70-gene signature as an aid for treatment decisions in early breast cancer: updated results of the phase 3 randomised MINDACT trial with an exploratory analysis by age.

BACKGROUND: The MINDACT trial showed excellent 5-year distant metastasis-free survival of 94·7% (95% CI 92·5-96·2) in patients with breast cancer of high clinical and low genomic risk who did not receive chemotherapy. We present long-term follow-up results together with an exploratory analysis by age. METHODS: MINDACT was a multicentre, randomised, phase 3 trial done in 112 academic and community hospitals in nine European countries. Patients aged 18-70 years, with histologically confirmed primary invasive breast cancer (stage T1, T2, or operable T3) with up to three positive lymph nodes, no distant metastases, and a WHO performance status of 0-1 were enrolled and their genomic risk (using the MammaPrint 70-gene signature) and clinical risk (using a modified version of Adjuvant! Online) were determined. Patients with low clinical and low genomic risk results did not receive chemotherapy, and patients with high clinical and high genomic risk did receive chemotherapy (mostly anthracycline-based or taxane-based, or a combination thereof). Patients with discordant risk results (ie, patients with high clinical risk but low genomic risk, and those with low clinical risk but high genomic risk) were randomly assigned (1:1) to receive chemotherapy or not based on either the clinical risk or the genomic risk. Randomisation was done centrally and used a minimisation technique that was stratified by institution, risk group, and clinical-pathological characteristics. Treatment allocation was not masked. The primary endpoint was to test whether the distant metastasis-free survival rate at 5 years in patients with high clinical risk and low genomic risk not receiving chemotherapy had a lower boundary of the 95% CI above the predefined non-inferiority boundary of 92%. In the primary test population of patients with high clinical risk and low genomic risk who adhered to the treatment allocation of no chemotherapy and had no change in risk post-enrolment. Here, we present updated follow-up as well as an exploratory analysis of a potential age effect (≤50 years vs >50 years) and an analysis by nodal status for patients with hormone receptor-positive and HER2-negative disease. These analyses were done in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT00433589, and the European Clinical Trials database, EudraCT2005-002625-31. Recruitment is complete and further long-term follow-up is ongoing. FINDINGS: Between Feb 8, 2007, and July 11, 2011, 6693 patients were enrolled. On Feb 26, 2020, median follow-up was 8·7 years (IQR 7·8-9·7). The updated 5-year distant metastasis-free survival rate for patients with high clinical risk and low genomic risk receiving no chemotherapy (primary test population, n=644) was 95·1% (95% CI 93·1-96·6), which is above the predefined non-inferiority boundary of 92%, supporting the previous analysis and proving MINDACT as a positive de-escalation trial. Patients with high clinical risk and low genomic risk were randomly assigned to receive chemotherapy (n=749) or not (n=748); this was the intention-to-treat population. The 8-year estimates for distant metastasis-free survival in the intention-to-treat population were 92·0% (95% CI 89·6-93·8) for chemotherapy versus 89·4% (86·8-91·5) for no chemotherapy (hazard ratio 0·66; 95% CI 0·48-0·92). An exploratory analysis confined to the subset of patients with hormone receptor-positive, HER2-negative disease (1358 [90.7%] of 1497 randomly assigned patients, of whom 676 received chemotherapy and 682 did not) shows different effects of chemotherapy administration on 8-year distant metastasis-free survival according to age: 93·6% (95% CI 89·3-96·3) with chemotherapy versus 88·6% (83·5-92·3) without chemotherapy in 464 women aged 50 years or younger (absolute difference 5·0 percentage points [SE 2·8, 95% CI -0·5 to 10·4]) and 90·2% (86·8-92·7) versus 90·0% (86·6-92·6) in 894 women older than 50 years (absolute difference 0·2 percentage points [2·1, -4·0 to 4·4]). The 8-year distant metastasis-free survival in the exploratory analysis by nodal status in these patients was 91·7% (95% CI 88·1-94·3) with chemotherapy and 89·2% (85·2-92·2) without chemotherapy in 699 node-negative patients (absolute difference 2·5 percentage points [SE 2·3, 95% CI -2·1 to 7·2]) and 91·2% (87·2-94·0) versus 89·9% (85·8-92·8) for 658 patients with one to three positive nodes (absolute difference 1·3 percentage points [2·4, -3·5 to 6·1]). INTERPRETATION: With a more mature follow-up approaching 9 years, the 70-gene signature shows an intact ability of identifying among women with high clinical risk, a subgroup, namely patients with a low genomic risk, with an excellent distant metastasis-free survival when treated with endocrine therapy alone. For these women the magnitude of the benefit from adding chemotherapy to endocrine therapy remains small (2·6 percentage points) and is not enhanced by nodal positivity. However, in an underpowered exploratory analysis this benefit appears to be age-dependent, as it is only seen in women younger than 50 years where it reaches a clinically relevant threshold of 5 percentage points. Although, possibly due to chemotherapy-induced ovarian function suppression, it should be part of informed, shared decision making. Further study is needed in younger women, who might need reinforced endocrine therapy to forego chemotherapy. FUNDING: European Commission Sixth Framework Programme.

Standard Anthracycline Based Versus Docetaxel-Capecitabine in Early High Clinical and/or Genomic Risk Breast Cancer in the EORTC 10041/BIG 3-04 MINDACT Phase III Trial.

PURPOSE: MINDACT demonstrated that 46% of patients with early breast cancer at high clinical but low genomic risk on the basis of MammaPrint may safely avoid adjuvant chemotherapy. A second random assignment (R-C) compared docetaxel-capecitabine with an anthracycline-based regimen. PATIENTS AND METHODS: R-C randomly assigned patients 1:1 between standard anthracycline-based regimens, with or without taxanes (control) and experimental docetaxel 75 mg/m2 intravenously plus oral capecitabine 825 mg/m2 two times per day for 14 days (DC) every 3 weeks for 6 cycles. The primary end point was disease-free survival (DFS). Secondary end points included overall survival and safety. RESULTS: Of 2,832 patients, 1,301 (45%) were randomly assigned, and 97% complied with R-C assignment. In the control arm, 29.6% only received taxanes (0.5% of N0 patients). DFS events (n = 148) were much less than required (n = 422) as a result of a lower-than-expected accrual and event rate. At 5 years of median follow-up, DFS was not different between DC (n = 652) and control (n = 649; 90.7% [95% CI, 88% to 92.8%] v 88.8% [95% CI, 85.9% to 91.1%]; hazard ratio [HR], 0.83 [95% CI, 0.60 to 1.15]; P = .26). Overall survival (HR, 0.91 [95% CI, 0.54 to 1.53]) and DFS in the clinical high and genomic high-risk subgroup (86.1% v 88.1%; HR, 0.83 [95% CI, 0.58 to 1.21]) were similar in both arms. DC led to more grade 1 neuropathy (27.1% v 11.2%) and more grade 2 hand/foot syndrome (28.5% v 3.3%) and diarrhea (13.7% v 5.8%). Serious cardiac events occurred in 9 patients (control, n = 4; DC, n = 5). Fifty-three patients developed second cancers (control, n = 32; DC, n = 21; leukemia: 2 v 1). Five treatment-related deaths occurred (control, 2 [0.3%]; DC, 3 [0.5%]). CONCLUSION: Although underpowered, this second randomization in MINDACT did not show any improvement in outcome or safety with the use of DC compared with anthracycline-based chemotherapy.

Association Between 21-Gene Assay Recurrence Score and Locoregional Recurrence Rates in Patients With Node-Positive Breast Cancer.

Importance: The 21-gene assay recurrence score is increasingly used to personalize treatment recommendations for systemic therapy in postmenopausal women with estrogen receptor (ER)- or progesterone receptor (PR)-positive, node-positive breast cancer; however, the relevance of the 21-gene assay to radiotherapy decisions remains uncertain. Objective: To examine the association between recurrence score and locoregional recurrence (LRR) in a postmenopausal patient population treated with adjuvant chemotherapy followed by tamoxifen or tamoxifen alone. Design, Setting, and Participants: This cohort study was a retrospective analysis of the Southwest Oncology Group S8814, a phase 3 randomized clinical trial of postmenopausal women with ER/PR-positive, node-positive breast cancer treated with tamoxifen alone, chemotherapy followed by tamoxifen, or concurrent tamoxifen and chemotherapy. Patients at North American clinical centers were enrolled from June 1989 to July 1995. Medical records from patients with recurrence score information were reviewed for LRR and radiotherapy use. Primary analysis included 316 patients and excluded 37 who received both mastectomy and radiotherapy, 9 who received breast-conserving surgery without documented radiotherapy, and 5 with unknown surgical type. All analyses were performed from January 22, 2016, to August 9, 2019. Main Outcomes and Measures: The LRR was defined as a recurrence in the breast; chest wall; or axillary, infraclavicular, supraclavicular, or internal mammary lymph nodes. Time to LRR was tested with log-rank tests and Cox proportional hazards regression for multivariate models. Results: The final cohort of this study comprised 316 women with a mean (range) age of 60.4 (44-81) years. Median (interquartile range) follow-up for those without LRR was 8.7 (7.0-10.2) years. Seven LRR events (5.8%) among 121 patients with low recurrence score and 27 LRR events (13.8%) among 195 patients with intermediate or high recurrence score occurred. The estimated 10-year cumulative incidence rates were 9.7% for those with a low recurrence score and 16.5% for the group with intermediate or high recurrence score (P = .02). Among patients who had a mastectomy without radiotherapy (n = 252), the differences in the 10-year actuarial LRR rates remained significant: 7.7 % for the low recurrence score group vs 16.8% for the intermediate or high recurrence score group (P = .03). A multivariable model controlling for randomized treatment, number of positive nodes, and surgical type showed that a higher recurrence score was prognostic for LRR (hazard ratio [HR], 2.36; 95% CI, 1.02-5.45; P = .04). In a subset analysis of patients with a mastectomy and 1 to 3 involved nodes who did not receive radiation therapy, the group with a low recurrence score had a 1.5% rate of LRR, whereas the group with an intermediate or high recurrence score had a 11.1% LRR (P = .051). Conclusions and Relevance: This study found that higher recurrence scores were associated with increased LRR after adjustment for treatment, type of surgical procedure, and number of positive nodes. This finding suggests that the recurrence score may be used, along with accepted clinical variables, to assess the risk of LRR during radiotherapy decision-making.

Clinical and Genomic Risk to Guide the Use of Adjuvant Therapy for Breast Cancer.

BACKGROUND: The use of adjuvant chemotherapy in patients with breast cancer may be guided by clinicopathological factors and a score based on a 21-gene assay to determine the risk of recurrence. Whether the level of clinical risk of breast cancer recurrence adds prognostic information to the recurrence score is not known. METHODS: We performed a prospective trial involving 9427 women with hormone-receptor-positive, human epidermal growth factor receptor 2-negative, axillary node-negative breast cancer, in whom an assay of 21 genes had been performed, and we classified the clinical risk of recurrence of breast cancer as low or high on the basis of the tumor size and histologic grade. The effect of clinical risk was evaluated by calculating hazard ratios for distant recurrence with the use of Cox proportional-hazards models. The initial endocrine therapy was tamoxifen alone in the majority of the premenopausal women who were 50 years of age or younger. RESULTS: The level of clinical risk was prognostic of distant recurrence in women with an intermediate 21-gene recurrence score of 11 to 25 (on a scale of 0 to 100, with higher scores indicating a worse prognosis or a greater potential benefit from chemotherapy) who were randomly assigned to endocrine therapy (hazard ratio for the comparison of high vs. low clinical risk, 2.73; 95% confidence interval [CI], 1.93 to 3.87) or to chemotherapy plus endocrine (chemoendocrine) therapy (hazard ratio, 2.41; 95% CI, 1.66 to 3.48) and in women with a high recurrence score (a score of 26 to 100), all of whom were assigned to chemoendocrine therapy (hazard ratio, 3.17; 95% CI, 1.94 to 5.19). Among women who were 50 years of age or younger who had received endocrine therapy alone, the estimated (±SE) rate of distant recurrence at 9 years was less than 5% (≤1.8±0.9%) with a low recurrence score (a score of 0 to 10), irrespective of clinical risk, and 4.7±1.0% with an intermediate recurrence score and low clinical risk. In this age group, the estimated distant recurrence at 9 years exceeded 10% among women with a high clinical risk and an intermediate recurrence score who received endocrine therapy alone (12.3±2.4%) and among those with a high recurrence score who received chemoendocrine therapy (15.2±3.3%). CONCLUSIONS: Clinical-risk stratification provided prognostic information that, when added to the 21-gene recurrence score, could be used to identify premenopausal women who could benefit from more effective therapy. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00310180.).

Germline Genetic Variants in GATA3 and Breast Cancer Treatment Outcomes in SWOG S8897 Trial and the Pathways Study.

INTRODUCTION: GATA3 is a critical transcription factor in maintaining the differentiated state of luminal mammary epithelial cells. We sought to determine the prognostic and predictive roles of GATA3 genotypes for breast cancer. PATIENTS AND METHODS: Twelve single nucleotide polymorphisms (SNPs) were genotyped in 2 breast cancer cohorts, including the SWOG S8897 trial where patients were treated with adjuvant chemotherapy (CAF [cyclophosphamide, doxorubicin, 5-fluorouracil] vs. CMF [cyclophosphamide, methotrexate, 5-fluorouracil]) or untreated, and the observational Pathways Study. RESULTS: In the S8897 trial, rs3802604 and rs568727 were associated with disease-free survival and overall survival in the treated group, regardless of chemotherapy regimen. The GG genotype of rs3802604 conferred poorer overall survival (adjusted hazard ratio, 2.45; 95% confidence interval, 1.48-4.05) and disease-free survival (adjusted hazard ratio, 1.95; 95% confidence interval, 1.27-2.99) compared with the AA genotype. Similar associations were found for rs568727. In contrast, no association with either SNP was found in the untreated group. Subgroup analyses indicated that these 2 SNPs more strongly influenced outcomes in the patients who also received tamoxifen. However, the associations in the subgroup with tamoxifen treatment were not replicated in the Pathways Study, possibly owing to substantial differences between the 2 patient cohorts, such as chemotherapy regimen and length of follow-up. Results from joint analyses across these 2 cohorts were marginally significant, driven by the results in S8897. Bioinformatic analyses support potential functional disruption of the GATA3 SNPs in breast tissue. CONCLUSIONS: The present study provides some evidence for the predictive value of GATA3 genotypes for breast cancer adjuvant therapies. Future replication studies in appropriate patient populations are warranted.

Communicating Risks of Adjuvant Chemotherapy for Breast Cancer: Getting Beyond the Laundry List.

PURPOSE: According to the Institute of Medicine, high-quality cancer care should include effective communication between clinicians and patients about the risks and benefits, expected response, and impact on quality of life of a recommended therapy. In the delivery of oncology care, the barriers to and facilitators of communication about potential long-term and late effects, post-treatment expectations, and transition to survivorship care have not been fully defined. PATIENTS AND METHODS: We collected qualitative data through semistructured interviews with medical oncologists and focus groups with breast cancer survivors and applied the Theoretical Domains Framework to systematically analyze and identify the factors that may influence oncologists' communication with patients with breast cancer about the long-term and late effects of adjuvant therapy. RESULTS: Eight key informant interviews with medical oncologists and two focus groups with breast cancer survivors provided data. Both oncologists and patients perceived information on long-term effects as valuable in terms of improved clinical communication but had concerns about the feasibility of inclusion before treatment. They described the current approaches to communication of therapy risks as a brief laundry list that emphasized acute adverse effects and minimized more long-term issues. We describe the barriers to communication about potential long-term effects from the perspectives of both groups. CONCLUSION: This study provides insight into oncologists' communication with patients with breast cancer regarding the potential long-term and late effects of adjuvant chemotherapy and about setting realistic expectations for life after treatment. Opportunities to improve oncologists' communication about the potential toxicities of therapy, particularly regarding long-term and late effects, should be examined further.

Adjuvant Chemotherapy Guided by a 21-Gene Expression Assay in Breast Cancer.

BACKGROUND: The recurrence score based on the 21-gene breast cancer assay predicts chemotherapy benefit if it is high and a low risk of recurrence in the absence of chemotherapy if it is low; however, there is uncertainty about the benefit of chemotherapy for most patients, who have a midrange score. METHODS: We performed a prospective trial involving 10,273 women with hormone-receptor-positive, human epidermal growth factor receptor 2 (HER2)-negative, axillary node-negative breast cancer. Of the 9719 eligible patients with follow-up information, 6711 (69%) had a midrange recurrence score of 11 to 25 and were randomly assigned to receive either chemoendocrine therapy or endocrine therapy alone. The trial was designed to show noninferiority of endocrine therapy alone for invasive disease-free survival (defined as freedom from invasive disease recurrence, second primary cancer, or death). RESULTS: Endocrine therapy was noninferior to chemoendocrine therapy in the analysis of invasive disease-free survival (hazard ratio for invasive disease recurrence, second primary cancer, or death [endocrine vs. chemoendocrine therapy], 1.08; 95% confidence interval, 0.94 to 1.24; P=0.26). At 9 years, the two treatment groups had similar rates of invasive disease-free survival (83.3% in the endocrine-therapy group and 84.3% in the chemoendocrine-therapy group), freedom from disease recurrence at a distant site (94.5% and 95.0%) or at a distant or local-regional site (92.2% and 92.9%), and overall survival (93.9% and 93.8%). The chemotherapy benefit for invasive disease-free survival varied with the combination of recurrence score and age (P=0.004), with some benefit of chemotherapy found in women 50 years of age or younger with a recurrence score of 16 to 25. CONCLUSIONS: Adjuvant endocrine therapy and chemoendocrine therapy had similar efficacy in women with hormone-receptor-positive, HER2-negative, axillary node-negative breast cancer who had a midrange 21-gene recurrence score, although some benefit of chemotherapy was found in some women 50 years of age or younger. (Funded by the National Cancer Institute and others; TAILORx ClinicalTrials.gov number, NCT00310180 .).

Accuracy of the online prognostication tools PREDICT and Adjuvant! for early-stage breast cancer patients younger than 50 years.

IMPORTANCE: Online prognostication tools such as PREDICT and Adjuvant! are increasingly used in clinical practice by oncologists to inform patients and guide treatment decisions about adjuvant systemic therapy. However, their validity for young breast cancer patients is debated. OBJECTIVE: To assess first, the prognostic accuracy of PREDICT's and Adjuvant! 10-year all-cause mortality, and second, its breast cancer-specific mortality estimates, in a large cohort of breast cancer patients diagnosed <50 years. DESIGN: Hospital-based cohort. SETTING: General and cancer hospitals. PARTICIPANTS: A consecutive series of 2710 patients without a prior history of cancer, diagnosed between 1990 and 2000 with unilateral stage I-III breast cancer aged <50 years. MAIN OUTCOME MEASURES: Calibration and discriminatory accuracy, measured with C-statistics, of estimated 10-year all-cause and breast cancer-specific mortality. RESULTS: Overall, PREDICT's calibration for all-cause mortality was good (predicted versus observed) meandifference: -1.1% (95%CI: -3.2%-0.9%; P = 0.28). PREDICT tended to underestimate all-cause mortality in good prognosis subgroups (range meandifference: -2.9% to -4.8%), overestimated all-cause mortality in poor prognosis subgroups (range meandifference: 2.6%-9.4%) and underestimated survival in patients < 35 by -6.6%. Overall, PREDICT overestimated breast cancer-specific mortality by 3.2% (95%CI: 0.8%-5.6%; P = 0.007); and also overestimated it seemingly indiscriminately in numerous subgroups (range meandifference: 3.2%-14.1%). Calibration was poor in the cohort of patients with the lowest and those with the highest mortality probabilities. Discriminatory accuracy was moderate-to-good for all-cause mortality in PREDICT (0.71 [95%CI: 0.68 to 0.73]), and the results were similar for breast cancer-specific mortality. Adjuvant!'s calibration and discriminatory accuracy for both all-cause and breast cancer-specific mortality were in line with PREDICT's findings. CONCLUSIONS: Although imprecise at the extremes, PREDICT's estimates of 10-year all-cause mortality seem reasonably sound for breast cancer patients <50 years; Adjuvant! findings were similar. Prognostication tools should be used with caution due to the intrinsic variability of their estimates, and because the threshold to discuss adjuvant systemic treatment is low. Thus, seemingly insignificant mortality overestimations or underestimations of a few percentages can significantly impact treatment decision-making.

70-Gene Signature as an Aid to Treatment Decisions in Early-Stage Breast Cancer.

BACKGROUND: The 70-gene signature test (MammaPrint) has been shown to improve prediction of clinical outcome in women with early-stage breast cancer. We sought to provide prospective evidence of the clinical utility of the addition of the 70-gene signature to standard clinical-pathological criteria in selecting patients for adjuvant chemotherapy. METHODS: In this randomized, phase 3 study, we enrolled 6693 women with early-stage breast cancer and determined their genomic risk (using the 70-gene signature) and their clinical risk (using a modified version of Adjuvant! Online). Women at low clinical and genomic risk did not receive chemotherapy, whereas those at high clinical and genomic risk did receive such therapy. In patients with discordant risk results, either the genomic risk or the clinical risk was used to determine the use of chemotherapy. The primary goal was to assess whether, among patients with high-risk clinical features and a low-risk gene-expression profile who did not receive chemotherapy, the lower boundary of the 95% confidence interval for the rate of 5-year survival without distant metastasis would be 92% (i.e., the noninferiority boundary) or higher. RESULTS: A total of 1550 patients (23.2%) were deemed to be at high clinical risk and low genomic risk. At 5 years, the rate of survival without distant metastasis in this group was 94.7% (95% confidence interval, 92.5 to 96.2) among those not receiving chemotherapy. The absolute difference in this survival rate between these patients and those who received chemotherapy was 1.5 percentage points, with the rate being lower without chemotherapy. Similar rates of survival without distant metastasis were reported in the subgroup of patients who had estrogen-receptor-positive, human epidermal growth factor receptor 2-negative, and either node-negative or node-positive disease. CONCLUSIONS: Among women with early-stage breast cancer who were at high clinical risk and low genomic risk for recurrence, the receipt of no chemotherapy on the basis of the 70-gene signature led to a 5-year rate of survival without distant metastasis that was 1.5 percentage points lower than the rate with chemotherapy. Given these findings, approximately 46% of women with breast cancer who are at high clinical risk might not require chemotherapy. (Funded by the European Commission Sixth Framework Program and others; ClinicalTrials.gov number, NCT00433589; EudraCT number, 2005-002625-31.).

Prospective Validation of a 21-Gene Expression Assay in Breast Cancer.

BACKGROUND: Prior studies with the use of a prospective-retrospective design including archival tumor samples have shown that gene-expression assays provide clinically useful prognostic information. However, a prospectively conducted study in a uniformly treated population provides the highest level of evidence supporting the clinical validity and usefulness of a biomarker. METHODS: We performed a prospective trial involving women with hormone-receptor-positive, human epidermal growth factor receptor type 2 (HER2)-negative, axillary node-negative breast cancer with tumors of 1.1 to 5.0 cm in the greatest dimension (or 0.6 to 1.0 cm in the greatest dimension and intermediate or high tumor grade) who met established guidelines for the consideration of adjuvant chemotherapy on the basis of clinicopathologic features. A reverse-transcriptase-polymerase-chain-reaction assay of 21 genes was performed on the paraffin-embedded tumor tissue, and the results were used to calculate a score indicating the risk of breast-cancer recurrence; patients were assigned to receive endocrine therapy without chemotherapy if they had a recurrence score of 0 to 10, indicating a very low risk of recurrence (on a scale of 0 to 100, with higher scores indicating a greater risk of recurrence). RESULTS: Of the 10,253 eligible women enrolled, 1626 women (15.9%) who had a recurrence score of 0 to 10 were assigned to receive endocrine therapy alone without chemotherapy. At 5 years, in this patient population, the rate of invasive disease-free survival was 93.8% (95% confidence interval [CI], 92.4 to 94.9), the rate of freedom from recurrence of breast cancer at a distant site was 99.3% (95% CI, 98.7 to 99.6), the rate of freedom from recurrence of breast cancer at a distant or local-regional site was 98.7% (95% CI, 97.9 to 99.2), and the rate of overall survival was 98.0% (95% CI, 97.1 to 98.6). CONCLUSIONS: Among patients with hormone-receptor-positive, HER2-negative, axillary node-negative breast cancer who met established guidelines for the recommendation of adjuvant chemotherapy on the basis of clinicopathologic features, those with tumors that had a favorable gene-expression profile had very low rates of recurrence at 5 years with endocrine therapy alone. (Funded by the National Cancer Institute and others; ClinicalTrials.gov number, NCT00310180.).

Genome-wide DNA methylation profiling reveals parity-associated hypermethylation of FOXA1.

Early pregnancy in women by the age of 20 is known to have a profound effect on reduction of lifelong breast cancer risk as compared to their nulliparous counterparts. Additional pregnancies further enhance the protection against breast cancer development. Nationwide trend of delayed pregnancy may contribute to the recently reported increase in the incidence of advanced breast cancer among young women in this country. The underlying mechanism for the parity-associated reduction of breast cancer risk is not clearly understood. The purpose of the current study is to use whole-genome DNA methylation profiling to explore a potential association between parity and epigenetic changes in breast tissue from women with early parity and nulliparity. Breast tissue was collected from age-matched cancer-free women with early parity (age < 20; n = 15) or nulliparity (n = 13). The methyl-CpG binding domain-based capture-sequencing technology was used for whole-genome DNA methylation profiling. Potential parity-associated hypermethylated genes were further verified by locus-specific pyrosequencing, using an expanded cohort of parous (n = 19) and nulliparous (n = 16) women that included the initial samples used in the global analysis. Our study identified six genes that are hypermethylated in the parous group (P < 0.05). Pyrosequencing confirmed parity-associated hypermethylation at multiple CpG islands of the FOXA1 gene, which encodes a pioneer factor that facilitates chromatin binding of estrogen receptor α. Our work identifies several potential methylation biomarkers for parity-associated breast cancer risk assessment. In addition, the results are consistent with the notion that parity-associated epigenetic silencing of FOXA1 contributes to long-term attenuation of the estrogenic impact on breast cancer development.

The EORTC 10041/BIG 03-04 MINDACT trial is feasible: results of the pilot phase.

BACKGROUND: The MINDACT (Microarray In Node-negative and 1-3 node positive Disease may Avoid ChemoTherapy) trial investigates the clinical utility of the 70-gene profile (MammaPrint) for the selection of breast cancer patients for adjuvant chemotherapy (CT) together with standard clinicopathological criteria. We present the results of the pilot phase consisting of first 800 patients included. METHODS: MINDACT has enrolled 6600 patients, classified into high or low risk by MammaPrint and clinicopathological risk through Adjuvant! Online. Patients with both clinical (C) and genomic (G) high risks are offered adjuvant CT; those with both C and G low risks do not receive CT; patients with discordant risk are randomised for the decision of adjuvant CT based on C or G risk. CT randomisation of anthracycline-based versus docetaxel/capecitabine and endocrine therapy randomisation between letrozole and tamoxifen→letrozole are offered. RESULTS: During the pilot phase 46% of screened patients were enrolled. Main reasons for non-enrolment were node positivity before trial amendment, sample quality problems and failure to meet logistic settings. Among the 800 patients, 386 (48%) were C-low/G-low, 198 (24.8%) as C-high/G-high, 75 (9.4%) as C-low/G-high and 141 (17.6%) as C-high/G-low. In total 216 (27%) cases were discordant. The difference between patients with C-high (42%) and G-high risk (34%) is 8.25% (95% confidence interval (CI), 4.7-11.8%; P<.0001). Compliance with the treatment decision was high (>92%). CONCLUSIONS: The logistically complex MINDACT trial is feasible in a multinational setting. The proportion of discordant patients, the potential reduction in CT by using the genomic signature and compliance to treatment assignment are in accordance with the trial hypotheses.

Cancer and Leukemia Group B Pathology Committee guidelines for tissue microarray construction representing multicenter prospective clinical trial tissues.

Practice-changing evidence requires confirmation, preferably in multi-institutional clinical trials. The collection of tissue within such trials has enabled biomarker studies and evaluation of companion diagnostic tests. Tissue microarrays (TMAs) have become a standard approach in many cooperative oncology groups. A principal goal is to maximize the number of assays with this precious tissue. However, production strategies for these arrays have not been standardized, possibly decreasing the value of the study. In this article, members of the Cancer and Leukemia Group B Pathology Committee relay our experiences as array facility directors and propose guidelines regarding the production of high-quality TMAs for cooperative group studies. We also discuss statistical issues arising from having a proportion of patients available for TMAs and the possibility that patients with TMAs fail to represent the greater study population.

Independent prognostic value of screen detection in invasive breast cancer.

BACKGROUND: Mammographic screening has led to a proportional shift toward earlier-stage breast cancers at presentation. We assessed whether the method of detection provides prognostic information above and beyond standard prognostic factors and investigated the accuracy of predicted overall and breast cancer-specific survival by the computer tool Adjuvant! among patients with screen-detected, interval, and nonscreening-related carcinomas. METHODS: We studied 2592 patients with invasive breast cancer who were treated at the Netherlands Cancer Institute from January 1, 1990, through December 31, 2000. Overall and breast cancer-specific survival probabilities among patients with mammographically screen-detected (n = 958), interval (n = 417), and nonscreening-related (n = 1217) breast carcinomas were compared. Analyses were adjusted for clinicopathologic characteristics and adjuvant systemic therapy. Because of gradual implementation of population-based screening in the Netherlands, analyses were stratified a priori according to two periods of diagnosis. All statistical tests were two-sided. RESULTS: Screen detection was associated with reduced mortality (adjusted hazard ratio for all-cause mortality = 0.74, 95% confidence interval = 0.63 to 0.87, P < .001, and adjusted hazard ratio for breast cancer-specific mortality = 0.62, 95% confidence interval = 0.50 to 0.78, P < .001, respectively) compared with nonscreening-related detection. The absolute adjusted reduction in breast cancer-specific mortality was 7% at 10 years. The prognostic value of the method of detection was independent of the period of diagnosis and was similar across tumor size and lymph node status categories, indicating its prognostic value beyond stage migration. Adjuvant! underestimated breast cancer-specific survival in patients with screen-detected (-3.2%) and interval carcinomas (-5.4%). CONCLUSIONS: Screen detection was found to be independently associated with better prognosis for overall and breast cancer-specific survival and to provide prognostic information beyond stage migration among patients with invasive breast cancer. We propose that the method of detection should be taken into account when estimating individual prognosis.

Gene polymorphisms in cyclophosphamide metabolism pathway,treatment-related toxicity, and disease-free survival in SWOG 8897 clinical trial for breast cancer.

PURPOSE: There are no established genetic markers for prediction of outcomes after cyclophosphamide (CP)-containing adjuvant therapy for breast cancer. In an ancillary study to a SWOG (Southwest Oncology Group) trial (S8897), we investigated functional polymorphisms in 4 genes in CP pharmacokinetic pathways in relation to hematologic toxicity and disease-free survival (DFS). EXPERIMENTAL DESIGN: Germline DNA was available from 458 women who were at high risk of relapse and was randomized to CAF (CP, intravenous doxorubicin, and 5-fluorouracil) versus CMF (CP, intravenous methotrexate, and 5-fluorouracil) ± tamoxifen, and from 874 women who had a presumed favorable prognosis and did not receive adjuvant therapy. Odds ratios for grade 3 and 4 hematologic toxicity in the treated group and hazard ratios for DFS associated with selected functional polymorphisms in CYP2B6CYP3A4GSTA1 and GSTP1 were estimated by logistic regression and Cox proportional hazard regression. RESULTS: Compared with women with AA genotypes, those with at least 1 GSTP1 variant G allele had reduced risk of grade 3 and 4 neutropenia [odds ratios (OR) = 0.63, 95% CI = 0.41-0.97] and leucopenia (OR = 0.59, 95% CI = 0.39-0.89). No other associations between single nucleotide polymorphisms and toxicity or survival were found in the treated or untreated group. CONCLUSION: Known genetic variants in genes involved in CP pharmacokinetics may not have major effects on DFS in breast cancer patients. The lower risk of developing high-grade hematologic toxicity among women with variant GSTP1 alleles suggests that genetic markers in combination with clinical factors may be useful in defining a subgroup of women who are less susceptible to adverse hematologic toxicities with CP-containing therapies.

Estrogen plus progestin and breast cancer incidence and mortality in postmenopausal women.

CONTEXT: In the Women's Health Initiative randomized, placebo-controlled trial of estrogen plus progestin, after a mean intervention time of 5.6 (SD, 1.3) years (range, 3.7-8.6 years) and a mean follow-up of 7.9 (SD, 1.4) years, breast cancer incidence was increased among women who received combined hormone therapy. Breast cancer mortality among participants in the trial has not been previously reported. OBJECTIVE: To determine the effects of therapy with estrogen plus progestin on cumulative breast cancer incidence and mortality after a total mean follow-up of 11.0 (SD, 2.7) years, through August 14, 2009. DESIGN, SETTING, AND PARTICIPANTS: A total of 16,608 postmenopausal women aged 50 to 79 years with no prior hysterectomy from 40 US clinical centers were randomly assigned to receive combined conjugated equine estrogens, 0.625 mg/d, plus medroxyprogesterone acetate, 2.5 mg/d, or placebo pill. After the original trial completion date (March 31, 2005), reconsent was required for continued follow-up for breast cancer incidence and was obtained from 12,788 (83%) of the surviving participants. MAIN OUTCOME MEASURES: Invasive breast cancer incidence and breast cancer mortality. RESULTS: In intention-to-treat analyses including all randomized participants and censoring those not consenting to additional follow-up on March 31, 2005, estrogen plus progestin was associated with more invasive breast cancers compared with placebo (385 cases [0.42% per year] vs 293 cases [0.34% per year]; hazard ratio [HR], 1.25; 95% confidence interval [CI], 1.07-1.46; P = .004). Breast cancers in the estrogen-plus-progestin group were similar in histology and grade to breast cancers in the placebo group but were more likely to be node-positive (81 [23.7%] vs 43 [16.2%], respectively; HR, 1.78; 95% CI, 1.23-2.58; P = .03). There were more deaths directly attributed to breast cancer (25 deaths [0.03% per year] vs 12 deaths [0.01% per year]; HR, 1.96; 95% CI, 1.00-4.04; P = .049) as well as more deaths from all causes occurring after a breast cancer diagnosis (51 deaths [0.05% per year] vs 31 deaths [0.03% per year]; HR, 1.57; 95% CI, 1.01-2.48; P = .045) among women who received estrogen plus progestin compared with women in the placebo group. CONCLUSIONS: Estrogen plus progestin was associated with greater breast cancer incidence, and the cancers are more commonly node-positive. Breast cancer mortality also appears to be increased with combined use of estrogen plus progestin. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00000611.

The lack, need, and opportunities for decision-making and informational tools to educate primary-care physicians and women about breast cancer chemoprevention.

This perspective on Vogel et al. (beginning on page 696 in this issue of the journal) examines tamoxifen and raloxifene prescription patterns and why these agents are little used for breast cancer prevention despite their effectiveness in definitive trials, Food and Drug Administration approval, and American Society of Clinical Oncology Guidelines Committee endorsement for this purpose. The complexity of weighing the positive and negative aspects of the drugs and estimating net benefit is discussed, as is the need for informational resources such as interactive Internet-based tools to allow better individualized decisions about the options for chemoprevention.

Manganese superoxide dismutase polymorphism, treatment-related toxicity and disease-free survival in SWOG 8897 clinical trial for breast cancer.

To date, the few studies of associations between a functional polymorphism in the oxidative stress-related gene manganese superoxide dismutase (SOD2) and breast cancer survival have been inconsistent. In a homogeneous patient population from a large cooperative group trial Southwest Oncology Group (SWOG) 8897, we evaluated this polymorphism in relation to both treatment-related toxicity and disease-free survival (DFS). Among 458 women who received cyclophosphamide-containing adjuvant chemotherapy, those with variant C alleles, related to higher antioxidant activity, experienced less grade 3-4 neutropenia (OR = 0.52, 95% CI = 0.29-0.92) but had worse DFS (HR = 1.59, 95% CI = 0.99-2.55) than women with TT genotypes. No associations were observed among 874 women who were followed without adjuvant therapy. Our results are consistent with the hypothesis that women with higher SOD2 antioxidant activity may experience less treatment-related toxicity but shorter time to disease recurrence or death after breast cancer adjuvant chemotherapy, supporting the modifying effects of oxidative stress-related enzymes on cancer treatment toxicity and efficacy.

Ki67 in breast cancer: prognostic and predictive potential.

The leading parameters that define treatment recommendations in early breast cancer are oestrogen-receptor, progesterone-receptor, and human epidermal growth-factor status. Although some pathologists report Ki67 in addition to other biological markers, the existing guidelines of the American Society of Clinical Oncology do not include Ki67 in the list of required routine biological markers. The advent of new genetic tests has emphasised the role of proliferative genes, including Ki67, as prognostic and predictive markers. Additionally, randomised studies have retrospectively reviewed data and reported on the role of Ki67 in breast cancer. In light of new data, we have re-assessed evidence that could change guidelines to include Ki67 in the standard pathological assessment of early breast cancers. This review provides an update on the current knowledge on Ki67 and of the evidence in the published work about the prognostic and predictive role of this marker, and provides information on the laboratory techniques used to determine Ki67.