Influence of HER2 expression on prognosis in metastatic triple-negative breast cancer-results from an international, multicenter analysis coordinated by the AGMT Study Group.

BACKGROUND: Triple-negative breast cancer (TNBC) is associated with poor prognosis, and new treatment options are urgently needed. About 34%-39% of primary TNBCs show a low expression of human epidermal growth factor receptor 2 (HER2-low), which is a target for new anti-HER2 drugs. However, little is known about the frequency and the prognostic value of HER2-low in metastatic TNBC. PATIENTS AND METHODS: We retrospectively included patients with TNBC from five European countries for this international, multicenter analysis. Triple-negativity had to be shown in a metastatic site or in the primary breast tumor diagnosed simultaneously or within 3 years before metastatic disease. HER2-low was defined as immunohistochemically (IHC) 1+ or 2+ without ERBB2 gene amplification. Survival probabilities were calculated by the Kaplan-Meier method, and multivariable hazard ratios (HRs) were estimated by Cox regression models. RESULTS: In total, 691 patients, diagnosed between January 2006 and February 2021, were assessable. The incidence of HER2-low was 32.0% [95% confidence interval (CI) 28.5% to 35.5%], with similar proportions in metastases (n = 265; 29.8%) and primary tumors (n = 425; 33.4%; P = 0.324). The median overall survival (OS) in HER2-low and HER2-0 TNBC was 18.6 and 16.1 months, respectively (HR 1.00; 95% CI 0.83-1.19; P = 0.969). Similarly, in multivariable analysis, HER2-low had no significant impact on OS (HR 0.95; 95% CI 0.79-1.13; P = 0.545). No difference in prognosis was observed between HER2 IHC 0/1+ and IHC 2+ tumors (HR 0.89; 95% CI 0.69-1.17; P = 0.414). CONCLUSIONS: In this large international dataset of metastatic TNBC, the frequency of HER2-low was 32.0%. Neither in univariable nor in multivariable analysis HER2-low showed any influence on OS.

Assessment of the management of carcinomatous meningitis from breast cancer globally: a study by the Breast International Group Brain Metastasis Task Force.

BACKGROUND: Carcinomatous meningitis (CM) is a severe complication of breast cancer. The Breast International Group (BIG) carried out a survey to describe the approach to CM internationally. PATIENTS AND METHODS: A questionnaire on the management of CM was developed by the Brain Metastases Task Force of BIG and distributed to its groups, requesting one answer per group site. RESULTS: A total of 241 sites responded, 119 from Europe, 9 from North America, 39 from Central/South America, 58 from Asia, and 16 in Australia/New Zealand, with 24.5% being general hospitals with oncology units, 44.4% university hospitals, 22.4% oncology centers, and 8.7% private hospitals. About 56.0% of sites reported seeing <5 cases annually with 60.6% reporting no increase in the number of cases of CM recently. Nearly 63.1% of sites investigate for CM when a patient has symptoms or radiological evidence, while 33.2% investigate only for symptoms. For diagnosis, 71.8% of sites required a positive cerebrospinal fluid cytology, while magnetic resonance imaging findings were sufficient in 23.7% of sites. Roughly 97.1% of sites treat CM and 51.9% also refer patients to palliative care. Intrathecal therapy is used in 41.9% of sites, mainly with methotrexate (74.3%). As many as 20 centers have a national registry for patients with breast cancer with central nervous system metastases and of those 5 have one for CM. Most (90.9%) centers would be interested in participating in a registry as well as in studies for CM, the latter preferably (62.1%) breast cancer subtype specific. CONCLUSIONS: This is the first study to map out the approach to CM from breast cancer globally. Although guidelines with level 1 evidence are lacking, there is a high degree of homogeneity in the approach to CM globally and great interest for conducting studies in this area.

Endothelin-1 genetic polymorphism as predictive marker for bevacizumab in metastatic breast cancer.

Biomarkers for bevacizumab efficacy in metastatic breast cancer (MBC) are of urgent need. The genetic variability of genes involved in angiogenesis could explain the interpatient variability of drug effects. For this biomarker study DNA was extracted from tumor blocks or blood samples of patients with human epidermal growth factor receptor 2 (HER2)-negative MBC treated with bevacizumab in combination with chemotherapy (bevacizumab cohort, 163 patients) or chemotherapy only (control cohort, 105 patients). We assessed the correlation of 10 single-nucleotide polymorphisms (SNPs) in genes modulating angiogenesis (vascular endothelial growth factor-A (VEGF-A), VEGF receptor 1 (VEGFR-1), serine threonine kinase 39 (STK39)) or hypertension (endothelin-1 and uromodulin) with outcome and toxicity. In the bevacizumab cohort, the SNP rs5370-TT in endothelin-1 (EDN1) showed a significantly shorter median overall survival (OS, 6.3 vs 21.3 months; hazard ratio (HR) 2.89, 95% confidence interval (CI) 1.34-6.26; log-rank P=0.0069) and a trend toward worse median progression-free survival (3.5 vs 7.9 months; HR 2.05, 95% CI 0.96-4.39; log-rank P=0.065) compared with the alternate genotypes combined. Similarly, patients harboring the VEGF-936 (rs3025039) TT alleles showed a significantly shorter median OS than patients with VEGF-936 CC or CT (14.9 vs 21.3 months; HR 2.37, 95% CI 1.09-5.13; P=0.0286). In multivariate analysis including important clinical parameters like disease-free survival (DFS), adjuvant chemotherapy, ECOG (Eastern Cooperative Oncology Group) performance score, histologic subtype, grade, hormone receptor status, visceral metastases and treatment line, only the association of rs5370 (EDN1) with OS was still statistically significant (P=0.012). In the control cohort, no association of the EDN1 genotype with outcome was seen, suggesting a predictive value for bevacizumab. In conclusion, the SNP rs5370 in endothelin-1 could help identifying patients who unlikely gain any benefit from bevacizumab.

Epirubicin and docetaxel with or without capecitabine as neoadjuvant treatment for early breast cancer: final results of a randomized phase III study (ABCSG-24).

BACKGROUND: This randomized phase III trial compared pathologic complete response (pCR) rates of early breast cancer (EBC) following neoadjuvant epirubicin-docetaxel (ED)±capecitabine (C), and evaluated the addition of trastuzumab in HER2-positive tumors. PATIENTS AND METHODS: Patients with invasive breast cancer (except T4d) were randomly assigned to receive six 3-weekly cycles of ED (both 75 mg/m2)±C (1000 mg/m2, twice daily, days 1-14). Patients with HER2-positive disease were further randomized to receive trastuzumab (8 mg/kg, then 6 mg/kg every 3 weeks) or not. Primary end point: pCR rate at the time of surgery. RESULTS: Five hundred thirty-six patients were randomized to ED (n=266) or EDC (n=270); 93 patients were further randomized to trastuzumab (n=44) or not (n=49). pCR rate was significantly increased with EDC (23.0% versus 15.4% ED, P=0.027), and nonsignificantly further increased with trastuzumab (38.6% EDC versus 26.5% ED, P=0.212). Rates of axillary node involvement at surgery and breast conservation were improved with EDC versus ED, but not significantly; the addition of trastuzumab had no further impact. Hormone receptor status, tumor size, grade, and C (all P≤0.035) were independent prognostic factors for pCR. Trastuzumab added to ED±C significantly increased the number of serious adverse events (35 versus 18; P=0.020), mainly due to infusion-related reactions. CONCLUSION: These findings show that the integration of C into a neoadjuvant taxane-/anthracycline-based regimen is a feasible, safe, and effective treatment option, with incorporation of trastuzumab in HER2-positive disease. CLINICAL TRIAL NUMBER: NCT00309556, www.clinicaltrials.gov.