ST-Segment Elevation Myocardial Infarction (STEMI) Management in the Era of COVID-19: A Systematic and Critical Review of Published Guidance Reports.

Background: Coronavirus disease 2019 (COVID-19) had a major impact on healthcare systems worldwide. During the early phase of the pandemic many elective procedures were postponed. At the same time, the safe and effective management of medical emergencies such as ST-segment elevation myocardial infarction (STEMI) has been a challenge. Methods: A systematic literature search was conducted aiming to identify published guidance reports by national or international societies regarding the management of patients suffering STEMI in the era of COVID-19. Results: Among 1681 articles initially retrieved, six fulfilled the inclusion criteria and were included in the systematic review. Two reports were international consensus documents, while four reports were national guidance statements from Asian countries (Taiwan, India, Iran, and China). Most documents were drafted during the early phase of the pandemic. According to the international consensus documents, percutaneous coronary intervention (PCI) should be regarded as the reperfusion method of choice. On the other hand, in three out of four national consensus statements (Taiwan, Iran and China) fibrinolysis was considered as the reperfusion method of choice for STEMI in suspected/confirmed patients with COVID-19, unless contraindicated or in the presence of high cardiovascular risk clinical features. Authors of all documents underlined the need for early COVID-19 testing in patients with STEMI to better determine the next therapeutical steps. Conclusions: National and international consensus statements for STEMI management in the era of COVID-19 have been published mainly during the early peak phase of the pandemic. Authors recognise that these recommendations are mainly based on expert opinions and observational data. As global immunization rates increase and methods for rapid COVID-19 detection are widely available, the implementation of traditional evidence-based practices used before the pandemic is becoming more feasible.

Cardiac Injury in COVID-19: A Systematic Review of Relevant Meta-Analyses.

Background: Cardiac injury (CI) is not a rare condition among hospitalized patients with coronavirus disease 2019 (COVID-19). Its prognostic value has been extensively reported through the literature, mainly in the context of observational studies. An impressive number of relevant meta-analyses has been conducted. These meta-analyses present similar and consistent results; yet interesting methodological issues emerge. Methods: A systematic literature search was conducted aiming to identify all relevant meta-analyses on (i) the incidence, and (ii) the prognostic value of CI among hospitalized patients with COVID-19. Results: Among 118 articles initially retrieved, 73 fulfilled the inclusion criteria and were included in the systematic review. Various criteria were used for CI definition mainly based on elevated cardiac biomarkers levels. The most frequently used biomarker was troponin. 30 meta-analyses reported the pooled incidence of CI in hospitalized patients with COVID-19 that varies from 5% to 37%. 32 meta-analyses reported on the association of CI with COVID-19 infection severity, with only 6 of them failing to show a statistically significant association. Finally, 46 meta-analyses investigated the association of CI with mortality and showed that patients with COVID-19 with CI had increased risk for worse prognosis. Four meta-analyses reported pooled adjusted hazard ratios for death in patients with COVID-19 and CI vs those without CI ranging from 1.5 to 3. Conclusions: The impact of CI on the prognosis of hospitalized patients with COVID-19 has gained great interest during the pandemic. Methodological issues such as the inclusion of not peer-reviewed studies, the inclusion of potentially overlapping populations or the inclusion of studies with unadjusted analyses for confounders should be taken into consideration. Despite these limitations, the adverse prognosis of patients with COVID-19 and CI has been consistently demonstrated.

Mechanisms of resistance to cyclin-dependent kinase 4/6 inhibitors.

Cyclin-dependent kinase (CDK) 4/6 inhibitors have emerged in the treatment of metastatic hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer. However, most patients will eventually present disease progression, highlighting the inevitable resistance of cancer cells to CDK4/6 inhibition. Several studies have suggested that resistance mechanisms involve aberrations of the molecules that regulate the cell cycle, and the re-wiring of the cell to escape CDK4/6 dependence and turn to alternative pathways. Loss of retinoblastoma function, overexpression of CDK 6, upregulation of cyclin E, overexpression of CDK 7, and dysregulation of several signaling pathways, notably the PI3/AKT/mTOR pathway, have been implicated in the development of resistance to CDK4/6 inhibitors. Overlap with endocrine resistance mechanisms might be possible. Combinational therapeutic strategies should be explored in order to prevent resistance and optimize the management of patients after progression under CDK 4/6 inhibition.

Chlamydia pneumoniae-associated pleuropericarditis: a case report and systematic review of the literature.

BACKGROUND: Chlamydia pneumoniae is a common cause of atypical community acquired pneumonia (CAP). The diagnostic approach of chlamydial infections remains a challenge. Diagnosis of delayed chlamydial-associated complications, involving complex autoimmune pathophysiological mechanisms, is still more challenging. C. pneumoniae-related cardiac complications have been rarely reported, including cases of endocarditis, myocarditis and pericarditis. CASE PRESENTATION: A 40-year old female was hospitalized for pleuropericarditis following lower respiratory tract infection. The patient had been hospitalized for CAP (fever, dyspnea, chest X-ray positive for consolidation on the left upper lobe) 5 weeks ago and had received ceftriaxone and moxifloxacin. Four weeks after her discharge, the patient presented with fever, shortness of breath and pleuritic chest pain and was readmitted because of pericardial and bilateral pleural effusions (mainly left). The patient did not improve on antibiotics and sequential introduction of colchicine and methylprednisolone was performed. The patient presented impressive clinical and laboratory response. Several laboratory and clinical assessments failed to demonstrate any etiological factor for serositis. Chlamydial IgM and IgG antibodies were positive and serial measurements showed increasing kinetics for IgG. Gold standard polymerase chain reaction of respiratory tract samples was not feasible but possibly would not have provided any additional information since CAP occurred 5 weeks ago. The patient was discharged under colchicine and tapered methylprednisolone course. During regular clinic visits, she remained in good clinical condition without pericardial and pleural effusions relapse. CONCLUSIONS: C. pneumoniae should be considered as possible pathogen in case of pleuritis and/or pericarditis during or after a lower respiratory tract infection. In a systematic review of the literature only five cases of C. pneumoniae associated pericarditis were identified. Exact mechanisms of cardiovascular damage have not yet been defined, yet autoimmune pathways might be implicated.

The Effectiveness of Atezolizumab in Metastatic Large Cell Neuroendocrine Carcinoma of the Lungs: Insights from the LANCE Pilot Study.

BACKGROUND: Large cell neuroendocrine carcinoma (LCNEC) presents significant treatment challenges due to its rarity and limited therapeutic options. The LANCE study was designed to explore the survival benefits of incorporating atezolizumab in chemotherapy for metastatic LCNEC. METHODS: In this non-randomized study, patients with metastatic LCNEC were prospectively enrolled and assigned to receive either standard chemotherapy plus atezolizumab followed by maintenance with atezolizumab or standard chemotherapy alone. The primary outcomes measured were 12- and 24-month survival rates, progression-free survival (PFS), and overall survival (OS) between the two groups. RESULTS: Of the 22 patients screened, 17 met the inclusion criteria and received either atezolizumab plus platinum-based chemotherapy (n = 10) or chemotherapy alone (n = 7). After a median follow-up of 23.3 months, the 12-month survival rate was 57.1% (95% CI: 32.6-100%) and 14.3% (95% CI: 2.33-87.7%) for the atezolizumab and the chemotherapy-only groups, respectively. The survival benefit for the atezolizumab group was sustained at 24 months (45.7% vs. 14.3%). Overall survival was significantly higher for the atezolizumab group, and PFS was non-significantly associated with the addition of atezolizumab (log-rank p = 0.04 and 0.05, respectively). CONCLUSIONS: This pilot study suggests that the addition of atezolizumab to standard platinum-based chemotherapy may provide a substantial survival benefit compared with chemotherapy alone in the first-line treatment of metastatic LCNEC.

BRAF/MEK inhibition in NSCLC: mechanisms of resistance and how to overcome it.

Targeted therapy for oncogenic genetic alterations has changed the treatment paradigm of advanced non-small cell lung cancer (NSCLC). Mutations in the BRAF gene are detected in approximately 4% of patients and result in hyper-activation of the MAPK pathway, leading to uncontrolled cellular proliferation. Inhibition of BRAF and its downstream effector MEK constitutes a therapeutic strategy for a subset of patients with NSCLC and is associated with clinical benefit. Unfortunately, the majority of patients will develop disease progression within 1 year. Preclinical and clinical evidence suggests that resistance mechanisms involve the restoration of MAPK signaling which becomes inhibition-independent due to upstream or downstream alterations, and the activation of bypass pathways, such as the PI3/AKT/mTOR pathway. Future research should be directed to deciphering the mechanisms of cancer cells' oncogenic dependence, understanding the tissue-specific mechanisms of BRAF-mutant tumors, and optimizing treatment strategies after progression on BRAF and MEK inhibition.

Emerging therapies in thymic epithelial tumors (Review).

Thymic epithelial tumors (TETs), including thymomas and thymic carcinomas, are rare malignancies arising from the thymus gland. The optimal management requires a multidisciplinary approach. Standard first-line systemic treatment involves cytotoxic chemotherapeutic regimens; however, alternative options for systemic treatment are required. Current research focuses on the unique profile of immune-related pathogenic mechanisms of TETs, involving an overlap with certain autoimmune phenotypes, as well as on determining the landscape of oncogenic molecular alterations and the role of tumor angiogenesis. The aim of the present review is to summarize the current clinical investigation on immunotherapy and targeted agents in the management of TETs. Regarding immune checkpoint inhibitors, efficacy results are promising in certain subsets of patients; however, caution is required concerning their toxicity. Anti-angiogenic agents, mainly potent small-molecule inhibitors, have demonstrated antitumor activity in TETs, whereas other targeted agents, including KIT inhibitors and epigenetic agents, are associated with encouraging, yet still modest results for unselected populations, in the absence of predictive biomarkers. Future research should focus on identifying predictive biomarkers for patients with TETs, and should implement multicenter collaborations and appropriate clinical trials tailored for rare tumor types.

Bcl-2 pathway inhibition in solid tumors: a review of clinical trials.

Due to their key role in the pathogenesis of cancer through the regulation of apoptosis, the B-cell leukemia/lymphoma-2 (BCL-2) family proteins have been an attractive target for cancer therapy for the past decades. Throughout the years, many Bcl-2 family inhibitors have been developed, with Venetoclax being now successfully used in treating hematological malignancies. Although their effectiveness in the treatment of solid tumors is yet to be established, some preclinical evidence indicates their possible clinical application. This review aims to summarize current data from completed clinical trials that used Bcl-2 protein family inhibitors as monotherapy or in combination with other agents for the treatment of solid malignancies. We managed to include clinical trials of various phases which analyze the pharmacokinetics and pharmacodynamics of the drugs, as well as the effectiveness and adverse effects. Active and recruiting clinical trials are also briefly presented and future prospects and challenges are discussed.

Comprehensive clinical evaluation of CAR-T cell immunotherapy for solid tumors: a path moving forward or a dead end?

INTRODUCTION: Chimeric Antigen Receptor (CAR)-T cell therapy is a form of adoptive cell therapy that has demonstrated tremendous results in the treatment of hematopoietic malignancies, leading to the US Food and Drug Administration (FDA) approval of four CD19-targeted CAR-T cell products. With the unprecedented success of CAR-T cell therapy in hematological malignancies, hundreds of preclinical studies and clinical trials are currently undergoing to explore the translation of this treatment to solid tumors. However, the clinical experience in non-hematologic malignancies has been less encouraging, with only a few patients achieving complete responses. Tumor-associated antigen heterogeneity, inefficient CAR-T cell trafficking and the immunosuppressive tumor microenvironment are considered as the most pivotal roadblocks in solid tumor CAR-T cell therapy. MATERIALS AND METHODS: We reviewed the relevant literature/clinical trials for CAR-T cell immunotherapy for solid tumors from Pubmed and ClinicalTrials.gov. CONCLUSION: Herein, we provide an update on solid tumor CAR-T cell clinical trials, focusing on the studies with published results. We further discuss some of the key hurdles that CAR-T cell therapy is encountering for solid tumor treatment as well as the strategies that are exploited to overcome these obstacles.

Capecitabine-associated enterocolitis: Narrative literature review of a rare adverse event and a case presentation.

Capecitabine is an oral 5-fluorouracil prodrug with antimetabolite activity commonly used in advanced colorectal and breast cancer. It presents with a generally good toxicity profile and most of the adverse events can be managed effectively. Enterocolitis is a rare, under-reported, but potentially fatal adverse event associated with capecitabine use. To the best of our knowledge, there are 21 cases of capecitabine-related enterocolitis reported in the literature. We herein present a narrative literature review of enteritis/colitis cases associated with capecitabine use, with highlight to the most common clinical presentation, common imaging and microscopic findings and management approach. We furthermore present a case of severe capecitabine-related enteritis.

Takotsubo Cardiomyopathy in Cancer Patients Treated with Immune Checkpoint Inhibitors: A Systematic Review and Meta-Summary of Included Cases.

BACKGROUND: There are emerging reports of Takotsubo syndrome (TTS) in cancer patients treated with immune checkpoint inhibitors (ICIs); however, the association of the two remains uncertain. METHODS: A systematic literature review was performed in the PubMed database and web sources (Google Scholar) according to the Preferred Reporting Items for Systematic reviews and Meta-analyses (PRISMA) guidelines. Case reports/series or studies including cancer patients treated with ICIs and presenting with TTS were considered. RESULTS: Seventeen cases were included in the systematic review. Most patients were males (59%) with median age of 70 years (30-83). Most common tumor types were lung cancer (35%) and melanoma (29%). Most patients were on first-line immunotherapy (35%) and after the first cycle (54%) of treatment. The median time on immunotherapy at the time of TTS presentation was 77 days (1-450). The most used agents were pembrolizumab and the combination of nivolumab-ipilimumab (35%, respectively). Potential stressors were recognized in 12 cases (80%). Six patients (35%) presented with concurrent cardiac complications. Corticosteroids were used in the management of eight patients (50%). Fifteen patients (88%) recovered from TTS, two patients (12%) relapsed, and one patient died. Immunotherapy was reintroduced in five cases (50%). CONCLUSION: TTS may be associated with immunotherapy for cancer. Physicians should be alert for TTS diagnosis in any patient with myocardial infarction-like presentation under treatment with ICIs.

Prone Positioning in Patients With COVID-19: Analysis of Multicenter Registry Data and Meta-analysis of Aggregate Data.

BACKGROUND/AIM: Evidence suggests a beneficial effect of prone positioning (PP) in COVID-19. MATERIALS AND METHODS: Meta-analysis of individual (7 investigators' groups) and aggregate data (PubMed/EMBASE) regarding the impact of PP on the ratio of arterial partial pressure of oxygen to fraction of inspired oxygen (PO2/FiO2) in patients with COVID-19. RESULTS: Among 121 patients (mean age±SD 59.1±10.7 years, 55% males, 57% intubated) the mean post-versus pre- PP PO2/FiO2 difference was: (i) 50.4±64.3 mmHg, p<0.01, (ii) similar in awake (58.7±72.1 mmHg) versus intubated patients (44.1±57.5 mmHg, p=NS), (iii) inversely correlated with body mass index (r=-0.43, p<0.01). Meta-analysis of 23 studies (n=547, weighted age 58.3±4.1, 73% males, 59% intubated) showed a pooled PO2/FiO2 difference of 61.8 [95% confidence intervals=49.9-73.6] mmHg. Meta-regression analysis revealed no associations with baseline demographics, the time in PP before assessment, and the risk of bias of the studies. CONCLUSION: PP seems to improve oxygenation of patients with COVID-19.

Immune Checkpoint Blockade in Hormone Receptor-Positive Breast Cancer: Resistance Mechanisms and Future Perspectives.

Anti-programmed cell death protein 1 immunotherapy has been incorporated in the treatment algorithm of triple-negative breast cancer (TNBC). However, clinical trial results for patients with hormone receptor (HR)-positive disease appear less compelling. HR-positive tumors exhibit lower levels of programmed death-ligand 1 expression in comparison with their triple-negative counterparts. Moreover, signaling through estrogen receptor alters the immune microenvironment, rendering such tumors immunologically "cold." To explain differential responses to immune checkpoint blockade, this review interrogates differences between HR-positive and TNBC. Starting from distinct genomic features, we further present disparities concerning the tumor microenvironment and finally, we summarize early-phase clinical trial results on promising novel immunotherapy combinations.

Malignant Superior Vena Cava Syndrome: State of the Art.

Superior vena cava syndrome (SVCS) is a clinical entity characterized by signs and symptoms arising from the obstruction or occlusion of the thin-walled superior vena cava (SVC) and can result in significant morbidity and mortality. Despite the rise of benign cases of SVCS, as a thrombotic complication of intravascular devices, it is most commonly seen secondary to malignancy as a consequence of thrombosis, direct invasion of tumor cells inside the vessel, or external compression. SVCS can be the initial presentation of a previously undiagnosed tumor in up to 60% of cases. Lung cancer and non-Hodgkin lymphoma (NHL) are responsible for up to 85%-90% of malignancy-related SVCS, while metastatic cancers account for approximately 10%. Herein, we review the pathophysiology, etiology, clinical presentation, diagnosis, and management of malignancy-related SVCS.

Systematic review with meta-analysis: COVID-19 outcomes in patients receiving anti-TNF treatments.

BACKGROUND: Accumulating evidence suggests a beneficial effective of tumour necrosis factor-alpha (TNF-α) inhibitors on the outcomes of COVID-19 disease, which, however is not validated by all studies. AIMS: To perform a systematic review and meta-analysis of existing reports to investigate the impact of anti-TNF treatments on the clinical outcomes of COVID-19 patients. METHODS: A systematic search at PubMed and SCOPUS databases using specific keywords was performed. All reports of COVID-19 outcomes for patients receiving anti-TNF therapy by September 2021 were included. Pooled effect measures were calculated using a random-effects model. The Newcastle Ottawa Scale for observational studies was used to assess bias. Studies that were not eligible for meta-analysis were described qualitatively. RESULTS: In total, 84 studies were included in the systematic review, and 35 were included in the meta-analysis. Patients receiving anti-TNF treatment, compared to non-anti-TNF, among COVID-19 cases had a lower probability of hospitalisation (eight studies, 2555 patients, pooled OR = 0.53, 95% CI: 0.42-0.67, I2  = 0) and severe disease defined as intensive care unit admission or death (two studies, 1823 patients, pooled OR = 0.63, 95% CI: 0.41-0.96, I2  = 0), after adjustment for validated predictors of adverse disease outcomes. No difference was found for the risk for hospitalisation due to COVID-19 in populations without COVID-19 for patients receiving anti-TNF treatment compared to non-anti-TNF (three studies, 5 994 958 participants, pooled risk ratio = 0.97, 95% CI: 0.68-1.39, I2  = 20) adjusted for age, sex and comorbidities. CONCLUSIONS: TNF-α inhibitors are associated with a lower probability of hospitalisation and severe COVID-19 when compared to any other treatment for an underlying inflammatory disease.

Vaccine-Related Autoimmune Hepatitis: Emerging Association with SARS-CoV-2 Vaccination or Coincidence?

BACKGROUND: There is an increasing number of liver injury cases resembling autoimmune hepatitis (AIH) following SARS-CoV-2 vaccination; however, an association has not yet been established. METHODS/MATERIALS: A literature review was performed to identify articles regarding the association of AIH with vaccination, emphasizing on SARS-CoV-2 vaccines, and the proposed mechanisms. We then performed a literature search for AIH-like cases following SARS-CoV-2 vaccination, and we evaluated the included cases for AIH diagnosis using simplified diagnostic criteria (SDC), and for vaccination causality using the Naranjo score for adverse drug reactions. RESULTS: We identified 51 AIH-like cases following SARS-CoV-2 vaccination. Forty cases (80%) were characterized as "probable", "at least probable", or "definite" for AIH diagnosis according to SDC. Forty cases (78.4%) were characterized as "probable", four (7.8%) as "possible", and three (5.8%) as "definite" for vaccine-related AIH according to the Naranjo score. CONCLUSION: SARS-CoV-2 vaccine-related AIH carries several phenotypes and, although most cases resolve, immunosuppressive therapy seems to be necessary. Early diagnosis is mandatory and should be considered in any patient with acute or chronic hepatitis after SARS-CoV-2 vaccination, especially in those with pre-existing liver disease.

Early Occurrence of Adverse Events in Hospitalized Patients With COVID-19 and Beneficial Effect of Anticoagulation.

BACKGROUND/AIM: This study analyzed the characteristics of patients with COVID-19 with major events during the first days of hospitalization. PATIENTS AND METHODS: This is a retrospective analysis of prospectively collected data from consecutive patients admitted to two hospitals in Athens, Greece. The characteristics of patients with COVID-19 who suffered the primary endpoint (venous thromboembolic events, intubation, and death) during the first days of hospitalization were analyzed. RESULTS: Among 95 patients included in the analysis, 21 presented with major adverse events during a median follow-up of 13 days. More than 50% of these patients presented with a major event during the first 3 days. Anticoagulation treatment was inversely associated with the cumulative incidence of the primary endpoint [hazard ratio=0.16 (95% confidence interval=0.06-0.47)]. Patients with major events were older, with lower baseline SatO2, and higher number of Wells' criteria and Charlson comorbidity index. Among these patients, those with hypertension were at higher risk for early occurrence of events (≤ first three days of hospitalization). CONCLUSION: Major adverse events may occur early in hospitalized patients with COVID-19 with a high-risk profile. Anticoagulation treatment appears to reduce this risk and thus prompt thromboprophylaxis should be employed in these patients.

Assessment of Seroconversion after SARS-CoV-2 Vaccination in Patients with Lung Cancer.

Background: SARS-CoV-2 mortality rates are significantly higher in patients with lung cancer compared with the general population. However, little is known on their immunization status after vaccination. Methods: To evaluate the humoral response (seroconversion) of patients with lung cancer following vaccination against SARS-COV-2 (Group A), we obtained antibodies against SARS-CoV-2 spike (S) protein both at baseline and at different time points after the first dose of SARS-CoV-2 vaccine (two to three weeks [T1], six weeks ± one week [T2], 12 weeks ± three weeks [T3], and 24 weeks ± three weeks [T4]). Antibodies were also acquired from a control cohort of non-lung cancer patients (Group B) as well as a third cohort containing healthy controls (Group C) at all time points and at T4, respectively, to make comparisons with Group A. Analysis of antibody response at different time points, association with clinicopathologic parameters, and comparisons with control groups were performed. Results: A total of 125 patients with lung cancer were included in the analysis (96 males [74.3%], median age of 68 years [46−91]. All study participants received two vaccine doses (BNT162b2, mRNA-1273, AZD1222). Analysis of anti-SARS-CoV-2 S antibody titers showed minimal response at T1 (0.4 [0.4−48.6] IU/mL). Antibody response peaked at T2 (527.0 [0.4−2500] IU/mL) and declined over T3 (323.0 [0.4−2500] IU/mL) and T4 (141.0 [0.4−2500] IU/mL). Active smokers had lower antibody titers at T2 (p = 0.04), T3 (p = 0.04), and T4 (p < 0.0001) compared with former or never smokers. Peak antibody titers were not associated with any other clinicopathologic characteristic. No significant differences were observed compared with Group B. However, lung cancer patients exhibited significantly decreased antibody titers compared with Group C at T4 (p < 0.0001). Conclusions: Lung cancer patients demonstrate sufficient antibody response six weeks after the first dose of vaccine against SARS-CoV-2 when vaccinated with two-dose regimens. Rapidly declining antibody titers six weeks after the first dose underline the need for a third dose three months later, in patients with lung cancer, and especially active smokers.

A case of trastuzumab-induced dermatomyositis.

Human epidermal growth factor receptor 2 (HER-2) is a checkpoint, controlling cell proliferation and differentiation. Trastuzumab, a humanized monoclonal antibody directed against HER-2, is nowadays standard treatment for breast cancer patients whose tumors express HER-2. It is generally well tolerated, with a small number of patients developing mild adverse reactions. Dermatomyositis is a rare adverse event of trastuzumab therapy not well described in the literature. We herein present a case of a patient treated for hormone-sensitive invasive ductal carcinoma, who presented with symptoms of proximal muscle weakness, arthralgias, skin rash, and generalized fatigue. The symptoms started after the sixth cycle of trastuzumab and progressively deteriorated. The patient's medical and family history was unremarkable. Disease progression as a possible cause of dermatomyositis had been ruled out, and laboratory evaluation revealed moderate elevation of serum muscle proteins and acute-phase reactants. Trastuzumab treatment was discontinued, and 3 months later, the patient was free of symptoms without any further intervention.

The changing treatment of metastatic her2-positive breast cancer.

Human epidermal growth factor receptor 2 (HER2)-overexpressing breast cancer has been historically associated with an aggressive disease course with common distant metastasis and poor prognosis. HER2-targeting therapies have significantly changed treatment and drastically improved outcomes for this group of patients. However, primary or acquired resistance to anti-HER2 regimens leads almost universally to disease progression, often with difficult to treat central nervous system (CNS) metastases. The current review summarized the existing therapeutic options for HER2-positive metastatic disease in the first, second and further line setting. Furthermore, novel agents currently under development were presented, which have demonstrated encouraging results in heavily pretreated patients or specific subgroups, such as HR-positive/HER2-positive tumors and CNS disease.