Duration of Adjuvant Aromatase-Inhibitor Therapy in Postmenopausal Breast Cancer.

BACKGROUND: For postmenopausal women with hormone-receptor-positive breast cancer, the most effective duration for adjuvant therapy with an aromatase inhibitor remains unclear. METHODS: In this prospective, phase 3 trial, we randomly assigned postmenopausal women with hormone-receptor-positive breast cancer who had received 5 years of adjuvant endocrine therapy to receive the aromatase inhibitor anastrozole for an additional 2 years (2-year group, receiving a total of 7 years) or an additional 5 years (5-year group, receiving a total of 10 years). The primary end point was disease-free survival. The primary analysis included all the patients who were still participating in the trial and who had no recurrence 2 years after randomization (i.e., when treatment in the 2-year group had ended). Secondary end points were overall survival, contralateral breast cancer, second primary cancer, and clinical bone fracture. RESULTS: Among the 3484 women who were enrolled in the trial, 3208 remained in the trial without disease progression after the first 2 years of extended anastrozole treatment following randomization. Among these women, disease progression or death occurred in 335 women in each treatment group in the primary-analysis set at 8 years (hazard ratio, 0.99; 95% confidence interval [CI], 0.85 to 1.15; P = 0.90). No between-group differences occurred in most secondary end points, and subgroup analyses did not indicate differences in any particular subgroup. The risk of clinical bone fracture was higher in the 5-year group than in the 2-year group (hazard ratio, 1.35; 95% CI, 1.00 to 1.84). CONCLUSIONS: In postmenopausal women with hormone-receptor-positive breast cancer who had received 5 years of adjuvant endocrine therapy, extending hormone therapy by 5 years provided no benefit over a 2-year extension but was associated with a greater risk of bone fracture. (Funded by AstraZeneca and the Austrian Breast and Colorectal Cancer Study Group; ABCSG-16/SALSA ClinicalTrials.gov number, NCT00295620.).

Is the CTS5 a helpful decision-making tool in the extended adjuvant therapy setting?

PURPOSE: The Clinical Treatment Score post-5 years (CTS5) is an easy-to-use tool estimating the late distant recurrence (LDR) risk in patients with hormone receptor-positive breast cancer after 5 years of endocrine therapy (ET). Apart from evaluating the prognostic value and calibration accuracy of CTS5, the aim of this study is to clarify if this score is able to identify patients at higher risk for LDR who will benefit from extended ET. METHODS: Prognostic power, calibration, and predictive value of the CTS5 was tested in patients of the prospective ABCSG-06 and -06a trials (n = 1254 and 860 patients, respectively). Time to LDR was analyzed with Cox regression models. RESULTS: Higher rates of LDR in the years five to ten were observed in high- and intermediate-risk patients compared to low-risk patients (HR 4.02, 95%CI 2.26-7.15, p < 0.001 and HR 1.93, 95%CI 1.05-3.56, p = 0.035). An increasing continuous CTS5 was associated with increasing LDR risk (HR 2.23, 95% CI 1.74-2.85, p < 0.001). Miscalibration of CTS5 in high-risk patients could be observed. Although not reaching significance, high-risk patients benefitted the most from prolonged ET with an absolute reduction of the estimated 5-year LDR of - 6.1% (95%CI - 14.4 to 2.3). CONCLUSION: The CTS5 is a reliable prognostic tool that is well calibrated in the lower and intermediate risk groups with a substantial difference of expected versus observed LDR rates in high-risk patients. While a numerical trend in favoring prolonged ET for patients with a higher CTS5 was found, a significantly predictive value for the score could not be confirmed. CLINICAL TRIAL REGISTRATION: ABCSG-06 trial (NCT00309491), ABCSG-06A7 1033AU/0001 (NCT00300508).

Impact of Imaging-Guided Localization on Performance of Tailored Axillary Surgery in Patients with Clinically Node-Positive Breast Cancer: Prospective Cohort Study Within TAXIS (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

BACKGROUND: Tailored axillary surgery (TAS) is a novel surgical concept for clinical node-positive breast cancer. It consists of the removal of the sentinel lymph nodes (LNs), as well as palpably suspicious nodes. The TAS technique can be utilized in both the upfront and neoadjuvant chemotherapy (NACT) setting. This study assessed whether/how imaging-guided localization (IGL) influenced TAS. PATIENTS AND METHODS: This was a prospective observational cohort study preplanned in the randomized phase-III OPBC-03/TAXIS trial. IGL was performed at the surgeon's discretion for targeted removal of LNs during TAS. Immediate back-up axillary lymph node dissection (ALND) followed TAS according to TAXIS randomization. RESULTS: Five-hundred patients were included from 44 breast centers in six countries, 151 (30.2%) of whom underwent NACT. IGL was performed in 84.4% of all patients, with significant variation by country (77.6-100%, p < 0.001). No difference in the median number of removed (5 vs. 4, p = 0.3) and positive (2 vs. 2, p = 0.6) LNs by use of IGL was noted. The number of LNs removed during TAS with IGL remained stable over time (p = 0.8), but decreased significantly without IGL, from six (IQR 4-6) in 2019 to four (IQR 3-4) in 2022 (p = 0.015). An ALND was performed in 249 patients, removing another 12 (IQR 9-17) LNs, in which a median number of 1 (IQR 0-4) was positive. There was no significant difference in residual nodal disease after TAS with or without IGL (68.0% vs. 57.6%, p = 0.2). CONCLUSIONS: IGL did not significantly change either the performance of TAS or the volume of residual nodal tumor burden. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03513614.

Explained variation and degrees of necessity and of sufficiency for competing risks survival data.

In this contribution, the Schemper-Henderson measure of explained variation for survival outcomes is extended to accommodate competing events (CEs) in addition to events of interest. The extension is achieved by moving from the unconditional and conditional survival functions of the original measure to unconditional and conditional cumulative incidence functions, the latter obtained, for example, from Fine and Gray models. In the absence of CEs, the original measure is obtained as a special case. We define explained variation on the population level and provide two different types of estimates. Recently, the authors have achieved a multiplicative decomposition of explained variation into degrees of necessity and degrees of sufficiency. These measures are also extended to the case of competing risks survival data. A SAS macro and an R function are provided to facilitate application. Interesting empirical properties of the measures are explored on the population level and by an extensive simulation study. Advantages of the approach are exemplified by an Austrian study of breast cancer with a high proportion of CEs.

Trends in use of neoadjuvant systemic therapy in patients with clinically node-positive breast cancer in Europe: prospective TAXIS study (OPBC-03, SAKK 23/16, IBCSG 57-18, ABCSG-53, GBG 101).

PURPOSE: The aim of this study was to evaluate clinical practice heterogeneity in use of neoadjuvant systemic therapy (NST) for patients with clinically node-positive breast cancer in Europe. METHODS: The study was preplanned in the international multicenter phase-III OPBC-03/TAXIS trial (ClinicalTrials.gov Identifier: NCT03513614) to include the first 500 randomized patients with confirmed nodal disease at the time of surgery. The TAXIS study's pragmatic design allowed both the neoadjuvant and adjuvant setting according to the preferences of the local investigators who were encouraged to register eligible patients consecutively. RESULTS: A total of 500 patients were included at 44 breast centers in six European countries from August 2018 to June 2022, 165 (33%) of whom underwent NST. Median age was 57 years (interquartile range [IQR], 48-69). Most patients were postmenopausal (68.4%) with grade 2 and 3 hormonal receptor-positive and human epidermal growth factor receptor 2-negative breast cancer with a median tumor size of 28 mm (IQR 20-40). The use of NST varied significantly across the countries (p < 0.001). Austria (55.2%) and Switzerland (35.8%) had the highest percentage of patients undergoing NST and Hungary (18.2%) the lowest. The administration of NST increased significantly over the years (OR 1.42; p < 0.001) and more than doubled from 20 to 46.7% between 2018 and 2022. CONCLUSION: Substantial heterogeneity in the use of NST with HR+/HER2-breast cancer exists in Europe. While stringent guidelines are available for its use in triple-negative and HER2+ breast cancer, there is a need for the development of and adherence to well-defined recommendations for HR+/HER2-breast cancer.

Breast surgery after neoadjuvant therapy.

PURPOSE OF REVIEW: The standard of care in breast surgery has changed, from mastectomy to breast conserving surgery whenever possible, and from axillary dissection to sentinel node biopsy. Neoadjuvant systemic approaches have broadened the indications for organ-conserving and less mutilating surgery, but also raise important questions of balancing locoregional treatment de-escalation and protecting excellent long-term outcomes. RECENT FINDINGS: Recent studies have aimed at investigating the safety of de-escalating surgical approaches not only in the upfront breast surgery situation but also after neoadjuvant systemic therapy. This pertains to both the safety of breast conserving surgery - including more complex oncoplastic approaches - within the new (posttherapeutic) anatomical extent of the residual disease, but more controversially to de-escalating surgical treatment of the axilla. While sentinel node biopsy appears to be the standard of care for node-negative disease also after primary systemic therapy, the optimal procedure in situations of posttherapeutic node-positive disease remains highly controversial. SUMMARY: Both breast and axillary surgery after neoadjuvant systemic therapy for women with breast cancer has undergone multiple paradigm changes in recent years. For the primary tumor in the breast, breast-conserving surgery constitutes the standard of care, and unnecessary mastectomies should be strongly discouraged. For axillary surgery, sentinel-node biopsy should be aimed at, and completion axillary dissections minimized for situations of extensive disease and or poor neoadjuvant treatment response. Additional techniques such as targeted axillary dissection are currently under evaluation in clinical trials.

Breast conservation and axillary management after primary systemic therapy in patients with early-stage breast cancer: the Lucerne toolbox.

Primary systemic therapy is increasingly used in the treatment of patients with early-stage breast cancer, but few guidelines specifically address optimal locoregional therapies. Therefore, we established an international consortium to discuss clinical evidence and to provide expert advice on technical management of patients with early-stage breast cancer. The steering committee prepared six working packages to address all major clinical questions from diagnosis to surgery. During a consensus meeting that included members from European scientific oncology societies, clinical trial groups, and patient advocates, statements were discussed and voted on. A consensus was reached in 42% of statements, a majority in 38%, and no decision in 21%. Based on these findings, the panel developed clinical guidance recommendations and a toolbox to overcome many clinical and technical requirements associated with the diagnosis, response assessment, surgical planning, and surgery of patients with early-stage breast cancer. This guidance could convince clinicians and patients of the major clinical advancements purported by primary systemic therapy, the use of less extensive and more targeted surgery to improve the lives of patients with breast cancer.

Palbociclib with adjuvant endocrine therapy in early breast cancer (PALLAS): interim analysis of a multicentre, open-label, randomised, phase 3 study.

BACKGROUND: Palbociclib added to endocrine therapy improves progression-free survival in hormone-receptor-positive, HER2-negative, metastatic breast cancer. The PALLAS trial aimed to investigate whether the addition of 2 years of palbociclib to adjuvant endocrine therapy improves invasive disease-free survival over endocrine therapy alone in patients with hormone-receptor-positive, HER2-negative, early-stage breast cancer. METHODS: PALLAS is an ongoing multicentre, open-label, randomised, phase 3 study that enrolled patients at 406 cancer centres in 21 countries worldwide with stage II-III histologically confirmed hormone-receptor-positive, HER2-negative breast cancer, within 12 months of initial diagnosis. Eligible patients were aged 18 years or older with an Eastern Cooperative Oncology Group performance score of 0 or 1. Patients were randomly assigned (1:1) in permuted blocks of random size (4 or 6), stratified by anatomic stage, previous chemotherapy, age, and geographical region, by use of central telephone-based and web-based interactive response technology, to receive either 2 years of palbociclib (125 mg orally once daily on days 1-21 of a 28-day cycle) with ongoing standard provider or patient-choice adjuvant endocrine therapy (tamoxifen or aromatase inhibitor, with or without concurrent luteinising hormone-releasing hormone agonist), or endocrine therapy alone, without masking. The primary endpoint of the study was invasive disease-free survival in the intention-to-treat population. Safety was assessed in all randomly assigned patients who started palbociclib or endocrine therapy. This report presents results from the second pre-planned interim analysis triggered on Jan 9, 2020, when 67% of the total number of expected invasive disease-free survival events had been observed. The trial is registered with ClinicalTrials.gov (NCT02513394) and EudraCT (2014-005181-30). FINDINGS: Between Sept 1, 2015, and Nov 30, 2018, 5760 patients were randomly assigned to receive palbociclib plus endocrine therapy (n=2883) or endocrine therapy alone (n=2877). At the time of the planned second interim analysis, at a median follow-up of 23·7 months (IQR 16·9-29·2), 170 of 2883 patients assigned to palbociclib plus endocrine therapy and 181 of 2877 assigned to endocrine therapy alone had invasive disease-free survival events. 3-year invasive disease-free survival was 88·2% (95% CI 85·2-90·6) for palbociclib plus endocrine therapy and 88·5% (85·8-90·7) for endocrine therapy alone (hazard ratio 0·93 [95% CI 0·76-1·15]; log-rank p=0·51). As the test statistic comparing invasive disease-free survival between groups crossed the prespecified futility boundary, the independent data monitoring committee recommended discontinuation of palbociclib in patients still receiving palbociclib and endocrine therapy. The most common grade 3-4 adverse events were neutropenia (1742 [61·3%] of 2840 patients on palbociclib and endocrine therapy vs 11 [0·3%] of 2903 on endocrine therapy alone), leucopenia (857 [30·2%] vs three [0·1%]), and fatigue (60 [2·1%] vs ten [0·3%]). Serious adverse events occurred in 351 (12·4%) of 2840 patients on palbociclib plus endocrine therapy versus 220 (7·6%) of 2903 patients on endocrine therapy alone. There were no treatment-related deaths. INTERPRETATION: At the planned second interim analysis, addition of 2 years of adjuvant palbociclib to adjuvant endocrine therapy did not improve invasive disease-free survival compared with adjuvant endocrine therapy alone. On the basis of these findings, this regimen cannot be recommended in the adjuvant setting. Long-term follow-up of the PALLAS population and correlative studies are ongoing. FUNDING: Pfizer.

Conventional versus reverse sequence of neoadjuvant epirubicin/cyclophosphamide and docetaxel: sequencing results from ABCSG-34.

BACKGROUND: Preoperative chemotherapy containing anthracyclines and taxanes is well established in early-stage breast cancer. Previous studies have suggested that the chemotherapy sequence may matter but definitive evidence is missing. ABCSG trial 34 evaluated the activity of the MUC1 vaccine tecemotide when added to neoadjuvant treatment; the study provided the opportunity for the second randomisation to compare two different anthracycline/taxane sequences. METHODS: HER2-negative early-stage breast cancer patients were recruited to this randomised multicentre Phase 2 study. Patients in the chemotherapy cohort (n = 311) were additionally randomised to a conventional or reversed sequence of epirubicin/cyclophosphamide and docetaxel. Residual cancer burden (RCB) with/without tecemotide was defined as primary study endpoint; RCB in the two chemotherapy groups was a key secondary endpoint. RESULTS: No significant differences in terms of RCB 0/I (40.1% vs. 37.2%; P = 0.61) or pathologic complete response (pCR) rates (24.3% vs. 25%, P = 0.89) were observed between conventional or reverse chemotherapy sequence. No new safety signals were reported, and upfront docetaxel did not result in decreased rates of treatment delay or discontinuation. CONCLUSION: Upfront docetaxel did not improve chemotherapy activity or tolerability; these results suggest that upfront neoadjuvant treatment with anthracyclines remains a valid option.

Efficacy and safety of tailored and dose-dense adjuvant chemotherapy and trastuzumab for resected HER2-positive breast cancer: Results from the phase 3 PANTHER trial.

BACKGROUND: Dose-dense (DD) adjuvant chemotherapy improves outcomes in early breast cancer (BC). However, there are no phase 3 randomized data to inform on its combination with trastuzumab for patients with human epidermal growth factor receptor 2 (HER2)-positive disease. METHODS: This was a protocol-predefined secondary analysis of the randomized phase 3 Pan-European Tailored Chemotherapy (PANTHER) trial. Women 65 years old or younger with node-positive or high-risk, node-negative BC were randomized 1:1 to either tailored (according to hematologic nadirs) and DD epirubicin and cyclophosphamide followed by docetaxel or standard 5-fluorouracil, epirubicin, and cyclophosphamide plus docetaxel every 3 weeks. Patients with HER2-positive disease received 1 year of adjuvant trastuzumab. The primary endpoint was BC relapse-free survival. In addition, HER2-positive patients and an equal number of HER2-negative patients matched for age, treatment group, and institution who were enrolled at Swedish sites were asked to participate in a predefined study of cardiac safety and underwent echocardiography or multigated acquisition scanning and electrocardiography at the baseline and at 4 and 6 years of follow-up. RESULTS: There were 342 HER2-positive patients; 335 received at least 1 dose of trastuzumab, and 29 patients discontinued trastuzumab prematurely. Relapse-free survival was not statistically significantly in favor of the tailored and DD group (hazard ratio, 0.68; 95% confidence interval, 0.37-1.27; P = .231). Cardiac outcomes after 4 and 6 years of follow-up did not differ significantly between HER2-positive and HER2-negative patients or between the 2 treatment groups. CONCLUSIONS: The combination of DD chemotherapy and trastuzumab decreased the relative risk for relapse by 32% in comparison with standard treatment, a statistically nonsignificant difference. Its efficacy and safety merit further evaluation as part of both escalation and de-escalation strategies.