Prognostic and predictive value of ERβ1 and ERβ2 in the Intergroup Exemestane Study (IES)-first results from PathIES†

BACKGROUND

Intergroup Exemestane Study (IES) was a randomised study that showed a survival benefit of switching adjuvant endocrine therapy after 2-3 years from tamoxifen to exemestane. PathIES aimed to assess the potential prognostic and predictive value of ERβ1 and ERβ2 expression in primary tumours in order to determine benefit in the two treatment arms.

PATIENTS AND METHODS

Primary tumour samples were available for 1256 patients (27% IES population). ERβ1 and ERβ2 expression was dichotomised at the median IHC score (high if ERβ1 ≥ 191, ERβ2 ≥ 164). Hazard ratios (HRs) were estimated by multivariable Cox proportional hazards models adjusting for clinicopathological factors. Treatment effects with biomarker expressions were determined by interaction tests. Analysis explored effects of markers both as a continuous variable and with dichotomised cut-offs.

RESULTS

Neither ERβ1 nor ERβ2 were associated with disease-free survival (DFS) or overall survival (OS) in the whole cohort. In patients treated with continued tamoxifen, high ERβ1 expression compared with low was associated with better DFS [HR = 0.38:95% confidence interval (CI) 0.21-0.68, P = 0.001]. DFS benefit of exemestane over tamoxifen (HR = 0.40:95% CI 0.22-0.70) was found in the low ERβ1 subgroup (interaction P = 0.01). No significant difference with treatment was observed for ERβ2 expression in either DFS or OS.

CONCLUSION

In the PathIES population, exemestane appeared to be superior to tamoxifen among patients with low ERβ1 expression but not in those with high ERβ1 expression. This is the first trial of its kind to report a parameter potentially predicting benefit of an aromatase inhibitor when compared with tamoxifen and an independent validation is warranted.

Extreme chromosomal instability forecasts improved outcome in ER-negative breast cancer: a prospective validation cohort study from the TACT trial

BACKGROUND

Chromosomal instability (CIN) has been shown to be associated with drug resistance and poor clinical outcome in several cancer types. However, in oestrogen receptor (ER)-negative breast cancer we have previously demonstrated that extreme CIN is associated with improved clinical outcome, consistent with a negative impact of CIN on tumour fitness and growth. The aim of this current study was to validate this finding using previously defined CIN thresholds in a much larger prospective cohort from a randomised, controlled, clinical trial.

PATIENTS AND METHODS

As a surrogate measurement of CIN, dual centromeric fluorescence in situ hybridisation was performed for both chromosomes 2 and 15 on 1173 tumours from the breast cancer TACT trial (CRUK01/001). Each tumour was scored manually and the mean percentage of cells deviating from the modal centromere number was used to define four CIN groups (MCD1-4), where tumours in the MCD4 group were defined as having extreme CIN.

RESULTS

In a multivariate analysis of disease-free survival, with a median follow-up of 91 months, increasing CIN was associated with improved outcome in patients with ER-negative cancer (P trend = 0.03). A similar pattern was seen in ER-negative/HER2-negative cancers (Ptrend = 0.007).

CONCLUSIONS

This prospective validation cohort study further substantiated the association between extreme CIN and improved outcome in ER-negative breast cancers. Identifying such patients with extreme CIN may help distinguish good from poor prognostic groups, and therefore support treatment and risk stratification in this aggressive breast cancer subtype.

Guidelines for time-to-event end point definitions in breast cancer trials: results of the DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials)†

BACKGROUND

Using surrogate end points for overall survival, such as disease-free survival, is increasingly common in randomized controlled trials. However, the definitions of several of these time-to-event (TTE) end points are imprecisely which limits interpretation and cross-trial comparisons. The estimation of treatment effects may be directly affected by the definitions of end points. The DATECAN initiative (Definition for the Assessment of Time-to-event Endpoints in CANcer trials) aims to provide recommendations for definitions of TTE end points. We report guidelines for randomized cancer clinical trials (RCTs) in breast cancer.

PATIENTS AND METHODS

A literature review was carried out to identify TTE end points (primary or secondary) reported in publications of randomized trials or guidelines. An international multidisciplinary panel of experts proposed recommendations for the definitions of these end points based on a validated consensus method that formalize the degree of agreement among experts.

RESULTS

Recommended guidelines for the definitions of TTE end points commonly used in RCTs for breast cancer are provided for non-metastatic and metastatic settings.

CONCLUSION

The use of standardized definitions should facilitate comparisons of trial results and improve the quality of trial design and reporting. These guidelines could be of particular interest to those involved in the design, conducting, reporting, or assessment of RCT.

Learning from the QUEST multicentre feasibility randomization trials in breast reconstruction after mastectomy

BACKGROUND

Breast reconstruction aims to improve health-related quality of life after mastectomy. However, evidence guiding patients and surgeons in shared decision-making concerning the optimal type or timing of surgery is lacking.

METHODS

QUEST comprised two parallel feasibility phase III randomized multicentre trials to assess the impact of the type and timing of latissimus dorsi breast reconstruction on health-related quality of life when postmastectomy radiotherapy is unlikely (QUEST A) or highly probable (QUEST B). The primary endpoint for the feasibility phase was the proportion of women who accepted randomization, and it would be considered feasible if patient acceptability rates exceeded 25 per cent of women approached. A companion QUEST Perspectives Study (QPS) of patients (both accepting and declining trial participation) and healthcare professionals assessed trial acceptability.

RESULTS

The QUEST trials opened in 15 UK centres. After 18 months of recruitment, 17 patients were randomized to QUEST A and eight to QUEST B, with overall acceptance rates of 19 per cent (17 of 88) and 22 per cent (8 of 36) respectively. The QPS recruited 56 patients and 51 healthcare professionals. Patient preference was the predominant reason for declining trial entry, given by 47 (53 per cent) of the 88 patients approached for QUEST A and 22 (61 per cent) of the 36 approached for QUEST B. Both trials closed to recruitment in December 2012, acknowledging the challenges of achieving satisfactory patient accrual.

CONCLUSION

Despite extensive efforts to overcome recruitment barriers, it was not feasible to reach timely recruitment targets within a feasibility study. Patient preferences for breast reconstruction types and timings were common, rendering patients unwilling to enter the trial.

NEOCENT: a randomised feasibility and translational study comparing neoadjuvant endocrine therapy with chemotherapy in ER-rich postmenopausal primary breast cancer

Neoadjuvant endocrine therapy is an alternative to chemotherapy for women with oestrogen receptor (ER)-positive early breast cancer (BC). We aimed to assess feasibility of recruiting patients to a study comparing chemotherapy versus endocrine therapy in postmenopausal women with ER-rich primary BC, and response as well as translational endpoints were assessed. Patients requiring neoadjuvant therapy were randomised to chemotherapy: 6 × 3-weekly cycles FE₁₀₀C or endocrine therapy: letrozole 2.5 mg, daily for 18-23 weeks. Primary endpoints were recruitment feasibility and tissue collection. Secondary endpoints included clinical, radiological and pathological response rates, quality of life and translational endpoints. 63/80 patients approached were eligible, of those 44 (70, 95% CI 57-81) were randomised. 12 (54.5, 95% CI 32.2-75.6) chemotherapy patients showed radiological objective response compared with 13 (59.1, 95% CI 36.4-79.3) letrozole patients. Compared with baseline, mean Ki-67 levels fell in both groups at days 2-4 and at surgery [fold change: 0.24 (95% CI 0.12-0.51) and 0.24; (95% CI 0.15-0.37), respectively]. Plasma total cfDNA levels rose from baseline to week 8 [fold change: chemotherapy 2.10 (95% CI 1.47-3.00), letrozole 1.47(95% CI 0.98-2.20)], and were maintained at surgery in the chemotherapy group [chemotherapy 2.63; 95% CI 1.56-4.41), letrozole 0.95 (95% CI 0.71-1.26)]. An increase in plasma let-7a miRNA was seen at surgery for patients with objective radiological response to chemotherapy. Recruitment and tissue collection endpoints were met; however, a larger trial was deemed unfeasible due to slow accrual. Both regimens were equally efficacious. Dynamic changes were seen in Ki-67 and circulating biomarkers in both groups with increases in cfDNA and let-7a miRNA persisting until surgery for chemotherapy patients.

Comparison of patient reported quality of life and impact of treatment side effects experienced with a taxane-containing regimen and standard anthracycline based chemotherapy for early breast cancer: 6 year results from the UK TACT trial (CRUK/01/001)

BACKGROUND

The TACT trial (CRUK/01/001) compared adjuvant sequential FEC-docetaxel (FEC-D) chemotherapy with standard anthracycline-based chemotherapy of similar duration in women with early breast cancer. Results at a median of 5 years suggested no improvement in disease-free survival with FEC-D. Given differing toxicity profiles of the regimens, the impact on quality of life (QL) was explored.

METHODS

Patients from 44 centres completed standardised QL questionnaires before chemotherapy, after cycles 4 and 8, at 9, 12, 18 and 24 months and at 6 years follow-up. Patient diaries assessed frequency, associated distress and impact on daily activity of 15 treatment related side effects.

FINDINGS

830 patients (415 FEC-D; 415 controls) contributed assessments during 0-24 months; 362 of whom participated again at 6 years. During chemotherapy, FEC-D impaired global health/QL and depression rates and significantly more QL domains than standard regimens. Novel diary card ratings highlighted significantly more distress and interference with daily activities due to FEC-D side effects compared with standard treatment. In both groups, most QL parameters returned to baseline levels by 2 years and were unchanged at 6 years.

INTERPRETATION

Within expected negative effects of chemotherapy on wide ranging QL domains FEC-D patients reported greater toxicity, disruption and distress during treatment with no improvement in disease outcome at 5 years than patients receiving standard anthracycline-based chemotherapy. Findings should inform future patients of relative costs and benefits of adjuvant chemotherapy.

Assessment of microtubule-associated protein (MAP)-Tau expression as a predictive and prognostic marker in TACT; a trial assessing substitution of sequential docetaxel for FEC as adjuvant chemotherapy for early breast cancer

The TACT trial is the largest study assessing the benefit of taxanes as part of adjuvant therapy for early breast cancer. The goal of this translational study was to clarify the predictive and prognostic value of Tau within the TACT trial. Tissue microarrays (TMA) were available from 3,610 patients. ER, PR, HER2 from the TACT trial and Tau protein expression was determined by immunohistochemistry on duplicate TMAs. Two parallel scoring systems were generated for Tau expression ('dichotomised' vs. 'combined' score). The positivity rate of Tau expression was 50 % in the trial population (n = 2,483). Tau expression correlated positively with ER (p < 0.001) and PR status (p < 0.001); but negatively with histological grade (p < 0.001) and HER2 status (p < 0.001). Analyses with either scoring systems for Tau expression demonstrated no significant interaction between Tau expression and efficacy of docetaxel. Contrary to the hypothesis that taxane benefit would be enriched in Tau negative/low patients, the only groups with a suggestion of a reduced event rate in the taxane group were the HER2-positive, Tau positive subgroups. Tau expression was seen to be a prognostic factor on univariate analysis associated with an improved DFS, independent of the treatment group (p < 0.001). It had no prognostic value in ER-negative tumours and the weak prognostic effect of Tau in ER-positive tumours (p = 0.02) diminished, when considering ER as an ordinal variable. On multivariable analyses, Tau had no prognostic value in either group. In addition, no significant interaction between Tau expression and benefit from docetaxel in patients within the PR-positive and negative subsets was seen. This is now the second large adjuvant study, and the first with quantitative analysis of ER and Tau expression, failing to show an association between Tau and taxane benefit with limited utility as a prognostic marker for Tau in ER-positive early breast cancer patients.

Second cancer risk and mortality in men treated with radiotherapy for stage I seminoma

BACKGROUND

Patients with stage I testicular seminoma are typically diagnosed at a young age and treatment is associated with low relapse and mortality rates. The long-term risks of adjuvant radiotherapy in this patient group are therefore particularly relevant.

METHODS

We identified patients and obtained treatment details from 12 cancer centres (11 United Kingdom, 1 Norway) and ascertained second cancers and mortality through national registries. Data from 2629 seminoma patients treated with radiotherapy between 1960 and 1992 were available, contributing 51,151 person-years of follow-up.

RESULTS

Four hundred and sixty-eight second cancers (excluding non-melanoma skin cancers) were identified. The standardised incidence ratio (SIR) was 1.61 (95% confidence interval (CI): 1.47-1.76, P<0.0001). The SIR was 1.53 (95% CI: 1.39-1.68, P<0.0001) when the 32 second testicular cancers were also excluded. This increase was largely due to an excess risk to organs in the radiation field; for pelvic-abdominal sites the SIR was 1.62 (95% CI: 1.43-1.83), with no significant elevated risk of cancers in organs elsewhere. There was no overall increase in mortality with a standardised mortality ratio (SMR) of 1.06 (95% CI: 0.98-1.14), despite an increase in the cancer-specific mortality (excluding testicular cancer deaths) SMR of 1.46 (95% CI: 1.30-1.65, P<0.0001).

CONCLUSION

The prognosis of stage I seminoma is excellent and it is important to avoid conferring long-term increased risk of iatrogenic disease such as radiation-associated second cancers.

Abstract S4-07: Effects of bisphosphonate treatment on recurrence and cause-specific mortality in women with early breast cancer: A meta-analysis of individual patient data from randomised trials

Background: Disseminated tumour cells can remain dormant in the bone marrow for years prior to subsequent activation and the development of overt metastases. Bisphosphonates (BP) have profound effects on bone physiology and could potentially modify the metastatic disease process. Variable outcomes in terms of disease recurrence have been reported, with efficacy apparently influenced by menopausal status.

Methods: We sought individual patient data for meta-analysis from 41 randomised trials that compared BP to no BP (placebo or open control). Primary outcomes were time to recurrence, time to first distant recurrence and breast cancer mortality. Predefined subgroup comparisons were of type of BP (amino-/non-amino), duration and schedule of BP treatment, menopausal status, age, ER status, concomitant chemotherapy and site of distant recurrence (bone/other).

Results: Data on 17,751 women (75% of 23,573 randomised in relevant trials) have so far been received, with around 3,300 breast cancer recurrences and 2,500 deaths. Effects on breast cancer mortality, recurrence and bone metastases for 17,016 women in the locked database and for 10,540 who were postmenopausal are shown below.

No. eventsRate Ratio (SE)10 year gain2p valueAll women (n = 17,016)Breast cancer mortality2,0490.91 (0.04)1.7%0.04Breast cancer recurrence3,2840.94 (0.04)1.0%0.13Distant recurrence2,7510.92 (0.04)1.3%0.05Bone recurrence8250.79 (0.07)1.4%0.002Other distant recurrence1,9260.99 (0.05)0.1%0.8Postmenopausal women (n = 10,540)Breast cancer mortality1,1070.83 (0.06)3.1%0.004Breast cancer recurrence1,8090.86 (0.05)3.0%0.002Distant recurrence1,5030.83 (0.05)3.3%0.0007Bone recurrence4450.65 (0.08)2.9%0.00001Other distant recurrence1,0580.93 (0.06)0.7%0.26

Reductions in bone recurrence for postmenopausal women were similar irrespective of bisphosphonate type, treatment schedule, ER status, nodal involvement or use of concomitant chemotherapy. There were no improvements in bone (RR = 1.00, 2p = 0.97) or other recurrence for premenopausal women. Adjuvant bisphosphonates also reduced bone fractures (RR = 0.83, 2p = 0.009).

Conclusion: Adjuvant bisphosphonates reduce bone recurrences and improve breast cancer survival in postmenopausal but not premenopausal women.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr S4-07.

Abstract P2-19-10: Quality of life following mastectomy and breast reconstruction (QUEST): Learning from two feasibility randomized controlled clinical trials

Background: Breast reconstruction (BRR) aims to improve health related quality of life (HRQL) after mastectomy, but with poor evidence to date informing the optimal type or timing of surgery to guide shared-decision making. Systematic reviews show the paucity of randomised trials (RCT) with only two-singe centre RCTs. Although, an RCT has theoretical advantages, there have been concerns that clinicians may not share clinical equipoise regarding recommending types of BRR surgery that is sensitive to patient preferences. The aim of the QUEST trials (CRUK/08/027) was to determine the optimal types of latissimus dorsi (LD) BRR (Trial A) when there is no expectation for post-mastectomy radiotherapy (PMRT), and timings of LDBRR when PMRT is recommended (Trial B), that would benefit HRQL during five years post-operatively. As this was the first attempt at a multi-centre RCT, the main trial was preceded by a feasibility phase to demonstrate that recruitment was achievable and that randomization was acceptable to patients. An embedded qualitative study, the QUEST Perspective Study (QPS) assessed the perceptions of equipoise of patients and health care professionals (HCPs) for the types of surgery.

Methods: QUEST comprised two parallel phase III multicentre feasibility RCTs to assess HRQL impact of the type of LDBRR when PMRT is unlikely (Trial A, LD - implant assisted (LDI) versus extended autologous LD (ALD)). Trial B evaluated optimal timings of LDBRR comparing staged - delayed ALD (skin-preserving sub-pectoral expander implant then ALD) to immediate ALD when PMRT was likely.

Eligible patients comprised mastectomy recommended for invasive breast cancer or DCIS in the context of technical feasibility for ALD and preferred synchronous breast reduction. The primary endpoint was the proportion of eligible women approached who accepted randomisation. QPS explored patients and HCPs’ acceptability of the trial and randomisation using semi-structured telephone interviews and questionnaires.

Results: The QUEST trials opened in May 2011 with 15 UK centres participating. After 18 months of recruitment, 17 patients had been entered in Trial A and 8 in trial B with acceptance rates of 19% (17/88) and 22% (8/36) for trial A and B respectively. Patient preference was the predominant reason for eligible patients approached about the trial not being randomised with 47 of the 88 (53%) for Trial A and 22 of 36 (61%) eligible for Trial B, declining for that reason. Patient acceptance rates for randomisation increased from 19% during the first 6 months to 29% from 7-12 months for Trial A; corresponding figures for Trial B were 11% and 27%. The recruitment challenges and funding cessation caused the Trial Steering Committee to recommend trial closure in December 2012.

Conclusion: Despite the need for clinical evidence, patients retained strong preferences for breast reconstruction type and timing, amidst ‘standardised’ trial processes. Patient acceptance rates did improve during the trial, but it was not possible to meet target recruitment within the constraints of a feasibility trial.

Funding for this NCRN portfolio trial (92581226) was from Cancer Research UK (CRUK) and BUPA Foundation funding for QPS.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-19-10.

Abstract P6-07-15: The effect of taxanes in ER+ early breast cancer is likely to be mitigated by chromosomal instability

Background: Mechanisms of tumour sensitivity to microtubule-stabilizing (MTS) agents, such as taxanes, are still a matter of debate. Through an RNA interference screen for regulators of taxane resistance, our group identified a number of genes which initiated taxane resistance and Chromosomal INstability (CIN) (1) when silenced, suggesting that the cellular mechanisms that monitor faithful chromosome segregation may also impact upon taxane sensitivity. Consistent with this hypothesis, we previously reported in a small clinical trial cohort of ovarian cancers that CIN tumours (defined by overexpression of the CIN70 signature) appeared to be relatively resistant to paclitaxel in vivo (2). We have observed that repression of a subset of the CIN70 signature occurs in diploid cancer cells following paclitaxel exposure, contributing to cell death. Conversely, less efficient repression of these CIN70 genes occurs in CIN cells following paclitaxel exposure. Overexpression of the CIN70 signature is associated with poor clinical outcome and chromosomal instability is significantly correlated with high tumour grade in ER positive disease. We hypothesised that in ER+ tumours the effect of taxanes should decrease with tumour grade and relative chromosomal instability (3). We assessed this hypothesis by analysing the differences in the published taxane effect in the EBCTCG Chemotherapy overview (4) according to tumour grade.

Methods: Annual event rate ratios and 95% CIs were calculated from data on over 20,000 early breast cancer patients treated with chemotherapy (4). P-values for trend in taxane effect were calculated across 3 tumour grade categories or for heterogeneity between 2 categories.

Results: The table shows annual event rate ratios (CIs) for grade categories, for taxane-plus-anthracycline-based regimen versus the same, or more (&lt; doubled or ∼doubled) non-taxane cytotoxic chemotherapy. Significantly different taxane effects were observed across categories of tumour grade. For both endpoints taxane benefit increased with lower tumour grade, there was a smaller effect in high grade tumours and no evidence the treatment benefit decreased with follow up time.

Abstract P2-14-01: Fulvestrant vs exemestane for treatment of metastatic breast cancer in patients with acquired resistance to non-steroidal aromatase inhibitors – a meta-analysis of EFECT and SoFEA (CRUKE/03/021 & CRUK/09/007)

Background: Optimal endocrine treatment (trt) for post-menopausal women with ER+ advanced breast cancer (ABC) progressing on or following a non-steroidal (NS) aromatase inhibitor (AI) is unclear. The EFECT study showed no difference in efficacy between the steroidal antiestrogen fulvestrant (F) & steroidal AI exemestane (E) in this setting (HR = 0.96, 95%CI: 0.82, 1.13; p = 0.65). Pre-clinical data suggest F may be more effective in a low estrogen environment. SoFEA investigated F combined with anastrozole (F+A) in patients (pts) with acquired resistance to previous AI compared with F alone & F alone vs. E. The combination of F+A was no better than F (HR = 1.00, 95%CI: 0.83, 1.21; p = 0.98) nor F alone better than E (HR = 0.95, 95%CI: 0.79, 1.14; p = 0.56); the lack of added benefit for F+A is consistent with previous 1st-line studies that have assessed this combination versus A alone (FACT & SWOG-S0226).

Methods: SoFEA is a multi-center partially blinded randomized phase III study postmenopausal women were allocated to F plus A (F+A n=243), F plus placebo (n = 231) or E (n = 249). Similarly, EFECT is a randomized, double-blind, placebo controlled, multi-center phase III trial of F (n = 351) versus E (n = 342) in postmenopausal women (see table). However, given the differences in prior endocrine therapy/responsiveness within SoFEA & EFECT populations, an individual pt meta-analysis combining data from SoFEA & EFECT will be conducted enabling exploration of putative effects within specific pt subgroups to establish evidence in support, or not, of a pt subgroup sensitive to F at the dose used in these trials. Subgroups to be analysed include receptor status, visceral involvement, AI sensitivity, age, NSAI setting & time on NSAI.

Results: 723 pts (480 in F & E) were enrolled from 82 UK & 4 South Korean centers (03/2004-04/2010) in SoFEA. 693 pts were enrolled from 138 centers worldwide (08/2003-11/2005) in EFECT. Trt was well tolerated in both trials; serious adverse events were rare. The meta-analysis will be conducted in July 2012 & results presented.

Conclusion: Combining individual pt data from SoFEA & EFECT via meta-analysis will provide definitive clinical information on pt's response to F at the dose used in these studies, in particular whether certain pts with acquired resistance to NSAI do experience benefit of use of this antiestrogen as opposed to E.

Abstract PD07-07: Prediction of antiproliferative response to lapatinib by HER3 in an exploratory analysis of HER2-non-amplified (HER2−) breast cancer in the MAPLE presurgical study (CRUK E/06/039)

Aim: To identify pretreatment biomarker predictors of Ki67 response to lapatinib in women with HER2− primary breast cancer.

Background: Lapatinib is an EGFR/HER2 inhibitor. Its clinical use is restricted to HER2 overexpressing disease. The MAPLE (Molecular Antiproliferative Predictors of Lapatinib's Effects) presurgical window of opportunity study of lapatinib vs placebo was conducted in women with HER2-amplified (HER2+) or HER2− primary disease. Ki67 (primary end-point) was reduced by a geomean 46% (95%CI 23–63%, p = 0.002) and 27% (95%CI 8–42%, p = 0.008) in HER2+ and HER2− disease, respectively (Leary et al, AACR 2012). We have now assessed whether predictive biomarkers of the antiproliferative response in HER2− disease could be identified.

Methods: 121 primary breast cancer patients were randomized (3:1) to 14 days of 1500mg/d lapatinib or placebo before surgery. Biopsies were taken before treatment and at surgery. Ki67 responders were defined as having a &gt;/=50% reduction in Ki67 compared to baseline (Ellis, P et al, Breast Cancer Res Treat 1998, 48, 107). ER, PgR, HER2, EGFR, pAKT, pERK1/2 (nuclear and cytoplasmic), stathmin and apoptosis (TUNEL) were assessed by IHC (+FISH for HER2[all cases]) and scored visually by continuous methods. HER2, HER3, epiregulin (epir), amphiregulin (amphir) and neuregulin (neur) were assessed by qrtPCR.

Results: Three of the 121 patients were excluded because of inadequate biopsy material. Ninety-one of the remaining 118 patients received lapatinib: 7/19 (37%) HER2+ cases and 10/72 (14%) HER2− cases were Ki67 responders. Thus while the proportion of Ki67 responders was higher for HER2+ disease there was a similar or higher absolute number of responders with HER2− disease. All of the following relates to patients with HER2− disease. None of the pretreatment levels of ER, PgR, pAKT, pERK1/2, EGFR, epir, amphir or neur were associated with Ki67 response (p &gt; 0.20). However, HER3 (p = 0.01) and HER2 (p = 0.06) mRNA levels were associated with greater Ki67 response. There was a tendency for Ki67 response to be greater with lower baseline Ki67 (p = 0.07). Multivariate analysis showed only HER3 mRNA levels to be independently significant. HER2 and HER3 mRNA levels were highly correlated (rho = 0.67, p &lt; 0.001), a relationship confirmed in 2 other datasets (Wang et al, Breast Cancer Res, 2011, 13, R92; Dunbier et al, submitted). All Ki67 responders were above the median for both HER3 and HER2 expression.

Conclusions: Lapatinib is antiproliferative in a subgroup of HER2− tumours. This exploratory analysis indicates that they are characterized by high HER3 expression. The possible importance of high HER2:HER3 heterodimers in predicting this response is supported by the relationship between HER2 and HER3 expression. Further exploration of lapatinib is merited in HER2− cases with high HER3 expression.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD07-07.

Abstract P1-13-03: Mature analysis of UK Taxotere as Adjuvant Chemotherapy (TACT) trial (CRUK 01/001); effects of treatment and characterisation of patterns of breast cancer relapse

Introduction: TACT, an investigator-led study in 4162 women with node positive (N+ve) or high risk node negative (N-ve) early breast cancer (EBC), is the largest taxane trial unconfounded by treatment (trt) duration. At principal analysis, with 5 years follow-up (fup), no evidence of improved disease-free survival (DFS) was observed by switching to 4 cycles of docetaxel (D) after 4 cycles of FEC (Ellis, Lancet 2009). Results were provocative in suggesting differential effects according to ER & HER2 status. Longer fup provides opportunity to detect emergence of late trt effects overall & within phenotypic subgroups & explore patterns of recurrence, by tumor characteristics.

Patients & methods: TACT recruited women with histologically confirmed completely resected invasive EBC from 104 centers (UK (103), Belgium (1)) between 02/2001 & 07/2003. Centers chose FEC (600/60/600 mg/m2 q3wk × 8) or E-CMF (E 100mg/m2 q3wk × 4 → CMF 100mg/m2 PO d1-14 or 600mg/m2 IV d1&8/40/600 mg/m2 q4wk × 4) as their control, reflecting standard UK practice. Patients (pts) were randomized to FEC-D (FEC q3wk × 4 → D 100 mg/m2 q3wk × 4) or control. 2523 pts were from FEC centers (FEC = 1265: FEC-D = 1258) & 1639 from E-CMF centers (E-CMF = 824; FEC-D = 815). Endocrine therapy was given for 5 years. Few pts received HER2 directed therapy; 589 pts had unknown HER2 status. Median fup is now 97.5 months; this analysis updates DFS & overall survival in the ITT population. It also explores patterns of relapse by phenotypic & clinical characteristics. Analyses of trt effect are stratified by ER status due to issues of non-proportionality of hazard associated with length of fup.

Results: DFS events have been reported for 1329 pts (FEC-D=640, Control=689) giving an unadjusted hazard ratio (HR) & 95%CI (stratified by control regimen & ER status) of 0.93 (0.83, 1.03) overall; p = 0.16 in favor of FEC-D & for ER+ve/HER2-ve of 0.99 (0.84, 1.17), for ER+ve/HER2+ve) 0.97 (0.73, 1.30), for ER-ve/HER2+ve 0.74 (0.53, 1.03), & ER-ve/HER2-ve 0.93 (0.73, 1.17). 1017 patients have died (FEC-D=500, Control=517); unadjusted HR=0.98 (95%CI: 0.86, 1.10); p = 0.69 with intercurrent deaths (prior to distant relapse) reported for 80 pts (FEC-D=40, Control=40).

Annual event rates show different pattern of disease relapse by phenotypic subgroup

Long-term assessment of quality of life in the Intergroup Exemestane Study: 5 years post-randomisation

BACKGROUND

The Intergroup Exemestane Study (IES) (ISRCTN11883920) demonstrated improved survival for postmenopausal women with ER-positive/unknown primary breast cancer who switched to exemestane after 2-3 years tamoxifen, compared with those continuing on tamoxifen to complete 5 years therapy. This was achieved without detriment to on-treatment quality-of-life (QoL). We report on- and post-treatment QoL impact in IES.

METHODS

A total of 582 patients from 8 countries participated in the QoL substudy. Functional Assessment of Cancer Therapy-Breast (FACT-B) and endocrine symptom subscale (ES) were completed at baseline, 3, 6, 9, 12, 18, 24, 30, 36, 48 and 60 months. The primary endpoint was FACT-B Trial Outcome Index (TOI); secondary endpoints included severity of individual endocrine symptoms.

RESULTS

Both the groups showed gradual improvement in overall QoL and lessening of total endocrine symptoms post treatment compared with baseline (P<0.002). There was no evidence of any between-group differences in TOI. Vasomotor complaints remained high on treatment. Vaginal discharge was more frequent (P<0.01) with tamoxifen up to 24 months from baseline. In both the groups, post-treatment libido did not recover to baseline levels.

CONCLUSION

Clinical benefits of switching to exemestane are accompanied by good overall QoL. Although some symptoms persist, the majority of endocrine symptoms improve after treatment completion.

OT2-03-04: A Trial Model for the Future in the Search for Personalised Medicine – The UK POETIC and EPHOS-B Perioperative Trials Experience

Background

Perioperative therapy offers the opportunity to measure biological response to treatment in the primary tumor in early breast cancer (EBC), enhancing prospects for personalised medicine. Perioperative trials form an expanding component of the UK national breast cancer trials portfolio. Unlike traditional neoadjuvant studies, activity dovetails around timelines for standard treatment with no planned delay to primary surgery. Tissue samples collected prior to randomisation (baseline) & again at surgery address key biological endpoints & are essential for perioperative studies.

Methods: As the UK's largest perioperative trial, POETIC (ER+ve postmenopausal EBC, +/− aromatase inhibitor therapy, biomarker & disease outcome) aims to recruit 4000 patients from 100+ centres.

EPHOS-B (HER2+ve EBC, +/− lapatinib or trastuzumab) focuses on biomarker endpoints & aims to recruit 250 patients. Barriers to recruitment included 1) integration of research protocols into busy breast surgical clinics, extending a clinical trials culture across a multidisciplinary breast diagnostic team, & ensuring appropriate GCP training, 2) satisfying requirements for storing research tissue, 3) complying with government cancer wait times, 4) obtaining biomarker results within required timelines 5) ensuring completeness & quality of tissue samples. Additional challenges for EPHOS-B include managing requirements for scheduling of oncological therapy (e.g. trastuzumab) in pre-operative setting, delivery of such therapy outside the randomising hospital & rapid access to cardiac screening before randomisation.

Results: The following strategies were developed to overcome barriers 1) increasing collaborative working at sites & adopting a pragmatic approach to type of tissue required. Centres choose to provide both FFPE tissue & tissue in RNA-later, or FFPE tissue only; 2) working with national regulators to agree interpretation of current legislation in designation of when tissue is “in transit” (enabling it to reside outside a tissue bank) & “research” tissue (where transfer to a tissue bank is required); 3) agreement with government that procedures integral to perioperative trials comply with cancer wait times; 4) promoting reorganisation of site processes for obtaining essential biomarker results; 5) pilot lab work to inform site guidance on tissue collection procedures to ensure quality of samples received. A tracking database allows completeness of tissue samples to be monitored. Work to improve timelines for HER2 testing in EPHOS-B is ongoing, & challenges of delivering anti-HER2 therapy in this setting have been addressed.

Conclusions: Assessment of biological response to therapy in the primary tumor in EBC within national trials is feasible. Many barriers faced by POETIC have been overcome, & with recruitment now 100+ patients per month, newer centres benefit from earlier experience. Lessons learnt in POETIC apply to EPHOS-B, allowing investigators to focus on resolving more challenging issues specific to that trial. In many centres both trials have been important drivers in improving timeliness of molecular testing & therefore benefited the patient pathway in general as well as securing high quality trial data.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr OT2-03-04.

Blood urea nitrogen and serum bicarbonate in extremely low birth weight infants receiving higher protein intake in the first week after birth

OBJECTIVE

To determine correlation between early protein administration and serum blood urea nitrogen (BUN) or bicarbonate (HCO(3)(-)) in extremely low birth weight (ELBW) infants during the first week of life.

STUDY DESIGN

A retrospective review of 154 ELBWs was conducted. Laboratory and nutritional data from postnatal days 1, 4 and 7 were collected. Repeated measures models estimated the relationship of protein intake with BUN and HCO(3)(-) in the first week of life.

RESULT

In total, 359 separate BUN and HCO(3)(-) values were analyzed. Each gram per kilogram of protein administered was associated with an increase in mean BUN of 3.3 mg/dl. This effect decreased daily by 2.1 mg/dl. Each gram per kilogram of protein administered was associated with a decrease in mean HCO(3)(-) by 0.9 mmol/l.

CONCLUSION

The association between protein load and BUN is positive but decreasing over time. Protein is associated with a clinically insignificant decrease in HCO(3)(-). Concerns regarding metabolic derangement from early protein administration in ELBWs are unwarranted.

The Impact of Radiotherapy Dose on Local Control of Ewing's Sarcoma of Bone

Purpose. Improvements in the systemic management of Ewing's sarcoma of bone over the last 20 years have led to a dramatic improvement in survival. The corollary is that treatment of the primary disease requires re-evaluation, since a significant number of patients still suffer local relapse.Patients. The effect of radiation dose on local control was reviewed in a series of 96 patients treated between 1967 and 1986. Seventy-four had no metastases at presentation (M0), 22 had metastases (M1). The 5-year survival of all patients was 28%, and of M0 patients alone 37%. Although these figures are poor by today's standards, they are consistent with published studies whose patients were enrolled during the same calendar period. Although most deaths occurred by 5 years, survival continued to fall beyond 10 years, which has implications for follow-up in future studies.Results. The local control (LC) rate at 5 years was 56% for all patients and for M0 patients analyzed separately. There was no difference in either LC or survival between the first and second decades of the study. Primary site was a significant determinant of survival and local control, with better outcome for limb tumours compared to pelvic primaries. Chemotherapy also had a major effect on LC. Radiotherapy improved the probability of LC. Omission of radiotherapy, or a dose <40 Gy, was ineffective. In the dose range 40-66 Gy, there was no evidence of a dose-response relationship.

The cost-effectiveness of adjuvant chemotherapy for early breast cancer: A comparison of no chemotherapy and first, second, and third generation regimens for patients with differing prognoses

BACKGROUND

The risk of recurrence following surgery in women with early breast cancer varies, depending upon prognostic factors. Adjuvant chemotherapy reduces this risk; however, increasingly effective regimens are associated with higher costs and toxicity profiles, making it likely that different regimens may be cost-effective for women with differing prognoses. To investigate this we performed a cost-effectiveness analysis of four treatment strategies: (1) no chemotherapy, (2) chemotherapy using cyclophosphamide, methotrexate, and fluorouracil (CMF) (a first generation regimen), (3) chemotherapy using Epirubicin-CMF (E-CMF) or fluorouracil, epirubicin, and cyclophosphamide (FEC60) (a second generation regimens), and (4) chemotherapy with FEC60 followed by docetaxel (FEC-D) (a third generation regimen). These adjuvant chemotherapy regimens were used in three large UK-led randomised controlled trials (RCTs).

METHODS

A Markov model was used to simulate the natural progression of early breast cancer and the impact of chemotherapy on modifying this process. The probability of a first recurrent event within the model was estimated for women with different prognostic risk profiles using a parametric regression-based survival model incorporating established prognostic factors. Other probabilities, treatment effects, costs and quality of life weights were estimated primarily using data from the three UK-led RCTs, a meta-analysis of all relevant RCTs, and other published literature. The model predicted the lifetime costs, quality adjusted life years (QALYs) and cost-effectiveness of the four strategies for women with differing prognoses. Sensitivity analyses investigated the impact of uncertain parameters and model assumptions.

FINDINGS

For women with an average to high risk of recurrence (based upon prognostic factors and any other adjuvant therapies received), FEC-D appeared most cost-effective assuming a threshold of £20,000 per QALY for the National Health Service (NHS). For younger low risk women, E-CMF/FEC60 tended to be the optimal strategy and, for some older low risk women, the model suggested a policy of no chemotherapy was cost-effective. For no patient group was CMF chemotherapy the preferred option. Sensitivity analyses demonstrated cost-effectiveness results to be particularly sensitive to the treatment effect estimate for FEC-D and the future price of docetaxel.

INTERPRETATION

To our knowledge, this analysis is the first cost-effectiveness comparison of no chemotherapy, and first, second, and third generation adjuvant chemotherapy regimens for early breast cancer patients with differing prognoses. The results demonstrate the potential for different treatment strategies to be cost-effective for different types of patients. These findings may prove useful for policy makers attempting to formulate cost-effective treatment guidelines in the field of early breast cancer.

Abstract P5-10-07: TACT2 Randomised Adjuvant Trial in Early Breast Cancer (EBC): Tolerability and Toxicity of Standard 3 Weekly Epirubicin (E) Versus Accelerated Epirubicin (aE) Followed by Capecitabine (X) or CMF in 129 UK Hospitals (CRUK/05/019)

Introduction: TACT2, a multicentre phase III trial with E-CMF as control (NEAT Poole NEJM 2006), tests 2 hypotheses in a 2x2 factorial design: A) accelerating chemotherapy (CT) offers superior benefits (CALGB9741 Citron JCO 2003); B) the oral 5FU prodrug X gives similar efficacy but preferential side-effect profile to CMF. Here, focus is on hypothesis B with results for compliance, QL & acute toxicities (physician & patient (pt) reported) during CMF vs. X

Materials &

Methods: 4391 pts (4371 women, 20 men) with node+ve/high risk node-ve invasive EBC were recruited between Dec 2005-08. Treatment was E(100mg/m2 x 4) q3wk vs q2wk aE(100mg/m2 x 4 + pegfilgrastim 6mg d2) followed by classical CMF q4wk x 4 vs X(2500mg/m2/day x 14) q3wk x 4. Detailed CTCAE toxicity was assessed in a subset (38 centres, 2086 pts receiving ≥1 cycle CMF or X). 1279/2086 also participated in substudy of pt-reported outcomes (EORTC QLQ-C30 and TACT2-specific toxicities). 826 had complete dataset (baseline, cycles 4&8). P-values are trend tests across all grades & %grade 3+ are reported. QL assessed via linear regression models adjusted for baseline, end cycle 4 score, & aE vs E. P&lt;0.01 classed as significant

QL in cycles 5-8 was better with X than CMF for global QL& fatigue (P&lt;0.001). Pts reporting clinically meaningful deterioration (&gt;10 points): global QL CMF 106/398 (27%), X 79/428 (18%); fatigue CMF 164/398 (41%), X 122/428 (29%)).

Conclusion: TACT2, the largest adjuvant EBC trial with X, confirms that X has preferential side-effect profile and global QL compared to CMF, with no evidence that prior aE compromised treatment delivery. Dose delivery data are consistent with advanced disease observations that for some pts, 2000mg/m2/day may be correct dose.

Results: 4264 (97%) pts continued on CT beyond cycle 4. 3726 completed all 8 cycles (E-CMF 951 (85%), aE-CMF 938 (86%), E-X 932 (84%), aE-X 905 (83%). For cycles 5-8, %RDI &gt; 85% was 69% after E and 68% after aE. Cycles delivered on time CMF 59%, X 63%; cycles without dose reduction CMF 75%, X 62%. 15 deaths in total within 30 days of CT: 9 on CMF, 6 on X. Worst grade toxicities which differed between CMF & X during cycles 5-8: