Human Epidermal Growth Factor Receptor 2-Low Breast Cancer Brain Metastases: An Opportunity for Targeted Systemic Therapies in a High-Need Patient Population

PURPOSE

Trastuzumab deruxtecan is a new treatment option for patients with advanced human epidermal growth factor receptor 2 (HER2)-low breast cancer (BC). Although HER2-low status has been characterized in early and advanced BC, it has yet to be fully characterized in brain metastases (BrM).

METHODS

Patients who underwent surgery for BC BrM at Sunnybrook Health Sciences Centre and for whom HER2 status was available on resected BrM were studied. Estrogen receptor, progesterone receptor, and HER2 status were assessed on the basis of ASCO/College of American Pathologists (CAP) guidelines. HER2-zero was defined as immunohistochemistry (IHC) 0; HER2-low was defined as IHC 1+ or IHC 2+ with fluorescence in situ hybridization (FISH)-negative status. HER2-positive (HER2+) was defined as IHC 3+ or IHC 2+ with positive FISH. Clinicopathologic features were recorded. We also assessed the prognostic association between extent of HER2 expression and (1) brain-specific progression-free survival (bsPFS), as well as (2) overall survival (OS).

RESULTS

In this retrospective cohort of 102 patients with resected BC BrM, 53% (n = 54) were HER2+, 29.4% (n = 30) were HER2-low, and 17.6% (n = 18) had HER2-zero status. Among BrM that were triple-negative on the basis of ASCO/CAP guidelines, 63.6% (n = 14/22) were reclassified as being HER2-low. Sixty percent (n = 15/25) of BrM that were hormone receptor-positive/HER2-negative (HR+/HER2-) were reclassified as being HER2-low. In total, 51 patients had matched primary breast and BrM tissue available; results of HER2 status when categorized as HER2-zero, HER2-low, and HER2+ were concordant in 82.3% (n = 42/51) of cases (Cohen's kappa, 0.58; P = .07). There was no significant association between HER2-zero, HER2-low, and HER2+ status in BrM and either bsPFS or OS.

CONCLUSION

Among patients with surgically resected BrM, a high proportion of those with metastatic triple-negative BC and HR+/HER2- disease have HER2-low BrM with potential to benefit from HER2-targeted therapy.

Androgen Receptor Is Expressed in the Majority of Breast Cancer Brain Metastases and Is Subtype-Dependent

We aimed to evaluate the expression of the "targetable" androgen receptor (AR) in breast cancer brain metastases (BrM). An established, retrospective 57-patient cohort with metastatic breast cancer who underwent surgery for BrM at the Sunnybrook Odette Cancer Centre between 1999-2013 was studied. AR expression in BrM samples was assessed in triplicate using immunohistochemistry (IHC). AR positive status was defined as nuclear AR expression ≥ 10% by IHC using the SP107 antibody. The median age of patients was 52 years (range 32-85 years). 28 (49%) of BrM were HER2+, 17 (30%) were hormone receptor positive (HR+)/HER2-, and 12 (21%) were triple negative breast cancers (TNBCs). 56% (n = 32/57) of BrM were AR positive, and median AR expression was 20% (CI 1.6-38.3%). AR expression was different across breast cancer subtypes; AR was most frequently expressed in HER2+ (n = 21/28), followed by HR+/HER2- (n = 9/17), and lowest in TNBC (n = 2/12) BrM (p = 0.003). Patients with AR positive versus AR negative BrM had similar overall survival (12.5 vs. 7.9 months, p = 0.6), brain-specific progression-free survival (8.0 vs. 5.1 months, p = 0.95), and time from breast cancer diagnosis to BrM diagnosis (51 vs. 29 months, p = 0.16). AR is expressed in the majority of breast cancer BrM and represents a potential therapeutic target.

Type and timing of systemic therapy use predict overall survival for patients with brain metastases treated with radiation therapy

INTRODUCTION

This study aimed to investigate whether systemic therapy (ST) use surrounding radiation therapy (RT) predicts overall survival (OS) after RT for patients with brain metastases (BMs).

METHODS

Provincial RT and pharmacy databases were used to review all adult patients in British Columbia, Canada, who received a first course of RT for BMs between 2012 and 2016 (n = 3095). Multivariate analysis on a randomly selected subset was used to develop an OS nomogram.

RESULTS

In comparison to the 2096 non-recipients of ST after RT, the median OS of the 999 recipients of ST after RT was 5.0 (95% Confidence interval (CI) 4.1-6.0) months longer (p < 0.0001). Some types of ST after RT were independently predictive of OS: targeted therapy (hazard ratio (HR) 0.42, CI 0.37-0.48), hormone therapy (HR 0.45, CI 0.36-0.55), cytotoxic chemotherapy (HR 0.71, CI 0.64-0.79), and immunotherapy (HR 0.64, CI 0.37-1.06). Patients who discontinued ST after RT had 0.9 (CI 0.3-1.4) months shorter median OS than patients who received no ST before or after RT (p < 0.0001). In the multivariate analysis of the 220-patient subset, established prognostic variables (extracranial disease, performance status, age, cancer diagnosis, and number of BMs), and the novel variables "ST before RT" and "Type of ST after RT" independently predicted OS. The nomogram predicted 6- and 12-month OS probability and median OS (bootstrap-corrected Harrell's Concordance Index = 0.70).

CONCLUSIONS

The type and timing of ST use surrounding RT predict OS for patients with BMs.

Experience with Four French Catheters for Outpatient Coronary Angiography

Previous studies have demonstrated the efficacy and safety of outpatient cardiac catheterization on stable patients at low risk. We present our experience with four French catheters in 104 patients (72 male, 32 female, mean age 51 years old) with coronary angiography done as an outpatient procedure. No heparin was given during the procedure. After initial hemostasis had been attained, the patients returned to day center with vital signs monitored regularly. Patients were allowed ambulation after 4 hours' bed rest and were discharged the same afternoon. Normal coronary angiogram study was found in 76% of the study population. Single-vessel disease, double-vessel disease, triple-vessel disease, and left-main disease were found in 12%, 9.6%, 2%, and 1%, respectively. Nearly all of the patients demonstrated normal ventricular contraction (99%). Average procedural time was 20.2 +/- 4.4 minutes. Average hemostatic time was 8.4 +/- 3.1 minutes. No mortality directly attributed to the catheterization occurred in our study population. Moreover, there were no myocardial infarction, acute pulmonary edema, severe allergic reaction, and cerebrovascular accident. Femoral puncture site complication was only limited to superficial skin bruise. Quality of the cineangiogram was good in majority of the patients. Therefore, this study demonstrates that outpatient cardiac catheterization using four French Judkins catheter is a safe and cost-effective procedure.

Injection of vasodilators into arterial grafts through cardiac catheter to relieve spasm

Both native coronary artery and coronary bypass grafts may develop vasospasm after coronary artery bypass grafting. We recommend that whenever there is a high suspicion of vasospasm in arterial grafts and the native coronary artery unresponsive to or not suitable for usual vasodilator therapy, prompt selective graft arteriogram should be performed. Intraluminal injection of vasodilators such as calcium antagonists in combination with nitroglycerin may provide an effective antispastic therapy and this procedure could be lifesaving as demonstrated in the present report.

Radical-Mediated Diastereoselective Construction of a Chiral Synthon for Synthesis of Dolabellanes

[reaction: see text] A useful trans-substituted multifunctional cyclopentane with a chiral quaternary center was selectively synthesized by free radical Michael addition to the (Z)-propionate or -malonate derivatives. The stereoselectivity could be reversed by changing the configuration of the double bond.