Impact of Age on Clinical Outcomes and Efficacy of Adjuvant Dual Anti-HER2 Targeted Therapy.

BACKGROUND: Young age at breast cancer (BC) diagnosis has historically been a rationale for overtreatment. Limited data with short follow-up exist on the prognostic value of age at diagnosis in HER2-positive BC and the benefit of anti-HER2 therapy in young patients. METHODS: APHINITY (NCT01358877) is an international, placebo-controlled, double-blind randomized phase III trial in HER2-positive early BC patients investigating the addition of pertuzumab to adjuvant chemotherapy plus trastuzumab. The prognostic and predictive value of age on invasive disease-free survival (IDFS) as continuous and dichotomous variable (aged 40 years or younger and older than 40 years) was assessed. A subpopulation treatment effect pattern plot analysis was conducted to illustrate possible treatment-effect heterogeneity based on age as a continuous factor. RESULTS: Of 4804 included patients, 768 (16.0%) were aged 40 years or younger at enrollment. Median follow-up was 74 (interquartile range = 62-75) months. Young age was not prognostic either as dichotomous (hazard ratio [HR] = 1.06, 95% confidence interval [CI] = 0.84 to 1.33) or continuous (HR = 1.00, 95% CI = 1.00 to 1.01) variable. Lack of prognostic effect of age was observed irrespective of hormone receptor status and treatment arm. No statistically significant interaction was observed between age and pertuzumab effect (Pinteraction = 0.61). Adding pertuzumab improved IDFS for patients in the young (HR = 0.86, 95% CI = 0.56 to 1.32) and older (HR = 0.75, 95% CI = 0.62 to 0.92) cohorts. Similar results were observed irrespective of hormone receptor status. Subpopulation treatment effect pattern plot analysis confirmed the benefit of pertuzumab in 6-year IDFS across age subpopulations. CONCLUSIONS: In patients with HER2-positive early BC treated with modern anticancer therapies, young age did not demonstrate either prognostic or predictive value, irrespective of hormone receptor status.

Knowledge, Practice, and Attitudes of Physicians in Low- and Middle-Income Countries on Fertility and Pregnancy-Related Issues in Young Women With Breast Cancer.

PURPOSE: Fertility and pregnancy-related issues are highly relevant for young (≤ 40 years) patients with breast cancer. Limited evidence exists on knowledge, practice, and attitudes of physicians from low- and middle-income countries (LMICs) regarding these issues. METHODS: A 19-item questionnaire adapted from an international survey exploring issues about fertility preservation and pregnancy after breast cancer was sent by e-mail between November 2019 and January 2020 to physicians from LMICs involved in breast cancer care. Descriptive analyses were performed. RESULTS: A total of 288 physicians from Asia, Africa, America, and Europe completed the survey. Median age was 38 years. Responders were mainly medical oncologists (44.4%) working in an academic setting (46.9%). Among responders, 40.2% and 53.8% reported having never consulted the available international guidelines on fertility preservation and pregnancy after breast cancer, respectively. 25.0%, 19.1%, and 24.3% of responders answered to be not at all knowledgeable about embryo, oocyte, or ovarian tissue cryopreservation, respectively; 29.2%, 23.6%, and 31.3% declared that embryo, oocyte, and ovarian tissue cryopreservation were not available in their countries, respectively. 57.6% of responders disagreed or were neutral on the statement that controlled ovarian stimulation can be considered safe in patients with breast cancer. 49.7% and 58.6% of responders agreed or were neutral on the statement that pregnancy in breast cancer survivors may increase the risk of recurrence overall or only in those with hormone receptor-positive disease, respectively. CONCLUSION: This survey showed suboptimal knowledge, practice, and attitudes of physicians from LMICs on fertility preservation and pregnancy after treatment completion in young women with breast cancer. Increasing awareness and education on these aspects are needed to improve adherence to available guidelines and to promote patients' oncofertility counseling.

Body Mass Index and Weight Change in Patients With HER2-Positive Early Breast Cancer: Exploratory Analysis of the ALTTO BIG 2-06 Trial.

BACKGROUND: The association between obesity and prognosis in HER2-positive early breast cancer remains unclear, with limited data available. This study aimed to determine the impact of body mass index (BMI) at baseline and weight change after 2 years on outcomes of patients with HER2-positive early breast cancer. METHODS: ALTTO was a randomized phase III trial in patients with HER2-positive early breast cancer. BMI was collected at randomization and 2 years after. WHO BMI categories were used: underweight, <18.5 kg/m2; normal weight, 18.5 to <25 kg/m2; overweight, ≥25 to <30 kg/m2; and obese ≥30 kg/m2. A weight change from baseline of ≥5.0% and ≤5.0% was categorized as weight gain and weight loss. The impact of BMI at randomization and of weight change on disease-free survival (DFS), distant disease-free survival (DDFS), and overall survival (OS) were investigated with multivariate analyses, adjusting for baseline patients and tumor characteristics. RESULTS: A total of 8,381 patients were included: 187 (2.2%), 3,797 (45.3%), 2,690 (32.1%), and 1,707 (20.4%) were underweight, normal weight, overweight, and obese at baseline, respectively. Compared with normal weight, being obese at randomization was associated with a significantly worse DDFS (adjusted hazard ratio [aHR], 1.25; 95% CI, 1.04-1.50) and OS (aHR, 1.27; 95% CI, 1.01-1.60), but no significant difference in DFS (aHR, 1.14; 95% CI, 0.97-1.32). Weight loss ≥5.0% at 2 years after randomization was associated with significantly poorer DFS (aHR, 1.34; 95% CI, 1.05-1.71), DDFS (aHR, 1.46; 95% CI, 1.07-1.98), and OS (aHR, 1.83; 95% CI, 1.18-2.84). Hormone receptor and menopausal status but not anti-HER2 treatment type influenced outcomes. Toxicities were more frequent in obese patients. CONCLUSIONS: In patients with HER2-positive early breast cancer, obesity at baseline is a poor prognostic factor. Weight loss during treatment and follow-up negatively impacts clinical outcomes. Dietary counseling should be part of survivorship care programs.

Prognostic role of distant disease-free interval from completion of adjuvant trastuzumab in HER2-positive early breast cancer: analysis from the ALTTO (BIG 2-06) trial.

BACKGROUND: In HER2-positive breast cancer, time elapsed between completion of (neo)adjuvant trastuzumab and diagnosis of metastatic disease ('trastuzumab-free interval', TFI) is crucial to choose the optimal first-line treatment. Nevertheless, there is no clear evidence to support its possible prognostic role. METHODS: In the Adjuvant Lapatinib and/or Trastuzumab Treatment Optimisation (ALTTO) trial, patients with HER2-positive early breast cancer were randomised to 1 year of either trastuzumab alone, lapatinib alone, their sequence or their combination. This exploratory analysis included only patients in the trastuzumab alone or trastuzumab plus lapatinib arms who developed a distant disease-free survival (DDFS) event. Overall survival (OS) was defined as time between date of DDFS event and death; age at diagnosis, tumour size and hormone receptor status were the variables included in the multivariate models. RESULTS: Out of 8381 patients included in ALTTO, 404 patients in the trastuzumab alone and trastuzumab plus lapatinib arms developed a DDFS event, of which 201 occurred <12 months (group A) and 203 >12 months (group B) after completion of adjuvant trastuzumab. No significant difference in location of first DDFS event was observed (p=0.073); a numerically higher number of patients in group A than in group B developed brain metastasis (26% vs 15%). Choice of first-line therapy differed between the two groups (p=0.022): in group A, more patients received lapatinib (25% vs 11%) and less pertuzumab (8% vs 17%). Median OS was 29.3 and 18.4 months in groups B and A, respectively (adjusted HR 0.69; 95% CI 0.54-0.89; p=0.004). The longer OS for patients in group B was observed across the analysed subgroups without interaction according to hormone receptor status (p=0.814) nor type of administered adjuvant anti-HER2 treatment (p=0.233). CONCLUSIONS: TFI has prognostic value in patients with HER2-positive early breast cancer treated with adjuvant trastuzumab-based therapy. TFI is a valid tool to better individualise clinical recommendations and to design future first-line treatment trials for metastatic patients.

Endocrine therapy-based treatments in hormone receptor-positive/HER2-negative advanced breast cancer: systematic review and network meta-analysis.

BACKGROUND: Several endocrine therapy (ET)-based treatments are available for patients with advanced breast cancer. We assessed the efficacy of different ET-based treatments in patients with hormone receptor-positive/HER2-negative advanced breast cancer with endocrine-sensitive or endocrine-resistant disease. METHODS: We searched Medline and Cochrane Central Register of Controlled Trials up to 15 October 2019 and abstracts from major conferences from 2016 to October 2019. We included phase II/III randomised trials, comparing ≥2 ET-based treatments. Progression-free survival (PFS) and overall survival (OS) were analysed by network meta-analyses using MTC Bayesian models based on both fixed-effect and random-effect models; relative treatment effects were measured as HRs and 95% credibility intervals (CrI). All statistical tests were two-sided. Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed and this systematic review is registered in the PROSPERO database. RESULTS: 55 publications reporting on 32 trials (n=12 293 patients) were included. Regarding PFS in the endocrine sensitive setting (n=5200; 12 trials), the combination of cyclin-dependent kinases (CDK)4/6-inhibitors (CDK4/6i)+fulvestrant 500 mg (F500) was likely the most effective treatment (surface under the cumulative ranking curve (SUCRA)=97.3%), followed by CDK4/6i+aromatase inhibitor ±goserelin; there was no significant difference between them (HR 0.82; 95% CrI 0.54-1.25). Regarding OS (n=2157; five trials), the most effective treatment was probably CDK4/6i+F500 (SUCRA=97.3%); comparing CDK4/6i+F500 versus F500 held a HR of 0.77 (95% CrI 0.63-0.95). Regarding PFS in the endocrine-resistant setting (n=6635; 20 trials), CDK4/6i+F500 was likely the most effective treatment (SUCRA=95.7%), followed by capivasertib+F500, without significant difference between them (HR 0.91; 95% CrI 0.60-1.36). For OS (n=4377; 11 trials), the most effective treatments were capivasertib+F500 (SUCRA=84.7%) and CDK4/6i+F500 (SUCRA=69.9%). Comparing CDK4/6i+F500 versus F500 held a HR of 0.77 (95% CrI 0.67-0.89). CONCLUSIONS: CDK4/6i+F500 is likely the best treatment option in both endocrine-sensitive and endocrine-resistant diseases for PFS, and in endocrine-sensitive patients for OS. Concerning OS in endocrine-resistant patients, capivasertib+F500 and CDK4/6i+F500 are likely the best treatments. PROSPERO REGISTRATION NUMBER: CRD42018104628.

Long-term cardiac outcomes of patients with HER2-positive breast cancer treated in the adjuvant lapatinib and/or trastuzumab Treatment Optimization Trial.

BACKGROUND: Cardiotoxicity is the most significant adverse event associated with trastuzumab (T), the main component of HER2-positive breast cancer (BC) treatment. Less is known about the cardiotoxicity of dual HER2 blockade with T plus lapatinib (L), although this regimen is used in the metastatic setting. METHODS: This is a sub-analysis of the ALTTO trial comparing adjuvant treatment options for patients with early HER2-positive BC. Patients randomised to either T or concomitant T + L were eligible. Cardiac events (CEs) rates were compared according to treatment arm. RESULTS: With 6.9 years of median follow-up (FU) and 4190 patients, CE were observed in 363 (8.6%): 166 (7.9%) of patient in T + L arm vs. 197 (9.3%) in T arm (OR = 0.85 [95% CI, 0.68-1.05]). During anti-HER2 treatment 270 CE (6.4%) occurred while 93 (2.2%) were during FU (median time to onset = 6.6 months [IQR = 3.4-11.7]). While 265 CEs were asymptomatic (73%), 94 were symptomatic (26%) and four were cardiac deaths (1%). Recovery was observed in 301 cases (83.8%). Identified cardiac risk factors were: baseline LVEF < 55% (vs > 64%, OR 3.1 [95% CI 1.54-6.25]), diabetes mellitus (OR 1.85 [95% CI 1.25-2.75]), BMI > 30 kg/m2 (vs < 25 mg/kg2, OR 2.21 [95% CI 1.40-3.49]), cumulative dose of doxorubicin ≥240 mg/m2 (OR 1.36 [95% CI 1.01-1.82]) and of epirubicin≥ 480 mg/m2 (OR 2.33 [95% CI 1.55-3.51]). CONCLUSIONS: Dual HER2 blockade with T + L is a safe regimen from a cardiac perspective, but cardiac-focused history for proper patient selection is crucial. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Identifier: NCT00490139 (registration date: 22/06/2007); EudraCT Number: 2006-000562-36 (registration date: 04/05/2007); Sponsor Protocol Number: BIG2-06 /EGF106708/N063D.

Progress in adjuvant systemic therapy for breast cancer.

The prognosis of patients with early stage breast cancer has greatly improved in the past three decades. Following the first adjuvant endocrine therapy and chemotherapy trials, continuous improvements of clinical outcomes have been achieved through intense therapeutic escalation, albeit with increased health-care costs and treatment-related toxicities. In contrast to the advances achieved in surgery or radiotherapy, the identification of the patient subgroups that will derive clinical benefit from therapeutic escalation has proved to be a daunting process hindered by a lack of collaboration between scientific groups and by the pace of drug development. In the past few decades, initiatives towards de-escalation of systemic adjuvant treatment have achieved success. Herein, we summarize attempts to escalate and de-escalate adjuvant systemic treatment for patients with breast cancer and argue that new, creative trial designs focused on patients' actual needs rather than on maximizing drug market size are needed. Ultimately, the adoption of effective treatments that do not needlessly expose patients and health-care systems to harm demands extensive international collaboration between academic groups, governments, and pharmaceutical companies.

Combination therapies for the treatment of HER2-positive breast cancer: current and future prospects.

INTRODUCTION: HER2-positive disease is an aggressive subtype of breast cancer that has been revolutionized by anti-HER2 directed therapies. Multiple drugs have been developed and are currently in clinical use, including trastuzumab, lapatinib, pertuzumab, T-DM1, and neratinib, alone or combined in 'dual HER2-blockade' regimens. Areas covered: A comprehensive literature review was performed regarding the current state and the future of combination regimens containing anti-HER2 agents, focusing on their efficacy, toxicity, and cost-effectiveness. Expert commentary: The combination of trastuzumab/pertuzumab is approved in all disease settings, while trastuzumab/neratinib is approved in the adjuvant setting and trastuzumab/lapatinib in metastatic disease. Meanwhile, as breast cancer biology and resistance mechanisms become clearer, combinations with drugs like PI3K/Akt/mTOR inhibitors, CDK4/6 inhibitors, anti-PD(L)1 antibodies, endocrine therapy, and new anti-HER2 agents (panHER and HER2 tyrosine kinase inhibitors, bispecific antibodies, anti-HER3 antibodies, and antibody-drug conjugates) are being extensively tested in clinical trials. More specific strategies for the 'triple-positive' (estrogen receptor-positive/HER2-positive) disease are also being explored. However, there is an urgent need for the development of predictive biomarkers for a better tailoring of anti-HER2 directed therapy. This is the only way to further improve clinical outcomes and quality of life and to decrease costs and toxicities of unnecessary treatments.

Ovarian Function Suppression in Premenopausal Women with Early-Stage Breast Cancer.

OPINION STATEMENT: Breast cancers arising in young women are biologically more aggressive, and most of these patients are candidates to receive aggressive treatments that include the use of chemotherapy. As most of these tumors express the hormone receptors (i.e., luminal disease), these patients are also candidates to adjuvant endocrine therapy. Chemotherapy-induced amenorrhea showed to be prognostic in young patients with luminal breast cancer. However, the role of ovarian function suppression (OFS) in addition to standard adjuvant treatments has been largely debated over the past years. Recently, several studies have provided important insights on the role of OFS. Currently, the use of tamoxifen alone without prior cytotoxic therapy can be considered a very effective treatment option in young patients with hormone receptor-positive breast cancer at low risk of relapse. On the other hand, for patients at higher risk of relapse as those who are candidates to (neo)adjuvant chemotherapy, OFS proved to be beneficial, and therefore luteinizing hormone-releasing hormone agonists (LHRHa) should be considered in addition to tamoxifen or aromatase inhibitors (AI). However, toxicity is considerable and patients should be actively engaged in decision-making. Finally, in young breast cancer patients who are candidates to (neo)adjuvant chemotherapy, loss of ovarian function and fertility may be a concern. Besides other techniques, recent results showed that temporary OFS with LHRHa during cytotoxic treatment can be considered a reliable strategy to preserve gonadal function and fertility. Despite the recent advances in the field, several gray zones remain unanswered: the role of OFS plus AI in women who remained premenopausal after 5 years of tamoxifen, the optimal extended approach in women treated with 5 years of OFS plus AI, and the role of temporary OFS with LHRHa during chemotherapy in the specific subgroup of patients with BRCA mutations and in women undergoing this strategy after prior embryo/oocyte cryopreservation.

Adjuvant trastuzumab: a 10-year overview of its benefit.

INTRODUCTION: Anti-HER2 targeted therapy is one of the key advances in the treatment of breast cancer that have occurred in the last 20 years. In the adjuvant setting, the use of trastuzumab has led to prolonged and sustained survival benefit with very little toxicity as also confirmed by the 10-year follow-up results from the pivotal trials. Despite the survival improvement, several key issues are not entirely resolved in this field. These issues have led to multiple research efforts in de-escalating or escalating the standard treatment with chemotherapy and 1 year of adjuvant trastuzumab. Areas covered: In this paper, we present an in depth overview on the state of the art on these key issues of refining decision-making in adjuvant anti-HER2 therapy. Expert commentary: Despite many important research efforts in the field, chemotherapy plus trastuzumab for a total duration of 1 year remains the standard of care. However, recent data showed that besides standard anthracycline- and taxane-based cytotoxic therapy, alternative chemotherapy regimens can now be proposed to patients with small tumors without nodal involvement and to women at high-risk of developing cardiotoxicity. Of note, besides HER2 itself, biomarkers predicting patients who may truly benefit from anti-HER2 agents are still lacking.

Twenty years of anti-HER2 therapy-associated cardiotoxicity.

Over the past 20 years, the prognosis of HER2-positive breast cancer has been transformed by the development of anti-HER2 targeted therapies. In early clinical trials of trastuzumab (ie, the first anti-HER2 agent to be developed) cardiotoxicity became a major concern. In the first published phase 3 trial of trastuzumab, 27% of patients receiving anthracyclines and trastuzumab experienced cardiac events and 16% suffered from severe congestive heart failure. In subsequent trials conducted in advanced and early settings, the incidence of cardiac events was reduced through changes in chemotherapy regimens, more strict patient selection and close cardiac assessment. However, cardiotoxicity remains a significant problem in clinical practice that is likely to increase as new agents are approved and exposure times increase through improved patients' survival. Though numerous trials have led to improved understanding of many aspects of anti-HER2 therapy-related cardiotoxicity, its underlying physiopathology mechanisms are not well understood. The purpose of this article is to provide an in-depth review on anti-HER2 therapy-related cardiotoxicity, including data on both trastuzumab and the recently developed anti-HER2 targeted agents.