with better DFS than weak beta2 expression (P = 0.031). Multivariate analysis demonstrated that beta2 adrenoceptor (HR = 0.31, P = 0.039) and lymph node (HR = 2.85, P = 0.031) were independent predictors of DFS in hormone receptor positive breast cancer patients. In conclusion, this study showed that strong alpha2a expression occurred in ER positive and Her-2 negative breast cancers. In hormone receptor positive breast cancer patients, strong beta2 expression correlates with better DFS than weak beta2 expression. In hormone receptor positive breast cancer patients, beta2 ADR could be an independent predictors of DFS. Our results also suggest that the expression of beta2 adrenoceptor may be regulated by estrogen and progesterone or intercross may exist between the two pathways of beta2 adrenoceptor and hormone receptor.

176PD - Prediction of Late Breast Cancer Recurrence by the ROR (PAM50) Score in Postmenopausal Women in the Transatac Cohort

ABSTRACT Background Adjuvant endocrine therapy beyond 5 years is known to be of benefit to some oestrogen receptor (ER) positive breast cancer patients. We have shown previously that the IHC4 score and the ROR score are significantly correlated with distant recurrence in the cohort from the TransATAC study. Here we assess the relationship between the ROR score, RS (Oncotype Dx) and the IHC4 score in predicting distant recurrence beyond 5 years. Methods We determined the univariate and multivariate prognostic value of ROR score, RS, and IHC4 score for distant recurrence separately in years 0-5 and 5-10 of follow up for all patients (N = 940), and for node-negative (N = 683) and node-positive (N = 257) patients separately using proportional hazard models for time to distant recurrence. Results In years 0-5, all three scores add significant prognostic information on distant recurrence in a univariate model (ROR: ΔLR-χ2 = 41.50, P Conclusion Overall, all three scores provided significant additional prognostic information in the 5-10 year period, but ROR added most prognostic information in both the univariate and multivariate analysis and in node-negative patients. These results may be used to select patients who could benefit from hormonal therapy beyond 5 years. Disclosure J. Cuzick: Dr. Cuzick disclosed that he received grant support from and is a consultant for AstraZeneca. S. Ferree: Dr. Ferree disclosed that he is an employee of and shareholder in NanoString Technologies. J.W. Cowens: Dr. Cowens disclosed that he is an employees of and shareholder in NanoString Technologies. M. Dowsett: Dr. Dowsett disclosed that he received grant support from and is on the speaker's bureau, has received grant support and provided legal advice for AstraZeneca and has sponsored IHC4 in a NICE assessment. All other authors have declared no conflicts of interest.

311 - Endometrial Effects of Tamoxifen and Exemestane in Early Breast Cancer: Final Results of a Randomized Phase III Trial

ABSTRACT Background Tamoxifen (T) has been for a long time the treatment of choice in hormonal receptor positive early breast cancer patients (EBCP). It is known that T has partial estrogen agonistic activity on uterus determining an increase in gynecological symptoms. Long-term T treatment can lead to an increased incidence of endometrial cancer. The availability of aromatase inhibitors (AI) has modified the prescription options in postmenopausal breast cancer patients while remaining the standard of care in premenopausal setting. AI do not mediate their effects through the estrogen receptor potentially conferring tolerability advantages to women particularly in relation to their effects on the endometrium. So far some studies including all the available AI have been published which confirmed the lack of estrogen effects of AI on endometrium compared to T. In 2001 we started a phase III study comparing T and Exemestane (E) in EBCP in order to evaluate the differences in the endometrial changes recorded by transvaginal ultrasound (TVUS). Material and methods Postmenopausal hormonal receptor positive EBCP were randomly assigned to receive T or E. A baseline TVUS was performed and repeated after 6 and 12 months. The primary end-point, endometrial thickness (ET) was evaluated with T-test. Results From 2001 to 2008 220 patients were enrolled in our department. Patients' characteristics were well balanced in each arm. Definitive results are summarized in the table: ET (median) Baseline ET (median) After 6 m p (ET baseline vs 6 months) ET (median) After 12 m p (ET baseline vs 12 months) E 3 (1.4-5) 3 (1.17-9.3) NS 2.8 (0.02-13.5) NS T 3 (0.14-5) 6.64 (1.9-19.7) 6 (1.93-25.2) Conclusions Our results confirmed the data obtained in similar studies. In particular E was associated with significantly less endometrial thickening than T during the projected period of therapy in postmenopausal hormone receptor positive EBCP. Disclosure All authors have declared no conflicts of interest.