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
There is no optimal treatment for breast cancers lacking estrogen (ER) and progesterone (PgR) receptors in elderly women with co-morbidities that prevent use of “standard chemotherapy regimens” such as AC or CMF. The CASA trial studied pegylated liposomal doxorubicin (PLD) and low dose, metronomic cyclophosphamide+ methotrexate (CM) for older (>65), vulnerable women with operable, ER and PgR-negative breast cancer. After two years the trial closed early, due to slow and inadequate accrual, with 77 patients (38:PLD, 36:CM, 3:nil). Sixty-eight percent completed PLD; 83% completed CM (both 16-weeks). Patients on PLD reported worse quality of life, cognitive and physical functioning than non-PLD regimens (primarily CM). At a median follow-up of 42 months, 78% of randomized patients remained free of any breast cancer recurrence. Based on our limited experience, PLD and CM may be reasonable options for further study for elderly vulnerable patients with endocrine non-responsive breast cancer.
adjuvant treatment; endocrine non-responsive; chemotherapy; pegylated liposomal doxorubicin; elderly; breast cancer
Determination of hormone receptor (estrogen receptor and progesterone receptor) and human epidermal growth factor receptor 2 status in the primary tumor is clinically relevant to define breast cancer subtypes, clinical outcome, and the choice of therapy. Retrospective and prospective studies suggest that there is substantial discordance in receptor status between primary and recurrent breast cancer. Despite this evidence and current recommendations, the acquisition of tissue from metastatic deposits is not routine practice. As a consequence, therapeutic decisions for treatment in the metastatic setting are based on the features of the primary tumor. Reasons for this attitude include the invasiveness of the procedure and the unreliable outcome of biopsy, in particular for biopsies of lesions at complex visceral sites. Improvements in interventional radiology techniques mean that most metastatic sites are now accessible by minimally invasive methods, including surgery. In our opinion, since biopsies are diagnostic and changes in biological features between the primary and secondary tumors can occur, the routine biopsy of metastatic disease needs to be performed. In this review, we discuss the rationale for biopsy of suspected breast cancer metastases, review issues and caveats surrounding discordance of biomarker status between primary and metastatic tumors, and provide insights for deciding when to perform biopsy of suspected metastases and which one (s) to biopsy. We also speculate on the future translational implications for biopsy of suspected metastatic lesions in the context of clinical trials and the establishment of bio-banks of biopsy material taken from metastatic sites. We believe that such bio-banks will be important for exploring mechanisms of metastasis. In the future, advances in targeted therapy will depend on the availability of metastatic tissue.
Targeted immune checkpoint blockade augments anti-tumor immunity and induces durable responses in patients with melanoma and other solid tumors. It also induces specific “immune-related adverse events” (irAEs). IrAEs mainly include gastrointestinal, dermatological, hepatic and endocrinological toxicities. Off-target effects that arise appear to account for much of the toxicity of the immune checkpoint blockade. These unique “innocent bystander” effects are likely a direct result of breaking immune tolerance upon immune check point blockade and require specific treatment guidelines that include symptomatic therapies or systemic corticosteroids. What do we need going forward to limit immune checkpoint blockade-induced toxicity? Most importantly, we need a better understanding of the roles played by these agents in normal tissues, so that we can begin to predict potentially problematic side effects on the basis of their selectivity profile. Second, we need to focus on the predictive factors of the response and toxicity of the host rather than serially focusing on individual agents. Third, rigorous biomarker-driven clinical trials are needed to further elucidate the mechanisms of both the benefit and toxicity. We will summarize the double-edged sword effect of immunotherapeutics in cancer treatment.
checkpoint-blocking antibodies; immune response; toxicity; immune therapies; ipilimumab
For breast cancer patients with a metastatic sentinel node (SN), axillary dissection (AD) has been standard treatment. However, for patients with minimal SN involvement, AD may be overtreatment. IBCSG Trial 23-01 was designed to determine whether no AD is non-inferior to AD in patients with one or more micrometastatic (≤2 mm) SNs and tumour ≤5 cm.
In this multicentre trial patients were randomised to AD or no AD. Eligibility was limited to patients with clinically-palpable axillary lymph node(s) and a primary tumour ≤ 5 cm who, after sentinel node biopsy, had one or more micrometastatic (≤ 2 mm) sentinel lymphs nodes with no extracapsular extension. The primary endpoint was disease-free survival (DFS). Non-inferiority was defined as a hazard ratio of <1·25 for no AD vs. AD. The analysis was intention to treat. Patients were randomly allocated in a 1:1 ratio to AD or no AD with stratification by centre and menopausal status. There was no attempt to blind the treatment assignment. The trial is registered with ClinicalTrials.gov, NCT00072293. Per protocol, disease and survival information continues to be collected yearly.
From 2001 to 2010, 934 patients were randomised; 931 were evaluable (464 in the AD group and 467 in the no AD group). After a median follow-up of 5·0 (IQR 3.6–7.3) years, there were 124 DFS events, including breast-cancer-related events in 95 patients (local, 18; contralateral breast, 12; regional, 6; and distant, 59), and other events in 29 (second malignancy, 26; death without prior cancer event, 3). Five-year DFS was 87·8% (95% CI 84·4%–91·2%) in the no AD group and 84·4% (95% CI 80·7%–88·1%) in the AD group (log-rank p=0·16) (HR no AD vs. AD=0·78, 95% CI 0·55–1·11, non-inferiority p=0·0042). Patients with reported long-term surgical events (grade 3–4) included 1 sensory neuropathy (grade 3), 3 lymphedema (2 grade 3 and 1 grade 4), and 3 motor neuropathy (grade 3), all in the AD group, and 1 grade 3 motor neuropathy in the no AD group. One serious adverse event was reported, a post-operative infection in the axilla in the AD group.
AD in patients with early breast cancer represented in this study (most had tumours < 3 cm (92%; 856/931), received breast conserving surgery (91%; 845/931) and adjuvant systemic therapy (96%; 892/931)) should be avoided when the SN is minimally involved, thus eliminating complications of axillary surgery with no adverse effect on survival.
Supported in part: local participating centres, IBCSG central funds, CA075362 from the U.S. National Cancer Institute, and Swiss Cancer League/Cancer Research- Switzerland/Oncosuisse (ICPOCS 01688-03-2005). No pharmaceutical company funds were used.
breast cancer; sentinel node; axillary node; micrometastasis; sentinel node biopsy; axillary dissection; lymph node
We questioned the impact of pregnancy on disease-free survival (DFS) in women with history of breast cancer (BC) according to estrogen receptor (ER) status.
Patients and Methods
A multicenter, retrospective cohort study in which patients who became pregnant any time after BC were matched (1:3) to patients with BC with similar ER, nodal status, adjuvant therapy, age, and year of diagnosis. To adjust for guaranteed time bias, each nonpregnant patient had to have a disease-free interval at least equal to the time elapsing between BC diagnosis and date of conception of the matched pregnant one. The primary objective was DFS in patients with ER-positive BC. DFS in the ER-negative cohort, whole population, and overall survival (OS) were secondary objectives. Subgroup analyses included DFS according to pregnancy outcome and BC–pregnancy interval. With a two-sided α = 5% and β = 20%, 645 ER-positive patients were required to detect a hazard ratio (HR) = 0.65.
A total of 333 pregnant patients and 874 matched nonpregnant patients were analyzed, of whom 686 patients had an ER-positive disease. No difference in DFS was observed between pregnant and nonpregnant patients in the ER-positive (HR = 0.91; 95% CI, 0.67 to 1.24, P = .55) or the ER-negative (HR = 0.75; 95% CI, 0.51 to 1.08, P = .12) cohorts. However, the pregnant group had better OS (HR = 0.72; 95% CI, 0.54 to 0.97, P = .03), with no interaction according to ER status (P = .11). Pregnancy outcome and BC–pregnancy interval did not seem to impact the risk of relapse.
Pregnancy after ER-positive BC does not seem to reduce the risk of BC recurrence.
To examine the association of baseline body mass index (BMI) with the risk of recurrence or death in postmenopausal women with early-stage breast cancer receiving adjuvant tamoxifen or letrozole in the Breast International Group (BIG) 1-98 trial at 8.7 years of median follow-up.
Patients and Methods
This report analyzes 4,760 patients with breast cancer randomly assigned to 5 years of monotherapy with letrozole or tamoxifen in the BIG 1-98 trial with available information on BMI at randomization. Multivariable Cox modeling assessed the association of BMI with disease-free survival, overall survival (OS), breast cancer–free interval, and distant recurrence-free interval and tested for treatment-by-BMI interaction. Median follow-up was 8.7 years.
Seventeen percent of patients have died. Obese patients (BMI ≥ 30 kg/m2) had slightly poorer OS (hazard ratio [HR] = 1.19; 95% CI, 0.99 to 1.44) than patients with normal BMI (< 25 kg/m2), whereas no trend in OS was observed in overweight (BMI 25 to < 30 kg/m2) versus normal-weight patients (HR = 1.02; 95% CI, 0.86 to 1.20). Treatment-by-BMI interactions were not statistically significant. The HRs for OS comparing obese versus normal BMI were HR = 1.22 (95% CI, 0.93 to 1.60) and HR = 1.18 (95% CI, 0.91 to 1.52) in the letrozole and tamoxifen groups, respectively.
There was no evidence that the benefit of letrozole over tamoxifen differed according to patients' BMI.
To evaluate whether medullary breast cancer has a better prognosis compared with invasive ductal tumors.
Among 12 409 patients, 127 were recorded as invasive medullary tumors and 8096 invasive ductal tumors. Medullary and ductal invasive tumors were compared with regard to stage, age at diagnosis, grade, hormone receptor status, peritumoral vascular invasion, and local and systemic treatment. Pattern of relapse, distant recurrence-free interval (DRFI), and overall survival (OS) were determined for both histological groups. Two cohorts were investigated: a full cohort including the pathologist-determined medullary histology without regard to any other tumor features and a cohort restricted to patients with ER-negative grade 3 tumors.
Fourteen-year DRFI and OS percents for medullary tumors (n = 127) and invasive ductal tumors (n = 8096) of the full cohort were 76% and 64% [hazard ratio (HR) 0.52, P = 0.0005] and 66% and 57% (HR = 0.75, P = 0.03), respectively. For the restricted cohort, 14-year DRFI and OS percents for the medullary (n = 47) and invasive ductal tumors (n = 1407) were 89% and 63% (HR 0.24, P = 0.002) and 74% and 54% (HR = 0.55, P = 0.01), respectively. Competing risk analysis for DRFI favored medullary tumors (HR medullary/ductal = 0.32; 95% confidence interval = 0.13–0.78, P = 0.01).
Medullary tumors have a favorable prognosis compared with invasive ductal tumors.
breast cancer; histology; invasive ductal; medullary; prognosis
Rates and risk factors of local, axillary and supraclavicular recurrences can guide patient selection and target for postmastectomy radiotherapy (PMRT).
Patients and methods
Local, axillary and supraclavicular recurrences were evaluated in 8106 patients enrolled in 13 randomized trials. Patients received chemotherapy and/or endocrine therapy and mastectomy without radiotherapy. Median follow-up was 15.2 years.
Ten-year cumulative incidence for chest wall recurrence of >15% was seen in patients aged <40 years (16.1%), with ≥4 positive nodes (16.5%) or 0–7 uninvolved nodes (15.1%); for supraclavicular failures >10%: ≥4 positive nodes (10.2%); for axillary failures of >5%: aged <40 years (5.1%), unknown primary tumor size (5.2%), 0–7 uninvolved nodes (5.2%). In patients with 1–3 positive nodes, 10-year cumulative incidence for chest wall recurrence of >15% were age <40, peritumoral vessel invasion or 0–7 uninvolved nodes. Age, number of positive nodes and number of uninvolved nodes were significant parameters for each locoregional relapse site.
PMRT to the chest wall and supraclavicular fossa is supported in patients with ≥4 positive nodes. With 1–3 positive nodes, chest wall PMRT may be considered in patients aged <40 years, with 0–7 uninvolved nodes or with vascular invasion. The findings do not support PMRT to the dissected axilla.
adjuvant treatment; breast cancer; locoregional recurrence; postmastectomy radiotherapy
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
The prognostic significance of p53 protein expression in early breast cancer remains uncertain, with some but not all studies finding an association with poorer outcomes. Estrogen receptor (ER) expression is both a positive prognostic marker and predictive of response to endocrine therapies. The relationship between these biomarkers is unknown.
We constructed tissue microarrays (TMAs) from available pathological material from 1113 patients participating in two randomized clinical trials comparing endocrine therapy alone versus chemo-endocrine therapy in node-negative breast cancer. Expression of p53 defined as >10% positive nuclei was analyzed together with prior immunohistochemical assays of ER performed at central pathological review of whole tumor sections.
ER was present (i.e. >1% positive tumor cell nuclei) in 80.1% (880/1092). p53 expression was significantly more frequent when ER was absent, 125/212 (59%) than when ER was present, 171/880 (19%), p <0.0001. A significant qualitative interaction was observed such that p53 expression was associated with better disease-free survival (DFS) and overall survival (OS) among patients whose tumors did not express ER, but worse DFS and OS among patients whose tumors expressed ER. The interaction remained significant after allowance for pathologic variables, and treatment. Similar effects were seen when luminal and non-luminal intrinsic subtypes were compared.
Interpretation of the prognostic significance of p53 expression requires knowledge of concurrent expression of ER. The reason for the interaction between p53 and ER is unknown but may reflect qualitatively different p53 mutations underlying the p53 expression in tumors with or without ER expression.
Current Controlled Trials ACTRN12607000037404 (Trial VIII) and ACTRN12607000029493 (Trial IX).
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