Neoadjuvant chemotherapy (NACT) for early breast cancer can make breast-conserving surgery more feasible and might be more likely to eradicate micrometastatic disease than might the same chemotherapy given after surgery. We investigated the long-term benefits and risks of NACT and the influence of tumour characteristics on outcome with a collaborative meta-analysis of individual patient data from relevant randomised trials. We obtained information about prerandomisation tumour characteristics, clinical tumour response, surgery, recurrence, and mortality for 4756 women in ten randomised trials in early breast cancer that began before 2005 and compared NACT with the same chemotherapy given postoperatively. Primary outcomes were tumour response, extent of local therapy, local and distant recurrence, breast cancer death, and overall mortality. Analyses by intention-to-treat used standard regression (for response and frequency of breast-conserving therapy) and log-rank methods (for recurrence and mortality). Patients entered the trials from 1983 to 2002 and median follow-up was 9 years (IQR 5-14), with the last follow-up in 2013. Most chemotherapy was anthracycline based (3838 [81%] of 4756 women). More than two thirds (1349 [69%] of 1947) of women allocated NACT had a complete or partial clinical response. Patients allocated NACT had an increased frequency of breast-conserving therapy (1504 [65%] of 2320 treated with NACT vs 1135 [49%] of 2318 treated with adjuvant chemotherapy). NACT was associated with more frequent local recurrence than was adjuvant chemotherapy: the 15 year local recurrence was 21·4% for NACT versus 15·9% for adjuvant chemotherapy (5·5% increase [95% CI 2·4-8·6]; rate ratio 1·37 [95% CI 1·17-1·61]; p=0·0001). No significant difference between NACT and adjuvant chemotherapy was noted for distant recurrence (15 year risk 38·2% for NACT vs 38·0% for adjuvant chemotherapy; rate ratio 1·02 [95% CI 0·92-1·14]; p=0·66), breast cancer mortality (34·4% vs 33·7%; 1·06 [0·95-1·18]; p=0·31), or death from any cause (40·9% vs 41·2%; 1·04 [0·94-1·15]; p=0·45). Tumours downsized by NACT might have higher local recurrence after breast-conserving therapy than might tumours of the same dimensions in women who have not received NACT. Strategies to mitigate the increased local recurrence after breast-conserving therapy in tumours downsized by NACT should be considered-eg, careful tumour localisation, detailed pathological assessment, and appropriate radiotherapy. Cancer Research UK, British Heart Foundation, UK Medical Research Council, and UK Department of Health.

Purpose: To conduct meta-analyses of randomized trials of aromatase inhibitors (AIs) compared with tamoxifen either as initial monotherapy (cohort 1) or after 2 to 3 years of tamoxifen (cohort 2). Materials and Methods: Data submitted to the Early Breast Cancer Trialists' Collaborative Group were used in separate meta-analyses of two cohorts. Primary analyses involve postmenopausal women with tumors reported to be estrogen receptor positive. Log-rank P values are two-sided. Results: Cohort 1 comprised 9,856 patients with a mean of 5.8 years of follow-up. At 5 years, AI therapy was associated with an absolute 2.9% (SE = 0.7%) decrease in recurrence (9.6% for AI v 12.6% for tamoxifen; 2P < .00001) and a nonsignificant absolute 1.1% (SE = 0.5%) decrease in breast cancer mortality (4.8% for AI v 5.9% for tamoxifen; 2P = .1). Cohort 2 comprised 9,015 patients with a mean of 3.9 years of follow-up. At 3 years from treatment divergence (ie, approximately 5 years after starting hormonal treatment), AI therapy was associated with an absolute 3.1% (SE = 0.6%) decrease in recurrence (5.0% for AI v 8.1% for tamoxifen since divergence; 2P < .00001) and an absolute 0.7% (SE = 0.3%) decrease in breast cancer mortality (1.7% for AI v 2.4% for tamoxifen since divergence; 2P = .02). There was no convincing heterogeneity in the proportional recurrence reduction with respect to age, nodal status, tumor grade, or progesterone receptor status and no indication of an increase in nonbreast deaths with AIs in either cohort. Conclusion: AIs produce significantly lower recurrence rates compared with tamoxifen, either as initial monotherapy or after 2 to 3 years of tamoxifen. Additional follow-up will provide clearer information on long-term survival.

Purpose: Tamoxifen, which is actually the gold standard adjuvant treatment in estrogen receptor–positive early breast cancer, is associated with an increased risk of endometrial cancer and other life-threatening events. Moreover, many women relapse during or after tamoxifen therapy because of the development of resistance. Therefore new approaches are required. Patients and Methods: We conducted a prospective randomized trial to test the efficacy of switching postmenopausal patients who were already receiving tamoxifen to the aromatase inhibitor anastrozole. After 2 to 3 years of tamoxifen treatment, patients were randomly assigned either to receive anastrozole 1 mg/d or to continue receiving tamoxifen 20 mg/d, for a total duration of treatment of 5 years. Disease-free survival was the primary end point. Event-free survival, overall survival, and safety were secondary end points. Results: Four hundred forty-eight patients were enrolled. All women had node-positive, estrogen receptor–positive tumors. At a median follow-up time of 36 months, 45 events had been reported in the tamoxifen group compared with 17 events in the anastrozole group (P = .0002). Disease-free and local recurrence-free survival were also significantly longer in the anastrozole group (hazard ratio [HR] = 0.35; 95% CI, 0.18 to 0.68; P = .001 and HR = 0.15; 95% CI, 0.03 to 0.65; P = .003, respectively). Overall, more adverse events were recorded in the anastrozole group compared with the tamoxifen group (203 v 150, respectively; P = .04). However, more events were life threatening or required hospitalization in the tamoxifen group than in the anastrozole group (33 of 150 events v 28 of 203 events, P = .04). Conclusion: Switching to anastrozole after the first 2 to 3 years of treatment is well tolerated and significantly improves event-free and recurrence-free survival in postmenopausal patients with early breast cancer.

Increasing the dose intensity of cytotoxic therapy by shortening the intervals between cycles, or by giving individual drugs sequentially at full dose rather than in lower-dose concurrent treatment schedules, might enhance efficacy. To clarify the relative benefits and risks of dose-intense and standard-schedule chemotherapy in early breast cancer, we did an individual patient-level meta-analysis of trials comparing 2-weekly versus standard 3-weekly schedules, and of trials comparing sequential versus concurrent administration of anthracycline and taxane chemotherapy. The primary outcomes were recurrence and breast cancer mortality. Standard intention-to-treat log-rank analyses, stratified by age, nodal status, and trial, yielded dose-intense versus standard-schedule first-event rate ratios (RRs). Individual patient data were provided for 26 of 33 relevant trials identified, comprising 37 298 (93%) of 40 070 women randomised. Most women were aged younger than 70 years and had node-positive disease. Total cytotoxic drug usage was broadly comparable in the two treatment arms; colony-stimulating factor was generally used in the more dose-intense arm. Combining data from all 26 trials, fewer breast cancer recurrences were seen with dose-intense than with standard-schedule chemotherapy (10-year recurrence risk 28·0% vs 31·4%; RR 0·86, 95% CI 0·82-0·89; p<0·0001). 10-year breast cancer mortality was similarly reduced (18·9% vs 21·3%; RR 0·87, 95% CI 0·83-0·92; p<0·0001), as was all-cause mortality (22·1% vs 24·8%; RR 0·87, 95% CI 0·83-0·91; p<0·0001). Death without recurrence was, if anything, lower with dose-intense than with standard-schedule chemotherapy (10-year risk 4·1% vs 4·6%; RR 0·88, 95% CI 0·78-0·99; p=0·034). Recurrence reductions were similar in the seven trials (n=10 004) that compared 2-weekly chemotherapy with the same chemotherapy given 3-weekly (10-year risk 24·0% vs 28·3%; RR 0·83, 95% CI 0·76-0·91; p<0·0001), in the six trials (n=11 028) of sequential versus concurrent anthracycline plus taxane chemotherapy (28·1% vs 31·3%; RR 0·87, 95% CI 0·80-0·94; p=0·0006), and in the six trials (n=6532) testing both shorter intervals and sequential administration (30·4% vs 35·0%; RR 0·82, 95% CI 0·74-0·90; p<0·0001). The proportional reductions in recurrence with dose-intense chemotherapy were similar and highly significant (p<0·0001) in oestrogen receptor (ER)-positive and ER-negative disease and did not differ significantly by other patient or tumour characteristics. Increasing the dose intensity of adjuvant chemotherapy by shortening the interval between treatment cycles, or by giving individual drugs sequentially rather than giving the same drugs concurrently, moderately reduces the 10-year risk of recurrence and death from breast cancer without increasing mortality from other causes. Cancer Research UK, Medical Research Council.

PURPOSE: The logic behind the application of luteinizing hormone-releasing hormone (LHRH) agonists in combination with tamoxifen in premenopausal women is that LHRH agonists on the one hand suppress the tamoxifen-induced stimulation of the pituitary-ovarian function and, on the other hand, seem as effective as surgical castration. This meta-analysis combines all randomized evidence to compare the combined treatment with LHRH agonist alone with respect to overall survival, progression-free survival, and objective response in premenopausal women with advanced breast cancer. PATIENTS AND METHODS: Four clinical trials randomizing a total of 506 premenopausal women with advanced breast cancer to LHRH agonist alone or to the combined treatment of LHRH agonist plus tamoxifen were identified. Meta-analytic techniques were used to analyze individual patient data from these trials. RESULTS: With a median follow-up of 6.8 years, there was a significant survival benefit (stratified log-rank test, P = .02; hazards ratio [HR] = 0.78) and progression-free survival benefit (stratified log-rank test, P = .0003; HR = 0.70) in favor of the combined treatment. The overall response rate was significantly higher on combined endocrine treatment (stratified Mantel Haenszel test, P = .03; odds ratio = 0.67). CONCLUSION: The combination of LHRH agonist plus tamoxifen is superior to LHRH agonist alone in premenopausal women with advanced breast cancer. Therefore, if a premenopausal woman with advanced breast cancer is thought to be suitable for endocrine treatment, it is proposed that the combination of a LHRH agonist plus tamoxifen be considered as the new standard treatment.