Tumor heterogeneity and clinically invisible micrometastases in metastatic breast cancer-a call for enhanced surveillance strategies.

The biology of metastatic breast cancer (MBC) is understudied, primarily due to the difficulty of procuring multiple samples from patients with oligometastatic breast cancer. We developed a rapid postmortem tissue procurement program that allows the collection and analysis of numerous metastatic lesions, subclinical locations, and potential pre-metastatic niches that fall within this scope. We conducted a rapid postmortem tissue collection study on 9 patients with MBC. Patients and their families consented to donate tissues immediately after death in an IRB-approved study. Various disease subtypes, progression histories, organ involvement, and final causes of death are reported. In patients with hormone receptor-positive (HR+) disease, estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki-67 expression were heterogeneous across metastatic lesions within individual patients. Disease phenotype at the end of life trended toward complete loss of HR expression. Nearly all (n = 7) patients exhibited extensive tumor involvement of additional organs that had not been previously diagnosed clinically and were not retrospectively visible on recent imaging. Of these seven individuals, three included organs uncommonly associated with MBC: kidney, spleen, pancreas, and ovary. Finally, we identified clinically undetectable micrometastases in several organs uncommonly involved in MBC. Our findings raise several clinically relevant questions regarding the mechanisms of metastatic progression. Insights from this study argue for better surveillance strategies for monitoring MBC. We highlight the need to capture more accurate biomarker information in the context of heterogeneous disease and urge the consideration of treatment strategies that combine multiple targeted therapies.

Thrombopoietin Receptor Agonists for Thrombocytopenia Secondary to HER2-Targeted Antibody Drug Conjugates.

Trastuzumab emtansine and trastuzumab deruxtecan are widely used in breast cancer and other solid tumor malignancies. Thrombocytopenia is a common adverse event associated with the use of these agents that can lead to a treatment delay, reduction in dose intensity, and discontinuation. The role of thrombopoietin receptor agonists (TPO-RA) remains unknown in this setting. We report a case series of 6 individuals with breast cancer that experienced dose-reductions and therapy delays due to thrombocytopenia secondary to trastuzumab emtansine or trastuzumab deruxtecan therapy and received intervention with TPO-RA. All 6 were able to resume therapy with TPO-RA support.

HER2-targeted antibody-drug conjugates for breast cancer: ancestry and dose adjustment for thrombocytopenia.

BACKGROUND: Thrombocytopenia is a common adverse event on HER2-targeted therapies, fam-trastuzumab deruxtecan (T-DXd) and ado-trastuzumab emtansine (T-DM1). A reported association of Asian ancestry with this event merits investigation to rule out potential confounding. METHODS: Subjects in this retrospective cohort were female patients with HER2 positive breast cancer, of Asian or non-Hispanic White ancestry, who initiated T-DM1 or T-DXd from January 2017 through October 2021. Follow-up closed in January 2022. Primary endpoint was dose adjustment for thrombocytopenia. Competing endpoints were discontinuation of drug for other toxicity, disease progression, or for completion of prescribed cycles. The association between Asian ancestry and thrombocytopenia-related dose adjustment was tested at p < 0.01 in a proportional hazards model for the sub-distributions of 4 (primary and competing) endpoints. Covariates examined as potential confounders were age, metastatic disease, specific HER2-targeted drug, and prior drug switching for toxicity. RESULTS: Among 181 subjects, 48 reported Asian ancestry. Incidence of dose adjustment for thrombocytopenia was higher in patients with Asian ancestry and among patients switched to T-DXd after experiencing thrombocytopenia on T-DM1. Independent of specific drug and prior drug switching, Asian ancestry was associated with dose adjustment for thrombocytopenia (hazards ratio 2.95, 95% confidence interval 1.41-6.18) but not with competing endpoints. Among participants of Asian ancestry, the ancestral origin was usually China or the Philippines (where Chinese ancestry is common). CONCLUSIONS: The association between Asian ancestry and thrombocytopenia on HER2-targeted therapy is independent of age, metastatic disease, drug, and history of similar toxicity. This association may have a genetic basis linked to Chinese ancestry.

Immunogenicity and efficacy of pembrolizumab and doxorubicin in a phase I trial for patients with metastatic triple-negative breast cancer.

Currently there is a limited understanding for the optimal combination of immune checkpoint inhibitor and chemotherapy for patients with metastatic triple-negative breast cancer (mTNBC). Here we evaluate the safety, efficacy, and immunogenicity of a phase I trial for patients with mTNBC treated with pembrolizumab plus doxorubicin. Patients without prior anthracycline use and 0-2 lines of prior systemic chemotherapies received pembrolizumab and doxorubicin every 3 weeks for 6 cycles followed by pembrolizumab maintenance until disease progression or intolerance. The primary objectives were safety and objective response rate per RECIST 1.1. Best responses included one complete response (CR), five partial responses (PR), two stable disease (SD), and one progression of disease (PD). Overall response rate was 67% (95% CI 13.7%, 78.8%) and clinical benefit rate at 6 months was 56% (95% CI 21.2%, 86.3%). Median PFS was 5.2 months (95% CI 4.7, NA); median OS was 15.6 months (95% CI 13.3, NA). Grade 3-4 AEs per CTCAE 4.0 were neutropenia n = 4/10 (40%), leukopenia n = 2/10 (20%), lymphopenia n = 2/10 (20%), fatigue n = 2/10 (20%), and oral mucositis n = 1/10 (10%). Immune correlates showed increased frequencies of circulating CD3 + T cells (p = 0.03) from pre-treatment to cycle 2 day 1 (C2D1). An expansion of a proliferative exhausted-like PD-1 + CD8 + T cell population was identified in 8/9 patients, and exhausted CD8 + T cells were significantly expanded from pre-treatment to C2D1 in the patient with CR (p = 0.01). In summary, anthracycline-naïve patients with mTNBC treated with the combination of pembrolizumab and doxorubicin showed an encouraging response rate and robust T cell response dynamics.Trial registration: NCT02648477.

Phase 2 prospective open label study of neoadjuvant nab-paclitaxel, trastuzumab, and pertuzumab in patients with HER2-positive primary breast cancer.

BACKGROUND: The objective of this study was to evaluate the safety and efficacy of nab-paclitaxel, trastuzumab, and pertuzumab as neoadjuvant therapy (NAT) in patients with human epidermal growth factor receptor 2 HER2+ breast cancer (HER2+ BC) to determine pathologic complete response (pCR), invasive disease-free survival (iDFS), and overall survival. METHODS: Forty-five patients with HER2+ BC Stages II-III were to be enrolled from 2013 to 2017. Patients were treated with weekly nab-paclitaxel (100 mg/m2 intravenously), weekly trastuzumab (4 mg/kg loading dose, then 2 mg/kg), and six cycles of pertuzumab (840 mg loading dose, then 420 mg intravenously day 1 every 21 days). RESULTS: Median follow-up was 60 months (95% CI, 32.3-55.6) and pCR was 29/45 (64%). The 5-year iDFS for patients who achieved pCR (N = 29) was 96.3% (95% CI, 76.5-99.5) and non-pCR patients (N = 16) was 74.3% (95% CI, 39.1-91.0). The 5-year overall survival (N = 45) was 94.1% (95% CI, 77.6-98.5). Based on hormonal status, the 5-year iDFS for HR+ pCR patients (N = 14) was 92.3% (95% CI, 56.6-98.9) and for HR- (N = 15) was 100% (p = .3). CONCLUSIONS: This anthracycline/carboplatin-free regimen with nab-paclitaxel achieved a pCR rate of 64% in patients with HER2+ BC. The 5-year iDFS in patients with and without pCR was 96.3% and 74.3%, respectively. The pCR rate is comparable with docetaxel, carboplatin, trastuzumab, and pertuzumab therapy in the NAT setting, but with fewer treatment-associated toxicities. This finding suggests the possibility of safe avoidance of anthracyclines and carboplatin as components of NAT in patients with HER2+ BC.

Tumor-infiltrating exhausted CD8+ T cells dictate reduced survival in premenopausal estrogen receptor-positive breast cancer.

CD8+ tumor-infiltrating lymphocytes (TILs) are associated with improved survival in triple-negative breast cancer (TNBC) yet have no association with survival in estrogen receptor-positive (ER+) BC. The basis for these contrasting findings remains elusive. We identified subsets of BC tumors infiltrated by CD8+ T cells with characteristic features of exhausted T cells (TEX). Tumors with abundant CD8+ TEX exhibited a distinct tumor microenvironment marked by amplified interferon-γ signaling-related pathways and higher programmed death ligand 1 expression. Paradoxically, higher levels of tumor-infiltrating CD8+ TEX associated with decreased overall survival of patients with ER+ BC but not patients with TNBC. Moreover, high tumor expression of a CD8+ TEX signature identified dramatically reduced survival in premenopausal, but not postmenopausal, patients with ER+ BC. Finally, we demonstrated the value of a tumor TEX signature score in identifying high-risk premenopausal ER+ BC patients among those with intermediate Oncotype DX Breast Recurrence Scores. Our data highlight the complex relationship between CD8+ TILs, interferon-γ signaling, and ER status in BC patient survival. This work identifies tumor-infiltrating CD8+ TEX as a key feature of reduced survival outcomes in premenopausal patients with early-stage ER+ BC.

A pilot study of an accelerometer-equipped smartphone to monitor older adults with cancer receiving chemotherapy in Mexico.

OBJECTIVES: Older adults with cancer in developing countries face challenges accessing healthcare due to a lack of personnel and infrastructure. A decline in physical activity (defined as a decrease in the number of daily steps) may be a novel method for the timely detection of toxicity in older adults receiving chemotherapy in resource-constrained settings. MATERIALS AND METHODS: In this feasibility study, patients aged ≥65years starting first-line chemotherapy for solid tumors were given a smartphone with a pedometer application. Daily steps were monitored daily for one cycle. If a ≥15% decrease from baseline was identified, the patient was called and the presence of toxicity assessed. The intervention would be feasible if ≥75% of the subjects recorded steps for ≥75% of the planned chemotherapy days. RESULTS: Forty patients (median age 73; 57% [N=23] female) were included. Seventy percent (N=28) had stage III-IV disease with 45% (N=18) gastrointestinal, 23% (N=9) breast, and 32% (N=13) other malignancies. Mean pre-treatment daily steps was 3111 (Standard Deviation [SD] 1731), and median follow-up was 21days (range 2-28). Despite having limited exposure to mobile technology, most (93%) patients used the smartphone appropriately, and 85% found it easy to use. Sixty percent of patients (N=24) had toxicities managed over the phone, 27.5% (N=10) were sent for urgent medical attention and 15% (N=6) were hospitalized. CONCLUSION: Using smartphones to monitor older adults with cancer receiving chemotherapy in a resource-constrained setting is feasible and acceptable. A decrease in the number of daily steps was common and helped to identify chemotherapy toxicity.

Project connect online: randomized trial of an internet-based program to chronicle the cancer experience and facilitate communication.

PURPOSE: Evidence suggests that expressing emotions related to cancer and receiving interpersonal support can promote psychological and physical health in women diagnosed with breast cancer. However, adaptive expression of feelings and communication with one's social network can pose challenges for patients with cancer. We report on a randomized controlled trial of an intervention, Project Connect Online, for patients with breast cancer to create personal Web sites to chronicle their experience and communicate with their social network. PATIENTS AND METHODS: Women (N = 88) diagnosed with breast cancer (any stage, any interval since diagnosis) were randomly assigned to participate in a 3-hour workshop for hands-on creation of personal Web sites with a follow-up call to facilitate Web site use, or to a waiting-list control. Assessed before randomization and 6 months after the intervention, dependent variables included depressive symptoms, positive and negative mood, cancer-related intrusive thoughts, and perceived cancer-related benefits in life appreciation and strengthened relationships. RESULTS: Relative to control participants, women randomly assigned to Project Connect Online evidenced significant benefit 6 months later on depressive symptoms, positive mood, and life appreciation, but not negative mood, perceived strengthened relationships, or intrusive thoughts. Treatment status moderated the intervention effects, such that women currently undergoing medical treatment for cancer benefitted significantly more from the intervention on depressive symptoms and positive mood than did women not receiving treatment. CONCLUSION: Findings suggest the promise of an intervention to facilitate the ability of women diagnosed with breast cancer to chronicle their experience and communicate with their social network via the Internet.

Bevacizumab and albumin-bound paclitaxel treatment in metastatic breast cancer.

BACKGROUND: Miller et al demonstrated that the combination of bevacizumab and paclitaxel has significant activity in metastatic breast cancer (MBC). Because albumin-bound paclitaxel has been shown to have less toxicity, a better tumor delivery, and possibly better response for MBC, we combined it with bevacizumab to treat women with MBC. PATIENTS AND METHODS: This is a retrospective analysis. Billing records from March 2005 through December 2006 were reviewed to identify all patients treated with a combination of albumin-bound paclitaxel/bevacizumab. A total of 40 women were identified. They received a minimum of 2 courses. Patients with measurable disease were monitored for response using Response Evaluation Criteria in Solid Tumors. Women with bone-only disease were monitored with positron emission tomography (PET)/computed tomography/magnetic resonance imaging and tumor markers. All response data were confirmed by independent review. RESULTS: Of 33 women with measurable disease, 16 had objective responses to the albumin-bound paclitaxel/bevacizumab regimen (3 complete responses and 13 partial responses) for an overall response rate (ORR) of 48.5%. Median time to progression for responders was 128 days. Another 5 women had stable disease (SD) with a median duration of 135 days. Of 7 patients with bone-only disease, 2 had almost complete resolution of PET activity and 4 had SD (median, 148 days). Toxicity was acceptable with fatigue, neuropathy, pain, and hypertension being the most common complaints. CONCLUSION: In our limited series of women with advanced, heavily pretreated MBC treated with albumin-bound paclitaxel/bevacizumab, we saw a 48.5% ORR. The regimen was well tolerated. Randomized studies are needed to confirm efficacy and safety of this combination in treating breast cancer.

Lymph node status combined with lymphovascular invasion creates a more powerful tool for predicting outcome in patients with invasive breast cancer.

BACKGROUND: Multiple clinical, biologic, and pathologic factors are known to correlate with outcome in patients with invasive breast cancer. The utility of lymphovascular invasion as an additional useful prognostic indicator has been heretofore ill defined. The purpose of the current study was to determine whether the presence or absence of peritumoral lymphovascular invasion (LVI) contribute further significant information in assessing survival. METHODS: Using a prospective database of 1,258 patients with invasive breast cancer followed up for as long as 12 years, eight factors were evaluated for their impact on patient survival: lymph node status, LVI, age at diagnosis, tumor size, tumor palpability, estrogen and progesterone receptor status, and nuclear grade. RESULTS: Multivariate analysis revealed that both lymph node status and the presence or absence of LVI were highly significant independent predictors of outcome. CONCLUSIONS: Knowledge of both lymph node status and the presence or absence of LVI can be used to predict which subset of patients will do extremely well (node negative + LVI absent) or extremely poorly (node positive + LVI present). The combination of the two factors is most meaningful in patients with 1 to 3 positive nodes.

Chemotherapy-induced activation of hemostasis: effect of a low molecular weight heparin (dalteparin sodium) on plasma markers of hemostatic activation.

PURPOSE: To evaluate the effect of standard chemotherapeutic regimens on the hemostatic profile of patients with breast and lung carcinoma; and to evaluate the effect of a single dose of a low molecular weight (LMW) heparin, dalteparin sodium, administered prior to the chemotherapy on markers of hemostatic activation. PATIENTS AND METHODS: 11 patients with breast cancer and 10 patients with lung cancer receiving systemic chemotherapy were studied. 10 breast cancer patients and 9 lung cancer patients completed at least 1 cycle of treatment and had all hemostatic studies. Patients had a complete hemostatic and prothrombotic profile performed at study initiation. Markers of hemostatic activation consisting of immunoassays for thrombin-antithrombin (TAT) complex and D-dimer were measured in plasma samples obtained prior to chemotherapy and at 1, 24 and 48 h after treatment. A 2500 U dose of dalteparin was given prior to the 2nd cycle of chemotherapy; 5000 U of dalteparin was given prior to the 4th treatment cycle. RESULTS: Chemotherapy resulted in statistically significant increases in TAT and D-dimer for the 1, 24 and 48 h plasma samples in both the breast and lung cancer patients for all cycles of chemotherapy given without LMW heparin. There were statistically significant increases in basal thrombin generation over the 4 cycles of treatment which was unrelated to active cancer. Both pretreatment doses of dalteparin effectively prevented increases in the markers of hemostatic activation. However, in the lung cancer patients, who had significantly increased basal thrombin generation, the 5000 U dose dalteparin was more effective. CONCLUSION: Chemotherapy results in significant hemostatic activation in patients with breast and lung cancer. The effect of treatment appears to be cumulative. A single dose of LMW heparin administered prior to therapy can suppress hemostatic activation.