Trastuzumab Deruxtecan in HER2-Positive Metastatic Breast Cancer Patients with Brain Metastases: A DESTINY-Breast01 Subgroup Analysis.

DESTINY-Breast01 (NCT03248492) evaluated trastuzumab deruxtecan (T-DXd; DS-8201) in patients with heavily pretreated HER2-positive metastatic breast cancer (mBC). We present a subgroup of 24 patients with a history of treated brain metastases (BM), a population with limited treatment options. In patients with BMs, the confirmed objective response rate (cORR) was 58.3% [95% confidence interval (CI), 36.6%-77.9%], and the median progression-free survival (mPFS) was 18.1 months (95% CI, 6.7-18.1 months). In patients without BMs (n = 160), cORR was 61.3% and mPFS was 16.4 months. Eight patients (47.1%) experienced a best overall intracranial response of partial response or complete response. Seven patients (41.2%) had a best percentage change in brain lesion diameter from baseline consistent with stable disease. Two patients (8.3%) with BMs and two (1.3%) without BMs experienced progression in the brain. The safety profile of T-DXd was consistent with previous studies. The durable clinical activity of T-DXd in this population warrants further investigation. SIGNIFICANCE: Advances in treating HER2-positive metastatic breast cancer have greatly improved patient outcomes, but intracranial progression remains an important risk for which few therapeutic options are currently available. T-DXd demonstrated durable efficacy in patients with stable, treated BMs. This article is highlighted in the In This Issue feature, p. 2711.

Randomized phase-II evaluation of letrozole plus dasatinib in hormone receptor positive metastatic breast cancer patients.

The non-receptor tyrosine kinase Src activation plays a role in the malignant progression of breast cancer, including development of endocrine therapy resistance and survival of bone metastases. This study investigated whether adding Src kinase inhibitor dasatinib to aromatase inhibitor (AI) therapy improved outcomes in estrogen receptor (ER)-positive, HER2-negative metastatic breast cancer (MBC). Postmenopausal patients with ER-positive, HER2-negative MBC (0-1 prior chemotherapies and no prior AI for MBC) were eligible for this non-comparative, parallel group, phase-II study. Patients were randomized to letrozole (2.5 mg/day PO) alone or with dasatinib (100 mg/day PO). Patients with disease progression on letrozole alone could crossover to dasatinib plus continued letrozole. The primary endpoint was clinical-benefit-rate (CBR; complete response + partial response + stable disease ≥6 months). A total of 120 patients were randomized. The CBR of 71% (95% CI 58-83%) was observed with letrozole + dasatinib versus the projected CBR of the combination of 56%. The CBR of 66% (95% CI 52-77%) with letrozole alone also exceeded the projected CBR of 39% with letrozole alone. The CBR was 23% in the crossover arm of letrozole plus dasatinib in patients progressing on letrozole alone. Median progression-free survival with the combination was 20.1 months and 9.9 months with letrozole alone. Letrozole plus dasatinib was well tolerated, although 26% of patients required dasatinib dose reductions. In this non-comparative phase-II trial, the CBR of 71% and the median PFS of 20.1 months with letrozole + dasatinib are encouraging and suggest that dasatinib may inhibit the emergence of acquired resistance to AI therapy.

Giant malignant phyllodes tumor with metastasis to the brain.

We present the case of a 32-year-old African American woman with a giant malignant phyllodes tumor that metastasized to the lungs and subsequently the brain. Her treatment included six cycles of adjuvant therapy with AIM (Adriamycin®, ifosfamide, and mesna) followed by therapy with gemcitabine and docetaxel. A grand mal seizure led to discovery of a 6 × 5 × 5 cm brain mass which was resected. After resection, the patient developed pulmonary edema, repeat seizure activity, and massive intrathoracic progression before succumbing to her disease. This is an unpredictable and understudied neoplasm that can be aggressive and fatal in rare cases.

Five-year results of a phase II trial of preoperative 5-fluorouracil, epirubicin, cyclophosphamide followed by docetaxel with capecitabine (wTX) (with trastuzumab in HER2-positive patients) for patients with stage II or III breast cancer.

We aimed to increase pathologic complete response (pCR) in patients with invasive breast cancer by adding preoperative capecitabine to docetaxel following 5-fluorouracil, epirubicin, cyclophosphamide (FEC) (with trastuzumab for patients with HER2-positive disease) and to evaluate 5-year disease-free survival (DFS) associated with this preoperative regimen. Chemotherapy included four cycles of FEC100 (5-fluorouracil 500 mg/m2 , epirubicin 100 mg/m2 , cyclophosphamide 500 mg/m2 IV on Day 1 every 21 days) followed by 4 21-day cycles of docetaxel (35 mg/m2  days 1 and 8) concurrently with capecitabine (825 mg/m2 orally twice daily for 14 days followed by 7 days off) (wTX). For HER2-positive patients, treatment was modified by decreasing epirubicin to 75 mg/m2 and adding trastuzumab (H) in standard doses (FEC75-H →wTX-H). The study objective was to achieve a pCR rate in the breast and axillary lymph nodes of 37% in patients with HER2-negative breast cancer and of 67% in patients with HER2-positive breast cancer treated with preoperative trastuzumab. A total of 186 patients were enrolled on study. In an intent-to-treat analysis, the pCR rate was 31% (37/118, 95% CI: 24-40%) in the HER2-negative patients, 24% (15/62, 95% CI: 14-37%) in ER-positive/HER2-negative patients, 39% (22/56, 95% CI: 27-53%) in the ER-negative/HER2-negative patients, and 46% (29/63, 95% CI: 34-48%) in the HER2-positive patients. The pCR rate in the 40 trastuzumab-treated patients was 53% (21/40, 95% CI: 38-67%). Grade 3 and 4 adverse events included neutropenia, leukopenia, diarrhea, and hand-foot skin reactions. One trastuzumab-treated patient developed grade 3 cardiotoxicity, and 4 others experienced grade 1-2 decrements in left ventricular function; all five patients' cardiac function returned to their baseline upon completion of trastuzumab. At 5 years, disease-free survival was 70% in the HER2-negative population (78% in ER-positive/HER2-negative and 62% in the ER-negative/HER2-negative patients) and 80% in the HER2-positive patients (87% in the trastuzumab-treated HER2-positive patients). At 5 years, overall survival was 80% in the HER2-negative population (88% in ER-positive/HER2-negative and 71% in the ER-negative/HER2-negative patients) and 86% in the HER2-positive patients (94.5% in the trastuzumab-treated HER2-positive patients). FEC100 (FEC75 with trastuzumab) followed by weekly docetaxel plus capecitabine, with or without trastuzumab is a safe, effective preoperative cytotoxic regimen. However, the addition of capecitabine to docetaxel following FEC, with or without trastuzumab, did not increase pCR rates nor 5-year DFS over the rates that have been reported with standard preoperative doxorubicin/cyclophosphamide (AC) followed by paclitaxel, with or without trastuzumab. Therefore, the use of capecitabine as part of preoperative chemotherapy is not recommended.

Pathologic complete response after preoperative anti-HER2 therapy correlates with alterations in PTEN, FOXO, phosphorylated Stat5, and autophagy protein signaling.

BACKGROUND: To define protein molecular characteristics of tumor cells prior to, and immediately following, preoperative human epidermal growth factor receptor 2 (HER2)-targeted therapy that correlate with pathologic complete response (pCR) or non response (no pCR) to preoperative HER2-directed therapy and chemotherapy. METHODS: This open-label, phase II study randomized patients with HER2-positive stage II or III invasive breast cancer to trastuzumab, lapatinib, or both, 2 weeks prior to and during chemotherapy with FEC75 for 4 courses; then paclitaxel 80 mg/m2 weekly for 12 courses, then surgery. Core needle biopsies were collected at baseline and after 2 weeks of anti-HER2 therapy prior to chemotherapy. Data were correlated with pCR, defined as absence of invasive tumor in breast and lymph nodes. RESULTS: Of 100 enrolled patients, the analysis population included those who had surgery and received ≥75% chemotherapy (78% [n=78]). pCRs by arm are: trastuzumab (n=26), 54% [n=14]; lapatinib (n=29), 45% [n=13]; trastuzumab plus lapatinib (n=23), 74% [n=17]). Paired biopsy specimens were available for 49 patients (63%). Tumor cells of patients with pCR in the trastuzumab or lapatinib treatment arms showed nonphosphorylated FOXO, phosphorylated Stat5, and sparse signal-transduction protein network crosstalk representing different patterns of connections with PI3K and autophagy proteins compared with no pCR. CONCLUSION: In this exploratory study, pCR with preoperative anti-HER2 therapy and chemotherapy correlated with the levels and phosphorylation status of specific baseline signal pathway proteins in tumor cells. These data may provide candidate biomarkers to stratify initial treatment and potential combination therapies for future study. Tissue preservation technology introduced here makes this procedure widely feasible. TRIAL REGISTRATION: ClinicalTrials.gov: NCT00524303.

Our experience as a Health Volunteers Overseas-sponsored team in Huê´, Vietnam.

A group from Texas Oncology and Baylor Charles A. Sammons Cancer Center traveled to Huê´, Vietnam, as part of Health Volunteers Overseas. From February 21 to March 6, 2012, five Baylor Sammons medical oncologists and an oncology nurse worked with a medical oncologist and a surgeon at the Huê´ College of Medicine and Pharmacy, suggesting approaches based on available resources. The two groups worked together to find optimal solutions for the patients. What stood out the most for the Baylor Sammons group was the Huê´ team's remarkable work ethic, empathy for patients, and treatment resourcefulness. The Baylor Sammons group also identified several unmet needs that could potentially be addressed by future volunteers in Huê´, including creation of an outpatient hospice program, establishment of breast cancer screening, modernization of the pathology department, instruction in and better utilization of pain management, better use of clinic space, and the teaching of oncology and English to medical students. There was a mutual exchange of knowledge between the two medical teams. The Baylor Sammons group not only taught but also learned how to take good care of patients with limited resources.

Genome and transcriptome sequencing in prospective metastatic triple-negative breast cancer uncovers therapeutic vulnerabilities.

Triple-negative breast cancer (TNBC) is characterized by the absence of expression of estrogen receptor, progesterone receptor, and HER-2. Thirty percent of patients recur after first-line treatment, and metastatic TNBC (mTNBC) has a poor prognosis with median survival of one year. Here, we present initial analyses of whole genome and transcriptome sequencing data from 14 prospective mTNBC. We have cataloged the collection of somatic genomic alterations in these advanced tumors, particularly those that may inform targeted therapies. Genes mutated in multiple tumors included TP53, LRP1B, HERC1, CDH5, RB1, and NF1. Notable genes involved in focal structural events were CTNNA1, PTEN, FBXW7, BRCA2, WT1, FGFR1, KRAS, HRAS, ARAF, BRAF, and PGCP. Homozygous deletion of CTNNA1 was detected in 2 of 6 African Americans. RNA sequencing revealed consistent overexpression of the FOXM1 gene when tumor gene expression was compared with nonmalignant breast samples. Using an outlier analysis of gene expression comparing one cancer with all the others, we detected expression patterns unique to each patient's tumor. Integrative DNA/RNA analysis provided evidence for deregulation of mutated genes, including the monoallelic expression of TP53 mutations. Finally, molecular alterations in several cancers supported targeted therapeutic intervention on clinical trials with known inhibitors, particularly for alterations in the RAS/RAF/MEK/ERK and PI3K/AKT/mTOR pathways. In conclusion, whole genome and transcriptome profiling of mTNBC have provided insights into somatic events occurring in this difficult to treat cancer. These genomic data have guided patients to investigational treatment trials and provide hypotheses for future trials in this irremediable cancer.

The addition of hormone therapy to tamoxifen does not prevent hot flashes in women at high risk for developing breast cancer.

Tamoxifen significantly reduces the risk of developing breast cancer in women at increased-risk. The usefulness of tamoxifen has been limited by its side effect profile, especially its propensity to worsen vasomotor symptoms. Hormone therapy (HT) has long been utilized to reduce vasomotor symptoms in peri- and post-menopausal women. The aim of this study was to compare the incidence of hot flashes, weight gain and other side effects associated with taking tamoxifen alone versus tamoxifen in combination with HT in high-risk women. One hundred eighty high-risk women were enrolled into one of two parallel study cohorts to receive tamoxifen alone (93 women) or tamoxifen with HT (87 women). Women were monitored at baseline, 3 months and then yearly for assessments of menopausal symptoms and toxicities associated with tamoxifen alone versus tamoxifen plus HT. We also assessed for differences in menopausal symptoms and toxicities by type of HT (estrogen vs. estrogen and progestin combination). Hot flash scores increased at 3 months and at 1 year compared with baseline in women on tamoxifen alone as well as for women on HT. Women on tamoxifen with estrogen only replacement had the greatest increase in hot flash scores, although this was not significantly different than the increase seen with tamoxifen alone. About 47% of participants on tamoxifen gained weight and there was a strong trend towards less weight gain in women on the combination of tamoxifen and HT, most pronounced for those on tamoxifen with estrogen alone replacement therapy. The addition of HT to tamoxifen therapy does not ameliorate tamoxifen-induced vasomotor symptoms. Tamoxifen associated weight gain, however, may be lessened by the addition of HT.