The 13th St Gallen International Breast Cancer Conference (2013) Expert Panel reviewed and endorsed substantial new evidence on aspects of the local and regional therapies for early breast cancer, supporting less extensive surgery to the axilla and shorter durations of radiation therapy. It refined its earlier approach to the classification and management of luminal disease in the absence of amplification or overexpression of the Human Epidermal growth factor Receptor 2 (HER2) oncogene, while retaining essentially unchanged recommendations for the systemic adjuvant therapy of HER2-positive and ‘triple-negative’ disease. The Panel again accepted that conventional clinico-pathological factors provided a surrogate subtype classification, while noting that in those areas of the world where multi-gene molecular assays are readily available many clinicians prefer to base chemotherapy decisions for patients with luminal disease on these genomic results rather than the surrogate subtype definitions. Several multi-gene molecular assays were recognized as providing accurate and reproducible prognostic information, and in some cases prediction of response to chemotherapy. Cost and availability preclude their application in many environments at the present time. Broad treatment recommendations are presented. Such recommendations do not imply that each Panel member agrees: indeed, among more than 100 questions, only one (trastuzumab duration) commanded 100% agreement. The various recommendations in fact carried differing degrees of support, as reflected in the nuanced wording of the text below and in the votes recorded in supplementary Appendix S1, available at Annals of Oncology online. Detailed decisions on treatment will as always involve clinical consideration of disease extent, host factors, patient preferences and social and economic constraints.
surgery; radiation therapy; systemic adjuvant therapies; early breast cancer; St Gallen Consensus; subtypes
To develop a Risk Score (RS) to predict distant recurrence among premenopausal women with node-negative endocrine-responsive early breast cancer.
The Cox model was used to develop the RS using clinical and histopathological features from 378 women participating in the IBCSG Trial VIII who received endocrine therapy alone or following chemotherapy. The performance of the resulting model was validated on a cohort of 1005 patients from a single institution who received endocrine therapy alone.
In a multivariable analysis, the risk of distant recurrence was associated with tumor size, ER, Ki-67 and peritumoral vascular invasion. In the validation cohort, patients with high RS were at greater risk of distant recurrence compared to patients with low RS (HR, 17.41 ; 95% CI, 5.72 to 52.95).
In premenopausal women with node-negative endocrine-responsive early breast cancer, the RS identifies patients at higher risk of distant recurrence.
breast cancer; histopathological features; risk score; endocrine therapy; chemotherapy
The aim of adjuvant therapy in breast cancer is to reduce the risk of recurrence. Some patients develop metastases many years after apparently successful treatment of their primary cancer. Tumour dormancy may explain the long time between initial diagnosis and treatment of cancer, and occurrence of relapse. The regulation of the switch from clinical dormancy to cancer regrowth in locoregional and distant sites is poorly understood. In this review, we report some data supporting the existence of various factors that may explain cancer dormancy including genetic and epigenetic changes, angiogenic switch, microenvironment, and immunosurveillance. A better definition and understanding of these factors should allow the identification of patients at high risk of relapse and to develop new therapeutic strategies in order to improve prognosis.
tumor dormancy; breast cancers; angiogenesis; microenvironment; immune surveillance
Adjuvant tamoxifen therapy is effective for postmenopausal women with endocrine-responsive breast cancer. Cytochrome P450 2D6 (CYP2D6) enzyme metabolizes tamoxifen to clinically active metabolites, and CYP2D6 polymorphisms may adversely affect tamoxifen efficacy. In this study, we investigated the clinical relevance of CYP2D6 polymorphisms.
We obtained tumor tissues and isolated DNA from 4861 of 8010 postmenopausal women with hormone receptor–positive breast cancer who enrolled in the randomized, phase III double-blind Breast International Group (BIG) 1-98 trial between March 1998 and May 2003 and received tamoxifen and/or letrozole treatment. Extracted DNA was used for genotyping nine CYP2D6 single-nucleotide polymorphisms using polymerase chain reaction–based methods. Genotype combinations were used to categorize CYP2D6 metabolism phenotypes as poor, intermediate, and extensive metabolizers (PM, IM, and EM, respectively; n = 4393 patients). Associations of CYP2D6 metabolism phenotypes with breast cancer-free interval (referred to as recurrence) and treatment-induced hot flushes according to randomized endocrine treatment and previous chemotherapy were assessed. Cox proportional hazards models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs). All statistical tests were two-sided.
No association between CYP2D6 metabolism phenotypes and breast cancer-free interval was observed among patients who received tamoxifen monotherapy without previous chemotherapy (P = .35). PM or IM phenotype had a non-statistically significantly reduced risk of breast cancer recurrence compared with EM phenotype (PM or IM vs EM, HR of recurrence = 0.86, 95% CI = 0.60 to 1.24). CYP2D6 metabolism phenotype was associated with tamoxifen-induced hot flushes (P = .020). Both PM and IM phenotypes had an increased risk of tamoxifen-induced hot flushes compared with EM phenotype (PM vs EM, HR of hot flushes = 1.24, 95% CI = 0.96 to 1.59; IM vs EM, HR of hot flushes = 1.23, 95% CI = 1.05 to 1.43).
CYP2D6 phenotypes of reduced enzyme activity were not associated with worse disease control but were associated with increased hot flushes, contrary to the hypothesis. The results of this study do not support using the presence or absence of hot flushes or the pharmacogenetic testing of CYP2D6 to determine whether to treat postmenopausal breast cancer patients with tamoxifen.
The relationship between nail and bone may be measurable, thus making the fingernail a potentially valuable tool for assessing bone health for women receiving treatment for breast cancer. In the BIG 1-98 Fingernail Pilot Substudy, Bone Quality Test (BQT) scores of fingernails were measured at two assessment timepoints.
Thirteen eligible patients were enrolled into the substudy during their treatment with tamoxifen (4 patients) or letrozole (9 patients). Two fingernails were tested and BQT scores averaged for two assessments six months apart.
BQT scores collected six months later (second assessment) significantly decreased compared with those at first collection (p =0.007) regardless of treatment and prior fracture.
The reduction of BQT scores observed in the patients of our small exploratory study during exposure to bone-altering breast cancer treatments is an incentive for larger studies using this technique.
fingernail; bone quality test; breast cancer; hormonal therapy; letrozole
Adjuvant! © Online (Adjuvant!) is a user-friendly, web-based tool that provides estimates of adjuvant therapy outcomes for individual patients. While reliable evidence underpins estimates for most patient cohorts, there is a paucity of data on the effect of adding chemotherapy to complete estrogen blockade for premenopausal women with estrogen-receptor positive breast cancer.
International Breast Cancer Study Group (IBCSG) Trial 11-93 enrolled 174 premenopausal women with estrogen-receptor positive, node-positive breast cancer. Fifty-five percent of patients had 1 positive axillary lymph node and 97% had 3 or fewer positive nodes. Patients were randomized to receive ovarian function suppression plus five years of tamoxifen with or without anthracycline-based chemotherapy. Estimated hazard rates and corresponding 10-year relapse-free survival percents obtained from Trial 11-93 data were compared with those predicted using Adjuvant!.
The 10-year relapse-free survival percents predicted from Adjuvant! were 64.4% (95% CI, 61.9% to 67.2%) for endocrine therapy alone and 74.9% (95% CI, 73.1% to 76.8%) for chemoendocrine therapy. By contrast, these estimates in Trial 11-93 were 76.4% (95% CI, 65.8% to 84.0%) for endocrine therapy alone and 74.9% (95% CI, 64.5% to 82.7%) for chemoendocrine therapy. The Adjuvant! estimate for the endocrine alone control group is lower than that observed in Trial 11-93 (p=0.03), while the estimates for the two chemoendocrine therapy groups are similar.
Adjuvant! appears to underestimate the effectiveness of adjuvant endocrine therapy alone for premenopausal women with endocrine responsive breast cancer, thus overestimating the added benefit, if any, from chemotherapy for this patient population.
Adjuvant! © Online; Estrogen Receptor; Premenopausal; Chemotherapy; Endocrine Therapy; International Breast Cancer Study Group
A minority of early invasive breast cancers show a pattern of central necrosis and fibrosis (CNF). Previous studies have documented an adverse prognostic impact and association with other adverse pathological features, but its predictive importance for therapy selection is unknown.
We examined the prognostic and predictive value of CNF in two randomized clinical trials comparing chemoendocrine therapy with endocrine therapy alone in patients with node-negative breast cancer. A total of 1850 patients randomly assigned to treatment groups comparing endocrine with chemoendocrine therapy, and with centrally-assessed CNF, ER, PgR and HER2 were included in the analytic cohort. The median follow up was 10 years.
CNF was present in 84 of 1850 trial patients (4.5%). It was associated with tumor characteristics suggesting poor outcome, but was an independent adverse factor for disease-free survival. In the presence of CNF outcome was worse regardless of tumor grade, whereas in the absence of CNF, patients with grade 3 tumors had poorer outcome than those with grade 1-2 tumors. Among patients with estrogen receptor-absent tumors chemoendocrine therapy was superior to endocrine therapy alone only in the absence of CNF [HR (chemoendocrine:endocrine)=0.46 in CNF-absent, 0.90 in CNF-present], while among those with receptor-positive disease chemoendocrine therapy was beneficial only in the presence of CNF [HR=0.34 CNF-present, 0.96 CNF-absent].
The results suggest that the presence of CNF reflects a biological difference in early breast cancer that is important in modulating the efficacy of standard therapies. Accordingly we believe that its presence should be routinely reported.
central necrosis; fibrosis; chemotherapy; endocrine therapy; breast cancer
The current therapeutic strategy in breast cancer is to identify a target, such as estrogen receptor (ER) status, for tailoring treatments.
We investigated the patterns of recurrence with respect to ER status for patients treated in two randomized trials with 25 years' median follow-up.
In the ER-negative subpopulations most breast cancer events occurred within the first 5–7 years after randomization, while in the ER-positive subpopulations breast cancer events were spread through 10 years. In the ER-positive subpopulation, 1 year endocrine treatment alone significantly prolonged disease-free survival (DFS) with no additional benefit observed by adding one year of chemotherapy. In the small ER-negative subpopulation chemo-endocrine therapy had a significantly better DFS than endocrine alone or no treatment.
Despite small numbers of patients, “old-fashioned” treatments, and competing causes of treatment failure, the value of ER status as a target for response to adjuvant treatment is evident through prolonged follow-up.
breast cancer; chemotherapy; estrogen receptor; hormonal therapy
To compare the efficacy of chemoendocrine treatment with that of endocrine treatment (ET) alone for postmenopausal women with highly endocrine responsive breast cancer.
Patients and methods
In the International Breast Cancer Study Group (IBCSG) Trials VII and 12-93, postmenopausal women with node-positive, estrogen receptor (ER)-positive or ER-negative, operable breast cancer were randomized to receive either chemotherapy or endocrine therapy or combined chemoendocrine treatment. Results were analyzed overall in the cohort of 893 patients with endocrine-responsive disease, and according to prospectively-defined categories of ER, age and nodal status. STEPP analyses assessed chemotherapy effect. The median follow-up was 13 years.
Adding chemotherapy reduced the relative risk of a disease-free survival event by 19% (p=0.02) compared with ET alone. STEPP analyses showed little effect of chemotherapy for tumors with high levels of ER expression (p = 0.07), or for the cohort with one positive node (p = 0.03).
Chemotherapy significantly improves disease-free survival for postmenopausal women with endocrine-responsive breast cancer, but the magnitude of the effect is substantially attenuated if ER levels are high.
breast cancer; chemoendocrine therapy; estrogen receptors; postmenopausal
Background: The International Breast Cancer Study Group Trial VIII compared long-term efficacy of endocrine therapy (goserelin), chemotherapy [cyclophosphamide, methotrexate and fluorouracil (CMF)], and chemoendocrine therapy (CMF followed by goserelin) for pre/perimenopausal women with lymph-node-negative breast cancer.
Patients and methods: From 1990 to 1999, 1063 patients were randomized to receive (i) goserelin for 24 months (n = 346), (ii) six courses of ‘classical’ CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy (n = 360), or (iii) six courses of CMF plus 18 months goserelin (CMF→ goserelin; n = 357). Tumors were classified as estrogen receptor (ER) negative (19%), ER positive (80%), or ER unknown (1%); 19% of patients were younger than 40. Median follow-up was 12.1 years.
Results: For the ER-positive cohort, sequential therapy provided a statistically significant benefit in disease-free survival (DFS) (12-year DFS = 77%) compared with CMF alone (69%) and goserelin alone (68%) (P = 0.04 for each comparison), due largely to the effect in younger patients. Patients with ER-negative tumors whose treatment included CMF had similar DFS (12-year DFS CMF = 67%; 12-year DFS CMF→ goserelin = 69%) compared with goserelin alone (12-year DFS = 61%, P= NS).
Conclusions: For pre/perimenopausal women with lymph-node-negative ER-positive breast cancer, CMF followed by goserelin improved DFS in comparison with either modality alone. The improvement was the most pronounced in those aged below 40, suggesting an endocrine effect of prolonged CMF-induced amenorrhea.
amenorrhea; breast cancer; chemotherapy; goserelin; hormonal therapy, node negative
Background: On average, aromatase inhibitors are better than tamoxifen when used as initial or sequential therapy for postmenopausal women with endocrine-responsive early breast cancer. Because there may be contraindications to their use based on side-effects or cost, we investigated subgroups in which aromatase inhibitors may be more or less important.
Patients and methods: Breast International Group 1-98 trial randomized 6182 women among four groups comparing letrozole and tamoxifen with sequences of each agent; 5177 (84%) had centrally confirmed estrogen receptor (ER) positivity. We assessed whether centrally determined ER, progesterone receptor (PgR), human epidermal growth factor receptor 2, and Ki-67 labeling index, alone or in combination with other prognostic features, predicted the magnitude of letrozole effectiveness compared with either sequence or tamoxifen monotherapy.
Results: Individually, none of the markers significantly predicted differential treatment effects. Subpopulation treatment effect pattern plot analysis of a composite measure of prognostic risk revealed three patterns. Estimated 5-year disease-free survival for letrozole monotherapy, letrozole→tamoxifen, tamoxifen→letrozole, and tamoxifen monotherapy were 96%, 94%, 93%, and 94%, respectively, for patients at lowest risk; 90%, 91%, 93%, and 86%, respectively, for patients at intermediate risk; and 80%, 76%, 74%, and 69%, respectively, for patients at highest risk.
Conclusion: A composite measure of risk informs treatment selection better than individual biomarkers and supports the choice of 5 years of letrozole for patients at highest risk for recurrence.
aromatase inhibitor; breast cancer; prognostic factor; tamoxifen
Background: The benefit of adjuvant chemotherapy in postmenopausal patients with estrogen receptor (ER)-positive lymph node-negative breast cancer is being reassessed.
Patients and methods: After stratification by ER status, 1669 postmenopausal patients with operable lymph node-negative breast cancer were randomly assigned to three 28-day courses of ‘classical’ CMF (cyclophosphamide, methotrexate, 5-fluorouracil) chemotherapy followed by tamoxifen for 57 months (CMF→tamoxifen) or to tamoxifen alone for 5 years.
Results: ERs were positive in 81% of tumors. At a median follow-up of 13.1 years, patients with ER-positive breast cancers did not benefit from CMF [13-year disease-free survival (DFS) 64% CMF→tamoxifen, 66% tamoxifen; P = 0.99], whereas CMF substantially improved the prognosis of patients with ER-negative breast cancer (13-year DFS 73% versus 57%, P = 0.001). Similarly, breast cancer-free interval (BCFI) was identical in the ER-positive cohort but significantly improved by chemotherapy in the ER-negative cohort (13-year BCFI 80% versus 63%, P = 0.001). CMF had no influence on second nonbreast malignancies or deaths from other causes.
Conclusion: CMF is not beneficial in postmenopausal patients with node-negative ER-positive breast cancer but is highly effective within the ER-negative cohort. In the future, other markers of chemotherapy response may define a subset of patients with ER-positive tumors who may benefit from adjuvant chemotherapy.
adjuvant chemotherapy; breast cancer; estrogen receptor; postmenopause; tamoxifen
Postmenopausal women with hormone receptor-positive early breast cancer have persistent, long-term risk of breast cancer recurrence and death. Therefore, trials evaluating endocrine therapies for this patient population require extended follow-up. We present an update of efficacy outcomes in the Breast International Group (BIG) 1-98 study at 8.1 years median follow-up.
BIG 1-98 is a randomized, phase III, double-blind trial of 8010 postmenopausal women with hormone receptor-positive early breast cancer that compares five years of tamoxifen or letrozole monotherapy or sequential treatment with two years of one of these agents followed by three years of the other. The primary efficacy endpoint is disease-free survival (DFS: events comprise invasive breast cancer relapse, second primaries [contralateral breast and non-breast], or death without prior cancer event), and secondary endpoints are overall survival (OS), distant recurrence-free interval (DRFI) and breast cancer-free interval (BCFI). The monotherapy comparison includes patients randomized to tamoxifen × 5 years (n=2459) or letrozole × 5 years (n=2463). In 2005, after significant DFS benefit was reported for letrozole as compared with tamoxifen, a protocol amendment facilitated the crossover to letrozole of patients who were still receiving tamoxifen alone; Cox models and Kaplan-Meier estimates with inverse probability of censoring weighting (IPCW) are used to account for selective crossover to letrozole of 619 patients in the tamoxifen arm. The comparison of sequential treatments to letrozole monotherapy includes patients enrolled in the four-arm option of the trial and randomized to letrozole × 5 years (n=1546), letrozole × 2 years followed by tamoxifen × 3 years (n=1540), or tamoxifen × 2 years followed by letrozole × 3 years (n=1548). All patients have completed study treatment; follow up is continuing for those enrolled in the four-arm option. BIG 1-98 is registered at clinicaltrials.gov NCT00004205.
At a median follow-up of 8.7 years from randomization (range 0–12.4), letrozole monotherapy is significantly better than tamoxifen, whether using IPCW or intention-to-treat (ITT) analysis [IPCW: DFS HR 0.82 (95% CI 0.74–0.92), OS HR 0.79 (0.69–0.900, DRFI HR 0.79 (0.68–0.92), BCFI HR 0.80 (0.70–0.92); ITT: DFS HR 0.86 (0.78–0.96), OS HR 0.87 (0.77–0.999), DRFI HR 0.86 (0.74–0.998), BCFI HR 0.86 (0.76–0.98)]. At a median follow-up of 8.0 years from randomization (range 0–11.2), there were no statistically significant differences in any of the four endpoints for either sequence compared with letrozole monotherapy. Eight-year ITT estimates [each with SE ≤ 1.1%] for letrozole monotherapy, letrozole followed by tamoxifen, and tamoxifen followed by letrozole were 78.6%, 77.8%, 77.3% for DFS; 87.5%, 87.7%, 85.9% for OS; 89.9%, 88.7%, 88.1% for DRFI; and 86.1%, 85.3%, 84.3% for BCFI.
For postmenopausal women with endocrine-responsive early breast cancer, a reduction in breast cancer recurrence and mortality is obtained by letrozole monotherapy when compared to tamoxifen. Sequential treatments involving tamoxifen and letrozole do not improve outcome compared with letrozole monotherapy, but may represent useful strategies considering individual patient’s risk of recurrence and treatment tolerability: more thromboembolic events, vaginal bleeding, hot flushes and night sweats with tamoxifen, while more vaginal dryness, bone fractures, osteoporosis, arthralgia/myalgia, and higher grade cardiac events with letrozole.
Novartis, United States National Cancer Institute, International Breast Cancer Study Group.
aromatase inhibitor; letrozole; breast cancer; adjuvant therapy; endocrine therapy; tamoxifen
To evaluate the association between time from breast-conserving surgery (BCS) to radiotherapy and clinical outcome among patients treated with adjuvant endocrine therapy.
Patient information was obtained from three International Breast Cancer Study Group trials. Analysis was restricted to 964 patients treated with BCS and adjuvant endocrine therapy. Patients were divided into two groups based on the median number of days between BCS and radiotherapy and into 4 groups based on the quartile of time between BCS and radiotherapy. Endpoints were time to local recurrence (TLR), disease-free survival (DFS) and overall survival (OS). Proportional hazards regression analysis was used to perform comparisons after adjustment for baseline factors.
The median time between BCS and radiotherapy was 77 days. Radiotherapy timing was significantly associated with age, menopausal status, and estrogen receptor status. After adjustment for these factors no significant effect of radiotherapy delay of up to 20 weeks was found. Adjusted hazard ratios (HRs) (radiotherapy within 77 days vs. after 77 days) were 0.94 (95% CI 0.47–1.87) for TLR, 1.05 (95% CI 0.82–1.34) for DFS and 1.07 (95% CI 0.77–1.49) for OS. For TLR the adjusted HRs for ≤48 days, 49–77 days, and 78–112 days were 0.90 (CI 95% 0.34–2.37), 0.89 (95% CI, 0.33–2.25), and 0.89 (95% CI, 0.33–2.41), respectively relative to ≥ 113 days.
Radiotherapy delay of up to 20 weeks was significantly associated with baseline factors such as age, menopausal status, and estrogen-receptor status. After adjustment for these factors, timing of radiotherapy was not significantly associated with TLR, DFS, or OS.
breast cancer; radiotherapy; radiotherapy timing; breast-conserving surgery; endocrine therapy
Among postmenopausal women with endocrine-responsive breast cancer, the aromatase inhibitor letrozole, when compared with tamoxifen, has been shown to significantly improve disease-free survival (DFS) and time to distant recurrence (TDR). We investigated whether letrozole monotherapy prolonged overall survival (OS) compared with tamoxifen monotherapy.
Patients and Methods
Of 8,010 postmenopausal women with hormone receptor–positive, early breast cancer enrolled on the Breast International Group (BIG) 1-98 study, 4,922 were randomly assigned to 5 years of continuous adjuvant therapy with either letrozole or tamoxifen. Of 2,459 patients enrolled in the tamoxifen treatment arm, 619 (25.2%) selectively crossed over to either adjuvant or extended letrozole after initial trial results were presented in January 2005. To gain better estimates of relative treatment effects in the presence of selective crossover, we used inverse probability of censoring weighted (IPCW) modeling.
Weighted Cox models, by using IPCW, estimated a statistically significant, 18% reduction in the hazard of an OS event with letrozole treatment (hazard ratio [HR], 0.82; 95% CI, 0.70 to 0.95). Estimates of 5-year OS on the basis of IPCW were 91.8% and 90.4% for letrozole and tamoxifen, respectively. The HRs of DFS and TDR events by using IPCW modeling were 0.83 (95% CI, 0.74 to 0.94) and 0.80 (95% CI, 0.67 to 0.94), respectively (P < .05 for DFS, OS, and TDR). Median follow-up was 74 months.
Adjuvant treatment with letrozole, compared with tamoxifen, significantly reduces the risk of death, the risk of recurrent disease, and the risk of recurrence at distant sites in postmenopausal women with hormone receptor–positive breast cancer.
Endocrine therapy for breast cancer may affect cognition. The purpose of this study was to examine whether cognitive function improves after cessation of adjuvant endocrine therapy. Change in cognitive function was assessed in 100 postmenopausal breast cancer patients in the BIG 1-98 trial, who were randomized to receive 5 years of adjuvant tamoxifen or letrozole alone or in sequence. Cognitive function was evaluated by computerized tests during the fifth year of trial treatment (Y5) and 1 year after treatment completion (Y6). Cognitive test scores were standardized according to age-specific norms and the change assessed using the Wilcoxon signed-rank test. There was significant improvement in the composite cognitive function score from Y5 to Y6 (median of change = 0.22, effect size = 0.53, P < 0.0001). This improvement was consistent in women taking either tamoxifen or letrozole at Y5 (P = 0.0006 and P = 0.0002, respectively). For postmenopausal patients who received either adjuvant letrozole or tamoxifen alone or in sequence, cognitive function improved after cessation of treatment.
Cognitive function; Breast cancer; Aromatase inhibitor; Tamoxifen; Letrozole; Quality of life
Cognitive function in postmenopausal women receiving letrozole or tamoxifen as adjuvant endocrine treatment was compared during the fifth year of treatment in a substudy of the BIG 1-98 trial. In BIG 1-98 patients were randomized to receive adjuvant A) 5-years tamoxifen, B) 5-years letrozole, C) 2-years tamoxifen followed by 3-years letrozole, or D) 2-years letrozole followed by 3-years tamoxifen. The primary comparison was the difference in composite score for patients taking letrozole (B+C; N=65) versus tamoxifen (A+D; N=55). The patients taking letrozole had better overall cognitive function than those taking tamoxifen (difference in mean composite z-scores =0.28, p=0.04, 95% CI:0.02, 0.54, Cohen's D = 0.40 indicating small to moderate effect). In this substudy, breast cancer patients taking adjuvant letrozole during the fifth year of treatment had better cognitive function than those taking tamoxifen, suggesting aromatase inhibitors do not adversely impact cognition compared with tamoxifen.
Cognitive function; breast cancer; aromatase inhibitor; tamoxifen; letrozole; quality of life
The 12th St Gallen International Breast Cancer Conference (2011) Expert Panel adopted a new approach to the classification of patients for therapeutic purposes based on the recognition of intrinsic biological subtypes within the breast cancer spectrum. For practical purposes, these subtypes may be approximated using clinicopathological rather than gene expression array criteria. In general, systemic therapy recommendations follow the subtype classification. Thus, ‘Luminal A’ disease generally requires only endocrine therapy, which also forms part of the treatment of the ‘Luminal B’ subtype. Chemotherapy is considered indicated for most patients with ‘Luminal B', ‘Human Epidermal growth factor Receptor 2 (HER2) positive’, and ‘Triple negative (ductal)’ disease, with the addition of trastuzumab in ‘HER2 positive’ disease. Progress was also noted in defining better tolerated local therapies in selected cases without loss of efficacy, such as accelerated radiation therapy and the omission of axillary dissection under defined circumstances. Broad treatment recommendations are presented, recognizing that detailed treatment decisions need to consider disease extent, host factors, patient preferences, and social and economic constraints.
adjuvant therapies; early breast cancer; St Gallen Consensus; subtypes
Retrospective studies suggest that primary breast cancers lacking estrogen receptor (ER) and progesterone receptor (PR) and not overexpressing human epidermal growth factor receptor 2 (HER2; triple-negative tumors) are particularly sensitive to DNA-damaging chemotherapy with alkylating agents.
Patients and Methods
Patients enrolled in International Breast Cancer Study Group Trials VIII and IX with node-negative, operable breast cancer and centrally assessed ER, PR, and HER2 were included (n = 2,257). The trials compared three or six courses of adjuvant classical cyclophosphamide, methotrexate, and fluorouracil (CMF) with or without endocrine therapy versus endocrine therapy alone. We explored patterns of recurrence by treatment according to three immunohistochemically defined tumor subtypes: triple negative, HER2 positive and endocrine receptor absent, and endocrine receptor present.
Patients with triple-negative tumors (303 patients; 13%) were significantly more likely to have tumors > 2 cm and grade 3 compared with those in the HER2-positive, endocrine receptor–absent, and endocrine receptor–present subtypes. No clear chemotherapy benefit was observed in endocrine receptor–present disease (hazard ratio [HR], 0.90; 95% CI, 0.74 to 1.11). A statistically significantly greater benefit for chemotherapy versus no chemotherapy was observed in triple-negative breast cancer (HR, 0.46; 95% CI, 0.29 to 0.73; interaction P = .009 v endocrine receptor–present disease). The magnitude of the chemotherapy effect was lower in HER2-positive endocrine receptor–absent disease (HR, 0.58; 95% CI, 0.29 to 1.17; interaction P = .24 v endocrine receptor–present disease).
The magnitude of benefit of CMF chemotherapy is largest in patients with triple-negative, node-negative breast cancer.
Background: Peritumoral vascular invasion (PVI) may assist in assigning optimal adjuvant systemic therapy for women with early breast cancer.
Patients and methods: Patients participated in two International Breast Cancer Study Group randomized trials testing chemoendocrine adjuvant therapies in premenopausal (trial VIII) or postmenopausal (trial IX) node-negative breast cancer. PVI was assessed by institutional pathologists and/or central review on hematoxylin–eosin-stained slides in 99% of patients (analysis cohort 2754 patients, median follow-up >9 years).
Results: PVI, present in 23% of the tumors, was associated with higher grade tumors and larger tumor size (trial IX only). Presence of PVI increased locoregional and distant recurrence and was significantly associated with poorer disease-free survival. The adverse prognostic impact of PVI in trial VIII was limited to premenopausal patients with endocrine-responsive tumors randomized to therapies not containing goserelin, and conversely the beneficial effect of goserelin was limited to patients whose tumors showed PVI. In trial IX, all patients received tamoxifen: the adverse prognostic impact of PVI was limited to patients with receptor-negative tumors regardless of chemotherapy.
Conclusion: Adequate endocrine adjuvant therapy appears to abrogate the adverse impact of PVI in node-negative disease, while PVI may identify patients who will benefit particularly from adjuvant therapy.
adjuvant therapy; breast cancer; endocrine responsiveness; metastasis; prognosis; vascular invasion
Background: To compare the incidence and timing of bone fractures in postmenopausal women treated with 5 years of adjuvant tamoxifen or letrozole for endocrine-responsive early breast cancer in the Breast International Group (BIG) 1-98 trial.
Methods: We evaluated 4895 patients allocated to 5 years of letrozole or tamoxifen in the BIG 1-98 trial who received at least some study medication (median follow-up 60.3 months). Bone fracture information (grade, cause, site) was collected every 6 months during trial treatment.
Results: The incidence of bone fractures was higher among patients treated with letrozole [228 of 2448 women (9.3%)] versus tamoxifen [160 of 2447 women (6.5%)]. The wrist was the most common site of fracture in both treatment groups. Statistically significant risk factors for bone fractures during treatment included age, smoking history, osteoporosis at baseline, previous bone fracture, and previous hormone replacement therapy.
Conclusions: Consistent with other trials comparing aromatase inhibitors to tamoxifen, letrozole was associated with an increase in bone fractures. Benefits of superior disease control associated with letrozole and lower incidence of fracture with tamoxifen should be considered with the risk profile for individual patients.
aromatase inhibitor; bone fracture; hormonal therapy; letrozole; tamoxifen
Background: The role of adjuvant dose-intensive chemotherapy and its efficacy according to baseline features has not yet been established.
Patients and methods: Three hundred and forty-four patients were randomized to receive seven courses of standard-dose chemotherapy (SD-CT) or three cycles of dose-intensive epirubicin and cyclophosphamide (epirubicin 200 mg/m2 plus cyclophosphamide 4 mg/m2 with filgrastim and progenitor cell support). All patients were assigned tamoxifen at the completion of chemotherapy. The primary end point was disease-free survival (DFS). This paper updates the results and explores patterns of recurrence according to predicting baseline features.
Results: At 8.3-years median follow-up, patients assigned DI-EC had a significantly better DFS compared with those assigned SD-CT [8-year DFS percent 47% and 37%, respectively, hazard ratio (HR) 0.76; 95% confidence interval 0.58–1.00; P = 0.05]. Only patients with estrogen receptor (ER)-positive disease benefited from the DI-EC (HR 0.61; 95% confidence interval 0.39, 0.95; P = 0.03).
Conclusions: After prolonged follow-up, DI-EC significantly improved DFS, but the effect was observed only in patients with ER-positive disease, leading to the hypothesis that efficacy of DI-EC may relate to its endocrine effects. Further studies designed to confirm the importance of endocrine responsiveness in patients treated with dose-intensive chemotherapy are encouraged.
adjuvant treatment; dose-intensive chemotherapy; early breast cancer; endocrine responsiveness
International Breast Cancer Study Group (IBCSG) Trial 11-93 is the largest trial evaluating the role of the addition of chemotherapy to ovarian function suppress/ablation (OFS) and tamoxifen in premenopausal patients with endocrine-responsive early breast cancer.
IBCSG Trial 11-93 is a randomized trial comparing 4 cycles of adjuvant chemotherapy (AC: doxorubicin or epirubicin, plus cyclophosphamide) added to OFS and five years of tamoxifen versus OFS and tamoxifen without chemotherapy in premenopausal patients with node-positive, endocrine-responsive early breast cancer. 174 pts were randomized from May, 1993 to Nov, 1998. The trial was closed before the target accrual was reached due to low accrual rate.
Patients randomized tended to have lower risk node-positive disease and the median age was 45. After 10 years median follow up, there remains no difference between the two randomized treatment groups for disease-free (hazard ratio=1.02 (0.57-1.83); p=0.94) or overall survival (hazard ratio=0.97 (0.44-2.16); p=0.94).
This trial, although small, offers no evidence that AC chemotherapy provides additional disease control for premenopausal patients with lower-risk node-positive endocrine-responsive breast cancer who receive adequate adjuvant endocrine therapy. A large trial is needed to determine whether chemotherapy adds benefit to endocrine therapy for this population.
breast cancer; estrogen receptor; goserelin; ovarian ablation; ovarian function suppression; tamoxifen
The incidence of second non-breast primary cancer following adjuvant treatment was evaluated using data from patients enrolled from 1978 to 1999 in four International Breast Cancer Study Group (IBCSG) trials. The occurrence of these tumours as sites of first failure was assessed separately for two treatment comparisons: toremifene versus tamoxifen for five years in 1035 patients in IBCSG Trials 12-93 and 14-93 with a median follow-up of eight years and endocrine therapy (toremifene or tamoxifen) versus chemoendocrine therapy (CMF or AC plus toremifene or tamoxifen) in 1731 patients from IBCSG Trials III, VII and 12-93, with a combined median follow-up of 14 years. No significant differences in second non-breast primary tumours were observed in either comparison. In particular the incidences of second primary uterine tumours with toremifene and tamoxifen were similar and no significant increase of secondary leukaemias was observed with chemoendocrine therapy compared with endocrine therapy.
breast cancer; chemotherapy; endocrine therapy; second primary cancer
We explored in a phase I/II clinical trial the combination of valproic acid (VPA), a clinically available histone deacetylase inhibitor, with standard chemoimmunotherapy in patients with advanced melanoma, to evaluate its clinical activity, to correlate the clinical response with the biological activity of VPA and to assess toxicity. Patients were treated initially with VPA alone for 6 weeks. The inhibition of the target in non-tumour peripheral blood cells (taken as a potential surrogate marker) was measured periodically, and valproate dosing adjusted with the attempt to reach a measurable inhibition. After the treatment with valproate alone, dacarbazine plus interferon-α was started in combination with valproate. Twenty-nine eligible patients started taking valproate and 18 received chemoimmunotherapy and are assessable for response. We observed one complete response, two partial remissions and three disease stabilisations lasting longer than 24 weeks. With the higher valproate dosages needed to reach a measurable inhibition of the target, we observed an increase of side effects in those patients who received chemoimmunotherapy. The combination of VPA and chemoimmunotherapy did not produce results overtly superior to standard therapy in patients with advanced melanoma and toxicity was not negligible, casting some doubts on the clinical use of VPA in this setting (at least in the administration schedule adopted).
histone deacetylase inhibitor; epigenetic therapy; valproic acid; chemoimmunotherapy; melanoma