Abstract P4-13-13: Meta-analyses of visceral versus non-visceral metastases treated by AI & SERD agents as 2nd line endocrine therapy (ET) for HR+ breast cancer (BC)

There is a prevailing belief that ET for HR+ advanced BC is not as effective in patients with visceral metastases (VM) compared to non-visceral metastases (nVM), particularly with later lines of ET. Recently fulvestrant 500mg (Ful 500), has been reported to have greater efficacy in nVM compared to i) VM treated by Ful 500 but also compared to ii) nVM treated by Ful 250 (2nd line) and iii) nVM treated by aromatase inhibitor (AI), anastrozole (1st Line) – implying both site and agent related efficacy. Absence of significant overall survival (OS) difference in PALOMA 3 (2nd line) has increased the debate regarding when to add CDK 4/6is to ET, especially given the OS advantage for Ful 500 monotherapy in the 1st & 2nd line settings.

Patients & Methods: Anonymised, individual patient level data was obtained from randomised controlled trials (RCTs) involving AI & SERD used as mono-theraphy in 2nd or 3rd Line setting in known HR+ BC. All the trials were Phase 3 double-blind, placebo RCTs. All were rigorously assessed for clinical benefit (CB), progression free survival (PFS), duration of CB (DoCB) and OS. Details of the studies, types of ET and patient numbers are shown in the Table.

Results: Outcome data is presented for each study and then summarised under AI, SERD (Ful 250 or 500) and 'all Ets combined'. Odds ratios (Ors) & hazard ratios (HRs) for VM versus nVM by endocrine agents are shown in the Table.

AgentStudyTotal Pats.HR+ Pats.CBRPFSOSDoCBAI(n)(n)OR (95%Cis)HR (95%Cis)HR (95%Cis)HR (95%Cis)Exe00202301831.181.441.271.50Exe00211931681.151.951.832.12AnaEFECT3403360.941.521.201.10AnaSOFEA2492491.291.181.051.41subtotal7636871.11 (0.84-1.48)1.47*** (1.22-1.79)1.21* (1.01-1.45)1.43** (1.10-1.86)SERDFul 25000202191601.791.701.401.23Ful 25000212041771.281.811.322.06Ful 250EFECT3513450.791.401.311.03Ful 250SOFEA2312310.701.171.242.22Ful 250CONFIRM1521521.131.071.510.84Subtotal9268341.05 (0.75-1.45)1.39*** (1.16-1.67)1.34*** (1.14-1.57)1.36 (0.93-1.98)SERDFul 500CONFIRM1441442.24 (1.12-4.48)1.30 (0.90-1.87)1.33 (1.14-1.57)0.97 (0.55-1.66)All ETsTotal183316651.13 (0.92-1.39)1.42*** (1.26-1.59)1.28*** (1.14-1.44)1.35** (1.09-1.66)

[Pats=Patients; (n)=number; CBR-Clinical Benefit Rate; p-values p<0.05*, p<0.01**, p<0.001***]

Median PFS (months) for nVM for AI, SERD250, SERD500 & ‘all Ets combined’ were 5.4, 5.5, 11.0 & 5.5 respectively: for VM they were 2.9, 3.5, 5.5 & 3.2 respectively.

Median OS (months) for nVM for AI, SERD250, SERD500 & ‘all Ets combined’ was 24.2, 26.0, 35.4 & 25.4 respectively: for VM the figures were 22.8, 20.8, 26.4 & 22.0 respectively.Conclusions:1) In the 2nd line HR+ setting AI & Ful 250 both significantly increased PFS & OS in nVM versus VM. Longer PFS appears due to longer duration of control (DoCB) than increasing the number of patients responding (CBR).

2) Median OS for nVM ranged from 24 – 35 months versus 20.8-26.4 months for VM: for the majority of patients the 2nd line ET setting is not ‘immediately life threating’ and ET is therefore an option to consider.

3) These data on site of disease (nVM vs VM) contribute to the selection of which patients should receive endocrine mono- and which endocrine combination therapy (ie plus mTORi or CDK4/6i) in the second line setting.

Citation Format: Robertson JFR, Di Leo A, Johnston S, Chia S, Bliss J, Bradbury I, Campbell C. Meta-analyses of visceral versus non-visceral metastases treated by AI & SERD agents as 2nd line endocrine therapy (ET) for HR+ breast cancer (BC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-13-13.

Abstract P2-12-01: Dose- and exposure-response relationship and biomarker correlation analysis in breast tumors from patients treated with capivasertib, an AKT inhibitor, in the STAKT randomized, placebo controlled pre-surgical study

Background: Capivasertib (AZD5363), an AKT1,2,3 inhibitor, significantly improved progression-free and overall survival when added to paclitaxel in triple negative breast cancer (BC) patients (Schmid et al. ASCO 2018). We have previously reported in STAKT, robust target inhibition at 480mg BD versus placebo, including significant decreases in the primary biomarkers (PBs) - Ki67, pPRAS40 & pGSK3β - in primary BCs (Robertson et al. SABCS 2017). We now report the dose- and exposure-response relationship of capivasertib and the correlation between primary and secondary (pAKT, pS6, nuclear FOXO3a) tumor biomarkers.

Design: STAKT was a two-stage, double blind, randomized, placebo controlled 'window-of-opportunity' trial in newly diagnosed ER+ BC patients. Stage 1 assessed capivasertib at a dose of 480mg BD p.o. versus placebo. Stage 2 assessed capivasertib at two lower doses 360mg and 240mg BD. Tumor biopsies were taken prior to 1st dose and after 4.5 days of dosing. Evaluable patients (who required pre-defined minimum baseline PD values for PBs) included placebo (n=11), capivasertib at 480mg (n=17), 360mg (n=5) and 240mg (n=6). Blood samples for pharmacokinetic (PK) studies were scheduled at pre-dose; 2, 4, optional 6 & 8 hrs post first dose on Day 1; ˜2-4 h post last dose on Day 5 (before biopsy). The % change from baseline for PBs were evaluated against the following exposure variables (placebo=0): i) Dose, ii) Observed Cmax Day 1 (˜2h post-dose), iii) Observed plasma concentration on Day 5, iv) Model-predicted plasma concentration Day 5 at time of biopsy, and v) Model-predicted AUC on Day 5. Spearman correlation coefficient measured the strength and direction of association between biomarkers.

Results:

· Significant mean reductions in % change from baseline were observed for the PBs pGSK3β (-39%; p<0.006), pPRAS40 (-50%; p<0.0001) and Ki67 (-23%; p=0.052) at 480mg versus placebo. At 360mg and 240mg, mean % changes from baseline in pGSK3β were -27% and -9%, respectively; in pPRAS40 -45% and -28%, respectively; and in Ki67 0% and +22%, respectively.

· Dose-response relationships for individual % change from baseline could be described by an Emax model for all PBs. Overall, the correlation to PK exposure (observed or predicted) was similar to the correlation to dose.

· Correlation coefficient analyses between biomarkers at capivasertib 480mg BD identified- i) Positive correlations for pGSK3β with Ki67 (ρ = 0.52, p-value < 0.05) & with pS6 (ρ = 0.54, p-value<0.05); ii) Negative correlations between FOXO3a and Ki67 (ρ = -0.75, p-value<0.001) pGSK3β (ρ = -0.71, p-value<0.001) & also pS6 (ρ = -0.61, p-value<0.001).Correlation coefficients for lower doses are not robust due to small sample size in these groups.

Conclusions

· Capivasertib caused dose- and concentration- dependent effects on biomarkers after only 4.5 days.

· Significant changes in the PBs were demonstrated at 480 mg BD. Biomarker changes was observed at 360mg and 240mg BD, but statistical analysis was limited by the small sample size at lower doses.

· Correlation between a number of tumor biomarkers (relative changes) were identified for capivasertib 480mg BD.

Citation Format: Gee J, Coleman RE, Cheung KL, Evans A, Holcombe C, Skene A, Rea D, Ahmed S, Jahan A, Horgan K, Rauchhaus P, Littleford R, Finlay P, Cheung A, Cullberg M, de Bruin E, Foxley A, Koulai L, Pass M, Schiavon G, Rugman P, Deb R, Robertson JFR. Dose- and exposure-response relationship and biomarker correlation analysis in breast tumors from patients treated with capivasertib, an AKT inhibitor, in the STAKT randomized, placebo controlled pre-surgical study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-12-01.

Abstract P4-13-11: Meta-analyses of visceral versus non-visceral metastases treated by SERM, AI & SERD agents as 1st line endocrine therapy (ET) for HR+ breast cancer (BC)

Introduction: There is continuing debate whether efficacy of ET is different in non-visceral metastases (nVM) than VM. Recently fulvestrant 500mg, has been reported to have greater efficacy than an aromatase inhibitor (AI), anastrozole, particularly in nVM – implying efficacy may be both site and agent dependent. Absence of significant overall survival (OS) difference in PALOMA 1 & 3 has increased interest in site of disease, especially given the OS advantage for fulvestrant 500mg monotherapy.

Patients & Methods: Individual patient level data was obtained from 7 randomised controlled trials (RCTs) involving SERM, AI & SERD used as 1st Line ET in known HR+ BC were used in this meta-analysis (MA). Five were Phase 3 double-blind, placebo controlled RCTs. Details of the studies, type of ET and patient numbers are shown in Table. All were rigorously assessed for clinical benefit rate (CBR), progression free survival (PFS), duration of clinical benefit (DoCB) and OS.: Details of the studies, types of ET and patient numbers are shown in the Table. Aa two stage MA IPD meta-analysis was used to analyse these outcomesCBR, PFS, OS & DoCB. Peto method for pooled odds ratios was used to calculate p values and CI for CBR, yYusef pPeto method was used to calculate p-values and CI for PFS, OS, and DoCB. Random effect for trial was included when Tarone's test for heterogeneity was significant, otherwise fixed effect models were generated.

Results:

Outcome data is present for each study and then summarised under SERM, AI, SERD and 'all Ets combined'. Odds Ratios (Ors) & Hazard Ratios (HRs) for VM versus nVM by endocrine agent are shown in the Table

ETStudyNo. of Pats.HR+ Pats.CBRPFSOSDoCBSERM(n)(n)OR (95%CIs)HR (95%CIs)HR (95%CIs)HR (95%CIs)TamEORTC1891781.410.850.770.95Tam00273281441.330.981.051.26Tam00301821622.800.590.440.79Tam00252742091.100.780.730.78subtotal9736931.53** (1.11-2.10)0.79** (0.67-0.94)0.70* (0.52-0.94)0.92 (0.72-1.18)AIExeEORTC1821680.841.110.731.02Ana00273401543.850.550.361.06Ana00301711510.970.881.140.82AnaFALCON2322321.070.980.831.05AnaFIRST1031030.970.540.510.53Subtotal10288081.28 (0.73-2.22)0.80 (0.60-1.06)0.66* (0.45-0.95)0.92 (0.74-1.14)SERDFul 500CONFIRM1621622.940.630.561.15Ful 500FALCON2302302.710.410.450.61Ful 500FIRST1021024.110.580.440.55Subtotal4944943.06*** (2.00-4.06)0.56*** (0.45-0.70)0.50*** (0.39-0.65)0.71* (0.53-0.91)Total249519981.66*** (1.37-2.02)0.73*** (0.62-0.86)0.61*** (0.53-0.71)0.87* (0.75-1.00)CBR-Clinical Benefit Rate (n)= number of patients, pvalues p<0.05*, p<0.01**, p<0.001***

Conclusions: This is the largest reported individual patient MA for nVM versus VM in patients with known HR+ advanced BC and clinical outcomes (CBR, DoCB, PFS & OS) approved to regulatory standards.

1) nVM had significantly better clinical outcomes compared to VM when treated by anti-estrogen receptor blocking agents (SERM & SERD) but not when treated by Ais, which have a fundamentally different mechanism of action.

2) SERD (Fulvestrant 500mg) significantly increased all four clinical outcomes. For nVM compared to VM, fulvestrant put more patients into CB, kept them in remission (DoCB) for longer, resulting in 44% reduction in disease progression and a 50% reduction in death.

3) Site of metastases (ie nVM or VM) is one of the factors to consider when selecting patients for endocrine mono or combination ET (plus CDK4/6i) in the 1st Line setting.

Citation Format: Robertson JFR, Paridaens R, Bogaerts J, Lichfield J, Bradbury I, Campbell C. Meta-analyses of visceral versus non-visceral metastases treated by SERM, AI & SERD agents as 1st line endocrine therapy (ET) for HR+ breast cancer (BC) [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-13-11.

Abstract P4-04-06: AZD5363, an AKT inhibitor, significantly inhibits key biomarkers of the AKT pathway and Ki67, in a randomized, placebo, controlled study (STAKT) in human breast cancers

Background: AKT is an important intracellular control point through which Type 1 growth factors and IGFR signal. Mutations in PIK3CA, AKT and PTEN are prevalent in estrogen receptor positive (ER+) breast cancer (BC) and have been implicated in resistance to endocrine therapies. AZD5363 is an inhibitor of AKT 1, 2 and 3 currently in Phase 2 trials for BC and other solid cancers.

Design: The study examined whether AZD5363 impacts on key biomarkers within the AKT pathway and their subsequent effects on Ki67, a marker of tumor proliferation. STAKT is a multi-center, two-stage, double blind, randomized, placebo controlled, biomarker 'window-of-opportunity' trial in women with newly diagnosed, previously untreated ER+ BC who were deemed would require chemotherapy as part of their primary treatment regimen. Stage 1 assessed AZD5363 at a dose of 480mg bd p.o. versus matching placebo. Up to 30 patients per arm were permitted, to allow 12 subjects per arm with evaluable paired biopsies - obtained at baseline, and after 4.5 days of AZD5363 / placebo. Primary endpoint markers were pPRAS40, pGSK3β and Ki67 assessed by immunohistochemistry. pPRAS40 and pGSK3β were assessed by H-scores and measured separately for cytoplasmic (cyto), nuclear (nuc) and total (cyto+nuc) staining. Ki67 was assessed as % positive staining of 500 tumor nuclei. Laboratory staff were blinded to treatment arm and whether the biopsies were taken before or after AZD5363/placebo. Changes in marker expression (both absolute and %) between biopsies were calculated, and compared between the two groups. An ANOVA test was applied for normally distributed data and Wilcoxon Mann-Whitney used if not normally distributed.

Results: 28/36 patients were evaluable with patient & tumor characteristics as follows: 17 received AZD5363 and 11 placebo; the median ages were 48 & 49 years respectively. 27 patients were Caucasian and 1 African-American. Tumors were all ER+. For HER2 status 8 were positive & 9 negative in the AZD5363 treated group compared to 2 & 9 respectively in the placebo group.

For pPRAS40 and pGSK3β cyto was the predominant staining while for Ki67 staining was nuclear. Changes in each marker with associated p-values are shown in the table.

MarkerType of change vs baselineDegree of change in AZD5363 arm (n=17)p-value versus placebo arm (n=11)pPRAS40 (H-score)TotalAbsolute-83.8<0.0001Total%-50.2<0.0001CytoAbsolute-90.0<0.0001Cyto%-55.8<0.0001NucAbsolute+6.90.42Nuc%+8.90.94pGSK3β (H-score)TotalAbsolute-55.30.006Total%-39.00.006CytoAbsolute-53.60.006Cyto%-39.20.006NucAbsolute-2.80.065Nuc%-36.50.058Ki67 (% cells+)Absolute-9.60.031%-29.40.052

Conclusions• AZD5363 for 4.5 days caused highly significant falls in pGSK3β and pPRAS40, key markers of AKT pathway activation

• AZD53643 also caused a significant decline in Ki67 even after only 4.5 days of drug. This is one of the shortest 'window'-studies to report such an early effect on proliferation.

• Placebo controlled 'window' studies of this short duration can provide important evidence of the therapeutic potential early in a drug's development.

Citation Format: Robertson JFR, Coleman RE, Cheung KL, Evans A, Holcombe C, Skene A, Rea D, Ahmed S, Jahan A, Kelly S, Horgan K, Rauchhaus P, Littleford R, Foxley A, Lindemann JPO, Pass M, Rugman P, Deb R, Finlay P, Gee JMW. AZD5363, an AKT inhibitor, significantly inhibits key biomarkers of the AKT pathway and Ki67, in a randomized, placebo, controlled study (STAKT) in human breast cancers [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-04-06.

Abstract P3-13-01: Withdrawn

This abstract was withdrawn by the authors.

Abstract P2-08-09: Progression-free survival results in postmenopausal Asian women: Subgroup analysis from a phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON)

BACKGROUND

Fulvestrant is a selective estrogen receptor degrader (SERD) with no known agonist effects. In the open-label Phase 2 FIRST study, fulvestrant 500 mg suggested improved efficacy as first-line treatment vs anastrozole in patients with hormone receptor-positive locally advanced or metastatic breast cancer (LA/MBC). The Phase 3, randomized, double-blind, multicenter FALCON trial (NCT01602380) compared fulvestrant 500 mg with anastrozole 1 mg in patients with hormone receptor-positive LA/MBC who had not received prior hormonal therapy. The primary endpoint of the study, progression-free survival (PFS) assessed via RECIST 1.1, surgery/radiotherapy for disease worsening, or death (any cause), was met, as shown by a statistically significant improvement in PFS for fulvestrant 500 mg vs anastrozole. This analysis evaluated PFS in the Asian patient subgroup, which included all randomized patients from centers in China, Japan, and Taiwan.

METHODS

Eligible patients had ER and/or progesterone receptor-positive breast cancer, WHO performance status 0–2, and ≥1 measurable/non-measurable lesion(s). Patients were randomized (1:1) to receive fulvestrant 500 mg (IM on Days 0, 14, 28, and each 28 days thereafter) or anastrozole 1 mg daily, and were stratified according to LA or MBC; prior or no prior treatment with chemotherapy for LA/MBC; and measurable or non-measurable disease. The consistency of effect across patient subgroups was assessed via hazard ratios and 95% confidence intervals using a log-rank test.

RESULTS

In total, 462 patients were randomized (n=230 fulvestrant 500 mg; n=232 anastrozole). The Asian subgroup comprised 67 patients (n=34 fulvestrant 500 mg; n=33 anastrozole). PFS outcomes for the Asian and non-Asian subgroups are presented (Table). The most commonly reported adverse event (AE) was arthralgia (18.2% vs 12.1% of patients with fulvestrant 500 mg and anastrozole, respectively). The rate of AEs leading to discontinuation of treatment was 3.0% and 3.0%, respectively.

CONCLUSIONS

Based on a preliminary assessment of 67 patients, the treatment effect in the Asian patient subgroup from the FALCON trial appears to be broadly consistent with the non-Asian population.

PFS in Asian and non-Asian patient subgroupsGeographic regionNumber of patients (%) with event Hazard ratio (95% CI) Fulvestrant 500 mg n=230Anastrozole n=232 Asia19/34 (55.9%)22/33 (66.7%)0.81 (0.44, 1.50)Non-Asia124/196 (63.3%)144/199 (72.4%)0.79 (0.62, 1.01)

Citation Format: Shao Z, Ellis MJ, Robertson JFR, Grinsted LM, Fazal M, Noguchi S. Progression-free survival results in postmenopausal Asian women: Subgroup analysis from a phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-09.

Abstract P2-08-02: Progression-free survival results in patient subgroups from a Phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON)

BACKGROUND

Improved efficacy was suggested for fulvestrant 500 mg, a selective estrogen receptor degrader (SERD), vs anastrozole as first-line treatment for hormone receptor-positive locally advanced or metastatic breast cancer (LA/MBC) in the open-label Phase 2 FIRST trial. The Phase 3, randomized, double-blind, multicenter FALCON trial (NCT01602380) compared fulvestrant 500 mg with anastrozole 1 mg in patients with hormone receptor-positive LA/MBC who had not received prior hormonal therapy. The primary endpoint of the study was met, such that there was a statistically significant improvement in progression-free survival (PFS) for fulvestrant 500 mg vs anastrozole. We present an analysis of PFS for pre-specified patient subgroups in the FALCON trial.

METHODS

Eligible patients had ER and/or progesterone receptor (PgR)-positive breast cancer, WHO performance status 0–2 and ≥1 measurable/non-measurable lesion(s). Patients were randomized (1:1) to receive fulvestrant 500 mg (IM on Days 0, 14, 28, and each 28 days thereafter) or anastrozole 1 mg daily. The primary endpoint was PFS, assessed via RECIST 1.1, surgery/radiotherapy for disease worsening, or death (any cause). PFS was evaluated in patient subgroups defined by pre-specified baseline covariates. The consistency of effect across patient subgroups was assessed via hazard ratios and 95% confidence intervals using a log-rank test.

RESULTS

Overall, 462 patients were randomized to treatment: 230 received fulvestrant 500 mg and 232 received anastrozole. PFS outcomes in each patient subgroup are presented in the Table.

CONCLUSIONS

This analysis of patient subgroups from the FALCON trial suggests that treatment effects were largely consistent across the subgroups analyzed with some possible exceptions (e.g. patients with visceral vs non-visceral disease). Further work is ongoing to understand the possible treatment effect in these subgroups.

PFS in pre-specified patient subgroupsSubgroup Number of patients (%) with event Hazard ratio (95% CI)  Fulvestrant 500 mg n=230 Anastrozole n=232 Breast cancer type   Locally advanced11/28 (39.3%)14/32 (43.8%)0.79 (0.36, 1.73)Metastatic132/202 (65.3%)152/200 (76.0%)0.78 (0.62, 0.99)Prior chemotherapy for LA/MBC   Yes31/36 (86.1%)33/43 (76.7%)1.08 (0.66, 1.77)No112/194 (57.7%)133/189 (70.4%)0.75 (0.59, 0.97)Geographic regiona   US/Canada16/25 (64.0%)19/24 (79.2%)0.66 (0.34, 1.30)Non-US/Canada127/205 (62.0%)147/208 (70.7%)0.81 (0.64, 1.03)Measurable disease   Yes124/193 (64.2%)143/196 (73.0%)0.76 (0.60, 0.97)No19/37 (51.4%)23/36 (63.9%)0.99 (0.53, 1.82)ER-positive and PgR-positive   Yes103/175 (58.9%)127/179 (70.9%)0.73 (0.56, 0.94)No40/55 (72.7%)39/53 (73.6%)1.04 (0.67, 1.62)Bisphosphonate use at baseline   Yes44/61 (72.1%)53/62 (85.5%)0.69 (0.46, 1.03)No99/169 (58.6%)113/170 (66.5%)0.82 (0.63, 1.07)Visceral disease   Yes92/135 (68.1%)87/119 (73.1%)0.99 (0.74, 1.33)No51/95 (53.7%)79/113 (69.9%)0.59 (0.42, 0.84)ªData for Asia/non-Asia subgroups are presented in a separate abstract

Citation Format: Robertson JFR, Noguchi S, Shao Z, Grinsted LM, Fazal M, Ellis MJ. Progression-free survival results in patient subgroups from a Phase 3 randomized trial of fulvestrant 500 mg vs anastrozole for hormone receptor-positive advanced breast cancer (FALCON) [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P2-08-02.

Treatment of the axilla in patients with primary breast cancer and low burden axillary disease: Limitations of the evidence from randomised controlled trials

Invasive breast cancer is the second most common cancer worldwide. It is known to metastasise to the regional axillary lymph nodes but there has been debate over what is the best way to stage and treat the axilla in patients presenting with primary breast cancer. Multiple trials over the last two decades have led to a change in practice from routine axillary lymph node dissection to sentinel lymph node biopsy in patients who are clinically lymph node negative preoperatively. This has resulted in new questions regarding subsequent treatment of some patients. This review will critically appraise the evidence on axillary treatment in patients with low burden axillary disease and highlight limitations of relevant randomised controlled trials.

Factors influencing local control in patients undergoing breast conservation surgery for ductal carcinoma in situ

BACKGROUND

The aim of our study was to assess various predictors for local recurrence (LR) in patients undergoing breast conservation surgery (BCS) for ductal carcinoma in situ (DCIS).

MATERIALS AND METHODS

An audit was performed of 582 consecutive patients with DCIS between Jan 1975 to June 2008. In patients undergoing BCS, local guidelines reported a margin of ≥10 mm during the above period. Guideline with regard to margin of excision changes soon after this period. We retrospectively analysed clinical and pathological risk factors for local recurrence in patients undergoing BCS. Statistical analysis was carried out using SPSS version 19, and a cox regression model for multivariate analysis of local recurrence was used.

RESULTS

Overall 239 women had BCS for DCIS during the above period. The actuarial 5-year recurrence rate was 9.6%. The overall LR rate was 17% (40/239. LR was more common in patients ≤50 years: (10/31 patients, 32%) compared to patients > 50 years (30/208, 14%, P = 0.02). Forty three per cent of patients (6/14) with <5 mm margin developed LR which was significantly higher compared to patients with 5-9 mm margin (12%, 3/25) and with ≥10 mm margin (14%, 27/188, P = 0.01). On multivariate analysis age ≤50 years, <5 mm pathological margin were independent prognostic factors for local recurrence.

CONCLUSION

Our study shows that younger age (≤50 years) and a margin < 5 mm are poor prognostic factors for LR in patients undergoing breast conservation surgery for DCIS.

Abstract P5-14-01: A meta-analysis of clinical benefit rates for fulvestrant 500 mg versus alternative therapies for treatment of postmenopausal, estrogen receptor-positive advanced breast cancer

Background

Fulvestrant 500 mg has demonstrated improved efficacy vs fulvestrant 250 mg (time to progression [TTP]/progression free survival [PFS] and overall survival) in the treatment of postmenopausal women with advanced breast cancer (ABC). Few clinical trials have demonstrated a significant increase in clinical benefit rate (CBR) for one endocrine therapy (ET) over another for the treatment of ABC. This implies that TTP/PFS improvements have been achieved principally by prolonging time to developing acquired resistance. However, it would be beneficial to know whether CBR is also improved, indicating that more patients experience tumor remission. We performed a meta-analysis to determine if there was a difference in CBR between fulvestrant 500 mg and its comparators in randomized clinical trials (RCTs).

Methods

Five RCTs evaluating fulvestrant 500 mg were included: CONFIRM, China CONFIRM, FINDER1 and FINDER2 (vs fulvestrant 250 mg) as second-line ET and FIRST (vs anastrozole) as first-line ET. CBR was calculated as the proportion of patients experiencing a best objective response of stable disease for ≥24 weeks, complete response or partial response. Peto method was used to calculate odds ratios (ORs), 95% confidence intervals (CIs) and p values. Separate fixed effect (FE) models were constructed for first- and second-line data combined, and for second-line only data. For each model Tarone's test for heterogeneity assessed the assumption of constant trial effect.

Results

Unadjusted ORs for CBR from CONFIRM, FINDER1 and FINDER2, adjusted OR for China CONFIRM (as reported in the trial publications), and combined FE models are shown (Table).The OR (95% CI) of the FE model for all trials indicated that CBR was higher with fulvestrant 500 mg than with comparator treatments (OR: 1.34 [1.12-1.61]; FE p=0.001; Tarone's test p=0.91). When assessing second-line ET only, the OR was similar to the overall combined analysis.

ORs (95% CI) of CBR from individual trials and meta-analysis. nOR of CBR for fulvestrant 500 mg vs comparator (95% CI)First-lineFIRST2051.30 (0.72–2.38)Second-lineCONFIRM7361.28 (0.95–1.71)China CONFIRM2211.37 (1.04–1.80)FINDER1921.20 (0.53–2.74)FINDER2931.96 (0.84–4.54)Fixed effects modelFirst- and second-line combined13471.34 (1.12–1.61) FE p=0.001; Tarone's test p=0.91Second-line only11421.35 (1.11–1.63) FE p=0.002; Tarone's test p=0.81CBR, clinical benefit rate; CI, confidence interval; FE, fixed effects model; OR, odds ratio. Adjusted odds ratio and CI (as reported in the trial publications) are presented for China CONFIRM; unadjusted odds ratios and CIs are used for all other trials. FINDER1 and FINDER2 included fulvestrant 500 mg, 250 mg plus loading dose, and 250 mg treatment arms. Data shown for fulvestrant 500 mg versus 250 mg.

Conclusions

These data suggest that fulvestrant 500 mg is associated with a significant improvement in CBR of approximately 34% compared with comparator ETs (i.e. more tumors are placed into remission). This finding is consistent in both second- and first-line ET settings. We await the results of the Phase 3 FALCON first-line ET RCT to see if it supports this finding of increased CBR with fulvestrant 500 mg.

Citation Format: Robertson JFR, Zefei J, Di Leo A, Ohno S, Pritchard KI, Ellis M, Bradbury I, Campbell C. A meta-analysis of clinical benefit rates for fulvestrant 500 mg versus alternative therapies for treatment of postmenopausal, estrogen receptor-positive advanced breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-14-01.

Pilot randomised study of early intervention based on tumour markers in the follow-up of patients with primary breast cancer

BACKGROUND

This pilot study aimed to test the possibility of therapeutic benefit imparted by early intervention based on sequential tumour marker (TM) measurements during follow-up of primary breast cancer (PBC) patients.

METHODS

Patients with oestrogen receptor positive PBC with no clinical and/or radiological evidence of metastases were recruited and followed-up 3-monthly with clinical assessment and TM (CA15.3 and CEA) measurements. The clinical team was blinded to the TM results. Asymptomatic patients who developed raised TMs (based on pre-defined cut-offs) were randomised to either 'treatment change' (either start or change of adjuvant endocrine agent to another agent) or 'no change' (control). Patients who developed symptomatic metastases came off the study. The primary and secondary endpoints were intervals from randomisation to symptomatic metastases and to last follow-up/death respectively.

RESULTS

Eighty-five patients (median age = 54 years (30-72)) were recruited with a median follow-up of 81 months (1-124). Sixteen patients were randomised as described. There was no significant difference (treatment change versus no change) with regards to interval from randomisation to symptomatic metastases - 23 (2-62) and 22 (1-63) months respectively (p = 0.9), as well as interval from randomisation to last follow-up/death - 36 (7-63) and 37 (10-63) months respectively (p = 0.9).

CONCLUSIONS

Despite long follow-up (up to 10+ years), this small study has thus far shown no significant difference in outcome. However, we have confirmed the feasibility of this study design but a larger study will be required to show if there is a benefit to this approach.

Abstract OT3-2-09: FALCON: A randomised, double-blind, multicentre, phase III study comparing fulvestrant 500 mg with anastrozole 1 mg for postmenopausal women with hormone receptor-positive locally advanced or metastatic breast cancer who have not previously been treated with any hormonal therapy

Background: The Phase III CONFIRM study demonstrated that a higher dose (500 mg) of fulvestrant, an estrogen receptor (ER) antagonist for treatment of advanced breast cancer, was associated with a significant increase in progression-free survival (PFS) without increased toxicity versus fulvestrant 250 mg.Moreover, a Phase II study (FIRST) showed that first-line treatment with fulvestrant 500 mg was at least as effective as anastrozole 1 mg with a similar safety profile. The aim of the FALCON study is to investigate whether fulvestrant 500 mg is superior to anastrozole 1 mg as first-line endocrine therapy. FALCON is the only Phase III study in recent years to compare two endocrine therapies as first-line treatment in metastatic breast cancer (MBC); hence, results may potentially affect standard clinical practice in the future.

Trial design: This is a randomised, double-blind, double-dummy, international, multicentre study comparing efficacy and tolerability of fulvestrant with anastrozole (NCT01602380). Eligible patients are randomised 1:1 to receive fulvestrant 500 mg or anastrozole 1 mg, and stratified at randomisation based on whether (1) they have locally advanced or MBC (2) they have received prior chemotherapy for locally advanced or MBC or not and (3) they have measurable or non-measurable disease.

Eligibility criteria: Eligible are postmenopausal women with histologically confirmed, ER-positive, locally advanced or MBC who have not previously received any endocrine therapy. Patients may have received one line of cytotoxic chemotherapy but must show progressive disease prior to enrolment, have a World Health Organisation performance status of 0, 1 or 2 and at least one lesion that can be accurately assessed at baseline and is suitable for repeated assessment according to Response Evaluation Criteria in Solid Tumours (RECIST 1.1) guidelines.

Specific aims: The primary objective is to demonstrate the superior PFS of patients treated with fulvestrant 500 mg versus patients treated with anastrozole 1 mg. Secondary objectives include comparison of the overall survival (OS), the objective response rate (ORR), the clinical benefit rate (CBR) and quality of life (QoL) between the treatment groups, as well as safety and tolerability assessments.

Statistical methods: Comparison of PFS and OS for fulvestrant 500 mg versus anastrozole 1 mg will be performed using a stratified log-rank test. A multiple testing procedure will be used to control the overall type 1 error rate at 2.5% (1-sided). Results will be presented as an estimated hazard ratio, associated confidence interval and p-value. ORR and CBR will be analysed using a logistic regression model and examination of the odds ratio of the 2 treatment groups. A time to deterioration analysis will be performed for QoL endpoints.

Present accrual and target accrual: Recruitment is currently ongoing; on June 6, 2013, 101 patients had been randomised. The recruitment target is 450 patients; 124 study sites worldwide are currently initiated.

Contact information: Please contact the authors for specific information about this study.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr OT3-2-09.

A randomised trial of primary tamoxifen versus mastectomy plus adjuvant tamoxifen in fit elderly women with invasive breast carcinoma of high oestrogen receptor content: long-term results at 20 years of follow-up

BACKGROUND

Long-term analysis of a randomised trial in Nottingham comparing tamoxifen versus surgery as initial treatment demonstrated that in oestrogen receptor (ER)-unselected cases, surgery achieved better local control, with no difference in overall survival. It was suggested that for patients with ER-rich tumours, local control and survival may be comparable. We now present long-term follow-up of a randomised trial designed to address this clinical scenario.

PATIENTS AND METHODS

One hundred and fifty three fit elderly (≥70 years) women with clinically node-negative primary invasive breast carcinoma <5 cm of high ER content [histochemical (H) score ≥100] were randomised 2:1 to primary tamoxifen (Tam) (N = 100) or mastectomy with adjuvant tamoxifen (Mx + Tam) (N = 53).

RESULTS

With median follow-up of 78 months, there was no statistically significant difference in 10-year rates of regional recurrence (9.0% versus 7.5%), metastasis (8.0% versus 13.2%), breast cancer-specific survival (89.0% versus 86.8%) or overall survival (64.0% versus 66.0%) between Tam and Mx + Tam; however, local control was inferior with Tam (local failure rates 43.0% versus 1.9%; P < 0.001).

CONCLUSION

Irrespective of the degree of ER positivity, surgery achieved better local control. However, there was excellent and similar survival in both groups. Tam could be considered in those who are 'frail', refuse or prefer not to initially undergo surgery.

The sequential use of endocrine treatment for advanced breast cancer: where are we?

BACKGROUND

Hormone receptor-positive advanced breast cancer is an increasing health burden. Although endocrine therapies are recognised as the most beneficial treatments for patients with hormone receptor-positive advanced breast cancer, the optimal sequence of these agents is currently undetermined.

METHODS

We reviewed the available data on randomised controlled trials (RCTs) of endocrine therapies in this treatment setting with particular focus on RCTs reported over the last 15 years that were designed based on power calculations on primary end points.

RESULTS

In this paper, data are reviewed in postmenopausal patients for the use of tamoxifen, aromatase inhibitors and fulvestrant. We also consider the available data on endocrine crossover studies and endocrine therapy in combination with chemotherapy or growth factor therapies. Treatment options for premenopausal patients and those with estrogen receptor-/human epidermal growth factor receptor 2-positive tumours are also evaluated.

CONCLUSION

We present the level of evidence available for each endocrine agent based on its efficacy in advanced breast cancer and a diagram of possible treatment pathways.

Suppression of ovarian function in combination with an aromatase inhibitor as treatment for advanced breast cancer in pre-menopausal women

Trials have shown superiority of aromatase inhibitors (AIs) over tamoxifen for post-menopausal oestrogen receptor-positive advanced breast cancer (ER+ABC). We previously reported the use of goserelin plus anastrozole (G+A) as second-line endocrine therapy for pre-menopausal ER+ABC. We report clinical and endocrine data from G+A as first-line systemic therapy. Thirty-six patients (median age=44 years) with metastatic (N=28) and locally advanced disease were administered G+A for ≥6 months (unless progressed prior). Some (N=13) received further therapy with goserelin plus another AI (steroidal), exemestane (G+E). Serial serum hormone assays (oestradiol, dehydroepiandrosterone sulphate, testosterone, follicle stimulating hormone and luteinising hormone) were performed. Twenty-four patients (67%) derived clinical benefit (CB) (5% complete response, 31% partial response, 31% stable disease for ≥6 months) with median time to progression and duration of CB of 12 (2-47) and 24+(7-78+) months respectively. Ten patients were still receiving first-line G+A at analysis. Amongst 13 patients who went onto receive G+E, 38% achieved CB with a mean duration of 13+(7-32) months. Therapy was well tolerated with no withdrawals. The combination of G+A resulted in 98% reduction (from pre-treatment to 6-month) in median levels of oestradiol (from 574.5 pmol/L; inter-quartile range (IQR)=209-1426; (N=6) to 13.45 pmol/L; IOQ=5.5-31.5 (N=4) whilst the levels of other hormones had minimal fluctuations during therapy. The combinations of ovarian function suppression (using G) and AIs produce sustained CB and minimal side effects in pre-menopausal ER+ABC with significant reduction in oestradiol levels. Within the limitations of being a non-randomised study, they should be considered in appropriate patients with hormone-sensitive ABC.

Clinical validation of an autoantibody test for lung cancer

Background: Autoantibodies may be present in a variety of underlying cancers several years before tumours can be detected and testing for their presence may allow earlier diagnosis. We report the clinical validation of an autoantibody panel in newly diagnosed patients with lung cancer (LC).

Patients and methods: Three cohorts of patients with newly diagnosed LC were identified: group 1 (n = 145), group 2 (n = 241) and group 3 (n = 269). Patients were individually matched by gender, age and smoking history to a control individual with no history of malignant disease. Serum samples were obtained after diagnosis but before any anticancer treatment. Autoantibody levels were measured against a panel of six tumour-related antigens (p53, NY-ESO-1, CAGE, GBU4-5, Annexin 1 and SOX2). Assay sensitivity was tested in relation to demographic variables and cancer type/stage.

Results: The autoantibody panel demonstrated a sensitivity/specificity of 36%/91%, 39%/89% and 37%/90% in groups 1, 2 and 3, respectively, with good reproducibility. There was no significant difference between different LC stages, indicating that the antigens included covered the different types of LC well.

Conclusion: This assay confirms the value of an autoantibody panel as a diagnostic tool and offers a potential system for monitoring patients at high risk of LC.

A randomised trial of mastectomy only versus tamoxifen for treating elderly patients with operable primary breast cancer-final results at 20-year follow-up

A recent Cochrane review of trials involving elderly women with operable primary breast cancer showed no significant difference in overall survival between surgery (±adjuvant tamoxifen) and primary endocrine therapy using tamoxifen. We report the final results of a randomised pilot trial comparing primary tamoxifen and wedge mastectomy as initial treatment in this population. One hundred and thirty-one women >70 years with early operable primary breast cancer (<5 cm), unselected for oestrogen receptor (ER), entered the trial in 1982-1987. Sixty-eight patients were allocated to tamoxifen only and 67 to wedge mastectomy only, as primary treatment. At 20 years of follow-up, the median time to local failure was significantly shorter in the tamoxifen arm though approximately one-fifth of patients in this group did not develop local failure requiring mastectomy. There was no difference in regional recurrence, distant metastases or overall survival between the mastectomy and tamoxifen arms. In this small study, primary endocrine therapy achieved local control in 30% of those surviving at 5 years and 20% at 10 years, unselected for ER. The primary therapy used did not significantly affect regional recurrence, incidence of distant metastases or overall survival. Primary endocrine therapy should certainly be considered in those patients with ER positive tumours and who are unfit (based on life expectancy) for or refuse surgery.

Technical validation of an autoantibody test for lung cancer

Background: Publications on autoantibodies to tumour-associated antigens (TAAs) have failed to show either calibration or reproducibility data. The validation of a panel of six TAAs to which autoantibodies have been described is reported here.

Materials and methods: Three separate groups of patients with newly diagnosed lung cancer were identified, along with control individuals, and their samples used to validate an enzyme-linked immunosorbant assay. Precision, linearity, assay reproducibility and antigen batch reproducibility were all assessed.

Results: For between-replicate error, samples with higher signals gave coefficients of variation (CVs) in the range 7%–15%. CVs for between-plate variation were only 1%–2% higher. For between-run error, CVs were in the range 15%–28%. In linearity studies, the slope was close to 1.0 and correlation coefficient values were generally >0.8. The sensitivity and specificity of individual batches of antigen varied slightly between groups of patients; however, the sensitivity and specificity of the panel of antigens as a whole remained constant. The validity of the calibration system was demonstrated.

Conclusions: A calibrated six-panel assay of TAAs has been validated for identifying nearly 40% of primary lung cancers via a peripheral blood test. Levels of reproducibility, precision and linearity would be acceptable for an assay used in a regulated clinical setting.

Activity of fulvestrant in HER2-overexpressing advanced breast cancer

BACKGROUND

Human epidermal growth factor receptor 2 (HER2) overexpression increases the aggressiveness of breast cancer cells resulting in poorer prognosis. Patients with HER2-positive disease are less responsive to endocrine therapies. Trastuzumab monotherapy results in objective responses in only approximately 15% of patients. Fulvestrant retains activity in cells overexpressing HER2 that are resistant to other endocrine treatments. This retrospective study evaluated response to fulvestrant treatment among HER2-positive patients with advanced breast cancer (ABC).

PATIENTS AND METHODS

Clinical experience data from 10 treatment centres were pooled. Postmenopausal patients with predominantly hormone receptor-positive and HER2-positive disease were included. Clinical benefit (CB) was defined as the proportion of patients achieving a response to treatment (partial or complete) or stable disease lasting >/=6 months.

RESULTS

Data for 102 patients were analysed. Fulvestrant resulted in an overall CB rate of 42% (43/101) in HER2-positive patients and 40% (25/63) in patients with visceral disease. Median duration of treatment was 14.5 months (range 6-44 months). Fulvestrant showed activity up to the fourth line of endocrine therapy and up to the seventh line of overall therapy.

CONCLUSIONS

Results indicate that fulvestrant may be a suitable treatment option in extensively pre-treated patients with HER2-positive, hormone receptor-positive ABC. Further exploration of its use in this patient population is warranted.

Primary endocrine therapy in locally advanced breast cancers--the Nottingham experience

INTRODUCTION

There are trials comparing different neoadjuvant chemotherapy regimens for locally advanced primary breast cancer (LAPC). Few studies have evaluated alternative therapeutic approaches towards LAPC. A previous trial from our institute in LAPC patients unselected for oestrogen receptor (ER) status, comparing primary endocrine therapy versus multimodal treatment, showed no difference in breast cancer related deaths or overall survival. We report our experience of primary endocrine therapy in ER+ LAPC.

METHODS

Between 1988 and 2007, 195 ER+, non-inflammatory LAPC patients were treated with primary endocrine agents in our institute, due to patient choice, being unfit for chemotherapy, or recruitment into the above mentioned trial. All patients had disease assessable by UICC criteria.

RESULTS

Median age was 69 years. The median follow-up was 61 months. 154 patients (79%) received endocrine treatment alone. 185 patients (95%) derived clinical benefit (complete response/ partial response/ stable disease) for > or =6 months from primary endocrine therapy. Overall 5-year survival was 76% and 5-year breast cancer specific survival was 86%.

CONCLUSION

In selected group of ER+ LAPC patients, primary endocrine treatment achieves excellent survival outcome and is a viable alternative to other modalities of treatment.

Can computerised tomography replace bone scintigraphy in detecting bone metastases from breast cancer? A prospective study

BACKGROUND

The aim of this study was to determine whether bone scans (BS) can be avoided if pelvis was included in CT thorax and abdomen to detect bony metastases from breast cancer.

MATERIALS AND METHODS

Results of 77 pairs of CT (thorax, abdomen, and pelvis) and BS in newly diagnosed patients with metastatic breast cancer (MBC) were compared prospectively for 12 months. Both scans were blindly assessed by experienced radiologists and discussed at multidisciplinary team meetings regarding the diagnosis of bone metastases.

RESULTS

CT detected metastatic bone lesions in 43 (98%) of 44 patients with bone metastases. The remaining patient had a solitary, asymptomatic bony metastasis in shaft of femur. BS was positive in all patients with bone metastases. There were 11 cases of false positive findings on BS.

CONCLUSION

Our findings suggest routine BS of patients presenting with MBC is not required if CT (thorax, abdomen, and pelvis) is performed.

Protein kinase C isoform expression as a predictor of disease outcome on endocrine therapy in breast cancer

BACKGROUND

Although in vitro breast cancer models have demonstrated a role for protein kinase C (PKC) alpha and delta isoforms in endocrine insensitivity and resistance respectively, there is currently little clinical evidence to support these observations.

AIMS

To define the pattern of PKC alpha and delta expression using breast cancer cell lines, with and without endocrine resistance, and also breast cancer samples, where expression can be correlated with clinicopathological and endocrine therapy outcome data.

METHODS

PKC isoform expression was examined in tamoxifen responsive, oestrogen receptor positive (ER(+)), ER(+) acquired tamoxifen resistant (TAM-R) and oestrogen receptor negative (ER(-)) cell lines by western blotting and immunocytochemical analysis. PKC isoform expression was then examined by immunohistochemistry in archival breast cancer specimens from primary breast cancer patients with known clinical outcome in relation to endocrine response and survival on therapy.

RESULTS

ER(+) breast cancer cell lines expressed considerable PKC-delta but barely detectable levels of PKC-alpha, whereas ER(-) cell lines expressed PKC-alpha but little PKC-delta. ER(+) acquired TAM-R cell lines expressed substantial levels of both PKC-alpha and delta. In clinical samples, high PKC-delta expression correlated to endocrine responsiveness whereas PKC-alpha expression correlated to ER negativity. PKC-delta was an independent predictor of duration of response to therapy. Patients showing a PKC-delta(+)/PKC-alpha(-) phenotype had a six times longer endocrine response than patients with the PKC-delta(+)/ PKC-alpha(+) phenotype (equating to tamoxifen resistance in vitro).

CONCLUSIONS

Levels of PKC-alpha and delta expression appear to be indicative of response to anti-oestrogen therapy and could be useful in predicting a patient's suitability for endocrine therapy.

Neoadjuvant chemotherapy in locally advanced primary breast cancers: the Nottingham experience

AIM

Of our study was to assess and compare the outcome of patients undergoing anthracycline based neoadjuvant chemotherapy in locally advanced primary breast cancers with patients receiving mitoxantrone, methotrexate and mitomycin (MMM) as neoadjuvant agents.

METHODS

Records of 50 consecutive patients receiving anthrcycline based chemotherapy for locally advanced breast cancers from July 1996 to July 2004 were analysed with regard to locoregional recurrence, metastasis and survival. The MMM group comprised of 56 consecutive patients receiving MMM chemotherapy between 1989 and 1994. The unit protocol for patients receiving multimodal therapy has been neoadjuvant chemotherapy followed by Patey's mastectomy, radiotherapy and endocrine treatment if ER-positive. Patients were followed-up in the clinic until either death or the last clinic visit on or before December 2005 in the anthracycline group and on or before December 1999 in the MMM group.

RESULTS

There was no significant difference between the two groups with regard to number of patients, tumour size, grade, ER positivity and median duration of follow-up from start of chemotherapy. Significantly more patients in the anthracycline group had complete clinical response and 44% of the patients in anthracycline group had node negative disease compared to 4% in the MMM group. Anthracycline group when compared to MMM group had a lower incidence of locoregional recurrence (6% vs 19%), distant metastasis (20% vs 55%) and survival (82% vs 45%) at the end of follow-up, which was statistically significant.

CONCLUSION

Anthracycline based neoadjuvant chemotherapy has better response and significantly better outcome compared to MMM chemotherapy.

Survival of invasive breast cancer according to the Nottingham Prognostic Index in cases diagnosed in 1990-1999

The Nottingham Prognostic Index (NPI) is a well established and widely used method of predicting survival of operable primary breast cancer.

AIMS

Primary: To present the updated survival figures for each NPI Group. Secondary: From the observations to suggest reasons for the reported fall in mortality from breast cancer.

METHODS

The NPI is compiled from grade, size and lymph node status of the primary tumour. Consecutive cases diagnosed and treated at Nottingham City Hospital in 1980-1986 (n=892) and 1990-1999 (n=2,238) are compared. Changes in protocols towards earlier diagnosis and better case management were made in the late 1980s between the two data sets.

RESULTS

Case survival (Breast Cancer Specific) at 10 years has improved overall from 55% to 77%. Within all Prognostic groups there are high relative and absolute risk reductions. The distribution of cases to Prognostic groups shows only a small increase in the numbers in better groups.

CONCLUSION

The updated survival figures overall and for each Prognostic group for the NPI are presented.

Effects of fulvestrant 250mg in premenopausal women with oestrogen receptor-positive primary breast cancer

Fulvestrant (Faslodex) reduces markers of hormone sensitivity and proliferation in postmenopausal women. This Phase II double-blind, randomised, multicentre study compared the effects of a single 250mg intramuscular dose of fulvestrant and placebo 14-21 days prior to surgery of curative intent on the oestrogen receptor (ER), progesterone receptor and Ki67 levels in 66 premenopausal women with ER-positive primary breast cancer. There were no statistically significant differences between fulvestrant and placebo with respect to any of the three markers analysed. The most common adverse events in both groups were nausea, headache and pyrexia. Fulvestrant 250mg had no effects on markers of hormone-sensitivity and proliferation in premenopausal women with primary breast cancer when measured at 14-21 days after injection. These findings suggest that a higher fulvestrant dose may be required in this patient population. Further clinical trials are necessary to evaluate the efficacy of fulvestrant in premenopausal women.

Male breast cancer: a review of clinical management

AIMS

Male breast cancer incidence is 1% of all breast cancers and is increasing. We aim to present an overview of male breast cancer with particular emphasis on clinical management.

METHODS

Studies were identified by an online search of literature in the MEDLINE database till June 2006 followed by an extensive review of bibliographies.

RESULTS

Increased risk factors include genetic predisposition as in BRCA2 families; testicular dysfunction due to chromosomal abnormality such as Klinefelter's syndrome or environmental factors such as chronic heat exposure and radiation. Clinical assessment with biopsy is the hallmark of diagnosis. Earlier presentations are becoming commoner but there are wide geographical differences. Surgical treatment involves simple or modified radical mastectomy along with surgical assessment of the axilla, either via sentinel node biopsy in clinically node-negative disease or axillary sampling/clearance in node-positive disease. Reconstructions for restoring body image have been recently reported. Indications for adjuvant therapies are similar to that in women. For metastatic disease, tamoxifen is still the mainstay for oestrogen receptor positive disease. For oestrogen receptor negative disease, doxorubicin based chemotherapy regimens are used. In addition, the oft neglected psychological aspects of men having a "cancer of women" are increasingly being recognised.

CONCLUSIONS

There is, thus, need for further increasing awareness among men to reduce stigma associated with presentation of symptoms related to breast. This should be in addition to stressing to clinicians the ways of earlier detection and tailor-made "gender oriented" treatment of breast cancer in men.

Using array-comparative genomic hybridization to define molecular portraits of primary breast cancers

We analysed 148 primary breast cancers using BAC-arrays containing 287 clones representing cancer-related gene/loci to obtain genomic molecular portraits. Gains were detected in 136 tumors (91.9%) and losses in 123 tumors (83.1%). Eight tumors (5.4%) did not have any genomic aberrations in the 281 clones analysed. Common (more than 15% of the samples) gains were observed at 8q11-qtel, 1q21-qtel, 17q11-q12 and 11q13, whereas common losses were observed at 16q12-qtel, 11ptel-p15.5, 1p36-ptel, 17p11.2-p12 and 8ptel-p22. Patients with tumors registering either less than 5% (median value) or less than 11% (third quartile) total copy number changes had a better overall survival (log-rank test: P=0.0417 and P=0.0375, respectively). Unsupervised hierarchical clustering based on copy number changes identified four clusters. Women with tumors from the cluster with amplification of three regions containing known breast oncogenes (11q13, 17q12 and 20q13) had a worse prognosis. The good prognosis group (Nottingham Prognostic Index (NPI) <or=3.4) tumors had frequent loss of 16q24-qtel. Genes significantly associated with estrogen receptor (ER), Grade and NPI were used to build k-nearest neighbor (KNN) classifiers that predicted ER, Grade and NPI status in the test set with an average misclassification rate of 24.7, 25.7 and 35.7%, respectively. These data raise the prospect of generating a molecular taxonomy of breast cancer based on copy number profiling using tumor DNA, which may be more generally applicable than expression microarray analysis.

A gene-expression signature to predict survival in breast cancer across independent data sets

Prognostic signatures in breast cancer derived from microarray expression profiling have been reported by two independent groups. These signatures, however, have not been validated in external studies, making clinical application problematic. We performed microarray expression profiling of 135 early-stage tumors, from a cohort representative of the demographics of breast cancer. Using a recently proposed semisupervised method, we identified a prognostic signature of 70 genes that significantly correlated with survival (hazard ratio (HR): 5.97, 95% confidence interval: 3.0-11.9, P = 2.7e-07). In multivariate analysis, the signature performed independently of other standard prognostic classifiers such as the Nottingham Prognostic Index and the 'Adjuvant!' software. Using two different prognostic classification schemes and measures, nearest centroid (HR) and risk ordering (D-index), the 70-gene classifier was also found to be prognostic in two independent external data sets. Overall, the 70-gene set was prognostic in our study and the two external studies which collectively include 715 patients. In contrast, we found that the two previously described prognostic gene sets performed less optimally in external validation. Finally, a common prognostic module of 29 genes that associated with survival in both our cohort and the two external data sets was identified. In spite of these results, further studies that profile larger cohorts using a single microarray platform, will be needed before prospective clinical use of molecular classifiers can be contemplated.

Malignancy-induced autoimmunity to MUC1: initial antibody characterization

Numerous reports document the existence of autoantibodies to MUC1 in the circulation of individuals with breast and other solid malignancies, with the majority of researchers utilizing MUC1 peptides in their detection. This report documents the purification, using peptide and whole molecule, and characterization of such autoantibodies from an individual with an unusual, highly MUC1-positive, myosarcoma. Purification of autoantibodies from serum was performed using affinity chromatography against either MUC1 peptide or whole molecule MUC1 [derived both from the patient (Pt-MUC1) and from a pool of sera from patients with advanced breast cancer (ABC-MUC1)]. Enzyme-linked immunosorbent assays (ELISAs) were used to compare specificity of purified autoantibodies. Peptide epitopes were determined by Ptifcan system against 7-mer peptides covering the 20 amino acid repeat of the MUC1 extracellular domain. Substantially higher amounts of autoantibodies were isolated when purifying against Pt-MUC1 rather than either ABC-MUC1 or peptide. Whole molecule purified autoantibodies demonstrated an increased specificity for tumour-derived MUC1. Pt-MUC1 autoantibodies were of both the immunoglobulin (Ig)G and IgM class, whilst autoantibodies purified against ABC-MUC1 and MUC1 peptide were IgG only. A greater range of peptide epitopes was defined by those autoantibodies purified against whole molecule. This report presents data indicating the presence of autoantibodies to MUC1 in an individual diagnosed with a MUC1 over-expressing myosarcoma. Confirmation of these autoantibodies as being specific for tumour-associated MUC1 is given. Further, it suggests that, although autoantibodies are present that recognize core protein determinants, the initial, and dominant, immunizing epitope is not purely pretentious in nature.

Endocrine response after prior treatment with fulvestrant in postmenopausal women with advanced breast cancer: experience from a single centre

The pure anti-oestrogen fulvestrant has now been licensed for use in advanced breast cancer which has progressed on an anti-oestrogen. Optimal sequencing of various endocrine agents becomes very important in the therapeutic strategy. We report our experience of further endocrine response with another endocrine agent after prior fulvestrant treatment. Among all patients with advanced breast cancer who had been entered into five phase II/III trials using fulvestrant as first- to ninth-line endocrine therapy in our Unit since 1993, 54 patients who fulfilled the following criteria were studied for their subsequent endocrine response: (i) oestrogen receptor positive or unknown; (ii) having been on a subsequent endocrine therapy for > or =6 months unless the disease progressed before; and (iii) with disease assessable for response according to International Union Against Cancer criteria. Eleven patients had received an aromatase inhibitor prior to fulvestrant, which resulted in five CBs (clinical benefit = objective remission/stable disease (SD)) for > or =6 months). Twenty-eight patients achieved CB on fulvestrant. They went on subsequent endocrine therapy with two partial responses, 11 SDs and 15 PDs (progressive disease) at 6 months. The median survival from starting fulvestrant and subsequent endocrine therapy was respectively 46.6 and 18.2 months. Among the remaining 26 patients who progressed at 6 months on fulvestrant, there were three SDs and 23 PDs at 6 months on subsequent endocrine therapy. The median survival from starting fulvestrant and subsequent endocrine therapy was respectively 12.5 and 9.3 months. Of all these 54 patients, 30% (n = 16) therefore achieved CB using another (second- to tenth-line) endocrine agent (anastrozole = 26; tamoxifen = 12; megestrol acetate = 11; others = 5). It would thus appear that further endocrine response can be induced in a reasonable proportion of patients after failing fulvestrant.

Overview of tyrosine kinase inhibitors in clinical breast cancer

Studies of cell models and profiling of clinical breast cancer material to reveal the mechanisms of resistance to anti-oestrogen therapy, and to tamoxifen in particular, have reported that this phenomenon can be associated with increased expression and signalling through erbB Type 1 growth factor receptors, notably the epidermal growth factor receptor (EGFR) and HER2. Further molecular studies have revealed an intricate interlinking between such growth factor receptor pathways and oestrogen receptor (ER) signalling. Inhibition of receptor tyrosine kinase activity involved in the EGFR signalling cascade forms the basis for the use of EGFR specific tyrosine kinase inhibitors exemplified by gefitinib (ZD1839, Iressa) and erlotinib (OSI-774, Tarceva). Such agents have proved promising in pre-clinical studies and are currently in clinical trials in breast cancer, where gefitinib has been studied more extensively to date. Here, we present an overview of the current development of gefitinib in clinical breast cancer. This includes results from our clinical breast cancer trial 1839IL/0057 that demonstrate the efficacy of gefitinib within ER-positive, tamoxifen-resistant patients with locally advanced/metastatic disease, where parallel decreases in EGFR signal transduction and the Ki67 (MIB1) proliferation marker can be detected as predicted from model system studies. We also consider trials examining combination treatment with gefitinib and anti-hormonal strategies that will begin to address the clinically important question of whether gefitinib can delay/prevent onset of anti-hormone resistance.

Consensus statement. Workshop on therapeutic resistance in breast cancer: impact of growth factor signalling pathways and implications for future treatment

Anti-hormones (notably tamoxifen), chemotherapy and modern radiotherapeutic approaches are invaluable in the management of breast cancer, and collectively have contributed substantially to the improved survival in this disease. Moreover, there is promise that these successes will continue with the emergence of other endocrine agents (for example, aromatase inhibitors and pure anti-oestrogens). However, de novo and acquired resistance comprises a significant problem with all treatment approaches examined to date. This Workshop aimed to evaluate the contribution made by growth factor signalling pathways in the various resistant states, primarily focusing on resistance to anti-hormonal strategies and spanning experimental models and, where possible, clinical breast cancer data. The successes and limitations of therapeutic targeting of these pathways with various signal transduction inhibitors (STIs) were evaluated in model systems and from emerging clinical trials (including epidermal growth factor receptor inhibitors such as gefitinib). It was concluded that growth factor signalling is an important contributor in the development of endocrine resistance in breast cancer and that use of STIs provides a promising therapeutic strategy for this disease. However, the cancer cell is clearly able to harness alternative growth factor signalling pathways for growth and cell survival in the presence of STI monotherapy and, as a consequence, the efficacy of STIs is likely to be limited by the acquisition of resistance. A number of strategies were proposed from studies in model systems that appeared to enhance anti-tumour actions of existing STI monotherapy, notably including combination therapies targeting multiple pathways. With the increased availability of diverse STIs and improved drug delivery, there is much hope that the more complex therapeutic strategies proposed may ultimately be achievable in clinical practice.

Sensitivity to further endocrine therapy is retained following progression on first-line fulvestrant

There is a need for new endocrine agents that lack cross-resistance with currently available treatments to extend the endocrine treatment window and delay the need for cytotoxic chemotherapy. This retrospective analysis evaluated the response of postmenopausal patients with previously untreated metastatic/locally advanced breast cancer to further endocrine treatment following progression on first-line fulvestrant or tamoxifen. Patients received fulvestrant 250 mg (intramuscular injection every 28 days) plus matching tamoxifen placebo (once daily), or tamoxifen 20 mg (orally once daily) plus matching fulvestrant placebo (every 28 days) in a double-blind, randomized, phase III trial. Treatment continued until disease progression or withdrawal, when further endocrine therapy was initiated (at the treating physician's discretion). Information regarding subsequent therapies and responses was obtained by follow-up questionnaire. Two-hundred-and-forty-five questionnaires were returned (from 587 patients), 149 of which yielded follow-up data on patients receiving second-line endocrine therapy following fulvestrant (n=83) and tamoxifen (n=66). Second-line therapy produced objective responses (OR) in 6/44 (13.6%) and clinical benefit (CB) in 25/44 (56.8%) patients who had CB with fulvestrant and produced OR in 5/41 (12.2%) patients and CB in 27/41 (65.8%) patients who had CB with first-line tamoxifen. For patients deriving no CB from trial therapy, second-line therapy produced OR in 3/39 (7.7%) and CB in 15/39 (38.5%) patients in the fulvestrant group and OR in 4/25 (16.0%) and CB in 12/25 (48.0%) patients in the tamoxifen group. Results from this questionnaire-based study suggest that postmenopausal women with advanced breast cancer who respond to first-line fulvestrant or tamoxifen retain sensitivity to subsequent endocrine therapy.

Endocrine treatment options for advanced breast cancer--the role of fulvestrant

For many years, tamoxifen has been the 'gold standard' amongst anti-oestrogen therapies for breast cancer. However, the selective aromatase inhibitors (AIs), anastrozole, letrozole and exemestane, have demonstrated advantages over tamoxifen as first-line treatments for advanced disease. Anastrozole is also more effective as an adjuvant treatment in early, operable breast cancer and is being increasingly used in the adjuvant setting. Generally, the selective oestrogen receptor modulators (SERMs), such as toremifene, droloxifene, idoxifene, raloxifene, and arzoxifene, show minimal activity in tamoxifen-resistant disease and show no superiority over tamoxifen as first-line treatments. In addition to these agents, other treatment options for advanced disease include high-dose oestrogens and progestins. Response rates for high-dose oestrogens and tamoxifen are similar, but the use of oestrogens is limited by their toxicity profile. Consequently, there is a need for new endocrine treatment options for breast cancer, particularly for use in disease that is resistant to tamoxifen or AIs. Fulvestrant ('Faslodex') is a new type of steroidal oestrogen receptor (ER) antagonist that downregulates cellular levels of the ER and progesterone receptor and has no agonist activity. This paper reviews the key efficacy and tolerability data for fulvestrant in postmenopausal women in the context of other endocrine therapies and explores the potential role of fulvestrant within the sequencing of endocrine therapies for advanced breast cancer.

Patterns of metastatic breast carcinoma: influence of tumour histological grade

AIM

To assess if the pattern of metastatic spread of carcinoma of the breast varies according to tumour histological grade.

MATERIALS AND METHODS

The clinical details, histological features of the primary tumour, and imaging findings at presentation of patients with metastatic breast cancer have been recorded prospectively since 1997. The pattern of metastatic spread, age at metastasis, metastasis-free interval (MFI), and length of survival with metastases were analysed by tumour grade.

RESULTS

There was a significant association between histological high-grade tumours and high frequency of intra-pulmonary metastases (p=0.013); liver metastases (p=0.039); para-aortic lymphadenopathy (p=0.022) and metastatic presentation under 50 years of age (p=0.003). A significant correlation was also demonstrated between histological low-grade tumours and increased frequency of pleural disease (p=0.020); increased frequency of bone metastases (p=0.004); prolonged MFI (MFI>5 years; p<0.0001); and increased length of survival (p<0.0001).

CONCLUSION

There is a correlation between patterns of metastatic spread and tumour histological grade. This partly explains the negative prognostic value of high tumour grade, as metastases from grade 3 tumours more commonly occur at sites associated with a worse prognosis. This finding may also prove useful in interpreting imaging in patients who have a history of breast cancer and undergo subsequent imaging because of new symptoms.

Expression and co-expression of the members of the epidermal growth factor receptor (EGFR) family in invasive breast carcinoma

The epidermal growth factor receptor (EGFR) family plays an important role in breast carcinogenesis. Much interest has been focused recently on its members because of their potential role as prognostic indicators in breast cancer and their involvement in cancer therapy. We have evaluated more than 1500 cases of invasive breast carcinoma immunohistochemically using tissue microarray technology to examine the expression of EGFR family receptor proteins. We have found that 20.1 and 31.8% of cases were positive for EGFR and c-erbB-2, respectively, and 45 and 45.1% of tumours overexpressed for c-erbB-3 and c-erbB-4, respectively. The expression of either EGFR or c-erbB-2 was associated with other bad prognostic features and with poor outcome. Neither c-erbB-3 nor c-erbB-4 had any association with survival. c-erbB-2 had an independent prognostic effect on overall and disease-free survival (DFS) in all cases, as well as in the subset of breast carcinoma patients with nodal metastases. Several hetero- and homodimeric combinations have been reported between the EGFR members. Those dimers can evoke diverse signal transduction pathways with variable cellular responses. We stratified cases according to their co-expression of receptors into distinct groups with different receptor-positive combinations. Patients whose tumours co-expressed c-erbB-2 and c-erbB-3, as well as those whose tumours co-expressed EGFR, c-erbB-2 and c-erbB-4 showed an unfavourable outcome compared with other groups, while combined c-erbB-3 and c-erbB-4 expression was associated with a better outcome. In cases showing expression of one family member only (homodimers), we found a significant association between c-erbB-4 homodimer-expressing tumours and better DFS. In contrast, patients with c-erbB-2 homodimer-expressing tumours had a significant poorer DFS compared with other cases. These data imply that the combined profile expression patterns of the four receptor family members together provide more accurate information on the tumour behaviour than studying the expression of each receptor individually.

The role of PTEN and its signalling pathways, including AKT, in breast cancer; an assessment of relationships with other prognostic factors and with outcome

PTEN is a novel tumour suppressor gene located on chromosome 10. PTEN mutations are believed to exert their effects through the putative PI3K-AKT-mTOR signalling pathway. Specifically, loss of PTEN leads to activation of AKT, which in turn promotes anti-apoptotic and pro-cell cycle entry pathways believed to be essential in tumourigenesis. Whilst PTEN mutations are frequent in a variety of sporadic cancers and inherited cancer syndromes, it is not clear how frequently PTEN mutations and immunohistochemical loss of PTEN expression occur in sporadic breast cancer. This study used tissue microarrays (TMAs) to assess wild-type PTEN and pAKT immunohistochemical staining in 670 and 691 cases, respectively, of primary operable breast cancer. Scores of 0, 1, and 2 were given for negative, weakly positive, and strongly positive degrees of immunoreactivity, respectively. In addition, immunohistochemical assessment of epidermal growth factor receptor (EGFR), Her2, and proliferation by MIB1 expression was performed on the same TMAs and the scores were compared with those of PTEN and pAKT. Eight per cent of cases did not express wild-type PTEN. No correlation was observed between patient, tumour and outcome variables and PTEN. pAKT expression correlated inversely with adverse tumour variables such as tumour grade (p< 0.001) and correlated positively with ER status (p< 0.001). No correlation was seen between either PTEN or AKT and EGFR, Her2 or MIB1. No association of PTEN or pAKT was seen in Kaplan-Meier or multivariate analysis for overall survival. The results indicate that loss of PTEN expression is infrequent in breast cancer. PTEN and AKT do not appear to be prognostic markers. The study argues against the current model of a simple linear tumourigenic PTEN-PI3K-AKT-mTOR pathway in breast cancer. It also suggests that, in this group of breast cancers, the most common upstream regulator of AKT may be ER rather than PTEN, EGFR or Her2.

Brain metastases from breast cancer: identification of a high-risk group

AIMS

Brain metastases from breast cancer are an uncommon initial presentation of metastatic breast cancer, but brain metastases commonly occur later in women's metastatic illness. The aims of this study were to document the type, frequency, and temporal occurrence of brain metastases from breast cancer as well as the survival of women with such metastases, and to attempt to identify a subgroup of women at high risk of brain metastases who may benefit from pre-emptive medical intervention.

MATERIALS AND METHODS

The radiological reports of all women presenting with metastases aged under 70 years who had subsequently died were examined. The type, frequency, temporal occurrence and survival with brain metastases were documented. Correlations were sought between the frequency of brain metastases and age at metastatic presentation, tumour grade, histological type and oestrogen receptor (ER) status.

RESULTS

Of 219 patients who had died with metastatic disease and who were under 70 years of age at metastatic presentation, 49 (22%) developed brain metastases. The development of brain metastases was related to young age (P = 0.0002), with 43% of women under 40 years developing brain metastases. Brain metastases were more common in women whose tumours were ER negative (38%) compared with women with ER-positive disease (14%) (P = 0.0003). By combining age and ER status, it is possible to identify a group of women (age under 50 years and ER negative) with a 53% risk of developing brain metastases. This group included many women who had chemotherapy for visceral metastases, and 68% had either stable disease or disease response at other sites at the time of brain metastases presentation.

CONCLUSION

It is possible to identify a subgroup of women with metastatic breast cancer at high risk of brain metastases who may benefit from pre-emptive medical intervention, such as screening or prophylactic treatment.

Identification of carcinoma cells in peripheral blood samples of patients with advanced breast carcinoma using RT-PCR amplification of CK7 and MUC1

We have undertaken a pilot study to attempt to identify circulating carcinoma cells in a series of patients with advanced breast carcinoma, using reverse transcription-polymerase chain reaction (RT-PCR) to amplify mRNA of epithelial specific antigens. Using this method to amplify mRNA of MUC1 and cytokeratin 7 (CK7) the sensitivity of the technique was demonstrated by means of diluted concentrations of "spiked MCF7" cells in whole blood, showing a detection limit of 1 in 10(6) (CK7) and 1 in 10(5) (MUC1). Positive results were obtained from the peripheral blood of all nine female patients with advanced breast cancer for CK7 and eight of the nine patients for MUC1. CK7 was however detected in five of 11 healthy controls (eight females, three males) and MUC1 in one of the 11 controls. None of the control group were positive for both CK7 and MUC1, in contrast to eight of the nine patients with advanced breast carcinoma who were positive for both markers. The RT-PCR method thus appears sufficiently sensitive to identify circulating tumour cells in peripheral blood samples from patients with advanced breast carcinoma. However a high proportion of false-positive results was seen in the control population. More extensive investigation is required before the technique is likely to be of benefit clinically.

Fulvestrant is an effective and well-tolerated endocrine therapy for postmenopausal women with advanced breast cancer: results from clinical trials

Fulvestrant ('Faslodex') is a new type of endocrine treatment--an oestrogen receptor (ER) antagonist that downregulates the ER and has no agonist effects. Early efficacy data from phase I/II trials have demonstrated fulvestrant to be effective and well tolerated. Two randomised phase III trials have compared the efficacy of fulvestrant and the aromatase inhibitor, anastrozole, in postmenopausal women with advanced breast cancer progressing on prior endocrine therapy. Fulvestrant (intramuscular injection 250 mg month(-1)) was found to be at least as effective as anastrozole (orally 1 mg day(-1)) for time to progression (5.5 vs 4.1 months, respectively (hazard ratio (HR): 0.95; 95.14% confidence interval (CI), 0.82-1.10; P=0.48)) and objective response 19.2 vs 16.5%, respectively; treatment difference 2.75%; 95.14% CI, -2.27 to 9.05%; P=0.31). More recently, fulvestrant has also been shown to be noninferior to anastrozole in terms of overall survival, with median time to death being 26.4 months in fulvestrant-treated patients and 24.2 months in those treated with anastrozole (HR: 0.97; 95% CI, 0.78-1.21; P=0.82). In a further randomised phase III trial, fulvestrant was compared with tamoxifen as first-line therapy for advanced disease in postmenopausal women. In the overall population, efficacy differences favoured tamoxifen and noninferiority of fulvestrant could not be ruled out. In the prospectively defined subset of patients with ER-positive and/or progesterone receptor-positive disease, there was no statistically significant difference between fulvestrant and tamoxifen. This paper reviews the efficacy and tolerability results from these trials.

Fulvestrant: pharmacokinetics and pharmacology

Fulvestrant is a new type of oestrogen receptor (ER) antagonist with no agonist activity and a novel pharmacological profile. Fulvestrant has been shown to significantly reduce cellular levels of the ER and progesterone receptor in both preclinical studies and in clinical trials of postmenopausal women with primary breast cancer. This paper reviews the pharmacokinetics and metabolism of fulvestrant, which support the rationale for drug delivery as a single, once-monthly intramuscular injection, and show that this agent has minimal potential to be the subject, or cause, of significant cytochrome p450-mediated drug interactions.