Chemoresistance Evolution in Triple-Negative Breast Cancer Delineated by Single-Cell Sequencing.

Triple-negative breast cancer (TNBC) is an aggressive subtype that frequently develops resistance to chemotherapy. An unresolved question is whether resistance is caused by the selection of rare pre-existing clones or alternatively through the acquisition of new genomic aberrations. To investigate this question, we applied single-cell DNA and RNA sequencing in addition to bulk exome sequencing to profile longitudinal samples from 20 TNBC patients during neoadjuvant chemotherapy (NAC). Deep-exome sequencing identified 10 patients in which NAC led to clonal extinction and 10 patients in which clones persisted after treatment. In 8 patients, we performed a more detailed study using single-cell DNA sequencing to analyze 900 cells and single-cell RNA sequencing to analyze 6,862 cells. Our data showed that resistant genotypes were pre-existing and adaptively selected by NAC, while transcriptional profiles were acquired by reprogramming in response to chemotherapy in TNBC patients.

Overall Survival with Pembrolizumab in Early-Stage Triple-Negative Breast Cancer.

BACKGROUND: In patients with early-stage triple-negative breast cancer, the phase 3 KEYNOTE-522 trial showed significant improvements in pathological complete response and event-free survival with the addition of pembrolizumab to platinum-containing chemotherapy. Here we report the final results for overall survival. METHODS: We randomly assigned, in a 2:1 ratio, patients with previously untreated stage II or III triple-negative breast cancer to receive neoadjuvant therapy with four cycles of pembrolizumab (at a dose of 200 mg) or placebo every 3 weeks plus paclitaxel and carboplatin, followed by four cycles of pembrolizumab or placebo plus doxorubicin-cyclophosphamide or epirubicin-cyclophosphamide. After definitive surgery, patients received adjuvant pembrolizumab (pembrolizumab-chemotherapy group) or placebo (placebo-chemotherapy group) every 3 weeks for up to nine cycles. The primary end points were pathological complete response and event-free survival. Overall survival was a secondary end point. RESULTS: Of the 1174 patients who underwent randomization, 784 were assigned to the pembrolizumab-chemotherapy group and 390 to the placebo-chemotherapy group. At the data-cutoff date (March 22, 2024), the median follow-up was 75.1 months (range, 65.9 to 84.0). The estimated overall survival at 60 months was 86.6% (95% confidence interval [CI], 84.0 to 88.8) in the pembrolizumab-chemotherapy group, as compared with 81.7% (95% CI, 77.5 to 85.2) in the placebo-chemotherapy group (P = 0.002). Adverse events were consistent with the established safety profiles of pembrolizumab and chemotherapy. CONCLUSIONS: Neoadjuvant pembrolizumab plus chemotherapy followed by adjuvant pembrolizumab resulted in a significant improvement, as compared with neoadjuvant chemotherapy alone, in overall survival among patients with early-stage triple-negative breast cancer. (Funded by Merck Sharp and Dohme, a subsidiary of Merck [Rahway, NJ]; KEYNOTE-522 ClinicalTrials.gov number, NCT03036488.).

Breast cancer patient-derived whole-tumor cell culture model for efficient drug profiling and treatment response prediction.

Breast cancer (BC) is a complex disease comprising multiple distinct subtypes with different genetic features and pathological characteristics. Although a large number of antineoplastic compounds have been approved for clinical use, patient-to-patient variability in drug response is frequently observed, highlighting the need for efficient treatment prediction for individualized therapy. Several patient-derived models have been established lately for the prediction of drug response. However, each of these models has its limitations that impede their clinical application. Here, we report that the whole-tumor cell culture (WTC) ex vivo model could be stably established from all breast tumors with a high success rate (98 out of 116), and it could reassemble the parental tumors with the endogenous microenvironment. We observed strong clinical associations and predictive values from the investigation of a broad range of BC therapies with WTCs derived from a patient cohort. The accuracy was further supported by the correlation between WTC-based test results and patients' clinical responses in a separate validation study, where the neoadjuvant treatment regimens of 15 BC patients were mimicked. Collectively, the WTC model allows us to accomplish personalized drug testing within 10 d, even for small-sized tumors, highlighting its potential for individualized BC therapy. Furthermore, coupled with genomic and transcriptomic analyses, WTC-based testing can also help to stratify specific patient groups for assignment into appropriate clinical trials, as well as validate potential biomarkers during drug development.

Clinically relevant gene signatures provide independent prognostic information in older breast cancer patients.

BACKGROUND: The clinical utility of gene signatures in older breast cancer patients remains unclear. We aimed to determine signature prognostic capacity in this patient subgroup. METHODS: Research versions of the genomic grade index (GGI), 70-gene, recurrence score (RS), cell cycle score (CCS), PAM50 risk-of-recurrence proliferation (ROR-P), and PAM50 signatures were applied to 39 breast cancer datasets (N = 9583). After filtering on age ≥ 70 years, and the presence of estrogen receptor (ER) and survival data, 871 patients remained. Signature prognostic capacity was tested in all (n = 871), ER-positive/lymph node-positive (ER + /LN + , n = 335) and ER-positive/lymph node-negative (ER + /LN-, n = 374) patients using Kaplan-Meier and multivariable Cox-proportional hazard (PH) modelling. RESULTS: All signatures were statistically significant in Kaplan-Meier analysis of all patients (Log-rank P < 0.001). This significance remained in multivariable analysis (Cox-PH, P ≤ 0.05). In ER + /LN + patients all signatures except PAM50 were significant in Kaplan-Meier analysis (Log-rank P ≤ 0.05) and remained so in multivariable analysis (Cox-PH, P ≤ 0.05). In ER + /LN- patients all except RS were significant in Kaplan-Meier analysis (Log-rank P ≤ 0.05) but only the 70-gene, CCS, ROR-P, and PAM50 signatures remained so in multivariable analysis (Cox-PH, P ≤ 0.05). CONCLUSIONS: We found that gene signatures provide prognostic information in survival analyses of all, ER + /LN + and ER + /LN- older (≥ 70 years) breast cancer patients, suggesting a potential role in aiding treatment decisions in older patients.

Prognostic impact of HER2 biomarker levels in trastuzumab-treated early HER2-positive breast cancer.

BACKGROUND: Overexpression of human epidermal growth factor receptor 2 (HER2) caused by HER2 gene amplification is a driver in breast cancer tumorigenesis. We aimed to investigate the prognostic significance of manual scoring and digital image analysis (DIA) algorithm assessment of HER2 copy numbers and HER2/CEP17 ratios, along with ERBB2 mRNA levels among early-stage HER2-positive breast cancer patients treated with trastuzumab. METHODS: This retrospective study comprised 371 early HER2-positive breast cancer patients treated with adjuvant trastuzumab, with HER2 re-testing performed on whole tumor sections. Digitized tumor tissue slides were manually scored and assessed with uPath HER2 Dual ISH image analysis, breast algorithm. Targeted ERBB2 mRNA levels were assessed by the Xpert® Breast Cancer STRAT4 Assay. HER2 copy number and HER2/CEP17 ratio from in situ hybridization assessment, along with ERBB2 mRNA levels, were explored in relation to recurrence-free survival (RFS). RESULTS: The analysis showed that patients with tumors with the highest and lowest manually counted HER2 copy number levels had worse RFS than those with intermediate levels (HR = 2.7, CI 1.4-5.3, p = 0.003 and HR = 2.1, CI 1.1-3.9, p = 0.03, respectively). A similar trend was observed for HER2/CEP17 ratio, and the DIA algorithm confirmed the results. Moreover, patients with tumors with the highest and the lowest values of ERBB2 mRNA had a significantly worse prognosis (HR = 2.7, CI 1.4-5.1, p = 0.003 and HR = 2.8, CI 1.4-5.5, p = 0.004, respectively) compared to those with intermediate levels. CONCLUSIONS: Our findings suggest that the association between any of the three HER2 biomarkers and RFS was nonlinear. Patients with tumors with the highest levels of HER2 gene amplification or ERBB2 mRNA were associated with a worse prognosis than those with intermediate levels, which is of importance to investigate in future clinical trials studying HER2-targeted therapy.

Identification of a Notch transcriptomic signature for breast cancer.

BACKGROUND: Dysregulated Notch signalling contributes to breast cancer development and progression, but validated tools to measure the level of Notch signalling in breast cancer subtypes and in response to systemic therapy are largely lacking. A transcriptomic signature of Notch signalling would be warranted, for example to monitor the effects of future Notch-targeting therapies and to learn whether altered Notch signalling is an off-target effect of current breast cancer therapies. In this report, we have established such a classifier. METHODS: To generate the signature, we first identified Notch-regulated genes from six basal-like breast cancer cell lines subjected to elevated or reduced Notch signalling by culturing on immobilized Notch ligand Jagged1 or blockade of Notch by γ-secretase inhibitors, respectively. From this cadre of Notch-regulated genes, we developed candidate transcriptomic signatures that were trained on a breast cancer patient dataset (the TCGA-BRCA cohort) and a broader breast cancer cell line cohort and sought to validate in independent datasets. RESULTS: An optimal 20-gene transcriptomic signature was selected. We validated the signature on two independent patient datasets (METABRIC and Oslo2), and it showed an improved coherence score and tumour specificity compared with previously published signatures. Furthermore, the signature score was particularly high for basal-like breast cancer, indicating an enhanced level of Notch signalling in this subtype. The signature score was increased after neoadjuvant treatment in the PROMIX and BEAUTY patient cohorts, and a lower signature score generally correlated with better clinical outcome. CONCLUSIONS: The 20-gene transcriptional signature will be a valuable tool to evaluate the response of future Notch-targeting therapies for breast cancer, to learn about potential effects on Notch signalling from conventional breast cancer therapies and to better stratify patients for therapy considerations.

A population-based study on trajectories of HER2 status during neoadjuvant chemotherapy for early breast cancer and metastatic progression.

BACKGROUND: This study aimed to investigate the distribution and changes of HER2 status in untreated tumours, in residual disease and in metastasis, and their long-term prognostic implications. METHODS: This is a population-based cohort study of patients treated with neoadjuvant chemotherapy for breast cancer during 2007-2020 in the Stockholm-Gotland region which comprises 25% of the entire Swedish population. Information was extracted from the National Breast Cancer Registry and electronic patient charts to minimize data missingness and misclassification. RESULTS: In total, 2494 patients received neoadjuvant chemotherapy, of which 2309 had available pretreatment HER2 status. Discordance rates were 29.9% between primary and residual disease (kappa = 0.534), 31.2% between primary tumour and metastasis (kappa = 0.512) and 33.3% between residual disease to metastasis (kappa = 0.483). Adjusted survival curves differed between primary HER2 0 and HER2-low disease (p < 0.001), with the former exhibiting an early peak in risk for death which eventually declined below the risk of HER2-low. Across all disease settings, increasing the number of biopsies increased the likelihood of detecting HER2-low status. CONCLUSION: HER2 status changes during neoadjuvant chemotherapy and metastatic progression, and the long-term behaviours of HER2 0 and HER2-low disease differ, underscoring the need for obtaining tissue biopsies and for extended follow-up in breast cancer studies.

The role of serum thymidine kinase 1 activity in neoadjuvant-treated HER2-positive breast cancer: biomarker analysis from the Swedish phase II randomized PREDIX HER2 trial.

BACKGROUND: Thymidine kinase 1 (TK1) plays a pivotal role in DNA synthesis and cellular proliferation. TK1 has been studied as a prognostic marker and as an early indicator of treatment response in human epidermal growth factor 2 (HER2)-negative early and metastatic breast cancer (BC). However, the prognostic and predictive value of serial TK1 activity in HER2-positive BC remains unknown. METHODS: In the PREDIX HER2 trial, 197 HER2-positive BC patients were randomized to neoadjuvant trastuzumab, pertuzumab, and docetaxel (DPH) or trastuzumab emtansine (T-DM1), followed by surgery and adjuvant epirubicin and cyclophosphamide. Serum samples were prospectively collected from all participants at multiple timepoints: at baseline, after cycle 1, 2, 4, and 6, at end of adjuvant therapy, annually for a total period of 5 years and/or at the time of recurrence. The associations of sTK1 activity with baseline characteristics, pathologic complete response (pCR), event-free survival (EFS), and disease-free survival (DFS) were evaluated. RESULTS: No association was detected between baseline sTK1 levels and all the baseline clinicopathologic characteristics. An increase of TK1 activity from baseline to cycle 2 was seen in all cases. sTK1 level at baseline, after 2 and 4 cycles was not associated with pCR status. After a median follow-up of 58 months, 23 patients had EFS events. There was no significant effect between baseline or cycle 2 sTK1 activity and time to event. A non-significant trend was noted among patents with residual disease (non-pCR) and high sTK1 activity at the end of treatment visit, indicating a potentially worse long-term prognosis. CONCLUSION: sTK1 activity increased following neoadjuvant therapy for HER2-positive BC but was not associated with patient outcomes or treatment benefit. However, the post-surgery prognostic value in patients that have not attained pCR warrants further investigation. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02568839. Registered on 6 October 2015.

Pembrolizumab for Early Triple-Negative Breast Cancer.

BACKGROUND: Previous trials showed promising antitumor activity and an acceptable safety profile associated with pembrolizumab in patients with early triple-negative breast cancer. Whether the addition of pembrolizumab to neoadjuvant chemotherapy would significantly increase the percentage of patients with early triple-negative breast cancer who have a pathological complete response (defined as no invasive cancer in the breast and negative nodes) at definitive surgery is unclear. METHODS: In this phase 3 trial, we randomly assigned (in a 2:1 ratio) patients with previously untreated stage II or stage III triple-negative breast cancer to receive neoadjuvant therapy with four cycles of pembrolizumab (at a dose of 200 mg) every 3 weeks plus paclitaxel and carboplatin (784 patients; the pembrolizumab-chemotherapy group) or placebo every 3 weeks plus paclitaxel and carboplatin (390 patients; the placebo-chemotherapy group); the two groups then received an additional four cycles of pembrolizumab or placebo, and both groups received doxorubicin-cyclophosphamide or epirubicin-cyclophosphamide. After definitive surgery, the patients received adjuvant pembrolizumab or placebo every 3 weeks for up to nine cycles. The primary end points were a pathological complete response at the time of definitive surgery and event-free survival in the intention-to-treat population. RESULTS: At the first interim analysis, among the first 602 patients who underwent randomization, the percentage of patients with a pathological complete response was 64.8% (95% confidence interval [CI], 59.9 to 69.5) in the pembrolizumab-chemotherapy group and 51.2% (95% CI, 44.1 to 58.3) in the placebo-chemotherapy group (estimated treatment difference, 13.6 percentage points; 95% CI, 5.4 to 21.8; P<0.001). After a median follow-up of 15.5 months (range, 2.7 to 25.0), 58 of 784 patients (7.4%) in the pembrolizumab-chemotherapy group and 46 of 390 patients (11.8%) in the placebo-chemotherapy group had disease progression that precluded definitive surgery, had local or distant recurrence or a second primary tumor, or died from any cause (hazard ratio, 0.63; 95% CI, 0.43 to 0.93). Across all treatment phases, the incidence of treatment-related adverse events of grade 3 or higher was 78.0% in the pembrolizumab-chemotherapy group and 73.0% in the placebo-chemotherapy group, including death in 0.4% (3 patients) and 0.3% (1 patient), respectively. CONCLUSIONS: Among patients with early triple-negative breast cancer, the percentage with a pathological complete response was significantly higher among those who received pembrolizumab plus neoadjuvant chemotherapy than among those who received placebo plus neoadjuvant chemotherapy. (Funded by Merck Sharp & Dohme [a subsidiary of Merck]; KEYNOTE-522 ClinicalTrials.gov number, NCT03036488.).

Women with short survival after diagnosis of metastatic breast cancer: a population-based registry study.

PURPOSE: Despite therapeutic advances, overall survival of metastatic breast cancer (MBC) at the population level has seen little improvement over the past decades. Aggressive tumor biology or delay in access to cancer care might be contributing factors. With this retrospective population-based study we aimed to quantify and characterize patients with very short survival time following MBC diagnosis. METHODS: Women diagnosed with MBC between Jan 1st, 2005 and Dec 31st, 2016 were identified using the population-based Stockholm-Gotland breast cancer registry. Data regarding demographic and clinicopathological characteristics, survival, and treatment were extracted retrospectively from the registry and from patient charts. Patients who died within 90 days following diagnosis of MBC were identified and their characteristics were compared with all other patients diagnosed with MBC during the same period. RESULTS: Between 2005 and 2016, 3124 patients were diagnosed with MBC, of whom 498 (16.2%) died within 90 days of diagnosis. Nearly half (N = 233) did not receive any antitumoral treatment. Patients with short survival were older (p < 0.001), had higher primary tumor grade (p < 0.001), higher clinical stage at primary diagnosis (p = 0.002), and more often estrogen receptor (ER)-negative breast cancer (p < 0.001). Visceral metastases were more frequent (p < 0.001) and patients with short survival received adjuvant chemotherapy (p < 0.001) to a lesser extent compared to patients with a better prognosis. In multivariable analysis older age, time period of diagnosis, metastasis site, adjuvant chemotherapy, and primary tumor grade were independent predictors for short survival, whereas ER status was not. CONCLUSION: Nearly one out of six patients with MBC survive less than 3 months after diagnosis. Our findings demonstrate a different spectrum of MBC at population level and can potentially inform on individualized follow-up strategies and treatment algorithms.

Axillary evaluation in ductal cancer in situ of the breast: challenging the diagnostic accuracy of clinical practice guidelines.

BACKGROUND: Staging of the axilla is not routine in ductal cancer in situ (DCIS) although invasive cancer is observed in 20-25 per cent of patients at final pathology. Upfront sentinel lymph node dissection (SLND) is advocated in clinical practice guidelines in certain situations. These include expected challenges in subsequent SLN detection and when the risk for invasion is high. Clinical practice guidelines are, however, inconsistent and lead to considerable practice variability. METHODS: Clinical practice guidelines for upfront SLND in DCIS were identified and applied to patients included in the prospective SentiNot study. These patients were evaluated by six independent, blinded raters. Agreement statistics were performed to assess agreement and concordance. Receiver operating characteristic curves were constructed, to assess guideline accuracy in identifying patients with underlying invasion. RESULTS: Eight guidelines with relevant recommendations were identified. Interobserver agreement varied greatly (kappa: 0.23-0.9) and the interpretation as to whether SLND should be performed ranged from 40-90 per cent and with varying concordance (32-88 per cent). The diagnostic accuracy was low with area under the curve ranging from 0.45 to 0.55. Fifty to 90 per cent of patients with pure DCIS would undergo unnecessary SLNB, whereas 10-50 per cent of patients with invasion were not identified as 'high risk'. Agreement across guidelines was low (kappa = 0.24), meaning that different patients had a similar risk of being treated inaccurately. CONCLUSION: Available guidelines are inaccurate in identifying patients with DCIS who would benefit from upfront SLNB. Guideline refinement with detailed preoperative work-up and novel techniques for SLND identification could address this challenge and avoid overtreatment. LAY SUMMARY: The decision whether to operate on the axilla in women with a diagnosis of ductal cancer in situ (DCIS) is based on the risk of an undiagnosed underlying invasive cancer and on the concern that resection of the breast will not allow for accurate axillary mapping afterwards. Guidelines stem from older knowledge and are heterogeneous. In this study, different breast cancer guidelines were tested in a patient cohort from the SentiNot prospective trial for uniformity of interpretation and diagnostic accuracy. Results show that guidelines did not allow for easy and uniform interpretation and had the predictive ability of the toss of a coin. This suggests that guidelines regarding the need of axillary evaluation in patients operated for DCIS need to be revised and that techniques that will address the conundrum should be developed.

The decision whether to operate on the axilla in women with a diagnosis of ductal cancer in situ (DCIS) is based on the risk of an undiagnosed underlying invasive cancer and on the concern that resection of the breast will not allow for accurate axillary mapping afterwards. Guidelines stem from older knowledge and are heterogeneous. In this study, different breast cancer guidelines were tested in a patient cohort from the SentiNot prospective trial for uniformity of interpretation and diagnostic accuracy. Results show that guidelines did not allow for easy and uniform interpretation and had the predictive ability of the toss of a coin. This suggests that guidelines regarding the need of axillary evaluation in patients operated for DCIS need to be revised and that techniques that will address the conundrum should be developed.

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.

Correction: Quality of life under extended continuous versus intermittent adjuvant letrozole in lymph node-positive, early breast cancer patients: the SOLE randomised phase 3 trial.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Effects of Exercise on Chemotherapy Completion and Hospitalization Rates: The OptiTrain Breast Cancer Trial.

BACKGROUND: Exercise during chemotherapy is suggested to provide clinical benefits, including improved chemotherapy completion. Despite this, few randomized controlled exercise trials have reported on such clinical endpoints. From the OptiTrain trial we previously showed positive effects on physiological and health-related outcomes after 16 weeks of supervised exercise in patients with breast cancer undergoing chemotherapy. Here, we examined the effects of exercise on rates of chemotherapy completion and hospitalization, as well as on blood cell concentrations during chemotherapy. PATIENTS AND METHODS: Two hundred forty women scheduled for chemotherapy were randomized to 16 weeks of resistance and high-intensity interval training (RT-HIIT), moderate-intensity aerobic and high-intensity interval training (AT-HIIT), or usual care (UC). Outcomes included chemotherapy completion, hospitalization, hemoglobin, lymphocyte, thrombocyte, and neutrophil concentrations during chemotherapy. RESULTS: No significant between-groups differences were found in the proportion of participants who required dose reductions (RT-HIIT vs. UC: odds ratio [OR], 1.08; AT-HIIT vs. UC: OR, 1.39), or average relative dose intensity of chemotherapy between groups (RT-HIIT vs. UC: effect size [ES], 0.08; AT-HIIT vs. UC: ES, -0.07). A significantly lower proportion of participants in the RT-HIIT group (3%) were hospitalized during chemotherapy compared with UC (15%; OR, 0.20). A significantly lower incidence of thrombocytopenia was found for both RT-HIIT (11%) and AT-HIIT (10%) versus UC (30%; OR, 0.27; OR, 0.27). CONCLUSION: No beneficial effects of either RT-HIIT or AT-HIIT on chemotherapy completion rates were found. However, combined resistance training and high-intensity interval training were effective to reduce hospitalization rates, and both exercise groups had a positive effect on thrombocytopenia. These are important findings with potential positive implications for the health of women with breast cancer and costs associated with treatment-related complications. IMPLICATIONS FOR PRACTICE: Completing the prescribed chemotherapy regimen is strongly associated with a good prognosis for patients with primary breast cancer. Despite this, treatment-induced side effects make it necessary to reduce or alter the treatment regimen and can also lead to hospitalization. Exercise during chemotherapy is suggested to provide clinical benefits, including improved chemotherapy completion. This study showed that combined resistance and high-intensity interval training during chemotherapy resulted in lower hospitalization rates and a lower incidence of thrombocytopenia in women with breast cancer undergoing chemotherapy. However, no beneficial effects of either exercise program on chemotherapy completion rates were found, which is in contrast to previous findings in this population. The findings reported in the current article have positive implications for the health of women with breast cancer and costs associated with treatment-related complications.

Long-term (up to 16 months) health-related quality of life after adjuvant tailored dose-dense chemotherapy vs. standard three-weekly chemotherapy in women with high-risk early breast cancer.

PURPOSE: To prospectively compare HRQoL effects of two modern adjuvant chemotherapy breast cancer treatment regimens at six time-points up to 16 months after random assignment. METHODS: The open-label, randomized, Phase 3 "Panther trial" was conducted between February 2007 and September 2011. 760 women, aged 65 years and younger, after surgery for non-metastatic node-positive or high-risk node-negative breast cancer were randomized 1:1 to the experimental group (four cycles of tailored and dose-dense adjuvant epirubicin and cyclophosphamide/2 weeks followed by four cycles of tailored dose-dense docetaxel/2 weeks) or standard group (three cycles of fluorouracil and epirubicin-cyclophosphamide/3 weeks followed by three cycles of docetaxel/3 weeks). HRQoL was assessed at all Swedish centres using EORTC QLQ-C30 and EORTC QLQ-BR23 at six points during 16 months before randomization. RESULTS: Response rates to questionnaires were highest at baseline 728/780 (93%) and lowest 16 months after randomization, 557/750 (74%). HRQoL declined during treatment in both groups. At the end of treatment, the experimental group reported statistically significantly lower HRQoL (P < 0.001) than the standard group on global health status, physical functioning, role functioning, social functioning, fatigue, sexual functioning, and systemic therapy effects. No differences were found for emotional functioning, body image, and arm and breast symptoms. There were no statistically significant differences between the groups at the first follow-up and at subsequent assessments. HRQoL levels at the 16-month follow-up were similar to baseline values. CONCLUSIONS: Negative HRQoL impact of the dose-dense and tailored strategy appears to be prominent during treatment, but HRQoL recover once treatment ends. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00798070; isrctn.org Identifier: ISRCTN39017665.

Chemotherapy use near the end-of-life in patients with metastatic breast cancer.

INTRODUCTION: Very few data are available regarding the use of chemotherapy in patients with metastatic breast cancer (MBC) near the end-of-life, i.e., the final month. The aim of this study was to provide a descriptive analysis of its use in two different European geographic areas (Sweden and Greece). MATERIALS AND METHODS: We retrospectively collected data regarding clinicopathologic characteristics, survival, and use of chemotherapy during the final 30 days of life using two sources: for the Swedish cohort, patients who were diagnosed with MBC in 2010-2015 were identified from the Stockholm-Gotland population-based Breast Cancer Registry and treatment data were collected using hospital charts. For the Greek cohort, patients with MBC were identified from hospital charts at two hospitals in Athens and Crete. RESULTS: In the Swedish cohort, 1571 patients were identified; median overall survival was 16.96 months (95% CI 15.4-18.4). 23.2% of patients were treated with chemotherapy during the final month of life, with higher rates among patients ≤ 60 years (p < 0.001). Per OS monotherapy such as capecitabine or vinorelbine was most commonly used. In contrast, median OS in the Greek cohort (n = 966) was 49.8 months (95% CI 45.6-54.1) and 46.5% of patients received chemotherapy at the end-of-life, most commonly intravenous drug combinations. In multivariable analysis, age and albumin levels were statistically significantly associated with chemotherapy use in the Swedish cohort. CONCLUSION: Chemotherapy use near the end-of-life was common, which might negatively impact patient quality of life.

Efficacy and safety of cyclin dependent kinases 4/6 inhibitors in the treatment of metastatic breast cancer: a real-world experience.

BACKGROUND: Randomized trials have shown survival gains for patients with metastatic breast cancer (BC) treated with CDK4/6 inhibitors (CDK4/6i) in combination with endocrine agents. It is not unlikely that there may be discrepancies between the generally fit clinical study population and the real-world setting that could affect adherence to treatment guidelines, tolerance to treatment and outcome. MATERIAL AND METHODS: Consecutive patients with metastatic or locally advanced and unresectable BC that were treated between July 2017 and January 2020 at Karolinska University Hospital, Stockholm, Sweden and that had received at least one dose of CDK4/6i were included in this retrospective study. The primary endpoint was safety, including toxicity according to CTCAE 5 and rates of treatment interruptions, dose reductions and discontinuations. The secondary endpoint was efficacy based on the treating physicians' assessments in terms of progression free (PFS) and overall survival (OS), as well as the factors associated with patient outcome. RESULTS: Eighty-eight patients were included in the analysis, with a median age of 67.2 years. Grade 4 neutropenia occurred in 9.1% of patients and one episode of neutropenic infection was observed. Dose reductions were made in 38.6% of patients, while 11.4% discontinued treatment due to toxicity, most commonly non-hematologic. After a median follow-up of 18.33 months, median PFS was 13.30 months (95% CI, 11.39-15.21) and median OS could yet not be estimated. In multivariable analysis, number of prior chemotherapy lines was an independent predictor for shorter PFS (HR = 3.28, 95% CI 1.50-7.16, p = .003). CONCLUSIONS: CDK4/6i administered in a real-world setting exhibits a similar toxicity profile but higher incidence of treatment discontinuation compared to randomized trials. Efficacy of CDK4/6i among patients pretreated with multiple therapy lines is markedly reduced.

Neutropenic complications in the PANTHER phase III study of adjuvant tailored dose-dense chemotherapy in early breast cancer.

Introduction: Myelosuppresion is a common side effect of chemotherapy and granulocyte-colony stimulating factor (G-CSF) is often used to reduce the risk of neutropenic events. The purpose of this exploratory analysis was to investigate neutropenic complications in the phase III PANTHER trial of standard 3-weekly chemotherapy with 5-fluorouracil, epirubicin and cyclophosphamide plus docetaxel (FEC/D) versus bi-weekly tailored dose-dense EC/D adjuvant chemotherapy in breast cancer.Patients and methods: Febrile neutropenia, neutropenic infection and infection grade 3-4 according to CTC AE 3.0, were explored in relation to G-CSF use. Per cycle analysis was performed concerning dose reduction and dose delays in conjunction with G-CSF administration.Results: In the experimental group, 98.9% of patients received primary G-CSF support during EC and 97.4% during docetaxel, compared with 49.7% during FEC and 63.88% during docetaxel in the standard group. Overall, the use of G-CSF was associated with a lower risk for developing neutropenic events (OR 0.44, 95% CI 0.35-0.55, p < .001). Chemotherapy delays due to neutropenia and leukopenia were significantly decreased among patients that received G-CSF (OR 0.098, 95% CI 0.06-0.15 and OR 0.32, 95% CI 0.18-0.58, respectively).Discussion: In conclusion, G-CSF support reduces neutropenic events and permits increased relative dose intensity, which is essential for improved survival outcomes.

Off-tumor targets compromise antiangiogenic drug sensitivity by inducing kidney erythropoietin production.

Anti-VEGF drugs are commonly used for treatment of a variety of cancers in human patients, and they often develop resistance. The mechanisms underlying anti-VEGF resistance in human cancer patients are largely unknown. Here, we show that in mouse tumor models and in human cancer patients, the anti-VEGF drug-induced kidney hypoxia augments circulating levels of erythropoietin (EPO). Gain-of-function studies show that EPO protects tumor vessels from anti-VEGF treatment and compromises its antitumor effects. Loss of function by blocking EPO function using a pharmacological approach markedly increases antitumor activity of anti-VEGF drugs through inhibition of tumor angiogenesis. Similarly, genetic loss-of-function data shows that deletion of EpoR in nonerythroid cells significantly increases antiangiogenic and antitumor effects of anti-VEGF therapy. Finally, in a relatively large cohort study, we show that treatment of human colorectal cancer patients with bevacizumab augments circulating EPO levels. These findings uncover a mechanism of desensitizing antiangiogenic and anticancer effects by kidney-produced EPO. Our work presents conceptual advances of our understanding of mechanisms underlying antiangiogenic drug resistance.

The long-term prognostic and predictive capacity of cyclin D1 gene amplification in 2305 breast tumours.

BACKGROUND: Use of cyclin D1 (CCND1) gene amplification as a breast cancer biomarker has been hampered by conflicting assessments of the relationship between cyclin D1 protein levels and patient survival. Here, we aimed to clarify its prognostic and treatment predictive potential through comprehensive long-term survival analyses. METHODS: CCND1 amplification was assessed using SNP arrays from two cohorts of 1965 and 340 patients with matching gene expression array and clinical follow-up data of over 15 years. Kaplan-Meier and multivariable Cox regression analyses were used to determine survival differences between CCND1 amplified vs. non-amplified tumours in clinically relevant patient sets, within PAM50 subtypes and within treatment-specific subgroups. Boxplots and differential gene expression analyses were performed to assess differences between amplified vs. non-amplified tumours within PAM50 subtypes. RESULTS: When combining both cohorts, worse survival was found for patients with CCND1-amplified tumours in luminal A (HR = 1.68; 95% CI, 1.15-2.46), luminal B (1.37; 1.01-1.86) and ER+/LN-/HER2- (1.66; 1.14-2.41) subgroups. In gene expression analysis, CCND1-amplified luminal A tumours showed increased proliferation (P < 0.001) and decreased progesterone (P = 0.002) levels along with a large overlap in differentially expressed genes when comparing luminal A and B-amplified vs. non-amplified tumours. CONCLUSIONS: Our results indicate that CCND1 amplification is associated with worse 15-year survival in ER+/LN-/HER2-, luminal A and luminal B patients. Moreover, luminal A CCND1-amplified tumours display gene expression changes consistent with a more aggressive phenotype. These novel findings highlight the potential of CCND1 to identify patients that could benefit from long-term treatment strategies.