Pharmacokinetic (PK) analyses in CSF and plasma from TBCRC049, an ongoing trial to assess the safety and efficacy of the combination of tucatinib, trastuzumab and capecitabine for the treatment of leptomeningeal metastasis (LM) in HER2 positive breast cancer.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1044-1044
Author(s):  
Erica Michelle Stringer-Reasor ◽  
Barbara Jane O'Brien ◽  
Ariel Topletz-Erickson ◽  
Jason B White ◽  
Mina Lobbous ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Kinase Inhibitor ◽  
Plasma Concentrations ◽  
Clinical Signs ◽  
Leptomeningeal Metastasis ◽  
Newly Diagnosed ◽  
Her2 Positive ◽  
Safety And Efficacy ◽  
Her2 Breast Cancer ◽  
Metastatic Setting

1044 Background: Tucatinib is a potent and highly selective HER2-targeted tyrosine kinase inhibitor approved for use in combination with trastuzumab and capecitabine for patients with metastatic HER2+ breast cancer (MBC) who have received ≥1 prior HER2-based regimen in the metastatic setting, including patients with brain metastases (BM). TBCRC049 (NCT03501979) is an investigator-initiated phase 2 single-arm study currently enrolling to evaluate the safety and efficacy of tucatinib, trastuzumab and capecitabine in HER2+ BC with newly diagnosed LM. Here, we report the pre-specified pharmacokinetic (PK) analysis for the first 15 patients to determine bioavailability of tucatinib and its predominant metabolite, ONT-993, in the CSF. Methods: Eligible patients included adults with HER2+ MBC, KPS > 50, and newly diagnosed, untreated LM (defined as positive CSF cytology and/or radiographic evidence of LM, plus clinical signs/symptoms). Patients with treated or concurrent/new BM were allowed. The primary endpoint is overall survival with an accrual goal of 30 pts. Parallel PK samples were collected in plasma and CSF via Ommaya reservoir on day 1 of cycles 1 and 2 at 0h (baseline), 2-3h, 5-7h and 24h (optional) following initiation of tucatinib 300 mg BID. Tucatinib and ONT-993 were quantified in plasma (n=15) and CSF (n=13) using validated liquid chromatography-mass spectrometry methods. Results: Tucatinib and ONT-993 plasma concentrations were consistent with previous studies and exhibited high interindividual variability. Tucatinib and ONT-993 were detectable in the CSF within 2 hours post tucatinib administration; concentrations ranged from 0.57 to 25 ng/mL for tucatinib (IC50 for tucatinib against HER2 is 3.3 ng/mL) and 0.28 to 4.7 ng/mL for ONT-993. Tucatinib concentrations in the CSF per timepoint were in a similar range to unbound plasma (plasmaub) tucatinib. CSF to plasmaub ratios were generally consistent over time; the steady-state (cycle 2) median tucatinib CSF to plasmaub ratio was 0.83 (0.19 to 2.1). ONT-993 CSF to plasmaub ratios were similar to tucatinib CSF to plasmaub ratios. Conclusions: In patients with LM from HER2+MBC who were treated with tucatinib, trastuzumab, and capecitabine, tucatinib and ONT-993 were detectable in the CSF of all patients at median levels similar to plasmaub tucatinib. This is the first documented evidence of tucatinib distributing into the CSF in patients with HER2+MBC. Efficacy and safety of tucatinib, trastuzumab, and capecitabine in patients with HER2+ LM will be reported upon completion of TBCRC 049 accrual. Clinical trial information: NCT03501979 .

scholarly journals CTNI-02. TBCRC049: A PHASE II STUDY TO ASSESS THE SAFETY AND EFFICACY OF THE COMBINATION OF TUCATINIB, TRASTUZUMAB AND CAPECITABINE FOR THE TREATMENT OF LEPTOMENINGEAL METASTASIS IN HER2 POSITIVE BR1AST CANCER

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii41-ii41
Author(s):  
Rashmi Murthy ◽  
Barbara O’Brien ◽  
Donald Berry ◽  
Nicholas Navin ◽  
Jason Johnson ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Quality Of Life ◽  
Clinical Signs ◽  
Symptom Burden ◽  
Leptomeningeal Metastasis ◽  
Newly Diagnosed ◽  
Csf Cytology ◽  
Her2 Positive ◽  
Cns Disease

Abstract Treatment options for patients with leptomeningeal metastasis (LM) from HER2-positive breast cancer (HER2+ BC) are limited and prognosis is poor. Tucatinib is an oral, potent, HER2 specific tyrosine kinase inhibitor with good tolerability and combinatory anti-tumor activity, including partial responses in heavily treated patients and those with brain metastases (BM). This is a phase 2 single-arm study to evaluate the efficacy of tucatinib, trastuzumab and capecitabine in HER2+ BC with newly-diagnosed LM. CNS disease will be evaluated at screening and every 6 weeks by neuroaxis MRI, CSF cytology, and neurological assessments per RANO-LMD (adapted) and RANO-BM criteria. Extra-CNS disease will be evaluated at screening and every 12 weeks by CT scan per RECIST criteria. All patients will be followed for survival. Symptom burden and quality of life assessments, as well as correlative blood and CSF samples, will be collected. Eligible patients include adults with HER2+ BC, KPS > 50, and newly-diagnosed, untreated LM (defined as positive CSF cytology and/or radiographic evidence of LM, plus clinical signs/symptoms). Patients with treated or concurrent/new BM are allowed. Patients treated with capecitabine within the last 12 months are excluded. This study has a Gehan-like design with an interim futility analysis and overall intent to estimate OS. For the interim analysis, success is defined as CNS PFS for 12 weeks. Enrollment will end if fewer than two successes are observed in the first 15 patients. Secondary endpoints include safety, CNS PFS at 12 weeks, RR in CNS and extra-CNS, and symptom burden/quality of life. The regimen will be considered worthy of future study if the median OS is > 4.4 months. Fourteen of 30 patients have accrued thus far. The study is active at multiple Translational Breast Cancer Research Consortium sites around the country.

Neratinib in HER2-Positive Breast Cancer Patients

2019 ◽  
Vol 53 (6) ◽  
pp. 612-620 ◽  
Author(s):  
Rutugandha Paranjpe ◽  
Dima Basatneh ◽  
Gabriel Tao ◽  
Carmine De Angelis ◽  
Sobia Noormohammed ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Disease Free Survival ◽  
Common Adverse Effect ◽  
Stage I ◽  
Phase Iii ◽  
Therapeutic Window ◽  
Breast Cancer Patients ◽  
Her2 Positive ◽  
Safety And Efficacy ◽  
Her2 Breast Cancer

Objective:To review the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of neratinib in human epidermal growth factor receptor (HER2)+ breast cancer (BC). Data Sources: A PubMed search was performed using the term neratinib between September 12, 2018, and November 21, 2018. References of published articles and reviews were also assessed for additional information. Study Selection and Data Extraction: English-language preclinical and clinical studies on the chemistry, pharmacology, pharmacokinetics, safety, and efficacy of neratinib were evaluated. Data Synthesis: Neratinib, an irreversible inhibitor of HER1, HER2, and HER4, is Food and Drug Administration approved for the extended adjuvant treatment of stage I-III HER2+ BC to follow trastuzumab-based therapy. A phase III study has demonstrated statistically significant improvement in 5-year disease-free survival rate (90.2 vs 87.7; hazard ratio = 0.73, 95% CI = 0.57-0.92, P = 0.0083). Its most common adverse effect is diarrhea, observed in more than 90% of patients. The incidence of grade 3/4 diarrhea (~40%) is reduced by half with loperamide prophylaxis, which is recommended for the first 8 weeks of neratinib therapy. Other common adverse reactions are nausea and fatigue. The patients need to be monitored for liver function tests and drug interactions with acid-reducing agents, CYP3A4 inhibitors/inducers, and P-glycoprotein substrates with narrow therapeutic window. Relevance to Patient Care and Clinical Practice: American Society of Clinical Oncology and National Comprehensive Cancer Network clinical guidelines suggest the use of neratinib for extended adjuvant therapy following 1-year trastuzumab in stage I to III HER2+ BC. Diarrhea remains a clinically significant but manageable adverse event. Conclusion: Neratinib significantly improves treatment outcomes and has manageable toxicity in stage I to III HER2+ BC patients.

scholarly journals Pyrotinib in the treatment of women with advanced HER2 positive breast cancer: A multicenter, prospective, real-world study.

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. e13012-e13012
Author(s):  
Jifeng Feng ◽  
Lili Zhang ◽  
Xiaohong Wu ◽  
Jun Zhou ◽  
Mingzhen Zhu ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Real World ◽  
Kinase Inhibitor ◽  
Objective Response ◽  
Progression Free Survival ◽  
Efficacy Evaluation ◽  
Her2 Positive ◽  
Her2 Positive Breast Cancer ◽  
Her2 Breast Cancer ◽  
Positive Breast Cancer

e13012 Background: Pyrotinib is a newly-developed irreversible pan-ErbB receptor tyrosine kinase inhibitor. The efficacy of pyrotinib in patients with different baseline characteristics in the actual clinical practice has been rarely reported. This study analyzed the efficacy and safety of pyrotinib in the real world. Methods: Patients with histologically confirmed advanced HER2 positive breast cancer were included in the analyses. All patients received pyrotinib-based therapy were given pyrotinib once a day in a 21-day cycle. The primary endpoint was progression-free survival (PFS). Secondary endpoints included adverse events (AE), objective response rate (ORR), disease control rate (DCR), and overall survival (OS). Results: A total of 132 patients (median age: 52 years [29-78]) were enrolled from February 2019 to March 2020. 94(71.21%) patients had visceral metastatic lesions and 20 (15.15%) had brain metastases. HR+, HR-, or unknown HR status for primary tumor accounted for 56.82%, 42.42%, 0.76%, respectively. 115(87.12%) patients were previously administered with trastuzumab. 96(72.73%) patients received pyrotinib-based therapy as a second or further line of treatment. 94(71.21%) patients initiated pyrotinib treatment at 400 mg. Treatment regimens were pyrotinib plus capecitabine (55.30%), pyrotinib combined with trastuzumab (18.18%), and pyrotinib monotherapy (8.33%), pyrotinib combined with endocrine therapy, radiotherapy or antiangiogenic drugs (3.79%). A total of 132 patients were included in PFS analysis. mPFS was 12.0 months (95%CI 8.1-18.8). mPFS for patients without primary trastuzumab-resistant breast cancer was 14.1 months (95%CI 8.7-23.3). Patients receiving pyrotinib-based therapy as their ≥3 lines treatment had lower mPFS than those receiving pyrotinib-based therapy as their < 3 lines treatment (8.8 vs. 15.1 months, P= 0.119). mPFS in patients receiving regimen with and without capecitabine were 15.1 months and 8.4 months, respectively ( P= 0.081). As of data cutoff, mOS has not yet been reached. Among the 65 patients available for efficacy evaluation, 1 (1.54%) patient achieved complete response (CR), 24 (36.92%) patients had partial response (PR), 30 (46.15%) patients achieved stable disease (SD), and 10 (15.38%) patients had progression disease (PD), resulting in an ORR of 38.46% and DCR of 84.62%. The most common AE was diarrhea (84.17%), but only 5 (4.17%) patients were reported grade ≥ 3 diarrhea which could be well controlled. Other AEs with an incidence higher than 20.00% were anemia (36.67%), leukopenia (25.83%), vomiting (25.00%), neutropenia (22.50%). No treatment-related death occurred. Conclusions: Pyrotinib demonstrated an encouraging efficacy and manageable safety in patients with advanced HER2+ breast cancer. More data would be analyzed and reported in the future. Clinical trial information: ChiCTR1900021819.

scholarly journals Effects of Lapatinib on HER2-Positive and HER2-Negative Canine Mammary Carcinoma Cells Cultured In Vitro

Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 897
Author(s):  
Antonio Fernando Leis-Filho ◽  
Patrícia de Faria Lainetti ◽  
Priscila Emiko Kobayashi ◽  
Carlos Eduardo Fonseca-Alves ◽  
Renée Laufer-Amorim
Keyword(s):  
Breast Cancer ◽  
Cell Culture ◽  
Mammary Gland ◽  
Cell Cultures ◽  
Kinase Inhibitor ◽  
Predictive Marker ◽  
Her2 Positive ◽  
Her2 Breast Cancer ◽  
Mammary Gland Cancer

HER2 is a prognostic and predictive marker widely used in breast cancer. Lapatinib is a tyrosine kinase inhibitor that works by blocking the phosphorylation of the receptor HER2. Its use is related to relatively good results in the treatment of women with HER2+ breast cancer. Thus, this study aimed to verify the effects of lapatinib on four canine primary mammary gland carcinoma cell cultures and two paired metastatic cell cultures. Cultures were treated with lapatinib at concentrations of 100, 500, 1000 and 3000 nM for 24 h and the 50% inhibitory concentration (IC50) for each cell culture was determined. In addition, a transwell assay was performed to assess the ability of lapatinib to inhibit cell migration. Furthermore, we verified HER2 expression by RT-qPCR analysis of cell cultures and formalin-fixed paraffin-embedded tissues from samples corresponding to those used in cell culture. Lapatinib was able to inhibit cell proliferation in all cell cultures, but it was not able to inhibit migration in all cell cultures. The higher the expression of HER2 in a culture, the more sensitive the culture was to treatment. This relationship may be an indication that the expression of HER2 may be a predictive factor and opens a new perspective for the treatment of primary and metastatic mammary gland cancer.

Updated results of tucatinib versus placebo added to trastuzumab and capecitabine for patients with pretreated HER2+ metastatic breast cancer with and without brain metastases (HER2CLIMB).

2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 1043-1043
Author(s):  
Giuseppe Curigliano ◽  
Volkmar Mueller ◽  
Virginia F. Borges ◽  
Erika P. Hamilton ◽  
Sara A. Hurvitz ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Metastatic Breast Cancer ◽  
Brain Metastases ◽  
Kinase Inhibitor ◽  
Locally Advanced ◽  
Metastatic Breast ◽  
Total Study Population ◽  
Her2 Breast Cancer ◽  
Metastatic Setting ◽  
To Receive

1043 Background: Tucatinib (TUC) is an oral tyrosine kinase inhibitor (TKI) highly specific for HER2. TUC is approved for use in combination with trastuzumab (T) and capecitabine (C) in patients (pts) with and without brain metastases (BM) who have received 1 or more prior anti-HER2–based regimens in the metastatic setting. In the primary analysis from the pivotal HER2CLIMB trial, the addition of TUC to T and C in pts with HER2+ metastatic breast cancer showed a statistically significant and clinically meaningful prolongation of progression-free (PFS) (HR = 0.54 [95% CI: 0.42, 0.71]; P < 0.001) and overall survival (OS) (HR = 0.66 [95% CI: 0.50, 0.88]; P = 0.005) (Murthy, et al. NEJM 2020). TUC in combination with T and C was well tolerated with few discontinuations other than for disease progression. Based on these data, the protocol was amended for unblinding of sites to treatment assignment to allow for crossover from the placebo arm to receive TUC in combination with T and C. Methods: HER2CLIMB (NCT02614794) is a global, randomized, double-blind, placebo-controlled trial in pts with unresectable locally advanced or metastatic HER2+ breast cancer previously treated with T, pertuzumab, and T-emtansine (T-DM1), including pts with untreated, treated stable, or treated and progressing BM. Overall 612 pts were randomized 2:1 to receive TUC 300 mg BID or placebo, each in combination with T and C. Randomization was stratified by BM, ECOG performance status, and geographic region. Protocol prespecified analysis of OS, PFS (by investigator assessment) and safety in the total study population will be performed at approximately 2 years from the last patient randomized. Results: Updated Kaplan-Meier time-to-event analysis of OS and PFS with hazard ratios and 95% confidence intervals for TUC arm vs placebo arm will be presented overall, as well as for OS in the prespecified subgroups reported previously (Murthy, et al. NEJM 2020). Safety and tolerability assessments will include frequency of adverse events by severity, dose modifications and discontinuation of study medications. Conclusions: Conclusions will be presented in the presentation. Clinical trial information: NCT02614794 .

scholarly journals Single-cell profiling guided combinatorial immunotherapy for fast-evolving CDK4/6 inhibitor resistant HER2-positive breast cancer

2019 ◽  
Author(s):  
Qingfei Wang ◽  
Ian H. Guldner ◽  
Samantha M. Golomb ◽  
Longhua Sun ◽  
Jack Harris ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Single Cell ◽  
Kinase Inhibitor ◽  
Acquired Resistance ◽  
Tumor Evolution ◽  
Breast Cancer Patients ◽  
Her2 Positive ◽  
Therapy Regimen ◽  
Her2 Breast Cancer ◽  
Combinatorial Immunotherapy

AbstractDevelopment of acquired resistance to targeted cancer therapy is one of the most significant clinical challenges. Acquiring resistance under drug selection pressure is a result of evolutionary adaptation to a complex and dynamic tumor microenvironment (TME). New therapy regimens combining CDK4/6 inhibitor are under active investigation in clinical trials to treat HER2+ breast cancer patients. In parallel with clinical trial settings, in this study, we sought to prospectively model the tumor evolution in response to a targeted therapy regimen in vivo and identify a clinically actionable strategy to combat potential acquired resistance. Notably, despite a promising initial response, acquired resistance emerged rapidly to the anti-Her2/Neu antibody plus CDK4/6 inhibitor Palbociclib combination treatment. By leveraging high-throughput single-cell analyses of the evolving tumors over the course of treatments, we revealed a distinct immunosuppressive immature myeloid cell (IMC) population infiltrated in the resistant TME. Guided by single-cell transcriptome analysis, we demonstrated a combinatorial immunotherapy of IMC-targeting tyrosine kinase inhibitor cabozantinib and immune checkpoint blockades enhanced anti-tumor immunity, and overcame the resistance. Further, sequential combinatorial immunotherapy enabled a sustained control of the rapidly evolving CDK4/6 inhibitor-resistant tumors. Our study demonstrates a translational framework for treating rapidly evolving tumors through preclinical modeling and single-cell analyses. Our findings provide a rationale for an immediate clinical proposition of combinatorial immunotherapy for HER2+ breast cancer as a strategy to mitigate the emergence of resistance.

scholarly journals Fatty Acid Synthase Confers Tamoxifen Resistance to ER+/HER2+ Breast Cancer

Cancers ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 1132
Author(s):  
Javier A. Menendez ◽  
Adriana Papadimitropoulou ◽  
Travis Vander Steen ◽  
Elisabet Cuyàs ◽  
Bharvi P. Oza-Gajera ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Fatty Acid ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Promoter Activity ◽  
Fatty Acid Synthase ◽  
Endocrine Resistance ◽  
Gene Promoter ◽  
Her2 Positive ◽  
Her2 Breast Cancer

The identification of clinically important molecular mechanisms driving endocrine resistance is a priority in estrogen receptor-positive (ER+) breast cancer. Although both genomic and non-genomic cross-talk between the ER and growth factor receptors such as human epidermal growth factor receptor 2 (HER2) has frequently been associated with both experimental and clinical endocrine therapy resistance, combined targeting of ER and HER2 has failed to improve overall survival in endocrine non-responsive disease. Herein, we questioned the role of fatty acid synthase (FASN), a lipogenic enzyme linked to HER2-driven breast cancer aggressiveness, in the development and maintenance of hormone-independent growth and resistance to anti-estrogens in ER/HER2-positive (ER+/HER2+) breast cancer. The stimulatory effects of estradiol on FASN gene promoter activity and protein expression were blunted by anti-estrogens in endocrine-responsive breast cancer cells. Conversely, an AKT/MAPK-related constitutive hyperactivation of FASN gene promoter activity was unaltered in response to estradiol in non-endocrine responsive ER+/HER2+ breast cancer cells, and could be further enhanced by tamoxifen. Pharmacological blockade with structurally and mechanistically unrelated FASN inhibitors fully impeded the strong stimulatory activity of tamoxifen on the soft-agar colony forming capacity—an in vitro metric of tumorigenicity—of ER+/HER2+ breast cancer cells. In vivo treatment with a FASN inhibitor completely prevented the agonistic tumor-promoting activity of tamoxifen and fully restored its estrogen antagonist properties against ER/HER2-positive xenograft tumors in mice. Functional cancer proteomic data from The Cancer Proteome Atlas (TCPA) revealed that the ER+/HER2+ subtype was the highest FASN protein expressor compared to basal-like, HER2-enriched, and ER+/HER2-negative breast cancer groups. FASN is a biological determinant of HER2-driven endocrine resistance in ER+ breast cancer. Next-generation, clinical-grade FASN inhibitors may be therapeutically relevant to countering resistance to tamoxifen in FASN-overexpressing ER+/HER2+ breast carcinomas.

scholarly journals Neratinib plus trastuzumab is superior to pertuzumab plus trastuzumab in HER2-positive breast cancer xenograft models

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jamunarani Veeraraghavan ◽  
Carolina Gutierrez ◽  
Vidyalakshmi Sethunath ◽  
Sepideh Mehravaran ◽  
Mario Giuliano ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Tumor Regression ◽  
Complete Response ◽  
Estrogen Deprivation ◽  
Short Term ◽  
Her2 Positive ◽  
Her2 Breast Cancer ◽  
Proliferative Markers ◽  
Xenograft Models ◽  
Positive Breast Cancer

AbstractLapatinib (L) plus trastuzumab (T), with endocrine therapy for estrogen receptor (ER)+ tumors, but without chemotherapy, yielded meaningful response in HER2+ breast cancer (BC) neoadjuvant trials. The irreversible/pan-HER inhibitor neratinib (N) has proven more potent than L. However, the efficacy of N+T in comparison to pertuzumab (P) + T or L + T (without chemotherapy) remains less studied. To address this, mice bearing HER2+ BT474-AZ (ER+) cell and BCM-3963 patient-derived BC xenografts were randomized to vehicle, N, T, P, N+T, or P+T, with simultaneous estrogen deprivation for BT474-AZ. Time to tumor regression/progression and incidence/time to complete response (CR) were determined. Changes in key HER pathway and proliferative markers were assessed by immunohistochemistry and western blot of short-term-treated tumors. In the BT474-AZ model, while all N, P, T, N + T, and P + T treated tumors regressed, N + T-treated tumors regressed faster than P, T, and P + T. Further, N + T was superior to N and T alone in accelerating CR. In the BCM-3963 model, which was refractory to T, P, and P + T, while N and N + T yielded 100% CR, N + T accelerated the CR compared to N. Ki67, phosphorylated (p) AKT, pS6, and pERK levels were largely inhibited by N and N + T, but not by T, P, or P + T. Phosphorylated HER receptor levels were also markedly inhibited by N and N + T, but not by P + T or L + T. Our findings establish the efficacy of combining N with T and support clinical testing to investigate the efficacy of N + T with or without chemotherapy in the neoadjuvant setting for HER2+ BC.

scholarly journals De-escalation of radiation therapy in patients with stage I, node-negative, HER2-positive breast cancer

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Jose G. Bazan ◽  
Sachin R. Jhawar ◽  
Daniel Stover ◽  
Ko Un Park ◽  
Sasha Beyer ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Early Stage ◽  
Local Therapy ◽  
Adjuvant Radiation ◽  
Her2 Positive ◽  
Node Negative ◽  
Risk Of Death ◽  
Her2 Breast Cancer ◽  
Neoadjuvant Systemic Therapy ◽  
Increased Risk

AbstractIn the modern era, highly effective anti-HER2 therapy is associated with low local-regional recurrence (LRR) rates for early-stage HER2+ breast cancer raising the question of whether local therapy de-escalation by radiation omission is possible in patients with small-node negative tumors treated with lumpectomy. To evaluate existing data on radiation omission, we used the National Cancer Database (NCDB) to test the hypothesis that RT omission results in equivalent overall survival (OS) in stage 1 (T1N0) HER2+ breast cancer. We excluded patients that received neoadjuvant systemic therapy. We stratified the cohort by receipt of adjuvant radiation. We identified 6897 patients (6388 RT; 509 no RT). Patients that did not receive radiation tended to be ≥70 years-old (odds ratio [OR] = 3.69, 95% CI: 3.02–4.51, p < 0.0001), to have ≥1 comorbidity (OR = 1.33, 95% CI: 1.06–1.68, p = 0.0154), to be Hispanic (OR = 1.49, 95% CI: 1.00–2.22, p = 0.049), and to live in lower income areas (OR = 1.32, 95% CI: 1.07–1.64, p = 0.0266). Radiation omission was associated with a 3.67-fold (95% CI: 2.23–6.02, p < 0.0001) increased risk of death. While other selection biases that influence radiation omission likely persist, these data should give caution to radiation omission in T1N0 HER2+ breast cancer.

Sign in / Sign up

Export Citation Format

Share Document