Trastuzumab deruxtecan in HER2-positive advanced breast cancer with or without brain metastases: a phase 3b/4 trial.

Trastuzumab deruxtecan (T-DXd) intracranial activity has been observed in small or retrospective patient cohorts with human epidermal growth factor receptor 2-positive (HER2+) advanced/metastatic breast cancer (mBC) and stable or active (untreated/previously treated and progressing) brain metastases (BMs). The phase 3b/4 DESTINY-Breast12 study investigated T-DXd in patients with HER2+ mBC and is, to our knowledge, the largest prospective study of T-DXd in patients with BMs in this setting. Patients (stable/active BMs (n = 263) and no BMs (n = 241)) treated with one or more prior anti-HER2-based regimens received T-DXd (5.4 mg per kg). Primary endpoints were progression-free survival (PFS; BMs cohort) and objective response rate (ORR) per Response Evaluation Criteria in Solid Tumors version 1.1 (non-BMs cohort). Additional endpoints included central nervous system (CNS) PFS, ORR, time to second progression, CNS ORR (BMs cohort), incidence of new symptomatic CNS metastases (non-BMs cohort), time to progression, duration of response, overall survival and safety (both cohorts). No formal hypothesis testing was conducted for this single-arm, open-label study. In the BMs cohort, 12-month PFS was 61.6% (95% confidence interval (CI): 54.9-67.6), and 12-month CNS PFS was 58.9% (95% CI: 51.9-65.3). In the non-BMs cohort, ORR was 62.7% (95% CI: 56.5-68.8). Grade 3 or higher adverse events occurred in 51% (BMs cohort) and 49% (non-BMs cohort) of patients. Investigator-reported interstitial lung disease/pneumonitis occurred in 16% (grade ≥3: 3%) of patients with BMs and 13% (grade ≥3: 1%) of patients without BMs. These data show substantial and durable overall and intracranial activity for T-DXd, supporting its use in previously treated patients with HER2+ mBC irrespective of stable/active baseline BMs. ClinicalTrials.gov identifier: NCT04739761 .

The impact of expanded access programs for systemic anticancer therapy in an Irish cancer centre.

BACKGROUND: Expanded access programs (EAPs) allow cancer patients with unmet clinical need to obtain access to pre-authorisation treatments. There is no standardised process for implementing these programs nationally, and real-world data on their impact is lacking. AIMS: This study aimed to evaluate the prevalence of such EAPs and their impact in a cancer centre. METHODS: Data relating to adult cancer patients treated via EAPs from 2011 to 2021 in three Cork university hospitals was collated. Descriptive statistics were employed to get an overview of the impact these programs currently have on cancer care provision. RESULTS: We identified 193 patients who accessed EAPs during the study period, availing of 33 separate drugs for a total of 50 different cancer indications. The prevalence of EAP usage was shown to have been trending upwards in recent years with a total of 189 programs being accessed throughout the period. Drugs provided were from a number of different anti-cancer drug classes, particularly targeted therapies (n = 18) and immune checkpoint inhibitors (n = 17). Cancers from a wide range of both solid and liquid tumour types were treated with EAP drugs, and patients treated were from across a broad spectrum of ages (26-82, SD 11.99). CONCLUSIONS: EAPs have an increasing role in accessing novel cancer therapies in our community and by extension nationally. Equity of EAP access would be facilitated by a national registry of available agents which we have established. Assessment of their benefits and toxicities would be enhanced by the requirement for a real-world database as a condition of EAP approval.

Multimodal, Technology-Assisted Intervention for the Management of Menopause after Cancer Improves Cancer-Related Quality of Life-Results from the Menopause after Cancer (Mac) Study.

BACKGROUND: Vasomotor symptoms (VMSs) associated with menopause represent a significant challenge for many patients after cancer treatment, particularly if conventional menopausal hormone therapy (MHT) is contraindicated. METHODS: The Menopause after Cancer (MAC) Study (NCT04766229) was a single-arm phase II trial examining the impact of a composite intervention consisting of (1) the use of non-hormonal pharmacotherapy to manage VMS, (2) digital cognitive behavioral therapy for insomnia (dCBT-I) using Sleepio (Big Health), (3) self-management strategies for VMS delivered via the myPatientSpace mobile application and (4) nomination of an additional support person/partner on quality of life (QoL) in women with moderate-to-severe VMS after cancer. The primary outcome was a change in cancer-specific global QoL assessed by the EORTC QLC C-30 v3 at 6 months. Secondary outcomes included the frequency of VMS, the bother/interference of VMS and insomnia symptoms. RESULTS: In total, 204 women (82% previous breast cancer) with a median age of 49 years (range 28-66) were recruited. A total of 120 women completed the protocol. Global QoL scores increased from 62.2 (95%CI 58.6-65.4) to 70.4 (95%CI 67.1-73.8) at 6 months (p < 0.001) in the intention to treatment (ITT) cohort (n = 204) and from 62 (95%CI 58.6-65.4) to 70.4 (95%CI 67.1-73.8) at 6 months (p < 0.001) in the per-protocol (PP) cohort (n = 120). At least 50% reductions were noticed in the frequency of VMS as well as the degree of bother/interference of VMS at six months. The prevalence of insomnia reduced from 93.1% at the baseline to 45.2% at 6 months (p < 0.001). The Sleep Condition Indicator increased from 8.5 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.0005) in the ITT cohort and 7.9 (SEM 0.4) to 17.3 (SEM 0.5) (p < 0.001) in the PP cohort. CONCLUSIONS: A targeted composite intervention improves the quality of life for cancer patients with frequent and bothersome vasomotor symptoms with additional benefits on frequency, the bother/interference of VMS and insomnia symptoms.

The Sleepio After Cancer (SAC) study. Digital cognitive behavioural therapy for insomnia (dCBT-I) in women cancer patients - Trial protocol of a randomised controlled trial.

AIMS: This study will assess the efficacy of digital CBT for insomnia (dCBT-I) compared to sleep hygiene education (SHE) for the management of insomnia in women with cancer. BACKGROUND: 30% of patients with cancer meet insomnia diagnostic criteria and this can be detrimental to health outcomes. Insomnia disorder comprises a dissatisfaction with sleep quantity or quality characterized by difficulty initiating sleep, frequent awakenings, or early morning wakening without the ability to return to sleep, at least 3 nights per week, for at least 3 months, causing significant impairment or distress in areas of functioning. METHODS: We will recruit 308 women with a current or prior cancer diagnosis who are currently experiencing insomnia; defined as a score of 16 or less on the Sleep Condition Indicator (SCI). Participants will be randomised to dCBT-I or SHE. dCBT-I will be delivered online via 6 sessions. SHE will be provided in an online format. Assessments of sleep and other related parameters, through validated questionnaires, will be taken at 12 and 24 weeks following intervention. Once 24 week assessments are completed, participants will crossover to the alternate arm (either SHE or dCBT-I) and undergo a final assessment at week 36. OUTCOMES: The primary outcome will be the mean continuous change in SCI score in the intervention arm compared to the control arm at 24 weeks. Additionally, the proportion of women with an SCI > 16 at 24 weeks will be assessed. Secondary outcomes include fatigue, sleep related quality of life, depression, anxiety, and hot flush interference. REGISTRATION: This study is registered on ClinicalTrials.gov with number NCT05816460.

Pilot study of the implementation of G8 screening tool, Cognitive screening assessment and Chemotherapy Toxicity assessment in older adults with cancer in a Tertiary University Hospital in Ireland.

BACKGROUND: Comprehensive geriatric assessment (CGA) is recommended by international guidelines prior to initiation of systemic anti-cancer treatment (SACT). In practice, CGA is limited by time constraints, lack of resources and expert interpretation. AIMS: The primary objective of this pilot study was to establish the prevalence of frailty (assessed by G8), cognitive impairment (assessed by Mini-Cog), and risk of chemotherapy toxicity (assessed by CARG Chemo-Toxicity Calculator) among patients (pts) ≥65 years commencing SACT. We selected these three screening tools due to the ease of conducting them in a busy outpatient setting. In addition, they have been validated to predict frailty and risk of toxicity from SACT among older adults with cancer. METHODS: Eligible participants were identified from medical oncology clinics. Assessments were conducted in an outpatient setting by treating physicians. Pt records were reviewed to gather demographic and cancer details. Statistical analyses were conducted using SPSS statistical software. RESULTS: Sixty-three participants were enrolled. The mean age of participants was 73yrs (range=65-88). Thirty-three (52.4%) were female and 30 (47.6%) were male. The majority (n=38, 60.3%) had metastatic cancer. The mean G8 score was 11.9 (range=6-19). Eighty-three percent had a G8 score ≤14. Mini-Cog was positive in 13 pts (21%). The mean CARG score was 7.5 (range=0-16), and 80% had a risk of at least 50% grade ≥3 toxicity. Of these, 48 (76.2%) received chemotherapy and 15 (23.8%) received non-cytotoxic SACT. In multi-variate analyses, age, cancer type, treatment type, and disease stage did not impact G8, Mini-Cog, or CARG scores. CONCLUSIONS: Our study has several limitations but suggests that the majority of older adults with cancer would qualify for formal CGA assessment. The risk of high-grade toxicity from SACT is substantial in this cohort. Chronological age was not found to negatively impact pts' frailty, cognition, or risk of toxicity.

Pregnancy-associated breast cancer: evaluating maternal and foetal outcomes. A national study.

PURPOSE: Pregnancy-associated breast cancer (PABC) is defined as breast cancer diagnosed during the gestational period (gp-PABC) or in the first postpartum year (pp-PABC). Despite its infrequent occurrence, the incidence of PABC appears to be rising due to the increasing propensity for women to delay childbirth. We have established the first retrospective registry study of PABC in Ireland to examine specific clinicopathological characteristics, treatments, and maternal and foetal outcomes. METHODS: This was a national, multi-site, retrospective observational study, including PABC patients treated in 12 oncology institutions from August 2001 to January 2020. Data extracted included information on patient demographics, tumour biology, staging, treatments, and maternal/foetal outcomes. Survival data for an age-matched breast cancer population over a similar time period was obtained from the National Cancer Registry of Ireland (NCRI). Standard biostatistical methods were used for analyses. RESULTS: We identified 155 patients-71 (46%) were gp-PABC and 84 (54%) were pp-PABC. The median age was 36 years. Forty-four patients (28%) presented with Stage III disease and 25 (16%) had metastatic disease at diagnosis. High rates of triple-negative (25%) and HER2+ (30%) breast cancer were observed. We observed an inferior 5-year overall survival (OS) rate in our PABC cohort compared to an age-matched breast cancer population in both Stage I-III (77.6% vs 90.9%) and Stage IV disease (18% vs 38.3%). There was a low rate (3%) of foetal complications. CONCLUSION: PABC patients may have poorer survival outcomes. Further prospective data are needed to optimise management of these patients.

Competing mortality risks: predicted cardiovascular disease risk versus predicted risk of breast cancer mortality in patients receiving adjuvant chemotherapy in a single Irish center.

BACKGROUND: Due to advances in care, most women diagnosed with breast cancer do not die from the disease itself. Instead, cardiovascular disease (CVD) remains the most frequent cause of death. Many breast cancer patients are older and have established CVD risk factors. They are at further risk due to exposure to anthracyclines, HER2 targeted agents, endocrine therapy and radiotherapy. In this study, we compared the 10-year predicted risk of breast cancer mortality versus that of cardiovascular (CV) morbidity/mortality in breast cancer patients receiving adjuvant chemotherapy using online predictive risk calculators. Furthermore, we evaluated the predicted outcome of CV risk factor optimisation on their overall CV risk. METHODS: This was a cross sectional study. All patients with resected Stage I-III breast cancer who received adjuvant chemotherapy at our centre from September 2015 to November 2016 were identified. Data recorded included demographics, tumor characteristics, treatments and CV risk factors. To calculate predicted 10-year risk of CVD and impact of lifestyle changes, we used the JBS3 (Joint British Society) online risk calculator. To calculate the predicted 10-year risk of breast cancer mortality, we used the PREDICT calculator. Biostatistical methods included Wilcoxon signed rank test for predicted CVD risk pre and post cardiovascular risk optimization. RESULTS: We identified 102 patients. Of this cohort, 76 patients were ≥ 50 years & 26 were < 50 years of age. The group had significant baseline cardiovascular risk factors: increased BMI (68 %, n = 70), ex-smoking (34 %, n = 35), current smoking (13 %, n = 13), hypertension (47 %, n = 47) and dyslipidemia (57 %). Of the total group, 48 % had a high (> 20 %) and 37 % had a moderate (10-20 %) 10-year predicted breast cancer mortality risk. Regarding 10-year predicted risk of CVD, 11 % and 22 % fell into the high (> 20 %) and moderate (10-20 %) risk categories, respectively. Assuming CV risk factor optimisation, there was a predicted improvement in median 10-year CV risk from 26.5 to 9.9 % (p = .005) in the high CVD risk group and from 14.0 to 6.6 % (p < .001) in the moderate CVD risk group. CONCLUSIONS: Benefits predicted with a CVD risk intervention model indicates that this should be incorporated into routine breast oncology care.

A Multicenter Retrospective Review of Systemic Anti-Cancer Treatment and Palliative Care Provided to Solid Tumor Oncology Patients in the 12 Weeks Preceding Death in Ireland.

BACKGROUND: Systemic anti-cancer treatment (SACT) can improve symptoms and survival in patients with incurable cancer but there may be harmful consequences. Information regarding the use of SACT at the end-of-life and its impact on patients has not been described in Ireland. AIMS: The study aimed to quantify and describe the use of SACT at end-of-life. The primary outcome of interest was the number of patients who received treatment in the last 12, 4 and 2 weeks of life. Secondary outcomes included the frequency of admissions and procedures, location of death, and timing of specialist palliative care (SPC) referral. METHODS: Retrospective review. Fisher exact testing was used for analyses. Patients were included if they died between January 2015 and July 2017 and received at least 1 dose of treatment for a solid tumor malignancy. RESULTS: Five hundred and eighty two patients were included. Three hundred and thirty eight (58%), 128 (22%) and 36 (6%) received treatment in the last 12, 4 and 2 weeks of life respectively. Patients who received chemotherapy in the last 12 weeks of life were more likely to be admitted to hospital, undergo a procedure, and die in hospital than those who did not (P < 0.001 for all). Median time of SPC referral before death was shorter in those patients who received chemotherapy than those who did not (61 v129 days, p = 0.0001). CONCLUSION: Patients who received chemotherapy had a higher likelihood of hospital admission, invasive procedure, and in-hospital death. They were less likely to have been referred early to SPC services.

Virtual oncology clinics during the COVID-19 pandemic.

BACKGROUND: The COVID-19 pandemic has resulted in radical changes in the delivery of healthcare worldwide. Our oncology service (at an Irish national cancer centre) rapidly transitioned to the use of telemedicine or virtual clinics (VC) to minimise potential risk of exposure to COVID-19 amongst an immunosuppressed, high-risk population. Our study aimed to evaluate the use of VC in this setting. METHODS: An 18-point questionnaire was designed to investigate the patient experience of VC during the COVID-19 pandemic in Ireland and compliance with guidelines developed in Ireland to conduct VC and the role of VC in the future. Questionnaires were distributed following the receipt of verbal consent from patients during the VC. Descriptive statistics were utilised for data analysis using SPSS®. RESULTS: One hundred and four patients returned completed surveys (n = 104/164, 63% response rate). Overall satisfaction levels were high with most patients (n = 58/100, 58%; no answer provided (NAP), n = 4) equally satisfied or nearly equally satisfied with VC in comparison to a usual clinic encounter. The majority of patients felt that there should be a role for VC in the future (n = 84/102, 82%; NAP, n = 2). The majority of patients (n = 61/99, 61%; NAP, n = 5) were very relieved to avoid a hospital visit due to perceived risk of potential exposure to COVID-19. CONCLUSION: The majority of oncology patients were satisfied with a VC encounter. VC may have a role in the future of medical care in Ireland post the COVID-19 pandemic.

N-Linked glycosylation profiles of therapeutic induced senescent (TIS) triple negative breast cancer cells (TNBC) and their extracellular vesicle (EV) progeny.

Triple negative breast cancer (TNBC) has poor clinical outcomes and limited treatment options. Chemotherapy, while killing some cancer cells, can result in therapeutic-induced-senescent (TIS) cells. Senescent cells release significantly more extracellular vesicles (EVs) than non-senescent cells. Recently, N- and O-linked glycosylation alterations have been associated with senescence. We aimed to profile the N-linked glycans of whole cells, membrane, cytoplasm and EVs harvested from TIS TNBC cells and to compare these to results from non-senescent cells. TIS was induced in the Cal51 TNBC cells using the chemotherapeutic agent paclitaxel (PTX). Ultra-performance liquid chromatography (UPLC) analysis of exoglycosidase digested N-linked glycans was carried out on TIS compared to non-treated control cells. LC-Mass spectrometry (MS) analysis of the N-linked glycans and lectin blotting of samples was carried out to confirm the UPLC results. Significant differences were found in the N-glycan profile of the Cal51 membrane, cytoplasm and EV progeny of TIS compared to non-senescent cells. Protein mass spectrometry showed that the TIS cells contain different glycan modifying enzymes. The lectin, calnexin demonstrated a lower kDa size (∼58 kDa) in TIS compared to control cells (∼90 kDa) while Galectin 3 demonstrated potential proteolytic cleavage with 32 kDa and ∼22 kDa bands evident in TIS compared to non-senescent control cells with a major 32 kDa band only. TIS CAL51 cells also demonstrated a reduced adhesion to collagen I compared to control non-senescent cells. This study has shown that therapeutic-induced-senescent TNBC cells and their EV progeny, display differential N-glycan moieties compared to non-senescent Cal51 cells and their resultant EV progeny. For the future, N-glycan moieties on cancer senescent cells and their EV progeny hold potential for (i) the monitoring of treatment response as a liquid biopsy, and (ii) cancer senescent cell targeting with lectin therapies.

A Phase II Trial of Cabozantinib in Hormone Receptor-Positive Breast Cancer with Bone Metastases.

BACKGROUND: We assessed the antitumor activity of cabozantinib, a potent multireceptor oral tyrosine kinase inhibitor, in patients with hormone receptor-positive breast cancer with bone metastases. PATIENTS AND METHODS: In this single-arm multicenter phase II study, patients received an initial starting dose of 100 mg, later reduced to 60 mg, per day. The primary endpoint was the bone scan response rate. Secondary endpoints included objective response rate by RECIST, progression-free survival (PFS), and overall survival (OS). RESULTS: Of 52 women enrolled, 20 (38%) experienced a partial response on bone scan and 6 (12%) had stable disease. Prior to the first repeat bone scan at 12 weeks, 19 (35%) patients discontinued study treatment because of early clinical progression or unacceptable toxicity. RECIST evaluation based on best overall response by computed tomography revealed stable disease in extraosseous tissues in 26 patients (50%) but no complete or partial responses. In 25 patients with disease control on bone scan at 12 weeks, only 3 (12%) patients developed extraosseous progression. The median PFS was 4.3 months, and median OS was 19.6 months. The most common grade 3 or 4 toxicities were hypertension (10%), anorexia (6%), diarrhea (6%), fatigue (4%), and hypophosphatemia (4%). CONCLUSION: Bone scans improved in 38% of patients with metastatic hormone receptor-positive breast cancer and remained stable in an additional 12% for a minimum duration of 12 weeks on cabozantinib. Further investigations should assess the activity of cabozantinib in combination with other hormonal and other breast cancer therapies and determine whether bone scan responses correlate with meaningful antitumor effects. ClinicalTrials.gov identifier. NCT01441947 IMPLICATIONS FOR PRACTICE: Most patients with metastatic hormone receptor-positive (HR+) breast cancer have bone involvement, and many have bone-only disease, which is difficult to evaluate for response. This phase II single-arm study evaluated the clinical activity of the small molecule MET/RET/VEGFR2 inhibitor cabozantinib in patients with metastatic HR+ breast cancer with bone metastases. This study met its primary endpoint, and cabozantinib treatment resulted in a significant bone scan response rate correlating with improved survival. This is the first study to use bone scan response as a primary endpoint in breast cancer. The results support further study of cabozantinib in HR+ breast cancer.

Effects of Celecoxib and Low-dose Aspirin on Outcomes in Adjuvant Aromatase Inhibitor-Treated Patients: CCTG MA.27.

Background: Celecoxib and low-dose aspirin might decrease risk of breast cancer recurrence. Methods: In the Canadian Cancer Trials Group MA.27, postmenopausal hormone receptor-positive breast cancer patients were randomly assigned (2 × 2) to adjuvant exemestane or anastrozole, and celecoxib or placebo. Low-dose aspirin of 81 mg or less was a stratification factor. Due to concerns about cardiac toxicity, celecoxib use was stopped in December 2004, while stratification by aspirin use was removed through protocol amendment. We examined the effects of celecoxib and low-dose aspirin on event-free survival (EFS), defined as time from random assignment to time of locoregional or distant disease recurrence, new primary breast cancer, or death from any cause; distant disease-free survival (DDFS); and overall survival (OS). All statistical tests were two-sided. Results: Random assignment to celecoxib (n = 811, 50.0%) or placebo (n = 811, 50.0%) was discontinued after 18 months (n = 1622). At a median of 4.1 years' follow-up, among 1622 patients, 186 (11.5%) patients had an EFS event: 80 (4.9%) had distant relapse, and 125 (7.7%) died from any cause. Celecoxib did not statistically significantly impact EFS, DDFS, or OS in univariate analysis (respectively, P = .92, P = .55, and P = .56) or multivariable analysis (respectively, P = .74, P = .60, and P = .76). Low-dose aspirin use (aspirin users n = 476, 21.5%; non-aspirin users n = 1733, 78.5%) was associated in univariate analyses with worse EFS (hazard ratio [HR] = 1.48, 95% confidence interval [CI] = 1.12 to 1.96, P = 0.006) and worse OS (HR = 1.87, 95% CI = 1.35 to 2.61, P < .001). After adjusting for baseline characteristics and treatment arm, aspirin use showed no statistical association with EFS (P = .08) and DDFS (P = .82), but was associated with statistically worse OS (HR = 1.67, 95% CI = 1.13 to 2.49, P = .01). Conclusion: Random assignment to short-term (≤18 months) celecoxib as well as use of low-dose aspirin showed no effect on DDFS and EFS in multivariable analysis. Low-dose aspirin increased "all-cause" mortality, presumably because of higher preexisting cardiovascular risks.

Extended Adjuvant Endocrine Therapy in Hormone Receptor-Positive Early Breast Cancer.

Despite meaningful, incremental improvements in detection, local treatment and adjuvant systemic treatments for breast cancer, there remains a significant risk of late relapse in hormone receptor (HR)-positive disease. 5 years of tamoxifen or an aromatase inhibitor for all patients with HR-positive early breast cancer is considered standard; however, there are now data to support an extended approach using up to 10 years of treatment. This review will provide some historical background on endocrine therapy and summarize the key clinical trials that demonstrate the small absolute benefit of extended adjuvant therapy. We provide suggested treatment algorithms for both premenopausal and postmenopausal patients and an overview of ongoing adjuvant trials.

Phase II and Biomarker Study of Cabozantinib in Metastatic Triple-Negative Breast Cancer Patients.

Currently, no targeted therapies are available for metastatic triplenegative breast cancer (mTNBC). We evaluated the safety, efficacy, and biomarkers of response to cabozantinib, a multikinase inhibitor, in patients with mTNBC. We conducted a single arm phase II and biomarker study that enrolled patients with measurable mTNBC. Patients received cabozantinib (60 mg daily) on a 3-week cycle and were restaged after 6 weeks and then every 9 weeks. The primary endpoint was objective response rate. Predefined secondary endpoints included progression-free survival (PFS), toxicity, and tissue and blood circulating cell and protein biomarkers. Of 35 patients who initiated protocol therapy, 3 (9% [95% confidence interval (CI): 2, 26]) achieved a partial response (PR). Nine patients achieved stable disease (SD) for at least 15 weeks, and thus the clinical benefit rate (PR+SD) was 34% [95% CI: 19, 52]. Median PFS was 2.0 months [95% CI: 1.3, 3.3]. The most common toxicities were fatigue, diarrhea, mucositis, and palmar-plantar erythrodysesthesia. There were no grade 4 toxicities, but 12 patients (34%) required dose reduction. Two patients had TNBCs with MET amplification. During cabozantinib therapy, there were significant and durable increases in plasma placental growth factor, vascular endothelial growth factor (VEGF), VEGF-D, stromal cell-derived factor 1a, and carbonic anhydrase IX, and circulating CD3 + cells and CD8 + T lymphocytes, and decreases in plasma soluble VEGF receptor 2 and CD14+ monocytes (all p < .05). Higher baseline concentrations of soluble MET (sMET) associated with longer PFS (p = .03). In conclusion, cabozantinib showed encouraging safety and efficacy signals but did not meet the primary endpoint in pretreated mTNBC. Exploratory analyses of circulating biomarkers showed that cabozantinib induces systemic changes consistent with activation of the immune system and antiangiogenic activity, and that sMET should be further evaluated a potential biomarker of response. IMPLICATIONS FOR PRACTICE: Triple-negative breast cancer (TNBC)-a disease with a dearth of effective therapies-often overexpress MET, which is associated with poor clinical outcomes. However, clinical studies of agents targeting MET and VEGF pathways-alone or in combination-have shown disappointing results. This study of cabozantinib (a dual VEGFR2/MET) in metastatic TNBC, while not meeting its prespecified endpoint, showed that treatment is associated with circulating biomarker changes, and is active in a subset of patients. Furthermore, this study demonstrates that cabozantinib therapy induces a systemic increase in cytotoxic lymphocyte populations and a decrease in immunosuppressive myeloid populations. This supports the testing of combinations of cabozantinib with immunotherapy in future studies in breast cancer patients.

The Evolving Role of Circulating Tumor Cells in the Personalized Management of Breast Cancer: from Enumeration to Molecular Characterization.

Circulating Tumor cells (CTCs) represent tumor cells in the blood stream dislodged from the primary tumor. The presence of CTCs in the bloodstream provides a unique opportunity to sample cancer tissue by means of a relatively less-invasive "liquid biopsy." Over the past decade, there has been a tremendous increase in the amount of research examining the potential clinical utility of CTCs in the management of cancer. A number of techniques to refine the sensitivity and range of CTC assays are also in development. In this article, we review the recent developments in the current and potential clinical applications of CTCs in breast cancer. CTC enumeration already has an established role as a prognostic biomarker in metastatic breast cancer, while molecular characterization of CTCs can serve as a potential predictive biomarker for therapy selection, pharmacodynamic evaluation, and identification of novel actionable targets for novel therapies. The role of CTCs in breast cancer screening and detection of recurrence is currently limited. Further development in techniques will be pivotal in enhancing the broad applicability of CTCs and advancing the field of personalized breast cancer therapy.

Isocitrate dehydrogenase 1 (IDH1) mutation in breast adenocarcinoma is associated with elevated levels of serum and urine 2-hydroxyglutarate.

Mutations in the IDH1 and IDH2 (isocitrate dehydrogenase) genes have been discovered across a range of solid-organ and hematologic malignancies, including acute myeloid leukemia, glioma, chondrosarcoma, and cholangiocarcinoma. An intriguing aspect of IDH-mutant tumors is the aberrant production and accumulation of the oncometabolite 2-hydroxyglutarate (2-HG), which may play a pivotal oncogenic role in these malignancies. We describe the first reported case of an IDH1 p.R132L mutation in a patient with hormone receptor-positive (HR+) breast adenocarcinoma. This patient was initially treated for locally advanced disease, but then suffered a relapse and metastasis, at which point an IDH1-R132 mutation was discovered in an affected lymph node. The mutation was subsequently found in the primary tumor tissue and all metastatic sites, but not in an uninvolved lymph node. In addition, the patient's serum and urine displayed marked elevations in the concentration of 2-HG, significantly higher than that measured in six other patients with metastatic HR+ breast carcinoma whose tumors were found to harbor wild-type IDH1. In summary, IDH1 mutations may impact a rare subgroup of patients with breast adenocarcinoma. This may suggest future avenues for disease monitoring through noninvasive measurement of 2-HG, as well as for the development and study of targeted therapies against the aberrant IDH1 enzyme.

Detection of cancer DNA in plasma of patients with early-stage breast cancer.

PURPOSE: Detecting circulating plasma tumor DNA (ptDNA) in patients with early-stage cancer has the potential to change how oncologists recommend systemic therapies for solid tumors after surgery. Droplet digital polymerase chain reaction (ddPCR) is a novel sensitive and specific platform for mutation detection. EXPERIMENTAL DESIGN: In this prospective study, primary breast tumors and matched pre- and postsurgery blood samples were collected from patients with early-stage breast cancer (n = 29). Tumors (n = 30) were analyzed by Sanger sequencing for common PIK3CA mutations, and DNA from these tumors and matched plasma were then analyzed for PIK3CA mutations using ddPCR. RESULTS: Sequencing of tumors identified seven PIK3CA exon 20 mutations (H1047R) and three exon 9 mutations (E545K). Analysis of tumors by ddPCR confirmed these mutations and identified five additional mutations. Presurgery plasma samples (n = 29) were then analyzed for PIK3CA mutations using ddPCR. Of the 15 PIK3CA mutations detected in tumors by ddPCR, 14 of the corresponding mutations were detected in presurgical ptDNA, whereas no mutations were found in plasma from patients with PIK3CA wild-type tumors (sensitivity 93.3%, specificity 100%). Ten patients with mutation-positive ptDNA presurgery had ddPCR analysis of postsurgery plasma, with five patients having detectable ptDNA postsurgery. CONCLUSIONS: This prospective study demonstrates accurate mutation detection in tumor tissues using ddPCR, and that ptDNA can be detected in blood before and after surgery in patients with early-stage breast cancer. Future studies can now address whether ptDNA detected after surgery identifies patients at risk for recurrence, which could guide chemotherapy decisions for individual patients.