Circulating microRNAs and therapy-associated cardiac events in HER2-positive breast cancer patients: an exploratory analysis from NeoALTTO.

PURPOSE: The relevance of cardiotoxicity in the context of HER2-positive breast cancer is likely to increase with increasing patient treatment exposure, number of treatment lines, and prolonged survival. Circulating biomarkers to early identify patients at risk of cardiotoxicity could allow personalized treatment and follow-up measures. The aim of this study is to examine the relationship between circulating microRNAs and adverse cardiac events in HER2-positive breast cancer patients. METHODS: We based our work on plasma samples from NeoALTTO trial obtained at baseline, after 2 weeks of anti-HER2 therapy, and immediately before surgery. Eleven patients experienced either a symptomatic or asymptomatic cardiac event. Circulating microRNAs were profiled in all patients presenting a cardiac event (case) and in an equal number of matched patients free of reported cardiac events (controls) using microRNA-Ready-to-Use PCR (Human panel I + II). Sensitivity analyses were performed by increasing the number of controls to 1:2 and 1:3. Normalized microRNA expression levels were compared between cases and controls using the non-parametric Kruskal-Wallis test. RESULTS: Eight circulating microRNAs resulted differentially expressed after 2 weeks of anti-HER2 therapy between patients experiencing or not a cardiac event. Specifically, the expression of miR-125b-5p, miR-409-3p, miR-15a-5p, miR-423-5p, miR-148a-3p, miR-99a-5p, and miR-320b increased in plasma of cases as compared to controls, while the expression of miR-642a-5p decreases. Functional enrichment analysis revealed that all these microRNAs were involved in cardiomyocyte adrenergic signaling pathway. CONCLUSION: This study provides proof of concept that circulating microRNAs tested soon after treatment start could serve as biomarkers of cardiotoxicity in a very early stage in breast cancer patients receiving anti-HER2 therapy.

Circulating tumor DNA for predicting recurrence in patients with operable breast cancer: a systematic review and meta-analysis.

BACKGROUND: The incorporation of circulating tumor DNA (ctDNA) into the management of operable breast cancer (BC) has been hampered by the heterogeneous results from different studies. We aimed to assess the prognostic value of ctDNA in patients with operable (non metastatic) BC. MATERIALS AND METHODS: A systematic search of databases (PubMed/Medline, Embase, and CENTRAL) and conference proceedings was conducted to identify studies reporting the association of ctDNA detection with disease-free survival (DFS) and overall survival (OS) in patients with stage I-III BC. Log-hazard ratios (HRs) were pooled at each timepoint of ctDNA assessment (baseline, after neoadjuvant therapy, and follow-up). ctDNA assays were classified as primary tumor-informed and non tumor-informed. RESULTS: Of the 3174 records identified, 57 studies including 5779 patients were eligible. In univariate analyses, ctDNA detection was associated with worse DFS at baseline [HR 2.98, 95% confidence interval (CI) 1.92-4.63], after neoadjuvant therapy (HR 7.69, 95% CI 4.83-12.24), and during follow-up (HR 14.04, 95% CI 7.55-26.11). Similarly, ctDNA detection at all timepoints was associated with worse OS (at baseline: HR 2.76, 95% CI 1.60-4.77; after neoadjuvant therapy: HR 2.72, 95% CI 1.44-5.14; and during follow-up: HR 9.19, 95% CI 3.26-25.90). Similar DFS and OS results were observed in multivariate analyses. Pooled HRs were numerically higher when ctDNA was detected at the end of neoadjuvant therapy or during follow-up and for primary tumor-informed assays. ctDNA detection sensitivity and specificity for BC recurrence ranged from 0.31 to 1.0 and 0.7 to 1.0, respectively. The mean lead time from ctDNA detection to overt recurrence was 10.81 months (range 0-58.9 months). CONCLUSIONS: ctDNA detection was associated with worse DFS and OS in patients with operable BC, particularly when detected after treatment and using primary tumor-informed assays. ctDNA detection has a high specificity for anticipating BC relapse.

A three-gene signature marks the time to locoregional recurrence in luminal-like breast cancer.

BACKGROUND: Gene expression profiling (GEP)-based prognostic signatures are being rapidly integrated into clinical decision making for systemic management of breast cancer patients. However, GEP remains relatively underdeveloped for locoregional risk assessment. Yet, locoregional recurrence (LRR), especially early after surgery, is associated with poor survival. PATIENTS AND METHODS: GEP was carried out on two independent luminal-like breast cancer cohorts of patients developing early (≤5 years after surgery) or late (>5 years) LRR and used, by a training and testing approach, to build a gene signature able to intercept women at risk of developing early LRR. The GEP data of two in silico datasets and of a third independent cohort were used to explore its prognostic value. RESULTS: Analysis of the first two cohorts led to the identification of three genes, CSTB, CCDC91 and ITGB1, whose expression, derived by principal component analysis, generated a three-gene signature significantly associated with early LRR in both cohorts (P value <0.001 and 0.005, respectively), overcoming the discriminatory capability of age, hormone receptor status and therapy. Remarkably, the integration of the signature with these clinical variables led to an area under the curve of 0.878 [95% confidence interval (CI) 0.810-0.945]. In in silico datasets we found that the three-gene signature retained its association, showing higher values in the early relapsed patients. Moreover, in the third additional cohort, the signature significantly associated with relapse-free survival (hazard ratio 1.56, 95% CI 1.04-2.35). CONCLUSIONS: Our three-gene signature represents a new exploitable tool to aid treatment choice in patients with luminal-like breast cancer at risk of developing early recurrence.

Early stage breast cancer follow-up in real-world clinical practice: the added value of cell free circulating tumor DNA.

PURPOSE: Physical examinations and annual mammography (minimal follow-up) are as effective as laboratory/imaging tests (intensive follow-up) in detecting breast cancer (BC) recurrence. This statement is now challenged by the availability of new diagnostic tools for asymptomatic cases. Herein, we analyzed current practices and circulating tumor DNA (ctDNA) in monitoring high-risk BC patients treated with curative intent in a comprehensive cancer center. PATIENTS AND METHODS: Forty-two consecutive triple negative BC patients undergoing neoadjuvant therapy and surgery were prospectively enrolled. Data from plasma samples and surveillance procedures were analyzed to report the diagnostic pattern of relapsed cases, i.e., by symptoms, follow-up procedures and ctDNA. RESULTS: Besides minimal follow-up, 97% and 79% of patients had at least 1 non-recommended imaging and laboratory tests for surveillance purposes. During a median follow-up of 5.1(IQR, 4.1-5.9) years, 13 events occurred (1 contralateral BC, 1 loco-regional recurrence, 10 metastases, and 1 death). Five recurrent cases were diagnosed by intensive follow-up, 5 by symptoms, and 2 incidentally. ctDNA antedated disseminated disease in all evaluable cases excepted two with bone-only and single liver metastases. The mean time from ctDNA detection to suspicious findings at follow-up imaging was 3.81(SD, 2.68), and to definitive recurrence diagnosis 8(SD, 2.98) months. ctDNA was undetectable in the absence of disease and in two suspected cases not subsequently confirmed. CONCLUSIONS: Some relapses are still symptomatic despite the extensive use of intensive follow-up. ctDNA is a specific test, sensitive enough to detect recurrence before other methods, suitable for clarifying equivocal imaging, and exploitable for salvage therapy in asymptomatic BC survivors.

Mammographic density to predict response to neoadjuvant systemic breast cancer therapy.

BACKGROUND: Mammographic density (MD) is a risk factor for breast cancer (BC) development, and recurrence. However, its predictive value has been less studied. Herein, we challenged MD as a biomarker associated with response in patients treated with neoadjuvant therapy (NAT). METHODS: Data on all NAT treated BC patients prospectively collected in the registry of Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy (2009-2019) were identified. Diagnostic mammograms were used to evaluate and score MD as categorized by the Breast Imaging-Reporting and Data System (BI-RADS), which identifies 4 levels of MD in keeping with relative increase of fibro-glandular over fat tissue. Each case was classified according to the following categories a (MD < 25%), b (26-50%), c (51-75%), and d (> 75%). The association between MD and pathological complete response (pCR), i.e., absence of BC cells in surgical specimens, was analyzed in multivariable setting used logistic regression models with adjustment for clinical and pathological variables. RESULTS: A total of 442 patients were analyzed, 120 of which (27.1%) attained a pCR. BI-RADS categories a, b, c, and d accounted for 10.0%, 37.8%, 37.1% and 15.2% of cases. Corresponding pCR were 20.5%, 26.9%, 30.5%, 23.9%, respectively. At multivariable analysis, when compared to cases classified as BI-RADS a, those with denser breast showed an increased likelihood of pCR with odds ratio (OR) of 1.70, 2.79, and 1.47 for b, c and d categories, respectively (p = 0.0996), independently of age, BMI [OR underweight versus (vs) normal = 3.76], clinical nodal and tumor status (OR T1/Tx vs T4 = 3.87), molecular subtype (HER2-positive vs luminal = 10.74; triple-negative vs luminal = 8.19). In subgroup analyses, the association of MD with pCR was remarkable in triple-negative (ORs of b, c and d versus a: 1.85, 2.49 and 1.55, respectively) and HER2-positive BC cases (ORs 2.70, 3.23, and 1.16). CONCLUSION: Patients with dense breast are more likely to attain a pCR at net of other predictive factors. The potential of MD to assist decisions on BC management and as a stratification factor in neoadjuvant clinical trials should be considered.

Blood-based genomics of triple-negative breast cancer progression in patients treated with neoadjuvant chemotherapy.

BACKGROUND: As neoadjuvant chemotherapy (NAC) is increasingly used in triple-negative breast cancer (TNBC), we investigated the value of circulating tumor DNA (ctDNA) for patient monitoring prior, during, and after NAC, and circulating tumor cells (CTCs) for disease characterization at clinical progression. MATERIALS AND METHODS: Forty-two TNBC patients undergoing NAC were prospectively enrolled. Primary tumor mutations identified by targeted-gene sequencing were validated and tracked in 168 plasma samples longitudinally collected at multiple time-points by droplet digital polymerase chain reaction. At progression, plasma DNA underwent direct targeted-gene assay, and CTCs were collected and analyzed for copy number alterations (CNAs) by low-pass whole genome sequencing. RESULTS: ctDNA detection after NAC was associated with increased risk of relapse, with 2-year event-free survival estimates being 44.4% [95% confidence interval (CI) 21.4%-92.3%] versus 77.4% (95% CI 57.8%-100%). ctDNA prognostic value remained worthy even after adjusting for age, residual disease, systemic inflammatory indices, and Ki-67 [hazard ratio (HR) 1.91; 95% CI 0.51-7.08]. During follow-up, ctDNA was undetectable in non-recurrent cases with the unique exception of one showing a temporary peak over eight samples. Conversely, ctDNA was detected in 8/11 recurrent cases, and predated the clinical diagnosis up to 13 months. Notably, recurrent cases without ctDNA developed locoregional, contralateral, and bone-only disease. At clinical progression, CTCs presented chromosome 10 and 21q CNAs whose network analysis showed connected modules including HER/PI3K/Ras/JAK signaling and immune response. CONCLUSION: ctDNA is not only associated with but is also predictive of prognosis in TNBC patients receiving NAC, and represents an exploitable tool, either alone or with CTCs, for personalized TNBC management.

Older age and comorbidity in breast cancer: is RT alone the new therapeutic frontier?

AIM: To assess the impact of age, comorbidities and endocrine therapy (ET) in older breast cancer (BC) patients treated with hypofractionated radiotherapy (Hypo-RT). METHODS: From June 2009 to December 2017, we enrolled in this study 735 ER-positive BC patients (stage pT1-T2, pNx-1, M0 and age ≥ 65 years) receiving hypo-RT and followed them until September 2019. Baseline comorbidities included in the hypertension-augmented Charlson Comorbidity Index were retrospectively retrieved. Logistic regression model estimated adjusted-odds ratios (ORs) of ET prescription in relation to baseline patient and tumor characteristics. Competing risk analysis estimated 5-year cumulative incidence function (CIF) of ET discontinuation due to side effects (with BC progression or death as competing events), and its effect on locoregional recurrence (LRR) and distant metastasis (DM) (with death as competing event). RESULTS: ET has been prescribed in 89% patients. In multivariable analysis, the odds of ET prescription was significantly reduced in older patients (≥ 80 years, OR 0.08, 95% CI 0.03-0.20) and significantly increased in patients with moderate comorbidity. Patients ≥ 80 years discontinued the prescribed therapy earlier and more frequently than younger (65-69 years) patients (p = 0.060). Five-year CIF of LLR, DM and death from causes other that BC were 1.7%, 2.2% and 7.5%, respectively. Patients who discontinued ET had higher chance of LRR (p = 0.004). ET use did not impact on OS in any of the analyzed groups. CONCLUSIONS: In older patients, ET did not show a benefit in terms of overall survival. Further studies focusing on tailored treatment approaches are warranted to offer the best care in terms of adjuvant treatment to these patients.

VMAT partial-breast irradiation: acute toxicity of hypofractionated schedules of 30 Gy in five daily fractions.

PURPOSE: To report acute toxicities in breast cancer (BC) patients (pts) recruited in a prospective trial and treated with accelerated partial-breast irradiation (APBI) using Volumetric Modulated Arc Therapy (VMAT) delivered with a hypofractionated schedule. METHODS: From March 2014 to June 2019, pts with early-stage BC (Stage I), who underwent breast conservative surgery (BCS), were recruited in a prospective study started at the National Cancer Institute of Milan. Pts received APBI with a hypofractionated schedule of 30 Gy in five daily fractions. Radiotherapy treatment (RT) was delivered using VMAT. Acute toxicity was assessed according to RTOG/EORTC criteria at the end of RT. RESULTS: Between March 2014 and June 2019, 151 pts were enrolled in this study. 79 Pts had right-side and 72 had left-side breast cancer. Median age was 69 (range 43-92). All pts presented with pathological stage IA BC, molecular classification was Luminal A in 128/151 (85%) and Luminal B in 23/151 (15%) cases. Acute toxicity, assessed at the end of RT, consisted of G1 erythema in 37/151 (24. 5%) pts and skin toxicities higher than G1, did not occur. Fibrosis G1 and G2 were reported in 41/151 (27. 1%) pts and in 2/151 pts (1. 3%), respectively. Edema G1 occurred in 8/151 (5. 3%) pts and asthenia G1 occurred in 1/151 (0. 6%) pts. CONCLUSIONS: APBI with VMAT proved to be feasible and can be a valid alternative treatment option after BCS in selected early breast cancer pts according to ASTRO guidelines. A longer follow-up is needed to assess late toxicity.

Axillary nodal involvement by primary tumor features in early breast cancer: an analysis of 2600 patients.

BACKGROUND: Primary tumor characteristics, which are readily available to all clinicians, may aid in selecting the optimal adjuvant therapy for patients with breast cancer (BC). Herein, we investigated the relationship between tumor size, hormone receptor and HER2 status, Ki67 and age with axillary lymph node metastases (ALNM) in early-BC patients. METHODS: We analyzed data on consecutive 2600 early-BC cases collected in the registry of Fondazione IRCC Istituto Nazionale dei Tumori, Milano, Italy. Correlation between Ki67 and primary tumor size (T-size) was calculated by Spearman's rank correlation coefficient. Association of ALNM with Ki67 and other tumor characteristics was investigated by logistic regression. Adjusted odds ratios (ORs) with 95% confidence intervals (95% CIs) were estimated in all cases, and separately analyzed according to age, T-size and BC subtype. RESULTS: Large tumor size strongly associated to ALNM, with an adjusted odds ratio (OR) for each 5-mm increase of 1.32 (95% CI 1.24-1.41), except for triple-negative BC (TNBC) cases. In tumors =10 mm, without lymphovascular invasion, representing the strongest predictor of ALNM (OR 6.09, 95% CI 4.93-7.53), Ki67 resulted particularly informative, with a fourfold increased odds of ALNM for values > 30%. CONCLUSIONS: These results raise the question whether axillary node status is redundant in cases with exceptionally good features, i.e., small tumors with low Ki67, or in those candidate to adjuvant systemic treatment/radiotherapy anyway including TNBC, and support the incorporation of primary BC tumor characteristics as stratification factors in ongoing trials aiming at de-escalating axillary surgical procedures.

Anticancer innovative therapy: Highlights from the ninth annual meeting.

The Ninth Annual Conference of "Anticancer Innovative Therapy", organized by Fondazione IRCCS Istituto Nazionale dei Tumori di Milano (Fondazione IRCCS INT) and hosted by Hotel Michelangelo, was held in Milan on 25 January 2019. Cutting-edge science was presented in two main scientific sessions: i) pre-clinical evidences and new targets, and ii) clinical translation. The Keynote lecture entitled "Cancer stem cells (CSCs): metabolic strategies for their identification and eradication" presented by M. Lisanti, was one of the highlights of the conference. One key concept of the meeting was how the continuous advances in our knowledge about molecular mechanisms in various fields of research (cancer metabolism reprogramming, epigenetic regulation, transformation/invasiveness, and immunology, among others) are driving cancer research towards more effective personalized antineoplastic strategies. Specifically, recent preclinical data on the following topics were discussed: 1. Polycomb group proteins in cancer; 2. A d16HER2 splice variant is a flag of HER2 addiction across HER2-positive cancers; 3. Studying chromatin as a nexus between translational and basic research; 4. Metabolomic analysis in cancer patients; 5. CDK4-6 cyclin inhibitors: clinical activity and future perspectives as immunotherapy adjuvant; and 6. Cancer stem cells (CSCs): metabolic strategies for their identification and eradication. In terms of clinical translation, several novel approaches were presented: 1. Developing CAR-T cell therapies: an update of preclinical and clinical development at University of North Carolina; 2. Vγ9Vδ2 T-cell activation and immune suppression in multiple myeloma; 3. Predictive biomarkers for real-world immunotherapy: the cancer immunogram model in the clinical arena; and 4. Mechanisms of resistance to immune checkpoint blockade in solid tumors. Overall, the pre-clinical and clinical findings presented could pave the way to identify novel actionable therapeutic targets to significantly enhance the care of persons with cancer.

Innovative therapy, monoclonal antibodies, and beyond: Highlights from the eighth annual meeting.

The eighth annual conference of "Innovative therapy, monoclonal antibodies, and beyond" was held in Milan on Jan. 26, 2018, and hosted by Fondazione IRCCS-Istituto Nazionale dei Tumori (Fondazione IRCCS INT). The conference was divided into two main scientific sessions, of i) pre-clinical assays and novel biotargets, and ii) clinical translation, as well as a third session of presentations from young investigators, which focused on recent achievements within Fondazione IRCCS INT on immunotherapy and targeted therapies. Presentations in the first session addressed the issue of cancer immunotherapy activity with respect to tumor heterogeneity, with key topics addressing: 1) tumor heterogeneity and targeted therapy, with the definition of the evolutionary Index as an indicator of tumor heterogeneity in both space and time; 2) the analysis of cancer evolution, with the introduction of the TRACERx Consortium-a multi-million pound UK research project focused on non-small cell lung cancer (NSCLC); 3) the use of anti-estrogen agents to boost immune recognition of breast cancer cells; and 4) the high degree of functional plasticity within the NK cell repertoire, including the expansion of adaptive NK cells following viral challenges. The second session addressed: 1) the effectiveness of radiotherapy to enhance the proportion of patients responsive to immune-checkpoint blockers (ICBs); 2) the use of MDSC scores in selecting melanoma patients with high probability to be responsive to ICBs; and 3) the relevance of the gut microbiome as a predictive factor, and the potential of its perturbation in increasing the immune response rate to ICBs. Overall, a picture emerged of tumor heterogeneity as the main limitation that impairs the effectiveness of anti-cancer therapies. Thus, the choice of a specific therapy based on reproducible and selective predictive biomarkers is an urgent unmet clinical need that should be addressed in order to increase the proportion of long-term responding patients and to improve the sustainability of novel drugs.

The use of breast imaging for predicting response to neoadjuvant lapatinib, trastuzumab and their combination in HER2-positive breast cancer: Results from Neo-ALTTO.

AIM: To determine the value of mammography and breast ultrasound (US) in predicting outcomes in HER2 positive breast cancer patients (pts) within Neo-ALTTO trial. PATIENTS AND METHODS: Mammography and US were required at baseline, week 6 and surgery. Two independent blinded investigators reviewed the measurements and assigned the corresponding response category. Pts showing complete or partial response according to RECIST (v1.1) were classified as responders. The association between imaging response at week 6 or prior to surgery was evaluated with respect to pathological complete response (pCR) and event-free Survival (EFS). RESULTS: Of the 455 pts enrolled in the trial, 267 (61%) and 340 (77%) had evaluable mammography and US at week 6; 248 (56%) and 309 (70%) pts had evaluable mammography and US prior to surgery. At week 6, 32% and 43% of pts were classified as responders by mammography and US, respectively. pCR rates were twice as high for responders than non-responders (week 6: 46% versus 23% by US, p < 0.0001; 41% versus 24% by mammography, p = 0.007). Positive and negative predictive values of mammography and US prior to surgery were 37% and 35%, and 82% and 70%, respectively. No significant correlation was found between response by mammography and/or US at week 6/surgery and EFS. CONCLUSIONS: Mammography and US were underused in Neo-ALTTO although US had the potential to assess early response whereas mammography to detect residual disease prior to surgery. Our data still emphasise the need for further imaging studies on pts treated with neoadjuvant HER2-targeted therapy.

Factors influencing acute and late toxicity in the era of adjuvant hypofractionated breast radiotherapy.

PURPOSE: To evaluate toxicity in breast cancer patients treated with anthracycline and taxane based chemotherapy and whole breast hypofractionated radiotherapy, and to identify the risk factors for toxicity. METHODS AND MATERIALS: 537 early breast cancer patients receiving hypofractionated radiotherapy after conservative surgery were enrolled from April 2009 to December 2014, in an Italian cancer institute. The dose was 42.4 Gy in 16 daily fractions, 2.65 Gy per fraction. The boost to the tumor bed was administered only in grade III breast cancer patients and in patients with close or positive margins. Acute and late toxicity were prospectively assessed during and after radiotherapy according to RTOG scale. The impact of patients clinical characteristics, performed treatments and dose inhomogeneities on the occurrence of an higher level of acute skin toxicity and late fibrosis has been evaluated by univariate and multivariate analysis. RESULTS: The mean age was 74 (range 46-91 yrs). 27% of patients received boost. 22% of cases (n = 119) received also chemotherapy. The median follow-up was 32 months. G1 and G2/G3 acute skin toxicity were 61.3% and 20.5% and G1 and G2/G3 late fibrosis 12.6% and 4.3% respectively. Chemotherapy (p = 0.04), diabetes (p = 0.04) and boost administration (p < 0.01) were found to be statistically significant on the occurrence of late fibrosis, but a multivariate analysis did not show any factors connected. The boost administration (p < 0.01), the breast volume (p = 0.05), dose inhomogeneities (p < 0.01) and boost volume (p = 0.04) were found to be statistically significant as concerns the occurrence of acute skin reaction at the univariate analysis, but only the boost administration (p = 0.02), at multivariate analysis. CONCLUSIONS: The results of our study, according to the large randomized trials, confirmed that hypofractionated whole breast irradiation is safe, and only the boost administration seems to be an important predictor for toxicity. Chemotherapy does not impact on acute and late skin toxicity.

Disease progression pattern in metastatic breast cancer patients treated with anti-HER2 therapies.

PURPOSE: Over the last decade a dramatic improvement in the treatment and prognosis of human epidermal growth factor receptor-2 (HER2) positive metastatic breast cancer (MBC) has been achieved. This study aimed to describe pattern, timing of metastases, and time to progression (TTP) of MBC patients (pts) treated with multiple lines of therapy with trastuzumab and/or lapatinib. METHODS: Clinical-pathologic features, treatment-lines and metastatic sites were collected from the institutional database; TTP was evaluated for each treatment-line. A meta-analysis of treatment-line estimates was performed; Q test and I (2)-index were used to detect and estimate heterogeneity. Cox's proportional hazards model and Fine and Gray's proportional subhazards model in a competing risks setting were used to detect differences in hazard rate and to estimate relative risks. RESULTS: 112 pts were analyzed. The median number of treatment-lines administered was 6 (range 1-17) and 524 (86 %) disease progression events were observed (median follow up 4.2 years). Distribution of metastases at baseline remained consistent across all lines. Having a given site affected by metastasis was a major risk factor of progression in that site. Hormone-receptor-positive pts resulted more likely to progress on bone (HR = 1.88). Elderly pts were less likely to progress on CNS (HR = 0.73). Median TTP resulted superior to 5 months up to the 6th line of treatment, reaching a plateau at the 9th treatment-line. CONCLUSIONS: These data suggest that risk factors for progression in HER2 positive MBC do not significantly differ between various distributions of metastases, and that MBC pts benefit from anti-HER2 therapy even in late treatment-lines.

Targeted therapy-induced diarrhea: A review of the literature.

PURPOSE OF RESEARCH: Revision of the literature on targeted therapy-induced diarrhea (TT-ID). PRINCIPAL RESULTS: TT-ID is frequent; the mechanisms are mainly secretive, followed by ischemic or autoimmune ones. The duration of TT-ID is protracted over time. Its intensity is of grade G1-G3 but may be fatal in patients with diffuse colitis or on ipilimumab. However, no specific guidelines are available on management of different grades of TT-ID. Preventive measures with antibiotics, probiotics or activated charcoal should be further investigated. Loperamide is the first choice drug followed by octreotide. The role of corticosteroids is controversial. CONCLUSION: Early assessment and management of TT-ID is essential to prevent the worsening of this side-effect, patients' hospitalization and dose reduction or oncological treatment discontinuation. Future research is needed to better understand the pathophysiological mechanisms of TT-ID and it should also be investigated whether a specific pharmacological and/or non pharmachological approach is indicated.

Human epidermal growth factor receptor 2 (HER2)-positive and hormone receptor-positive breast cancer: new insights into molecular interactions and clinical implications.

Recent data show a significant benefit from combining an anti-HER-2 agent with endocrine therapy in HER2-positive and hormone receptor (HR)-positive metastatic breast cancer. However, as the clinical outcomes achieved by these combinations do not favourably match those with chemotherapy, clinicians still perceive HER2-positive breast cancer as an homogeneous group and consider chemotherapy with anti-HER2 agents as the preferred treatment option, regardless of the HR status. Indeed, in HR-positive HER2-positive tumours, chemotherapy with anti-HER2 agents is the backbone of treatment, while endocrine therapy is commonly used in sequence when HR and HER2 are co-expressed rather than as a real alternative. Emerging biological and clinical data challenge this paradigm, suggesting that HER2-positive tumours are rather heterogeneous that HRs co-expression may account for part of this heterogeneity and, finally, that chemotherapy may represent an overtreatment in selected cases. The present review aims to summarise the biological features of HER2-positive breast cancer according to HR status, the role of the bi-directional cross-talk between HER2 and HR pathways on resistance development to anti-HER2 and endocrine therapy, and finally, the novel therapeutic strategies, including but not limited to chemotherapy, targeting these two pathways.