Our objectives were to determine whether clinic-pathological markers and immune-related gene signatures in breast cancer exhibit any change upon brain metastasis and whether previously reported genes significantly associated with brain metastases and the epithelial-mesenchymal transition (EMT) were reproducible and consistent in our dataset. Sixteen pair-matched samples from primary breast cancers and brain metastases diagnosed were collected from the Japan Clinical Oncology Group Breast Cancer Study Group. Gene expression profiles for immune-, brain metastases-, and EMT-related genes were compared between primary breast cancers and brain metastases. Potential therapeutic target genes of 41 FDA-approved or under-investigation agents for brain metastases were explored. Immune-related signatures exhibited significantly lower gene expression in brain metastases than in primary breast cancers. No significant differences were detected for the majority of genes associated with brain metastases and EMT in the two groups. Among 41 therapeutic target candidates, VEGFA and DNMT3A demonstrated significantly higher gene expression in brain metastases. We found that distinct patterns of gene expression exist between primary breast cancers and brain metastases. Further studies are needed to explore whether these distinct expression profiles derive from or underlie disease status and compare these features between metastases to the brain and other sites.

To define prognostic factors for breast cancer patients with brain metastases, compare their clinical courses and prognoses according to breast cancer subtypes, and analyze the causes of death in such patients. We retrospectively analyzed 1,466 patients diagnosed with brain metastases between April 1, 2001 and December 31, 2012, from 24 institutions of the Japan Clinical Oncology Group. Overall, 1,256 patients with brain metastases were included. The median overall survival (OS) was 8.7 months (95 % confidence interval [CI] 7.8-9.6 months). Univariate and multivariate analyses revealed that patients diagnosed with brain metastasis within 6 months of metastatic breast cancer diagnoses, asymptomatic brain disease, or HER2-positive/estrogen receptor-positive tumors had increased OS. Median OS after the development of brain metastases was 9.3 months (95 % CI 7.2-11.3) for the luminal type, 16.5 months (95 % CI 11.9-21.1) for the luminal-HER2 type, 11.5 months (95 % CI 9.1-13.8) for the HER2 type, and 4.9 months (95 % CI 3.9-5.9) for the triple-negative type. Luminal-HER2 type patients had significantly longer OS than patients with the luminal type (hazard ratio [HR] = 1.50, P < 0.0001) and triple-negative type (HR = 1.97, P < 0.0001); no significant differences were noted compared to HER2-type patients (HR = 1.19, P = 0.117). The prognosis and clinical course of patients with brain metastasis from breast cancer before and after developing brain metastases vary according to subtype. Focusing on the subtypes of breast cancer can optimize the prevention, early detection, and improved treatment of brain metastases.

BackgroundImmune checkpoint inhibitors are reported to be effective in patients with brain metastases. However, detailed characteristics of the brain metastasis immune microenvironment remain unexplored.ResultsThe median tumor-infiltrating lymphocyte (TIL) category in brain metastases was 5% (1–70%). In 46 pair-matched samples, the percentages of TILs were significantly higher in primary breast tumors than in brain metastases (paired t-test, P < 0.01). The numbers of CD4/CD8/Foxp3-positive cells were significantly higher in primary breast tumors than in brain metastases (paired t-test, P < 0.05 for all antibodies). In patients with triple-negative breast cancer specifically, low TIL numbers were associated with significantly shorter overall survival compared to high TIL numbers (log-rank test, P = 0.04).Materials and MethodsWe retrospectively identified 107 patients with breast cancer and brain metastases who had undergone surgery between 2001 and 2012 at 8 institutions, and collected 191 samples including brain metastases alone and primary tumors with pair-matched brain metastasis samples. Hematoxylin and eosin-stained slides were evaluated for TILs and categorized according to the extent of staining. Immunohistochemistry for CD4, CD8, Foxp3, PD-L1, PD-L2, and HLA class I was also performed.ConclusionsThere are significantly fewer TILs in brain metastases than in primary breast tumors.

PURPOSE Adjuvant trastuzumab monotherapy has not been compared with trastuzumab + chemotherapy. We investigated the relative value of trastuzumab monotherapy for older patients with breast cancer. METHODS This study was an open-label, randomized controlled study with a treatment selection design in which a noninferiority criterion was predefined. Patients aged 70-80 years with surgically treated human epidermal growth factor receptor 2–positive invasive breast cancer received trastuzumab monotherapy or trastuzumab + chemotherapy. The primary end point was disease-free survival (DFS) with assessment of prespecified hazard ratio (HR), relapse-free survival (RFS), adverse events (AEs), health-related quality of life (HRQoL), and restricted mean survival time (RMST). RESULTS The study involved 275 patients (mean age, 73.5 years) who were followed up for a mean of 4.1 years (range, 0.3-8.0 years). The percentages of patients by cancer stage were as follows: I (pT > 0.5 cm), 43.6%; IIA, 41.7%; IIB, 13.5%; and IIIA, 1.1%. Three-year DFS was 89.5% with trastuzumab monotherapy versus 93.8% with trastuzumab + chemotherapy (HR, 1.36; 95% CI, 0.72 to 2.58; P = .51). At 3 years, RMST differed by −0.39 months between arms (95% CI, −1.71 to 0.93; P = .56). Three-year RFS was 92.4% with trastuzumab monotherapy versus 95.3% with trastuzumab + chemotherapy (HR, 1.33; 95% CI, 0.63 to 2.79; P = .53). Common AEs were anorexia (7.4% v 44.3%; P < .0001) and alopecia (2.2% v 71.7%; P < .0001), and grade 3/4 nonhematologic AEs occurred in 11.9% versus 29.8% ( P = .0003) for trastuzumab monotherapy versus trastuzumab + chemotherapy, respectively. Clinically meaningful HRQoL deterioration rate showed significant differences at 2 months (31% for trastuzumab monotherapy v 48% for trastuzumab + chemotherapy; P = .016) and at 1 year (19% v 38%; P = .009). CONCLUSION The primary objective of noninferiority for trastuzumab monotherapy was not met. However, the observed loss of survival without chemotherapy was < 1 month at 3 years. Therefore, and in light of the lower toxicity and more favorable HRQoL profile, trastuzumab monotherapy can be considered an adjuvant therapy option for selected older patients.

No abstract