Year Of Adjuvant Trastuzumab Research Articles

Efficacy and Safety Profile of Different Schedules of Adjuvant Trastuzumab Therapy among Patients with HER2-Positive Breast Cancer: Real-World Experience from a Tertiary Cancer Center in South India

One year of adjuvant trastuzumab is the standard of care for HER2-positive breast cancer. In low–middle income countries, delivery of 1-year trastuzumab is challenging due to significant financial burden. Evidence for shorter durations of adjuvant trastuzumab is gaining popularity in this regard. In this study, we compared the effectiveness and safety of 1 year versus shorter durations of adjuvant trastuzumab practiced in our center. In total, 312 patients were included in this analysis. The median age was 52 years. More than two-thirds of patients (67.6%) had stage 2 disease and majority were hormone-receptor-positive (62.5%). The median follow-up duration was 50 months. The 4-year disease-free survival was 97.3%. The 4-year disease-free survival for shorter durations of adjuvant trastuzumab was 98% compared with 96.7% in 1-year trastuzumab therapy group. In univariate analysis, stage at diagnosis was the only factor which had statistically significant association with disease-free survival. In multivariate analysis, none of the variables were found to be predictive of survival. Two patients (0.6%) had significant left ventricular ejection fraction decline.Shorter durations of adjuvant trastuzumab have comparable 4-year disease-free survival to standard 1-year therapy and is an alternative adjuvant treatment option for HER2-positive breast cancer patients in resource-limited settings.

Long-Term Outcomes of Adjuvant Trastuzumab for 9 Weeks or 1 Year for ERBB2-Positive Breast Cancer

The standard adjuvant treatment for patients with ERRB2-positive breast cancer is chemotherapy plus 1 year of trastuzumab. Shorter durations of trastuzumab administration improve cardiac safety, but more information is needed about their effect on survival. To compare survival outcomes after 9-week vs 1-year administration of trastuzumab with the same adjuvant chemotherapy. This post hoc secondary analysis of an open-label, multicenter, noninferiority-design randomized clinical trial included women aged 18 years or older with early ERBB2-positive, axillary node-negative or axillary node-positive breast cancer who were enrolled from January 3, 2008, to December 16, 2014, at 65 centers in 7 European countries. The current exploratory analysis was conducted after achieving the maximum attainable follow-up data when the last patient enrolled had completed the last scheduled visit in December 2022. Chemotherapy consisted of 3 cycles of docetaxel administered at 3-week intervals followed by 3 cycles of fluorouracil, epirubicin, and cyclophosphamide at 3-week intervals. Trastuzumab was administered in both groups for 9 weeks concomitantly with docetaxel. In the 9-week group, no further trastuzumab was administered after chemotherapy, whereas in the 1-year group, trastuzumab was continued after chemotherapy to complete 1 year of administration. The primary objective was disease-free survival (DFS). Distant DFS and OS were secondary objectives. Survival between groups was compared using the Kaplan-Meier method and log-rank test or univariable Cox proportional hazards regression. Among the 2174 women analyzed, median age was 56 years (IQR, 48-64 years). The median follow-up time was 8.1 years (IQR, 8.0-8.9 years); 357 DFS events and 176 deaths occurred. Trastuzumab for 9 weeks was associated with shorter DFS compared with trastuzumab for 1 year (hazard ratio [HR], 1.36; 90% CI, 1.14-1.62); 10-year DFS was 80.3% in the 1-year group vs 78.6% in the 9-week group. The 5-year and 10-year OS rates were comparable between the 9-week and 1-year groups (95.0% vs 95.9% and 89.1% vs 88.2%, respectively; HR for all time points, 1.20; 90% CI, 0.94-1.54). In multivariable analyses, 9-week treatment was associated with shorter DFS compared with 1-year treatment (HR for recurrence or death, 1.36; 95% CI, 1.10-1.68; P = .005), but there was no between-group difference in OS (HR, 1.22; 95% CI, 0.90-1.64; P = .20). Only 4 patients (0.2%) died of a cardiac cause. In this secondary analysis of a randomized clinical trial, 1-year vs 9-week adjuvant trastuzumab was associated with improved DFS among patients with ERRB2-positive breast cancer receiving chemotherapy, but there was no significant difference in OS between the groups. ClinicalTrials.gov Identifier: NCT00593697.

Abstract PO1-20-07: Valosin-containing protein (VCP)/p97: A novel breast cancer susceptibility gene?

Abstract Introduction: Mutations in the valosin-containing protein (VCP, also known as p97) gene are associated with autosomal dominant inclusion-body myopathy with early-onset Paget disease and frontotemporal dementia. VCP is an ATPase that subserves a variety of cellular functions, prominently, organelle biogenesis and ubiquitin-dependent protein degradation. Recently, VCP has also been shown to physically interact with BRCA1 and is postulated to orchestrate the response to DNA double-strand breaks, a critical molecular prelude to homologous recombination DNA repair. Moreover, VCP is also involved in the removal of trapped poly [ADP-ribose] polymerase 1 (PARP1) from chromatin and may play a key role in the response of tumor cells to PARP inhibitors. Whether VCP acts as a breast cancer predisposition gene is currently unknown. These observations raise speculation as to whether pathologic variation in VCP may predispose to breast cancer. Case Description: A 45-year-old female presented with early-age, locally advanced invasive ductal carcinoma, grade 2, ER < 1%, PR 10%, HER2 IHC 3+, FISH ratio 5.4. The patient completed 6 cycles of neoadjuvant PTH and was surgically downstaged to ypT1bN1a at the time of her left mastectomy. She declined adjuvant radiation. She received 1 dose of trastuzumab emtansine which was discontinued due to intolerance and transitioned to complete 1 year of adjuvant trastuzumab and pertuzumab. Her medical history is significant for inclusion body myopathy with Paget disease of bone and/or frontotemporal dementia, which was diagnosed at age 36 after presenting with proximal muscle weakness. Bone scan was consistent with Paget’s disease and neurocognitive testing did not identify any abnormalities. Diagnosis was confirmed via whole genome germline sequencing which identified a pathogenic variant in VCP [c.463C >G (p.Arg155Gly)]. Germline resequencing of 155 known cancer predisposition genes did not identify any pathogenic variants. Whole exome genomic analysis of the patient’s breast cancer revealed an elevated homologous recombination score ( > 42), consistent with molecularly important role of VCP in homologous recombination breast cancer DNA repair. The patient’s family history is significant for muscular dystrophy in multiple family members on her paternal side, each of whom was deceased prior to age 60. Her paternal half-sister has both inclusion body myopathy and breast cancer, and her paternal cousin was diagnosed with breast cancer at age 46 (unknown genetic testing for each). No history of cancer on her maternal side. Discussion: This case raises the intriguing question of whether the VCP gene represents a heretofore unrecognized breast cancer predisposition gene. Further investigation into the role of VCP in tumorigenesis is warranted, and additional population studies are necessary to confirm VCP’s role in breast cancer predisposition. Given that cancers with homologous recombination deficiencies benefit from PARP inhibitors and VCP is involved in the function of the PARP1 protein, patients with mutations in the VCP gene may benefit from PARP inhibition. Citation Format: Alexis LeVee, Duveen Sturgeon, Joanne Mortimer, Kevin McDonnell. Valosin-containing protein (VCP)/p97: A novel breast cancer susceptibility gene? [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-20-07.

Nine-Week Versus One-Year Trastuzumab for Early Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer: 10-Year Update of the ShortHER Phase III Randomized Trial.

Clinical trials frequently include multiple end points that mature at different times. The initial report, typically based on the primary end point, may be published when key planned coprimary or secondary analyses are not yet available. Clinical trial updates provide an opportunity to disseminate additional results from studies, published in JCO or elsewhere, for which the primary end point has already been reported.We present the final analysis of the phase III noninferiority, randomized ShortHER trial comparing 9 weeks versus 1 year of adjuvant trastuzumab with chemotherapy in patients with human epidermal growth factor receptor 2-positive (HER2+) early breast cancer (BC). Women with HER2+ BC were randomly assigned to anthracycline-taxane combinations plus 1-year trastuzumab (arm A, long) or 9-week trastuzumab (arm B, short). Here, we report the second coprimary end point overall survival (OS), updated disease-free survival (DFS), and outcomes according to hormone receptor status, age, and nodal status. At a median follow-up of 9 years, 10-year DFS is 77% versus 78% in the long versus short arm, respectively. Ten-year OS is 89% versus 88% in the long versus short arm, respectively. 10-year DFS rates in the long versus short arm according to nodal status are N0 81% versus 85%; N1-3 77% versus 79%; and N4+ 63% versus 53%. Ten-year OS rates in long versus short arm according to nodal status are N0 89% versus 95%%; N1-3 92% versus 89%; and N4+ 84% versus 64%. The updated analysis of the ShortHER trial shows that 1-year trastuzumab is the standard treatment for patients with HER2+ early BC as noninferiority cannot be claimed. However, numerically, the differences for the patients at low or intermediate risk (N0/N1-3) is negligible, while patients with N4+ have a clear benefit with 1-year trastuzumab.

Abstract P2-01-04: Real-world clinical outcomes of patients with stage I HER2-positive breast cancer treated with adjuvant paclitaxel and trastuzumab

Abstract Background: One year of adjuvant trastuzumab with 12 cycles of weekly paclitaxel represents the standard of care for patients with pathological tumor size ≤2cm, node-negative, HER2-positive early breast cancer. Data supporting this indication derive from a single-arm, phase II trial that enrolled 410 patients in the United States only, where the 3 years invasive disease-free survival (DFS) rate was 98.7% (95% CI 97.6-99.8). Therefore, real-world data regarding the clinical outcomes of these patients are needed to confirm the efficacy and safety of this adjuvant anthracycline-free regimen in this population. Methods: We conducted a retrospective, observational, multicentric study to investigate survival outcomes of patients with stage I HER2-positive early breast cancer treated with adjuvant paclitaxel and trastuzumab in seven selected sites in two countries (Belgium and Italy). Eligible patients were men and women with early breast cancer of pathological tumor size between 5 and 20 mm, node-negative (N0 or N1mic), and treated with weekly adjuvant paclitaxel for 12 weeks and trastuzumab (6 mg/kg every 3 weeks administration for 1 year). Patients with a history of previous cancers were not included. The primary endpoint was disease-free survival (DFS) at 3 years from diagnosis. Thus, an optimal follow-up of 3 years from surgery was required. Baseline clinico-pathological characteristics, treatment data, disease recurrences and survival status were extracted from medical records. Survival analysis was performed using log-rank regression test. Results: Overall, 240 patients who received their adjuvant treatment between January 2014 and December 2018 were included in the analysis. The median age was 59.5 years (IQR 50.0-66.9), and 69.6% of patients were post-menopausal at the time of diagnosis. Seventy (31.8%) patients had hypertension and 20 (8.3%) had other cardiac comorbidities. Ductal carcinoma was the most represented histological type (86.3%). The median tumor size was 12mm (IQR 9-15), only seven (2.9%) patients had N1miC, and the majority of tumors (85.0%) were ER-positive. Breast-conserving surgery was performed in 80.8% of patients and 78.2% of patients had adjuvant radiotherapy. The median number of administrated cycles of weekly paclitaxel was 12 (range 1-12) and for trastuzumab 18 (range 1-19). Only one patient stopped trastuzumab prematurely because of safety reason. Aromatase inhibitors were the most frequently administered endocrine therapy (75.7% of patients with ER-positive disease). With a median follow-up of 4.7 (IQR 3.6-5.6) years, we observed a 3-year DFS rate of 98.8% (95% CI 96.2-99.6), with only three disease recurrences (one local and two distant) and four deaths (none of which was breast cancer related) during the duration of the follow-up. Conclusions: In this real-world clinical outcome of patients with stage I HER2-positive breast cancer treated with adjuvant trastuzumab and paclitaxel appeared excellent, with a 1.2% rate of recurrence at 3 years. Our data support the efficacy of an anthracycline-free regimen in this population. A longer follow-up will provide more mature data on overall survival and late relapses, especially in the ER-positive subgroup of patients. Citation Format: Veronique Debien, Elisa Agostinetto, Marianna Sirico, Flavia Jacobs, Chiara Molinelli, Michel Moreau, Marianne Paesmans, Ugo De Giorgi, Armando Santoro, Donatienne Taylor, François P. Duhoux, Andrea Botticelli, Giacomo Barchiesi, Matteo Lambertini, Evandro de Azambuja, Martine Piccart. Real-world clinical outcomes of patients with stage I HER2-positive breast cancer treated with adjuvant paclitaxel and trastuzumab [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-01-04.

Outcomes of patients with small and node-negative HER2-positive early breast cancer treated with adjuvant chemotherapy and anti-HER2 therapy-a sub-analysis of the ALTTO study.

Patients with small node-negative HER2-positive breast cancer are commonly treated with paclitaxel and 1 year of adjuvant trastuzumab. We performed a sub-analysis of the ALTTO trial to explore the long-term outcomes of patients with small node-negative tumours. The ALTTO trial randomised 8381 patients with early HER2-positive BC treated with adjuvant chemotherapy (anthracycline/taxane- or taxane/carboplatin-based), to trastuzumab (T), lapatinib (L), their sequence (T → L) or their combination (L + T). Patients with tumours ≤3 cm and node-negative were included in this sub-analysis. A total of 2821 patients were analysed (median follow-up of 7 years). The median age was 52 years, and most patients had tumours ≤2 cm (64.3%). The 7-year disease-free survival (DFS) was 88.1% (95% CI: 86.7-89.3%). DFS was similar for arms T, T + L and T⟶L and significantly lower for arm L (stratified log-rank P = 0.031). The 7-year overall survival rate was 95.9% (95% CI: [95.0-96.6%) and the 7-year time-to-distant recurrence was 93.4% (95% CI: 92.3-94.4%). With most patients treated with anthracycline-based regimens, ALTTO shows that patients with small tumours treated with trastuzumab and concomitant chemotherapy have excellent long-term outcomes, similar to those of the APT trial. Clinicaltrials.gov identifier NCT00490139.

Type of endocrine therapy and DFS in patients with early HER2+/HR+ BC: Analysis from the phase III randomized ShortHER trial.

547 Background: Optimal adjuvant endocrine therapy for HER2+/HR+ patients treated with chemotherapy and trastuzumab is still unclear. We evaluated the impact of the type of endocrine therapy on DFS in patients with HER2+/HR+ breast cancer enrolled in the phase III ShortHER trial. Methods: The Short-HER study randomized 1254 patients with HER2+ early breast cancer to receive 9 weeks vs 1 year of adjuvant trastuzumab combined with anthracycline-taxane chemotherapy. The type of adjuvant endocrine was collected every 6 months during the first 5 years of follow-up and was classified as: aromatase inhibitor (AI), tamoxifen and aromatase inhibitor (TAM-AI, in case of both drugs were administered for at least 1 year each), or tamoxifen (TAM). For premenopausal patients, the use of GnRH analogue was also collected. DFS was calculated from randomization to disease recurrence (locoregional or metastatic), second primary invasive cancer, or death. Results: 853 patients with HR+ BC (ER and/or PgR >10%) were included: 60% postmenopausal, 40% premenopausal. The pattern of endocrine therapy was: 55% AI, 22% TAM, 15% TAM-AI (8% missing data). Among premenopausal patients, 51% received GnRH. At a median follow up of 8.7 years (IQR 7.6-9.0), patients who received AI had a significantly better DFS as compared to patients who received TAM or TAM-AI: 7-yr DFS 87.3% vs 81.7%, log-rank P=0.017 (HR 1.46, 95%CI 1.05-2.03). In multivariate analysis including menopausal status, stage, and treatment arm, the type of endocrine therapy maintained a significant association with DFS (Table). In the subgroup of premenopausal patients, the use of GnRH was associated with numerically improved DFS: 86.6% vs 81.6%, log-rank P=0.168 (HR=0.70, 95%CI 0.43-1.16). Conclusions: In this post-hoc analysis of the ShortHER trial, adjuvant treatment with aromatase inhibitor was independently associated with improved DFS. Subgroup analysis in premenopausal patients suggests potential benefit with ovarian suppression. Clinical trial information: NCT00629278. [Table: see text]

41O Nine weeks vs 1-year adjuvant trastuzumab: Long term outcomes of the ShortHER randomised trial

The ShortHER trial randomised 1254 patients with HER2+ early breast cancer to chemotherapy plus 9 weeks vs 1 year adjuvant trastuzumab. The study was designed as a non inferiority trial with a DFS hazard ratio (HR) < 1.29 as the non inferiority margin. At the event driven analysis, the HR for DFS was 1.13 (90% CI 0.89-1.42) therefore non inferiority could not be claimed (P Conte et al, Ann Oncol 29:2328-2333). Here we report the overall survival (co-primary end point of the study) and the updated DFS curves according to risk categories of long vs short treatment arms.

PIK3CA Mutation in the ShortHER Randomized Adjuvant Trial for Patients with Early HER2+ Breast Cancer: Association with Prognosis and Integration with PAM50 Subtype.

We explored the prognostic effect of PIK3CA mutation in HER2+ patients enrolled in the ShortHER trial. The ShortHER trial randomized 1,253 patients with HER2+ breast cancer to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. PIK3CA hotspot mutations in exon 9 and 20 were analyzed by pyrosequencing. Expression of 60 genes, including PAM50 genes was measured using the nCounter platform. A mutation of the PIK3CA gene was detected in 21.7% of the 803 genotyped tumors. At a median follow-up of 7.7 years, 5-year disease-free survival (DFS) rates were 90.6% for PIK3CA mutated and 86.2% for PIK3CA wild-type tumors [HR, 0.84; 95% confidence interval (CI), 0.56-1.27; P = 0.417]. PIK3CA mutation showed a favorable prognostic impact in the PAM50 HER2-enriched subtype (n = 232): 5-year DFS 91.8% versus 76.1% (log-rank P = 0.049; HR, 0.46; 95% CI, 0.21-1.02). HER2-enriched/PIK3CA mutated versus wild-type tumors showed numerically higher tumor-infiltrating lymphocytes (TIL) and significant upregulation of immune-related genes (including CD8A, CD274, PDCD1, and MYBL2, a proliferation gene involved in immune processes). High TILs as well as the upregulation of PDCD1 and MYBL2 were associated with a significant DFS improvement within the HER2-enriched subtype (HR, 0.82; 95% CI, 0.68-0.99; P = 0.039 for 10% TILs increment; HR, 0.81; 95% CI, 0.65-0.99; P = 0.049 for PDCD1 expression; HR, 0.72; 95% CI, 0.53-0.99; P = 0.042 for MYBL2 expression). PIK3CA mutation showed no prognostic impact in the ShortHER trial. Within the HER2-enriched molecular subtype, patients with PIK3CA mutated tumors showed better DFS versus PIK3CA wild-type, which may be partly explained by upregulation of immune-related genes.

Do all patients with HER2 positive breast cancer require one year of adjuvant trastuzumab? A systematic review and meta-analysis

One year of adjuvant trastuzumab is considered the standard treatment for patients with HER2 positive breast cancer. However, a shorter duration of trastuzumab may be associated with reduced costs and side effects. Results from randomized trials with diverse non-inferiority margins comparing one year to a shorter duration of adjuvant trastuzumab are not consistent and have not been systematically reviewed using a non-inferiority meta-analysis approach.We conducted a systematic review and meta-analysis of randomized trials to assess whether a shorter duration of adjuvant trastuzumab was non-inferior to one year of treatment or not. The non-inferiority margin for the meta-analysis was pre-defined as the median of the margins of all the trials included. Data of 11,376 patients from 5 trials were analyzed. Non-inferiority margins in included studies varied from 1.15 to 1.53 with median of 1.29 for HR of DFS. A shorter duration of trastuzumab was non-inferior to one year of therapy for DFS (HR 1.13, 95%CI 1.03–1.24) but inconclusive for OS (HR 1.14, 95%CI 1.00–1.30). In a subgroup analysis for DFS outcome, shorter therapy was non-inferior in patients with ER positive disease (HR 1.10, 95%CI 0.95–1.28) and those with sequential therapy (HR 0.97, 95%CI 0.75–1.27) and when the duration of treatment was 6 months (HR 1.09, 95%CI 0.98–1.22). Although a shorter duration of adjuvant trastuzumab was non-inferior to one year of therapy for DFS in patients with HER2 positive breast cancer based on our HR margin of 1.29, any benefit of a shorter duration comes at a loss of efficacy with an increase in absolute risk up to 3.9% for 5 year DFS. Whether the potential increased risk is clinically acceptable for the benefits of a shorter duration remains debatable.

Evaluation of 1-Year vs Shorter Durations of Adjuvant Trastuzumab Among Patients With Early Breast Cancer

The optimum duration of adjuvant trastuzumab among patients with early breast cancer is uncertain but of great therapeutic relevance. To compare shorter durations with 1 year of adjuvant trastuzumab for patients with early breast cancer. PubMed, Embase, Cochrane Central Register of Clinical Trials, and conference proceedings were searched from January 1, 2005, to June 30, 2019, for relevant randomized clinical trials (RCTs). To be eligible, the trial had to be randomized, compare a shorter duration with 1 year of trastuzumab as adjuvant treatment, and include patients with early breast cancer. Individual patient data for disease-free survival (DFS) and overall survival (OS) were extracted from published survival curves of included RCTs; DFS and OS curves for each trial and the combined population were reconstructed. The DFS and OS hazard ratios (HRs) were estimated from the reconstructed survival curves as well as published estimates. The HR for DFS was used to test noninferiority using the median noninferiority margin of eligible RCTs. This study followed Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. The primary outcome was DFS; OS and cardiac toxic effects were secondary outcomes. There were 6 eligible RCTs with a median DFS noninferiority margin of 1.3 (range, 1.15-1.53), 5 of which had extractable individual patient data for 11 376 patients, 1659 DFS events, and 871 deaths. For shorter duration vs 1 year of trastuzumab, the 5-year DFS was 85.42% (95% CI, 84.41%-86.38%) vs 87.12% (95% CI, 86.15%-88.02%) (HR, 1.14; 95% CI, 1.03-1.25, 1-sided P for noninferiority = .004), and OS was 92.39% (95% CI, 91.61%-93.10%) vs 93.46% (95% CI, 92.73%-94.13%) (HR, 1.17; 95% CI, 1.02-1.33). Using trial-level published estimates from 6 RCTs, including 11 603 patients, 1760 DFS events, and 930 deaths, the HR for DFS was 1.15 (95% CI, 1.04-1.26; 1-sided P for noninferiority = .002) and, for OS, 1.17 (95% CI, 1.03-1.33). There was significantly less risk of congestive heart failure with shorter-duration trastuzumab (relative risk, 0.53; 95% CI, 0.38-0.74). In this study, a shorter duration of adjuvant trastuzumab was noninferior to its 1-year administration and resulted in lower rates of cardiac toxic effects. These results suggest that a shorter duration may be the preferred option for patients with low-risk disease or a predisposition to cardiac toxic effects.

Impact of Stopping Trastuzumab in Early Breast Cancer: APopulation-Based Study in Ontario, Canada.

Adjuvant trastuzumab for early-stage (I-III) HER2-positive breast cancer (BC) has led to statistically significant improvement in cancer outcomes but carries a risk of cardiotoxicity. Trastuzumab is discontinued early in many patients for asymptomatic changes in left ventricular ejection fraction. We evaluated the impact of early discontinuation of trastuzumab on cancer outcomes. We conducted a retrospective population-based cohort study of early BC patients treated with adjuvant trastuzumab in Ontario, Canada, 2007-2016. Four groups were analyzed: group A was full treatment, 17-18 cycles trastuzumab; group B was cardiac event (CE) within treatment period; group C was ≤16 cycles, no CEs, stopped within 30 days from last cardiac imaging; and group D was ≤16 cycles, no CEs, stopped more than 30 days from cardiac imaging. Primary outcome was disease-free survival (DFS); secondary outcomes were: overall survival, cancer-specific mortality, and cardiovascular mortality. Sensitivity analyses were performed 14 months after cycle 1 trastuzumab to control for early relapse. A total of 5547 patients met the inclusion criteria: group A = 3921, group B = 309, group C = 362, and group D = 955. The 5-year DFS was 94.1% in group A, 80.1% in group B, 81.4% in group C, and 82.4% in group D. Using a Cox model, the hazard ratio for 5-year DFS was 3.15 (95% confidence interval [CI] = 2.13 to 4.65) for group B, 1.94 (95% CI = 1.30 to 2.89) for group C, and 1.92 (95% CI = 1.46 to 2.53) for group D. Overall, 26 patients (0.5%) died of cardiac causes. BC patients in Ontario who did not complete adjuvant trastuzumab had a statistically significantly higher risk of BC relapse and death and low incidence of cardiac death. These findings support 1 year of adjuvant trastuzumab in early-stage BC.

Effect at One Year of Adjuvant Trastuzumab for HER2+ Breast Cancer Combined with Radiation or an Anthracycline on Left Ventricular Ejection Fraction

To determine the impact of radiation therapy (XRT) in addition to trastuzumab (TZB) adjuvant chemotherapy for HER2+ breast cancer on left ventricular systolic function, we assessed demographics, oncologic treatment history including XRT exposure, and serial measurements of left ventricular ejection fraction (LVEF) in 135 consecutively identified women receiving TZB for treatment of adjuvant breast cancer. Longitudinal mixed effects models were fit to identify baseline to treatment changes in LVEF among those receiving TZB with or without concomitant anthracycline or XRT. Women averaged 53 ± 3 years in age, 77% were white, 62% patients had 1 or more cardiovascular risk factors at baseline, and mean duration of TZB was 11 ± 5 months. Seventy-seven women were treated with XRT and received between 4000 and 5500 cGy of radiation. The LVEF declined by an average of 3.4% after 1 year for those in the study. Relative to baseline upon completion of adjuvant TZB, LVEF remained reduced for those receiving anthracycline with or without XRT (p=0.002 for both), or XRT alone (p=0.002), but not in those without these therapies. Amongst patients treated only with XRT and TZB, LVEF declined 3.1% on average in those with left-sided disease and 6.9% on average in those with right-sided disease (p= 0.06, p= 0.008 respectively). Among women receiving TZB for adjuvant treatment of HER-2 positive breast cancer, the administration of XRT, anthracycline, or the combination of the 2 is associated with a persistent post-treatment as opposed to a temporary treatment related decline in LVEF.

Cost-effectiveness of six months versus 1-year adjuvant trastuzumab in HER2 positive early breast cancer in Egypt

Introduction: Breast cancer is the most prevalent cancer among women in Egypt. Trastuzumab is administered with chemotherapy for patients with HER2-positive advanced breast cancer (HER2 + ve ABC) in the metastatic and adjuvant settings resulting in improved treatment outcomes, and long-term follow-up. Some studies have evaluated whether equivalent outcomes can be achieved with reduced treatment duration. This study evaluates the cost-effectiveness of 6-month versus 1-year trastuzumab treatments from payer perspective over a 10 year time horizon.Methods: A half-cycle corrected Markov model was developed with five mutually exclusive health states; patient with HER2 +ve ABC, disease-free survival (DFS), local or regional relapse, metastatic relapse, and death. A cycle length of 6 months was applied, direct medical costs including cost of treatments, day-care, surgery, health states and follow-up visits were collected, and indirect costs such as lost productivity were not estimated. The transition probabilities and utilities were extracted from published literature, and deterministic sensitivity analyses were conducted.Results: Among the HER2 +ve ABC patient population in Egypt, the total QALYs of the 6-month trastuzumab were estimated to be 2.99 compared with 2.93 for the 1-year trastuzumab which resulted in a difference of 0.06 QALYs. The total costs were EGP 271,647 ($106,947) and EGP 381,248 ($150,097), respectively. These costs yielded an ICER of –109,600 EGP/QALY (–43,149 $/QALY) for the 6-month trastuzumab. The 6-month trastuzumab is a dominant strategy when compared to 1-year trastuzumab, resulting in improved effectiveness at a reduced cost. All analyses results confirmed the dominance of 6-month trastuzumab and our model robustness.Conclusions: This study concluded that 6-month trastuzumab is a cost-effective option when compared to 1-year trastuzumab in patients with HER2 +ve ABC in Egypt. Our findings provide health care decision makers with additional insights to best allocate available resources concurrently with the improvement of the Egyptian patient’s outcomes.

Updated Bayesian Network Meta-Analysis of Adjuvant Targeted Treatment Regimens for Early Human Epidermal Growth Factor Receptor-2 Positive Breast Cancer.

PurposeCombining targeted agents with adjuvant chemotherapy prolongs survival in human epidermal growth factor receptor 2 (HER2)-positive breast cancer patients, but also increases the risk of adverse effects. The updated results of 3 randomized controlled trials (RCTs) were reported in 2019. Given the lack of adequate head-to-head pairwise assessment for anti-HER2 agents, network meta-analysis facilitates obtaining more precise inference for evidence-based therapy.MethodsRCTs comparing at least 2 anti-HER2 regimens in an adjuvant setting for HER2-positive early-stage breast cancer (EBC) were included. Hazard ratios for overall survival (OS) and disease free survival (DFS), with respective 95% confidence intervals were pooled for assessment of efficacy. A Bayesian statistical model was used, and odds ratios (ORs) for adverse events (AEs) were used to pool effect sizes.ResultsWe demonstrated that 1-year trastuzumab plus chemotherapy had increased efficacy compared to shorter or longer treatment duration. The OR of cardiac events gradually increased from 6 months to 1 and 2-year trastuzumab arms, relative to chemotherapy only. Compared to trastuzumab plus chemotherapy, dual HER2-targeting therapies increased DFS, especially for hormone receptor negative patients. Dual anti-HER2 blockade regimens revealed an increased probability of gastrointestinal reactions. As a second agent, pertuzumab showed significantly higher DFS and OS.ConclusionWe conclude that 1-year adjuvant trastuzumab should remain as the standard treatment for HER2-positive EBC patients, as it has greater efficacy and a manageable proportion of AEs. Clinical efficacy can be increased for hormone receptor-negative tumors by including a second HER2-targeted agent to the treatment regimen. For hormone receptor-positive cases with basal disease, it is acceptable to reduce the risk of cardiotoxicity by shortening the duration of trastuzumab.

Validation of the AJCC prognostic stage for HER2-positive breast cancer in the ShortHER trial

BackgroundThe 8th edition of the American Joint Committee on Cancer (AJCC) staging has introduced prognostic stage based on anatomic stage combined with biologic factors. We aimed to validate the prognostic stage in HER2-positive breast cancer patients enrolled in the ShortHER trial.MethodsThe ShortHER trial randomized 1253 HER2-positive patients to 9 weeks or 1 year of adjuvant trastuzumab combined with chemotherapy. Patients were classified according to the anatomic and the prognostic stage. Distant disease-free survival (DDFS) was calculated from randomization to distant relapse or death.ResultsA total of 1244 patients were included. Compared to anatomic stage, the prognostic stage downstaged 41.6% (n = 517) of patients to a more favorable stage category.Five-year DDFS based on anatomic stage was as follows: IA 96.6%, IB 94.1%, IIA 92.4%, IIB 87.3%, IIIA 81.3%, IIIC 70.5% (P < 0.001). Five-year DDFS according to prognostic stage was as follows: IA 95.7%, IB 91.4%, IIA 86.9%, IIB 85.0%, IIIA 77.6%, IIIC 67.7% (P < 0.001). The C index was similar (0.69209 and 0.69249, P = 0.975).Within anatomic stage I, the outcome was similar for patients treated with 9 weeks or 1 year trastuzumab (5-year DDFS 96.2% and 96.6%, P = 0.856). Within prognostic stage I, the outcome was numerically worse for patients treated with 9 weeks trastuzumab (5-year DDFS 93.7% and 96.3%, P = 0.080).ConclusionsThe prognostic stage downstaged 41.6% of patients, while maintaining a similar prognostic performance as the anatomic stage. The prognostic stage is valuable in counseling patients and may serve as reference for a clinical trial design. Our data do not support prognostic stage as guidance to de-escalate treatment.Trial registrationEUDRACT number: 2007-004326-25; NCI ClinicalTrials.gov number: NCT00629278.

Adjuvant Short-Course Trastuzumab in Breast Cancer

The standard duration of adjuvant trastuzumab is 1 year. But the decision to use for 1 year was chosen arbitrarily in clinical trials. Many patients from developing countries like India cannot afford 1 year of adjuvant trastuzumab. We retrospectively analysed 70 patients with HER2-positive breast cancer, who received short-course trastuzumab, and compared them with a matched historical cohort (n = 65) of HER2-positive breast cancer patients who did not receive trastuzumab. The 1-year DFS and OS of patients who received short-course trastuzumab were 91% and 96%, respectively. This cohort was matched for age, stage and menopausal status with a historical cohort (N = 65) of HER2-positive breast cancer who did not receive trastuzumab. The 1-year DFS (94 vs 71%, p = 0.045) and 1-year OS (94 vs 80%, p = 0.006) were superior for those who received short-course trastuzumab. Adjuvant short-course trastuzumab (weekly for 9 weeks) improved survival in HER2-positive breast cancer as compared to the historical cohort without trastuzumab.

Do all patients with HER2-positive breast cancer require one year of adjuvant trastuzumab?: A systematic review and meta-analysis.

522 Background: One year of adjuvant trastuzumab (T) remains the standard treatment for patients with HER2 positive breast cancer. Results from randomized trials with diverse non-inferiority margins comparing one year to a shorter duration of adjuvant T were not consistent, particularly with the PERSEPHONE and the final PHARE and Short-HER trials’ results. Our objective was to conduct a systematic review and meta-analysis of randomized trials in patients with HER2 positive breast cancer to assess whether a shorter duration of adjuvant T was non-inferior to one year of treatment. Methods: PubMed, EMBASE and The Cochrane Library were searched for eligible randomized trials. Hazard ratios (HR) for disease free and overall survival (DFS, OS) were weighted using generic inverse variance and pooled in a meta-analysis using random-effects models. The median of non-inferiority margins derived from each trial was calculated to set a non-inferiority margin of 1.29 for the pooled analysis. Subgroup analyses compared survival outcomes by estrogen receptor (ER) status, nodal status, length and timing of trastuzumab treatment. Results: Data of 11,376 patients from 5 trials were analyzed. A shorter duration of T was non-inferior to one year of therapy for DFS (HR 1.13, 95%CI 1.03-1.24) but worse for OS (HR 1.16, 95%CI 1.01-1.32). In addition, the non-inferiority for DFS was met for patients with ER positive disease (HR 1.1, 95%CI 0.95-1.28) and patients treated with 6 months (HR 1.09, 95%CI 0.98-1.22) or sequential T (HR 0.97, 95%CI 0.75-1.27). Conversely, the non-inferiority for DFS was not met for patients with ER negative disease (HR 1.22, 95%CI 1.06-1.41), patients treated with 9 weeks (HR 1.26, 95%CI 1.02-1.55) or concomitant T (HR 1.25, 95%CI 1.07-1.45) and patients with node negative (HR 1.12, 95% 0.93-1.35) or positive (HR 1.16, 95%CI 0.99-1.36) disease. Conclusions: Within the limitations of the available data and the different non-inferiority margins used in randomized trials, a shorter duration of adjuvant T is non-inferior to one year of therapy for DFS in patients with HER2 positive breast cancer, particularly in patients with ER positive disease. Further trials with appropriately chosen non-inferiority margins are needed to confirm the optimal duration of T in patients with low-risk disease.

Tailored dose-dense chemotherapy in combination with trastuzumab as adjuvant therapy for HER2-positive breast cancer: A secondary analysis of the phase III PANTHER trial.

553 Background: Dose-dense (DD) adjuvant chemotherapy improves outcomes in early breast cancer (BC). However, there are no data to inform on the combination of DD chemotherapy with trastuzumab for patients with HER2-positive disease. Methods: This is a protocol predefined secondary analysis of the randomized phase 3 PANTER 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/cyclophosphamide (4 cycles) followed by 4 cycles of docetaxel (tDD EC/D) or standard 3-weekly 5-fluorouracil/E/C (3 cycles) and D (3 cycles); Patients with HER2-positive disease received 1 year of adjuvant trastuzumab. In addition, HER2-positive and an equal number of matched for age, treatment group and institution, HER2-negative patients that were enrolled in Swedish sites were enrolled in a predefined study of cardiac safety and underwent echocardiography or MUGA and electrocardiography at baseline and at four and six years of follow-up. The primary endpoint was BC relapse-free survival (BCRFS). Results: There were 342 HER2-positive patients; 335 received at least one dose of trastuzumab, while 29 patients discontinued trastuzumab prematurely. BCRFS was not statistically significantly in favor of tDD EC/D (HR = 0.68, 95% CI 0.37 – 1.27, P= 0.231). Cardiac outcomes after four and six years of follow-up did not differ significantly between HER2-positive and HER2-negative patients, nor between tDD and standard treatment. Conclusions: To our knowledge, these are the only data on combining DD adjuvant chemotherapy and trastuzumab in BC. The combination decreased the risk for BC relapse by 32% compared to standard treatment, a statistically non-significant difference. Its efficacy and safety merit further evaluation as part of both escalation and de-escalation strategies. Clinical trial information: NCT00798070.

De-escalating adjuvant trastuzumab in human epidermal growth factor receptor 2 (HER2)-positive early-stage breast cancer: A systemic review and meta-analysis.

524 Background: One year of adjuvant trastuzumab in combination with chemotherapy is the standard of care in early-stage HER2 positive breast cancer. Existing data on shortening trastuzumab treatment show conflicting results. Methods: A search of PubMed and conferences identified randomized trials that compared abbreviated trastuzumab therapy to one year of treatment in early-stage HER2 positive breast cancer. Hazard ratios (HRs) and 95% confidence intervals (CI) were extracted for disease free survival (DFS) and overall survival (OS). Data on the number of DFS and distant relapse events were also collected as were the number of patients at risk in each group. Subgroup analyses evaluated the effect of nodal involvement, estrogen receptor (ER) expression and the duration of abbreviated trastuzumab (9-12 weeks versus 6 months). Odds ratios (ORs) and 95% CI were computed for pre-specified cardiotoxicity events including cardiac dysfunction and congestive heart failure (CHF). Results: Analysis included 6 trials comprising 11603 patients. In most studies adjuvant chemotherapy included anthracyclines and taxanes. Shorter trastuzumab treatment was associated with worse DFS (HR = 1.14, 95% CI 1.05-1.25, p = 0.002) and OS (HR = 1.15, 95% CI 1.02-1.29. p = 0.02). The effect on DFS was not influenced by ER status (p for the subgroup difference = 0.23), nodal involvement (p = 0.44) or the different duration of trastuzumab in the experimental arm (p = 0.08). In absolute terms, after an estimated median follow-up of 71 months, shorter treatment with trastuzumab was associated with an absolute increase in DFS events of 2.3%. Shorter trastuzumab treatment was associated with lower odds of cardiac dysfunction (OR = 0.67, 95% CI 0.55-0.81, p &lt; 0.001) and CHF (OR = 0.66, 95% CI 0.50-0.86, p = 0.003). Conclusions: Compared to one year, shorter duration of adjuvant trastuzumab is associated with significantly worse DFS and OS, despite favorable cardiotoxicity profile. One year of trastuzumab should remain the standard adjuvant treatment in early-stage HER2 positive breast cancer with appropriate cardiac monitoring.