Abstract S3-01: Breast cancer prevention using anastrozole in postmenopausal women at high risk

Background: Third generation aromatase inhibitors are the most effective endocrine treatment for hormone receptor positive breast cancer in postmenopausal women. Here, we assess the efficacy of anastrozole in postmenopausal women who do not have breast cancer, but are at high risk of developing the disease.

Methods: A multi-centre randomised placebo-controlled trial of 1mg/day oral anastrozole vs. matching placebo for five years was conducted in 3864 postmenopausal women at increased risk of breast cancer. The primary endpoint was the incidence of breast cancer (including ductal carcinoma in-situ (DCIS) and differences were assessed by the proportional hazards model. Detailed information on adverse events was collected.

Results: After a median follow up of 5.03 years, 125 breast cancers were recorded. A 53% reduction (95% CI (32-68%), P<0.0001) was seen in the anastrozole arm. Significant reductions were seen for all invasive (50%), oestrogen receptor positive invasive (58%) and in situ tumours (70%). Fractures were non-significantly higher (8.5% vs. 7.7%, P = 0.3) and musculoskeletal events were significantly higher in the anastrozole arm (1226 vs. 1124, RR = 1.10 (1.05-1.16)) but were very common in both arms (63.9% vs. 57.8%). Vasomotor symptoms were also increased with anastrozole (RR = 1.15 (1.08-1.22)). Cancers at other sites were significantly decreased (40 vs. 70, RR = 0.58 (0.39-0.85)). Deaths from breast cancer and other causes were similar in both arms.

Conclusions: Anastrozole is an effective agent for reducing breast cancer incidence in postmenopausal women at high risk. Anastrozole was well tolerated and side effects associated with oestrogen deprivation were only slightly higher than for placebo.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S3-01.

Selective oestrogen receptor modulators in prevention of breast cancer: an updated meta-analysis of individual participant data

BACKGROUND

Tamoxifen and raloxifene reduce the risk of breast cancer in women at elevated risk of disease, but the duration of the effect is unknown. We assessed the effectiveness of selective oestrogen receptor modulators (SERMs) on breast cancer incidence.

METHODS

We did a meta-analysis with individual participant data from nine prevention trials comparing four selective oestrogen receptor modulators (SERMs; tamoxifen, raloxifene, arzoxifene, and lasofoxifene) with placebo, or in one study with tamoxifen. Our primary endpoint was incidence of all breast cancer (including ductal carcinoma in situ) during a 10 year follow-up period. Analysis was by intention to treat.

RESULTS

We analysed data for 83,399 women with 306,617 women-years of follow-up. Median follow-up was 65 months (IQR 54-93). Overall, we noted a 38% reduction (hazard ratio [HR] 0·62, 95% CI 0·56-0·69) in breast cancer incidence, and 42 women would need to be treated to prevent one breast cancer event in the first 10 years of follow-up. The reduction was larger in the first 5 years of follow-up than in years 5-10 (42%, HR 0·58, 0·51-0·66; p<0·0001 vs 25%, 0·75, 0·61-0·93; p=0·007), but we noted no heterogeneity between time periods. Thromboembolic events were significantly increased with all SERMs (odds ratio 1·73, 95% CI 1·47-2·05; p<0·0001). We recorded a significant reduction of 34% in vertebral fractures (0·66, 0·59-0·73), but only a small effect for non-vertebral fractures (0·93, 0·87-0·99).

INTERPRETATION

For all SERMs, incidence of invasive oestrogen (ER)-positive breast cancer was reduced both during treatment and for at least 5 years after completion. Similar to other preventive interventions, careful consideration of risks and benefits is needed to identify women who are most likely to benefit from these drugs.

FUNDING

Cancer Research UK.

Relative effectiveness of letrozole alone or in sequence with tamoxifen for patients diagnosed with invasive lobular carcinoma

529

Background: BIG 1-98 is a randomized, phase III study that compares five years of tamoxifen (tam) or letrozole (let), (monotherapy arms), or their sequences (tam-let or let-tam) in post-menopausal women with ER+ early BC. In the monotherapy arms, the magnitude of benefit of adjuvant let compared with tam varies by histology (greater in invasive lobular carcinoma (ILC) than invasive ductal carcinoma (IDC)). In this analysis we investigate the magnitude of benefit of let compared to tam-let and let-tam according to histology (IDC and ILC) at 96 months of median follow-up. Methods: There were 4,634 patients enrolled in the let, tam-let and let-tam arms of BIG-98. This analysis includes patients with centrally-reviewed histological subtype (n=4,223); classified as classic ILC or IDC (n=3,790); and with centrally reviewed ER, PgR and Ki67 (n=3,212). Results: The 8-year DFS and OS univariate estimates (±SE) for IDC and ILC are presented in the Table. When correcting for classic clinicopathological variables, treatment assignment was not a significant predictor of DFS and OS. Conclusions: We observed a trend toward greater magnitude of benefit in favor of let monotherapy for ILC than IDC. In the ILC subset, improvements for both DFS and OS were seen for let when compared to tam-let or let-tam, though not statistically significant. This may be due to the reduced number of ILC patients across subgroups. The present analysis is consistent with previous data from the monotherapy arms where let was associated with better DFS and OS than tam for ILC, and suggests that let might be the preferred upfront regimen for patients diagnosed with ILC. Clinical trial information: NCT00004205. [Table: see text]

Long-term effects of continuing adjuvant tamoxifen to 10 years versus stopping at 5 years after diagnosis of oestrogen receptor-positive breast cancer: ATLAS, a randomised trial

BACKGROUND

For women with oestrogen receptor (ER)-positive early breast cancer, treatment with tamoxifen for 5 years substantially reduces the breast cancer mortality rate throughout the first 15 years after diagnosis. We aimed to assess the further effects of continuing tamoxifen to 10 years instead of stopping at 5 years.

METHODS

In the worldwide Adjuvant Tamoxifen: Longer Against Shorter (ATLAS) trial, 12,894 women with early breast cancer who had completed 5 years of treatment with tamoxifen were randomly allocated to continue tamoxifen to 10 years or stop at 5 years (open control). Allocation (1:1) was by central computer, using minimisation. After entry (between 1996 and 2005), yearly follow-up forms recorded any recurrence, second cancer, hospital admission, or death. We report effects on breast cancer outcomes among the 6846 women with ER-positive disease, and side-effects among all women (with positive, negative, or unknown ER status). Long-term follow-up still continues. This study is registered, number ISRCTN19652633.

FINDINGS

Among women with ER-positive disease, allocation to continue tamoxifen reduced the risk of breast cancer recurrence (617 recurrences in 3428 women allocated to continue vs 711 in 3418 controls, p=0·002), reduced breast cancer mortality (331 deaths vs 397 deaths, p=0·01), and reduced overall mortality (639 deaths vs 722 deaths, p=0·01). The reductions in adverse breast cancer outcomes appeared to be less extreme before than after year 10 (recurrence rate ratio [RR] 0·90 [95% CI 0·79–1·02] during years 5–9 and 0·75 [0·62–0·90] in later years; breast cancer mortality RR 0·97 [0·79–1·18] during years 5–9 and 0·71 [0·58–0·88] in later years). The cumulative risk of recurrence during years 5–14 was 21·4% for women allocated to continue versus 25·1% for controls; breast cancer mortality during years 5–14 was 12·2% for women allocated to continue versus 15·0% for controls (absolute mortality reduction 2·8%). Treatment allocation seemed to have no effect on breast cancer outcome among 1248 women with ER-negative disease, and an intermediate effect among 4800 women with unknown ER status. Among all 12,894 women, mortality without recurrence from causes other than breast cancer was little affected (691 deaths without recurrence in 6454 women allocated to continue versus 679 deaths in 6440 controls; RR 0·99 [0·89–1·10]; p=0·84). For the incidence (hospitalisation or death) rates of specific diseases, RRs were as follows: pulmonary embolus 1·87 (95% CI 1·13–3·07, p=0·01 [including 0·2% mortality in both treatment groups]), stroke 1·06 (0·83–1·36), ischaemic heart disease 0·76 (0·60–0·95, p=0·02), and endometrial cancer 1·74 (1·30–2·34, p=0·0002). The cumulative risk of endometrial cancer during years 5–14 was 3·1% (mortality 0·4%) for women allocated to continue versus 1·6% (mortality 0·2%) for controls (absolute mortality increase 0·2%).

INTERPRETATION

For women with ER-positive disease, continuing tamoxifen to 10 years rather than stopping at 5 years produces a further reduction in recurrence and mortality, particularly after year 10. These results, taken together with results from previous trials of 5 years of tamoxifen treatment versus none, suggest that 10 years of tamoxifen treatment can approximately halve breast cancer mortality during the second decade after diagnosis.

FUNDING

Cancer Research UK, UK Medical Research Council, AstraZeneca UK, US Army, EU-Biomed.

Design and baseline characteristics of the PODOSA (Prevention of Diabetes & Obesity in South Asians) trial: a cluster, randomised lifestyle intervention in Indian and Pakistani adults with impaired glycaemia at high risk of developing type 2 diabetes

OBJECTIVES

To describe the design and baseline population characteristics of an adapted lifestyle intervention trial aimed at reducing weight and increasing physical activity in people of Indian and Pakistani origin at high risk of developing type 2 diabetes.

DESIGN

Cluster, randomised controlled trial.

SETTING

Community-based in Edinburgh and Glasgow, Scotland, UK.

PARTICIPANTS

156 families, comprising 171 people with impaired glycaemia, and waist sizes ≥90 cm (men) and ≥80 cm (women), plus 124 family volunteers.

INTERVENTIONS

Families were randomised into either an intensive intervention of 15 dietitian visits providing lifestyle advice, or a light (control) intervention of four visits, over a period of 3 years.

OUTCOME MEASURES

The primary outcome is a change in mean weight between baseline and 3 years. Secondary outcomes are changes in waist, hip, body mass index, plasma blood glucose and physical activity. The cost of the intervention will be measured. Qualitative work will seek to understand factors that motivated participation and retention in the trial and families' experience of adhering to the interventions.

RESULTS

Between July 2007 and October 2009, 171 people with impaired glycaemia, along with 124 family volunteers, were randomised. In total, 95% (171/196) of eligible participants agreed to proceed to the 3-year trial. Only 13 of the 156 families contained more than one recruit with impaired glycaemia. We have recruited sufficient participants to undertake an adequately powered trial to detect a mean difference in weight of 2.5 kg between the intensive and light intervention groups at the 5% significance level. Over half the families include family volunteers. The main participants have a mean age of 52 years and 64% are women.

CONCLUSIONS

Prevention of Diabetes & Obesity in South Asians (PODOSA) is one of the first community-based, randomised lifestyle intervention trials in a UK South Asian population. The main trial results will be submitted for publication during 2013.

TRIAL REGISTRATION

Current controlled trials ISRCTN25729565 (http://www.controlled-trials.com/isrctn/).

Preoperative systemic therapy in locoregional management of early breast cancer: highlights from the Kyoto Breast Cancer Consensus Conference

Data reviewed at the Kyoto Breast Cancer Consensus Conference (KBCCC) showed that preoperative systemic therapy (PST) could optimize surgery through the utilization of information relating to pre- and post-PST tumor stage, therapeutic sensitivity, and treatment-induced changes in the biological characteristics of the tumor. As such, it was noted that the biological characteristics of the tumor, such as hormone receptors, human epidermal growth factor receptor-2, histological grade, cell proliferative activity, mainly defined by the Ki67 labeling index, and the tumor's multi-gene signature, should be considered in the planning of both systemic and local therapy. Furthermore, the timing of axillary sentinel lymph node diagnosis (i.e., before or after the PST) was also noted to be critical in that it may influence the likelihood of axillary preservation, even in node positive cases. In addition, axillary diagnosis with ultrasound and concomitant fine needle aspiration cytology or core needle biopsy (CNB) was reported to contribute to the construction of a treatment algorithm for patient-specific or individualized axillary surgery. Following PST, planning for breast surgery should therefore be based on tumor subtype, tumor volume and extent, therapeutic response to PST, and patient preference. Nomograms for predicting nodal status and drug sensitivity were also recognized as a tool to support decision-making in the selection of surgical treatment. Overall, review of data at the KBCCC showed that PST increases the likelihood of patients receiving localized surgery and individualized treatment regimens.

Patterns and risk factors for locoregional failures after mastectomy for breast cancer: an International Breast Cancer Study Group report

BACKGROUND

Rates and risk factors of local, axillary and supraclavicular recurrences can guide patient selection and target for postmastectomy radiotherapy (PMRT).

PATIENTS AND METHODS

Local, axillary and supraclavicular recurrences were evaluated in 8106 patients enrolled in 13 randomized trials. Patients received chemotherapy and/or endocrine therapy and mastectomy without radiotherapy. Median follow-up was 15.2 years.

RESULTS

Ten-year cumulative incidence for chest wall recurrence of >15% was seen in patients aged <40 years (16.1%), with ≥4 positive nodes (16.5%) or 0-7 uninvolved nodes (15.1%); for supraclavicular failures >10%: ≥4 positive nodes (10.2%); for axillary failures of >5%: aged <40 years (5.1%), unknown primary tumor size (5.2%), 0-7 uninvolved nodes (5.2%). In patients with 1-3 positive nodes, 10-year cumulative incidence for chest wall recurrence of >15% were age <40, peritumoral vessel invasion or 0-7 uninvolved nodes. Age, number of positive nodes and number of uninvolved nodes were significant parameters for each locoregional relapse site.

CONCLUSION

PMRT to the chest wall and supraclavicular fossa is supported in patients with ≥4 positive nodes. With 1-3 positive nodes, chest wall PMRT may be considered in patients aged <40 years, with 0-7 uninvolved nodes or with vascular invasion. The findings do not support PMRT to the dissected axilla.

Obesity and risk of recurrence or death after adjuvant endocrine therapy with letrozole or tamoxifen in the breast international group 1-98 trial

PURPOSE

To examine the association of baseline body mass index (BMI) with the risk of recurrence or death in postmenopausal women with early-stage breast cancer receiving adjuvant tamoxifen or letrozole in the Breast International Group (BIG) 1-98 trial at 8.7 years of median follow-up.

PATIENTS AND METHODS

This report analyzes 4,760 patients with breast cancer randomly assigned to 5 years of monotherapy with letrozole or tamoxifen in the BIG 1-98 trial with available information on BMI at randomization. Multivariable Cox modeling assessed the association of BMI with disease-free survival, overall survival (OS), breast cancer-free interval, and distant recurrence-free interval and tested for treatment-by-BMI interaction. Median follow-up was 8.7 years.

RESULTS

Seventeen percent of patients have died. Obese patients (BMI ≥ 30 kg/m(2)) had slightly poorer OS (hazard ratio [HR] = 1.19; 95% CI, 0.99 to 1.44) than patients with normal BMI (< 25 kg/m(2)), whereas no trend in OS was observed in overweight (BMI 25 to < 30 kg/m(2)) versus normal-weight patients (HR = 1.02; 95% CI, 0.86 to 1.20). Treatment-by-BMI interactions were not statistically significant. The HRs for OS comparing obese versus normal BMI were HR = 1.22 (95% CI, 0.93 to 1.60) and HR = 1.18 (95% CI, 0.91 to 1.52) in the letrozole and tamoxifen groups, respectively.

CONCLUSION

There was no evidence that the benefit of letrozole over tamoxifen differed according to patients' BMI.

Role of multidetector computed tomography in the diagnosis and management of patients attending the rapid access chest pain clinic, The Scottish computed tomography of the heart (SCOT-HEART) trial: study protocol for randomized controlled trial

Background

Rapid access chest pain clinics have facilitated the early diagnosis and treatment of patients with coronary heart disease and angina. Despite this important service provision, coronary heart disease continues to be under-diagnosed and many patients are left untreated and at risk. Recent advances in imaging technology have now led to the widespread use of noninvasive computed tomography, which can be used to measure coronary artery calcium scores and perform coronary angiography in one examination. However, this technology has not been robustly evaluated in its application to the clinic.

Methods/design

The SCOT-HEART study is an open parallel group prospective multicentre randomized controlled trial of 4,138 patients attending the rapid access chest pain clinic for evaluation of suspected cardiac chest pain. Following clinical consultation, participants will be approached and randomized 1:1 to receive standard care or standard care plus ≥64-multidetector computed tomography coronary angiography and coronary calcium score. Randomization will be conducted using a web-based system to ensure allocation concealment and will incorporate minimization. The primary endpoint of the study will be the proportion of patients diagnosed with angina pectoris secondary to coronary heart disease at 6 weeks. Secondary endpoints will include the assessment of subsequent symptoms, diagnosis, investigation and treatment. In addition, long-term health outcomes, safety endpoints, such as radiation dose, and health economic endpoints will be assessed. Assuming a clinic rate of 27.0% for the diagnosis of angina pectoris due to coronary heart disease, we will need to recruit 2,069 patients per group to detect an absolute increase of 4.0% in the rate of diagnosis at 80% power and a two-sided P value of 0.05. The SCOT-HEART study is currently recruiting participants and expects to report in 2014.

Discussion

This is the first study to look at the implementation of computed tomography in the patient care pathway that is outcome focused. This study will have major implications for the management of patients with cardiovascular disease.

Trial registration

ClinicalTrials.gov Identifier: NCT01149590

ANZ1001 SORBET: Study of estrogen receptor beta and efficacy of tamoxifen, a single arm, phase II study of the efficacy of tamoxifen in triple-negative but estrogen receptor beta-positive metastatic breast cancer

TPS1136

Background: Targeted therapies are needed for triple negative breast cancer (BC). ERβ is expressed in at least 20% of triple negative BCs.  ERβ binds estrogen and tamoxifen with a similar affinity to ERα.  ERβ has 5 isoforms but only ERβ1 is fully functional. ERβ expression has been shown to be significantly associated with improved distant disease free survival and better overall survival in tamoxifen treated ERα negative patients in retrospective studies.  This “proof of principle” study will determine the efficacy of tamoxifen in patients with triple negative but ERβ positive metastatic BC. Methods: This single arm phase II study, being conducted by the Australia and New Zealand Breast Cancer Trials Group, has a Simon's 2 stage optimal design. The primary end-point is objective response rate (complete and partial responses).  Progression free survival and clinical benefit rate will also be assessed. Eligibility criteria include histologically or cytologically confirmed metastatic triple negative BC (ER and PR absent, HER2 ISH negative or IHC 0 or 1) and measureable disease as per RECIST 1.1.  Consenting patients undergo central ERβ testing and confirmation of triple negative status on a metastatic biopsy sample. ERβ positive patients (ERβ1 nuclear staining with Allred score >4) are offered trial participation. To date 12 potentially eligible patients have been screened for ERβ; 4 had Allred score >4 (although 2 of these subsequently proved to be ineligible for the trial), 7 had Allred scores <4 and 1 result is pending. Consenting patients receive tamoxifen 20mg per oral daily until disease progression, unacceptable toxicity or withdrawal of consent. If there are ≥2 responses in the first stage of 28 patients, an additional 38 patients will be accrued. Tamoxifen will be considered worthy of further research if there are ≥6 responses in the total 66 patients recruited. Current accrual is 1. Registered on ANZCTR (12610000506099).

Weight change associated with anastrozole and tamoxifen treatment in postmenopausal women with or at high risk of developing breast cancer

Weight gain is commonly reported by breast cancer patients on tamoxifen or aromatase inhibitors. Since weight gain may impact on outcome and compliance we have prospectively assessed the effects of these agents on weight change in three randomised trials for the treatment or prevention of breast cancer. Data on weight change in postmenopausal women from three large clinical trials investigating endocrine therapy for the treatment or prevention of breast cancer were analysed (ATAC, IBIS-I and IBIS-II). In the IBIS-I study, mean weight change on tamoxifen was +0.1 kg (SD 0.1) compared with +0.3 kg (SD 0.1) in women taking the placebo (P = 0.3) between baseline and 12 months of follow-up. In the IBIS-II trial, no statistically significant difference was found between anastrozole and placebo after 12 months of follow-up [+0.8 kg (SD 5.3) vs. +0.5 kg (SD 7.4), P = 0.5]. In the ATAC trial, no statistically significant differences in weight gain between anastrozole and tamoxifen were found after 12 months of follow-up [+1.4 kg (SD 3.9) vs. +1.5 kg (SD 4.0), P = 0.4]. Significant baseline predictors for gaining more than 5 kg of weight after 12 months of follow-up were: being younger than 60 years old, smoking and mastectomy. All three trials demonstrate that weight gain occurs primarily within the first 12 months of active treatment in a subset of patients. In the prevention trials, weight gain does not differ between anastrozole, tamoxifen and placebo and also did not differ between anastrozole and tamoxifen in the treatment trial.

Proposals for uniform collection of biospecimens from neoadjuvant breast cancer clinical trials: timing and specimen types

In this Personal View, we outline proposals for uniform collection of biospecimens obtained in neoadjuvant breast cancer trials undertaken by the Breast International Group (BIG) and the National Cancer Institute-sponsored North American Breast Cancer Group (NABCG). These proposals aim to standardise collection of high-quality specimens, with respect to both type and timing, to enhance and allow integration of results obtained from neoadjuvant trials done by several groups. They should be considered in parallel with recommendations for tissue-specimen collection and handling previously developed by BIG and NABCG. We propose that tumour tissue (formalin-fixed, paraffin-embedded and samples dedicated for molecular studies) should be taken at baseline, 1-3 weeks after the start of treatment, and at definitive surgery, with clear prioritisation in the study protocol of number, order, and preservation of samples to be gathered. This step should be accompanied by blood collection (plasma, serum, and whole blood) whenever possible. We advocate strongly a move towards one diagnostic and research biopsy procedure in all women with breast cancers potentially suitable for neoadjuvant treatment. If possible, patients should be referred at the outset to specialised centres to give them the opportunity to participate in neoadjuvant clinical trials, thereby avoiding several biopsy procedures.

P3-14-28: ANZ 0502 NeoGem: A Phase II Trial Evaluating the Efficacy and Safety of Epirubicin and Cyclophosphamide Followed by Docetaxel with Gemcitabine (+ Trastuzumab If HER2 Positive) as Neoadjuvant Chemotherapy for Women with Large Operable or Locally Advanced Breast Carcinoma

Background

Neoadjuvant chemotherapy may provide an early indication of treatment effect and pathologic complete response (pCR) rate is a surrogate measure of disease-free and overall survival. Anthracyclines remain an important component of chemotherapy regimens for breast cancer (BC), adding a taxane conveys additional survival benefit. Gemcitabine (G) has established safety and efficacy in metastatic breast cancer (MBC) and combining G with docetaxel (D) shows preclinical synergy but not overlapping toxicities. In MBC, efficacy of trastuzumab (T) combined with single agent taxanes and G has been demonstrated for tumours that over-express human epidermal growth factor receptor 2 (HER2+). NeoGem aimed to evaluate the efficacy and safety of neoadjuvant epirubicin (E) and cyclophosphamide (C), followed by D and G +/− T (depending on HER2 status) in women with large operable or locally advanced BC.

Methods: Eligible patients (pts), ≥18 years, had unilateral, operable (at presentation) T2 (≥3cm), T3-4, N0-1, M0 primary BC, no prior chemotherapy or hormonal therapy and ECOG status 0–2. All pts received E (90mg/m2 i.v.) in combination with C (600mg/m2 i.v.) on day 1 q 21 for 4 cycles followed by D (75mg/m2 i.v.) on day 1 in combination with G (1000mg/m2 i.v.) on days 1 and 8 q 21 for 4 cycles. HER2+ pts received T (4mg/kg loading then 2mg/kg i.v.) concurrent with DG on days 1, 8 and 15 q 21 for 4 cycles. HER2+ pts received post-surgical T (6mg/kg) 3 weekly, for a total of one year of T therapy. Using a Simon's 2 stage trial design, the decision to proceed to stage 2 followed interim analysis of stage 1. Primary endpoint, pCR, was defined as no histologic evidence of invasive cancer in the breast. Secondary endpoint, pCRax, was defined as no histologic evidence of invasive cancer in the breast and axilla. EC followed by DG/DGT was expected to achieve a pCR rate of 35% in HER2 negative (HER2−) pts and 40% in HER2+, with the lowest limit of therapeutic efficacy being a pCR rate of 22% (HER2−) and 24% (HER2+). Hence 84 HER2− and 63 HER2+ pts were needed to detect significant differences in pCR rates (power 80%, 95% level of significance).

Results: Over 32 months 81 pts (63 HER2− and 18 HER2+) were enrolled, 78 (96% [61 HER2− and 17 HER2+]) proceeded to surgery. Of 78 pts, 21 (27%) achieved pCR and 19 (24%) achieved pCRax. Of the 61 HER2− pts, 12 (20% [95% CI: 12%-31%]) achieved pCR compared with 9 (53% [95%CI: 31%-74%]) of 17 HER2+ pts. Planned chemotherapy was completed by 67 pts (83%), 9 pts (11%) discontinued due to adverse events. Thirteen pts (16%) required DG dose reductions compared with 7 (8%) pts during EC; 57 (70%) pts had ≥ grade 3 neutropenia.

Conclusion: Efficacy in the HER2− cohort did not reach predetermined levels of significance (interim analysis); HER2+ recruitment proved too slow to continue. High haematological toxicity during DG, particularly neutropenia required use of supportive therapy (GCSF). Despite relatively small patient numbers, 53% pCR in the HER2+ cohort warrants further investigation.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-14-28.

P2-12-01: Immunohistochemical (IHC) BAG1 Expression Improves the Estimation of Residual Risk (RR) by IHC4 in Postmenopausal Patients Treated with Anastrozole or Tamoxifen: A TransATAC Study

Aim: To determine whether the incorporation of BAG1 staining improves the estimate of RR after endocrine therapy in postmenopausal patients with ER+ve tumours treated with endocrine therapy. Background: BAG1 encodes a protein (BCL2-associated athanogene 1) that binds to BCL2 and enhances its anti-apoptotic effects. BAG1 is included as a separate subgroup in the 21-gene OncotypeDx Recurrence Score (RS) that is used to assess RR after endocrine therapy in primary ER+ breast cancer. IHC4 is a 4-panel set of IHC markers (ER, PgR, HER2, Ki67) that was shown to provide as much prognostic accuracy as RS in the translational arm of the ATAC trial (TransATAC) of anastrozole versus tamoxifen alone or combined and subsequently independently validated (Cuzick et al, JCO, 2011, in press). Addition of extra markers such as BAG1 to IHC4 may improve the accuracy of the IHC4 and provide extra discriminatory power for oncologists.

Methods: Samples in triplicate TMAs from the TransATAC cohort were stained for BAG1 using the Genetex 3.10G3E2 antibody after validation using siRNA knockdown. Staining was scored separately as nuclear or cytoplasmic and categorized by intensity as 0, 1, 2 or 3. BAG1 IHC values were assessed for their correlation with BAG1 mRNA levels. The statistical analysis plan was pre-specified and tested possible additional information from BAG1 expression to the IHC4 in patients not treated with chemotherapy by change in the likelihood ratio chi-square (ΔLR-X2). Results were included only if there was also complete data for ER, PgR, Ki67 and HER2. Primary analysis was on the HER2−ve node-negative (N-neg) population; secondary analysis was on all N-neg patients. Follow-up was to 10 years and the primary end-point was time to distant recurrence (TTDR).

Results: Data on both nuclear and cytoplasmic BAG1 as well as the other 4 IHC parameters was available on 961 cases of which 855 were HER2−ve. There was a significant correlation between cytoplasmic and nuclear BAG1 (p=0.23, p&lt;0.0001) but the nuclear staining correlated better with mRNA levels and was therefore considered further. Weak but significant correlations were also seen with ER, PgR and tumour grade. In the univariate analysis nuclear BAG1 was significantly associated with worse TTDR in HER2−ve and all N-neg cases (X2=7.91, p=0.005 and X2=10.63, p=0.001 respectively). Nuclear BAG1 also contributed significantly in multivariate analyses in the 2 populations firstly when added to the clinical model (X2=4.99, p=0.02 and X2=5.93, p=0.015 respectively) and secondly when subtracted from clinical plus the IHC4 parameters (X2=5.55, p=0.02 and X2=4.50, p=0.03 respectively).

Conclusions: Nuclear BAG1 expression has significant value for estimating RR that is independent of standard clinical and IHC parameters and it improves the prediction of TTDR in the TransATAC population beyond that with the validated IHC4 score. Unlike IHC4 markers, BAG1 is not commonly measured in pathology work-up of breast cancers. The clinical utility of its addition to IHC4 will be tested by measuring its discrimination of high and low risk patients in clinical practice.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-12-01.

Risk of recurrence and chemotherapy benefit for patients with node-negative, estrogen receptor-positive breast cancer: recurrence score alone and integrated with pathologic and clinical factors

PURPOSE

The 21-gene breast cancer assay recurrence score (RS) is widely used for assessing recurrence risk and predicting chemotherapy benefit in patients with estrogen receptor (ER) -positive breast cancer. Pathologic and clinical factors such as tumor size, grade, and patient age also provide independent prognostic utility. We developed a formal integration of these measures and evaluated its prognostic and predictive value.

PATIENTS AND METHODS

From the National Surgical Adjuvant Breast and Bowel (NSABP) B-14 and translational research cohort of the Arimidex, Tamoxifen Alone or in Combination (TransATAC) studies, we included patients who received hormonal monotherapy, had ER-positive tumors, and RS and traditional clinicopathologic factors assessed (647 and 1,088, respectively). Individual patient risk assessments from separate Cox models were combined using meta-analysis to form an RS-pathology-clinical (RSPC) assessment of distant recurrence risk. Risk assessments by RS and RSPC were compared in node-negative (N0) patients. RSPC was compared with RS for predicting chemotherapy benefit in NSABP B-20.

RESULTS

RSPC had significantly more prognostic value for distant recurrence than did RS (P < .001) and showed better separation of risk in the study population. RSPC classified fewer patients as intermediate risk (17.8% v 26.7%, P < .001) and more patients as lower risk (63.8% v 54.2%, P < .001) than did RS among 1,444 N0 ER-positive patients. In B-20, the interaction of RSPC with chemotherapy was not statistically significant (P = .10), in contrast to the previously reported significant interaction of RS with chemotherapy (P = .037).

CONCLUSION

RSPC refines the assessment of distant recurrence risk and reduces the number of patients classified as intermediate risk. Adding clinicopathologic measures did not seem to enhance the value of RS alone nor the individual biology RS identifies in predicting chemotherapy benefit.

Disease-related outcomes with long-term follow-up: an updated analysis of the intergroup exemestane study

PURPOSE

Intergroup Exemestane Study (IES), an investigator-led study in 4,724 postmenopausal patients with early-stage breast cancer has demonstrated clinically important benefits from switching adjuvant endocrine therapy after 2 to 3 years of tamoxifen to exemestane. Now, with longer follow-up, a large number of non-breast cancer-related events have been reported. Exploratory analyses describe breast cancer-free survival (BCFS) and explore incidence and patterns of the different competing events.

PATIENTS AND METHODS

Patients who were disease-free after 2 to 3 years of adjuvant tamoxifen were randomly assigned to continue tamoxifen or switch to exemestane to complete 5 years of adjuvant endocrine therapy. At this planned analysis, the median follow-up was 91 months. Principal analysis focuses on 4,052 patients with estrogen receptor (ER) -positive and 547 with ER-unknown tumors.

RESULTS

In all, 930 BCFS events have been reported (exemestane, 423; tamoxifen, 507), giving an unadjusted hazard ratio (HR) of 0.81 (95% CI, 0.71 to 0.92; P = .001) in favor of exemestane in the ER-positive/ER unknown group. Analysis partitioned at 2.5 years after random assignment showed that the on-treatment benefit of switching to exemestane (HR, 0.60; 95% CI, 0.48 to 0.75; P < .001) was not lost post-treatment, but that there was no additional gain once treatment had ceased (HR, 0.94; 95% CI, 0.80 to 1.10; P = .60). Improvement in overall survival was demonstrated, with 352 deaths in the exemestane group versus 405 deaths in the tamoxifen group (HR, 0.86; 95% CI, 0.75 to 0.99; P = .04). Of these, 222 were reported as intercurrent deaths (exemestane, 107; tamoxifen, 115).

CONCLUSION

The protective effect of switching to exemestane compared with continuing on tamoxifen on risk of relapse or death was maintained for at least 5 years post-treatment and was associated with a continuing beneficial impact on overall survival.

Capecitabine versus classical cyclophosphamide, methotrexate, and fluorouracil as first-line chemotherapy for advanced breast cancer

PURPOSE

We compared oral capecitabine, administered intermittently or continuously, versus classical cyclophosphamide, methotrexate, and fluorouracil (CMF) as first-line chemotherapy for women with advanced breast cancer unsuited to more intensive regimens.

PATIENTS AND METHODS

Three hundred twenty-three eligible women were randomly assigned to capecitabine administered intermittently (1,000 mg/m(2) twice daily for 14 of every 21 days; n = 107) or continuously (650 mg/m(2) twice daily for 21 of every 21 days; n = 107), or to classical CMF (oral cyclophosphamide 100 mg/m(2) days 1 to 14 with intravenous methotrexate 40 mg/m(2) and fluorouracil 600 mg/m(2) on days 1 and 8 every 28 days; n = 109). The primary end point was quality-adjusted progression-free survival (PFS); secondary end points included PFS, overall survival (OS), objective tumor response, and adverse events. Intermittent and continuous capecitabine were to be compared first and, if similar (P > .05), combined for definitive comparisons versus CMF.

RESULTS

Quality-adjusted PFS (P = .2), objective tumor response rate (20%; P = .8), and PFS (median, 6 months; hazard ratio [HR], 0.86; 95% CI, 0.67 to 1.10; P = .2) were similar in women assigned capecitabine versus CMF. OS was longer in women assigned capecitabine rather than CMF (median, 22 v 18 months; HR, 0.72; 95% CI, 0.55 to 0.94; P = .02). Febrile neutropenia, infection, stomatitis, and serious adverse events were more common with CMF; hand-foot syndrome was more common with capecitabine.

CONCLUSION

Capecitabine improved OS by being similarly active, less toxic, and more tolerable than CMF. Capecitabine is a good first-line chemotherapy option for women with advanced breast cancer who are unsuited to more intensive regimens.

Assessment of letrozole and tamoxifen alone and in sequence for postmenopausal women with steroid hormone receptor-positive breast cancer: the BIG 1-98 randomised clinical trial at 8·1 years median follow-up

BACKGROUND

Postmenopausal women with hormone receptor-positive early breast cancer have persistent, long-term risk of breast-cancer recurrence and death. Therefore, trials assessing endocrine therapies for this patient population need extended follow-up. We present an update of efficacy outcomes in the Breast International Group (BIG) 1-98 study at 8·1 years median follow-up.

METHODS

BIG 1-98 is a randomised, phase 3, double-blind trial of postmenopausal women with hormone receptor-positive early breast cancer that compares 5 years of tamoxifen or letrozole monotherapy, or sequential treatment with 2 years of one of these drugs followed by 3 years of the other. Randomisation was done with permuted blocks, and stratified according to the two-arm or four-arm randomisation option, participating institution, and chemotherapy use. Patients, investigators, data managers, and medical reviewers were masked. The primary efficacy endpoint was disease-free survival (events were invasive breast cancer relapse, second primaries [contralateral breast and non-breast], or death without previous cancer event). Secondary endpoints were overall survival, distant recurrence-free interval (DRFI), and breast cancer-free interval (BCFI). The monotherapy comparison included patients randomly assigned to tamoxifen or letrozole for 5 years. In 2005, after a significant disease-free survival benefit was reported for letrozole as compared with tamoxifen, a protocol amendment facilitated the crossover to letrozole of patients who were still receiving tamoxifen alone; Cox models and Kaplan-Meier estimates with inverse probability of censoring weighting (IPCW) are used to account for selective crossover to letrozole of patients (n=619) in the tamoxifen arm. Comparison of sequential treatments to letrozole monotherapy included patients enrolled and randomly assigned to letrozole for 5 years, letrozole for 2 years followed by tamoxifen for 3 years, or tamoxifen for 2 years followed by letrozole for 3 years. Treatment has ended for all patients and detailed safety results for adverse events that occurred during the 5 years of treatment have been reported elsewhere. Follow-up is continuing for those enrolled in the four-arm option. BIG 1-98 is registered at clinicaltrials.govNCT00004205.

FINDINGS

8010 patients were included in the trial, with a median follow-up of 8·1 years (range 0-12·4). 2459 were randomly assigned to monotherapy with tamoxifen for 5 years and 2463 to monotherapy with letrozole for 5 years. In the four-arm option of the trial, 1546 were randomly assigned to letrozole for 5 years, 1548 to tamoxifen for 5 years, 1540 to letrozole for 2 years followed by tamoxifen for 3 years, and 1548 to tamoxifen for 2 years followed by letrozole for 3 years. At a median follow-up of 8·7 years from randomisation (range 0-12·4), letrozole monotherapy was significantly better than tamoxifen, whether by IPCW or intention-to-treat analysis (IPCW disease-free survival HR 0·82 [95% CI 0·74-0·92], overall survival HR 0·79 [0·69-0·90], DRFI HR 0·79 [0·68-0·92], BCFI HR 0·80 [0·70-0·92]; intention-to-treat disease-free survival HR 0·86 [0·78-0·96], overall survival HR 0·87 [0·77-0·999], DRFI HR 0·86 [0·74-0·998], BCFI HR 0·86 [0·76-0·98]). At a median follow-up of 8·0 years from randomisation (range 0-11·2) for the comparison of the sequential groups with letrozole monotherapy, there were no statistically significant differences in any of the four endpoints for either sequence. 8-year intention-to-treat estimates (each with SE ≤1·1%) for letrozole monotherapy, letrozole followed by tamoxifen, and tamoxifen followed by letrozole were 78·6%, 77·8%, 77·3% for disease-free survival; 87·5%, 87·7%, 85·9% for overall survival; 89·9%, 88·7%, 88·1% for DRFI; and 86·1%, 85·3%, 84·3% for BCFI.

INTERPRETATION

For postmenopausal women with endocrine-responsive early breast cancer, a reduction in breast cancer recurrence and mortality is obtained by letrozole monotherapy when compared with tamoxifen montherapy. Sequential treatments involving tamoxifen and letrozole do not improve outcome compared with letrozole monotherapy, but might be useful strategies when considering an individual patient's risk of recurrence and treatment tolerability.

FUNDING

Novartis, United States National Cancer Institute, International Breast Cancer Study Group.

Influence of comorbidities and age on risk of death without recurrence: a retrospective analysis of the Arimidex, Tamoxifen Alone or in Combination trial

PURPOSE

The Arimidex, Tamoxifen Alone or in Combination (ATAC) study was a double-blind randomized trial in which postmenopausal women with early-stage breast cancer were assigned to receive anastrozole, tamoxifen, or the combination. We have conducted a retrospective analysis to examine the effects of comorbidities and age on treatment received, breast cancer-related mortality, and competing causes of mortality.

PATIENTS AND METHODS

The current analyses were based on 10-year median follow-up data in the two monotherapy arms (anastrozole, n = 3,092; tamoxifen, n = 3,094) of the ATAC study. Baseline comorbidities and tumor and treatment characteristics were compared between women age less than 70 years and women age ≥ 70 years. The cumulative incidence of breast cancer-related and non-breast cancer-related mortality was assessed according to age and comorbidities.

RESULTS

One thousand six hundred sixty-two patients (27%) were age ≥ 70 years at study entry. Older women were more likely to undergo mastectomy (odds ratio [OR], 1.92; 95% CI, 1.71 to 2.16) and less likely to receive radiotherapy (OR, 0.49; 95% CI, 0.44 to 0.55) or chemotherapy (OR, 0.24; 95% CI, 0.18 to 0.29). Women age ≥ 70 years had an increased risk of recurrence compared with women age less than 70 years (hazard ratio [HR], 1.21; 95% CI, 1.08 to 1.37) and a substantially increased risk of death without recurrence (HR, 4.13; 95% CI, 3.53 to 4.83). The risk of death without recurrence increased with comorbidity score (10-year estimates of 8.4%, 20.0%, and 30.4% for Satariano score 0, 1, and 2+, respectively; P < .001).

CONCLUSION

Age influences the risk of recurrence, and age and comorbidities significantly influence the risk of death without recurrence. Formal assessment of comorbidities should be incorporated into decisions regarding adjuvant therapies.

Prognostic value of a combined estrogen receptor, progesterone receptor, Ki-67, and human epidermal growth factor receptor 2 immunohistochemical score and comparison with the Genomic Health recurrence score in early breast cancer

PURPOSE

We recently reported that the mRNA-based, 21-gene Genomic Health recurrence score (GHI-RS) provided additional prognostic information regarding distant recurrence beyond that obtained from classical clinicopathologic factors (age, nodal status, tumor size, grade, endocrine treatment) in women with early breast cancer, confirming earlier reports. The aim of this article is to determine how much of this information is contained in standard immunohistochemical (IHC) markers.

PATIENTS AND METHODS

The primary cohort comprised 1,125 estrogen receptor-positive (ER-positive) patients from the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial who did not receive adjuvant chemotherapy, had the GHI-RS computed, and had adequate tissue for the four IHC measurements: ER, progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), and Ki-67. Distant recurrence was the primary end point, and proportional hazards models were used with sample splitting to control for overfitting. A prognostic model that used classical variables and the four IHC markers (IHC4 score) was created and assessed in a separate cohort of 786 patients.

RESULTS

All four IHC markers provided independent prognostic information in the presence of classical variables. In sample-splitting analyses, the information in the IHC4 score was found to be similar to that in the GHI-RS, and little additional prognostic value was seen in the combined use of both scores. The prognostic value of the IHC4 score was further validated in the second separate cohort.

CONCLUSION

This study suggests that the amount of prognostic information contained in four widely performed IHC assays is similar to that in the GHI-RS. Additional studies are needed to determine the general applicability of the IHC4 score.

Recruiting South Asians to a lifestyle intervention trial: experiences and lessons from PODOSA (Prevention of Diabetes & Obesity in South Asians)

Background

Despite the growing emphasis on the inclusion of ethnic minority patients in research, there is little published on the recruitment of these populations especially to randomised, community based, lifestyle intervention trials in the UK.

Methods

We share our experience of recruitment to screening in the PODOSA (Prevention of Diabetes and Obesity in South Asians) trial, which screened 1319 recruits (target 1800) for trial eligibility. A multi-pronged recruitment approach was used. Enrolment via the National Health Service included direct referrals from health care professionals and written invitations via general practices. Recruitment within the community was carried out by both the research team and through our partnerships with local South Asian groups and organisations. Participants were encouraged to refer friends and family throughout the recruitment period.

Results

Health care professionals referred only 55 potential participants. The response to written invitations via general practitioners was 5.2%, lower than reported in other general populations. Community orientated, personal approaches for recruitment were comparatively effective yielding 1728 referrals (82%) to the screening stage.

Conclusions

The PODOSA experience shows that a community orientated, personal approach for recruiting South Asian ethnic minority populations can be successful in a trial setting. We recommend that consideration is given to cover recruitment costs associated with community engagement and other personalised approaches. Researchers should consider prioritising approaches that minimise interference with professionals' work and, particularly in the current economic climate, keep costs to a minimum. The lessons learned in PODOSA should contribute to future community based trials in South Asians.

Trial Registration

Current Controlled Trials ISRCTN25729565

Risk-targeted selection of agricultural holdings for post-epidemic surveillance: estimation of efficiency gains

Current post-epidemic sero-surveillance uses random selection of animal holdings. A better strategy may be to estimate the benefits gained by sampling each farm and use this to target selection. In this study we estimate the probability of undiscovered infection for sheep farms in Devon after the 2001 foot-and-mouth disease outbreak using the combination of a previously published model of daily infection risk and a simple model of probability of discovery of infection during the outbreak. This allows comparison of the system sensitivity (ability to detect infection in the area) of arbitrary, random sampling compared to risk-targeted selection across a full range of sampling budgets. We show that it is possible to achieve 95% system sensitivity by sampling, on average, 945 farms with random sampling and 184 farms with risk-targeted sampling. We also examine the effect of ordering samples by risk to expedite return to a disease-free status. Risk ordering the sampling process results in detection of positive farms, if present, 15.6 days sooner than with randomly ordered sampling, assuming 50 farms are tested per day.

Sitting time and waist circumference are associated with glycemia in U.K. South Asians: data from 1,228 adults screened for the PODOSA trial

OBJECTIVE

To investigate the independent contributions of waist circumference, physical activity, and sedentary behavior on glycemia in South Asians living in Scotland.

RESEARCH DESIGN AND METHODS

Participants were 1,228 (523 men and 705 women) adults of Indian or Pakistani origin screened for the Prevention of Type 2 Diabetes and Obesity in South Asians (PODOSA) trial. All undertook an oral glucose tolerance test, had physical activity and sitting time assessed by International Physical Activity Questionnaire, and had waist circumference measured.

RESULTS

Mean ± SD age and waist circumference were 49.8 ± 10.1 years and 99.2 ± 10.2 cm, respectively. One hundred ninety-one participants had impaired fasting glycemia or impaired glucose tolerance, and 97 had possible type 2 diabetes. In multivariate regression analysis, age (0.012 mmol ⋅ L⁻¹ ⋅ year⁻¹ [95% CI 0.006-0.017]) and waist circumference (0.018 mmol ⋅ L⁻¹ ⋅ cm⁻¹ [0.012-0.024]) were significantly independently associated with fasting glucose concentration, and age (0.032 mmol ⋅ L⁻¹ ⋅ year⁻¹ [0.016-0.049]), waist (0.057 mmol ⋅ L⁻¹ ⋅ cm⁻¹ [0.040-0.074]), and sitting time (0.097 mmol ⋅ L⁻¹ ⋅ h⁻¹ ⋅ day⁻¹ [0.036-0.158]) were significantly independently associated with 2-h glucose concentration. Vigorous activity time had a borderline significant association with 2-h glucose concentration (-0.819 mmol ⋅ L⁻¹ ⋅ h⁻¹ ⋅ day⁻¹ [-1.672 to 0.034]) in the multivariate model.

CONCLUSIONS

These data highlight an important relationship between sitting time and 2-h glucose levels in U.K. South Asians, independent of physical activity and waist circumference. Although the data are cross-sectional and thus do not permit firm conclusions about causality to be drawn, the results suggest that further study investigating the effects of sitting time on glycemia and other aspects of metabolic risk in South Asian populations is warranted.

Tamoxifen-induced reduction in mammographic density and breast cancer risk reduction: a nested case-control study

BACKGROUND

Mammographic breast density is a strong risk factor for breast cancer. Tamoxifen, which reduces the risk of breast cancer in women at high risk, also reduces mammographic breast density. However, it is not known if tamoxifen-induced reductions in breast density can be used to identify women who will benefit the most from prophylactic treatment with this drug.

METHODS

We conducted a nested case-control study within the first International Breast Cancer Intervention Study, a randomized prevention trial of tamoxifen vs placebo. Mammographic breast density was assessed visually and expressed as a percentage of the total breast area in 5% increments. Case subjects were 123 women diagnosed with breast cancer at or after their first follow-up mammogram, which took place 12-18 months after trial entry, and control subjects were 942 women without breast cancer. Multivariable logistic regression was used to adjust for other risk factors. All statistical tests were two-sided.

RESULTS

In the tamoxifen arm, 46% of women had a 10% or greater reduction in breast density at their 12- to 18-month mammogram. Compared with all women in the placebo group, women in the tamoxifen group who experienced a 10% or greater reduction in breast density had 63% reduction in breast cancer risk (odds ratio = 0.37, 95% confidence interval = 0.20 to 0.69, P = .002), whereas those who took tamoxifen but experienced less than a 10% reduction in breast density had no risk reduction (odds ratio = 1.13, 95% confidence interval = 0.72 to 1.77, P = .60). In the placebo arm, there was no statistically significant difference in breast cancer risk between subjects who experienced less than a 10% reduction in mammographic density and subjects who experienced a greater reduction.

CONCLUSION

The 12- to 18-month change in mammographic breast density is an excellent predictor of response to tamoxifen in the preventive setting.