Discontinuation rate and serious adverse events of chemoimmunotherapy as neoadjuvant treatment for triple-negative breast cancer: a systematic review and meta-analysis.

BACKGROUND: The use of combination of chemotherapy with immune checkpoint inhibitors (ICIs) has shown efficacy in triple-negative breast cancer (TNBC), and chemoimmunotherapy has been introduced in clinical practice. However, limited data are available on the discontinuation rate and serious adverse events of these treatments, particularly in the neoadjuvant setting. Herein, we carried out a comprehensive systematic review and meta-analysis to assess discontinuation rate and serious adverse events of chemoimmunotherapy compared to chemotherapy alone in phase II and III neoadjuvant clinical trials in TNBC. MATERIALS AND METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, EMBASE, Cochrane Library, and PubMed/Medline were searched for articles published from June 2008 to May 2023. The outcomes of interest were the discontinuation rate, serious adverse events, and grade 3-4 adverse events. RESULTS: Four studies were included in the analysis. The pooled odds ratios (ORs) for discontinuation rate and serious adverse events were 1.26 [95% confidence interval (CI) 0.78-2.06] and 1.79 (95% CI 1.4-2.28), respectively, in patients receiving chemoimmunotherapy compared to chemotherapy alone as neoadjuvant treatment for TNBC. The chemoimmunotherapy group had a higher risk of grade 3-4 adverse events (OR 1.30, 95% CI 1.07-1.59). The analysis showed substantial heterogeneity, and the risk of discontinuation rate was heavily influenced by the KEYNOTE-522 trial. CONCLUSIONS: Our findings highlight the need for clinical trials specifically focused on safety, quality of life, and treatment adherence in TNBC patients receiving neoadjuvant treatment. Close monitoring of tolerability remains crucial in this clinical setting.

Optimizing choices and sequences in the diagnostic-therapeutic landscape of advanced triple-negative breast cancer: An Italian consensus paper and critical review.

Triple-negative (TN) metastatic breast cancer (mBC) represents the most challenging scenario withing mBC framework, and it has been only slightly affected by the tremendous advancements in terms of drug availability and survival prolongation we have witnessed in the last years for advanced disease. However, although chemotherapy still represents the mainstay of TN mBC management, in the past years, several novel effective agents have been developed and made available in the clinical practice setting. Within this framework, a panel composed of a scientific board of 17 internationally recognized breast oncologists and 42 oncologists working within local spoke centers, addressed 26 high-priority statements, including grey areas, regarding the management of TN mBC. A structured methodology based on a modified Delphi approach to administer the survey and the Nominal Group Technique to capture perceptions and preferences on the management of TN mBC within the Italian Oncology community were adopted. The Panel produced a set of prioritized considerations/consensus statements reflecting the Panel position on diagnostic and staging approach, first-line and second-line treatments of PD-L1-positive/germline BRCA (gBRCA) wild-type, PD-L1-positive/gBRCA mutated, PD-L1-negative/gBRCA wild-type and PD-L1-negative/gBRCA mutated TN mBC. The Panel critically and comprehensively discussed the most relevant and/or unexpected results and put forward possible interpretations for statements not reaching the consensus threshold.

Health-related quality of life in breast cancer patients treated with CDK4/6 inhibitors: a systematic review.

BACKGROUND: Evaluation of health-related quality of life (HR-QoL) among cancer patients has gained an increasing importance and is now a key determinant of anticancer treatments' value. HR-QoL has been assessed in trials testing cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in breast cancer (BC), using various questionnaires at different timepoints. HR-QoL reports from BC patients treated with CDK4/6i in the real-world setting are also available. METHODS: We systematically reviewed the literature, searching for full-length articles, and selected conference abstracts reporting data on HR-QoL in BC patients at any stage and of any molecular subtype treated with abemaciclib, palbociclib or ribociclib. RESULTS: A total of 533 full-length articles and 143 abstracts were retrieved. After screening for eligibility, 38 records were included (31 clinical trials; 7 real-world reports). Assessment methods were heterogeneous across studies in terms of questionnaires, evaluation timepoints and endpoints. Overall, adding CDK4/6i to endocrine therapy did not worsen patients' HR-QoL, with a positive trend towards pain improvement. Gastrointestinal scores (diarrhea, nausea and appetite loss) statistically favored the control arm among metastatic BC patients receiving abemaciclib, whereas they were superimposable in the early setting. The combination of palbociclib and endocrine therapy showed similar HR-QoL outcomes compared with endocrine therapy alone, but determined better scores compared with chemotherapy. HR-QoL was specifically assessed in premenopausal patients treated with ribociclib, showing similar scores compared with postmenopausal patients. CONCLUSIONS: Despite methodological heterogeneity does not allow a proper comparison, HR-QoL was generally maintained with CDK4/6i. However, differences between abemaciclib, palbociclib and ribociclib exist and mainly rely on the distinct safety profiles of the compounds. These differences should be acknowledged and taken into account in the clinical practice.

T-DM1 versus pertuzumab, trastuzumab and a taxane as first-line therapy of early-relapsed HER2-positive metastatic breast cancer: an Italian multicenter observational study.

BACKGROUND: The current standard first-line treatment of human epidermal growth factor receptor 2 (HER2)-positive (+) metastatic breast cancer is the combination of pertuzumab, trastuzumab and a taxane (P + T + taxane), while standard second-line is ado-trastuzumab-emtansine (T-DM1). The registration trial of pertuzumab, however, did not include early-relapsing patients, defined as patients experiencing tumor relapse ≤12 months from the end of (neo)adjuvant anti-HER2 therapy. Conversely, the pivotal trial of T-DM1 included some patients relapsing ≤6 months after the end of (neo)adjuvant trastuzumab. Thus, a proportion of early-relapsing patients are currently eligible to receive T-DM1 as first-line treatment. Nevertheless, no direct comparison exists between the two regimens in this clinical setting. PATIENTS AND METHODS: We retrospectively compared T-DM1 versus P + T + taxane as first-line treatment in two cohorts of early-relapsing patients in an Italian 'real-world' setting, involving 14 public health care institutions. The primary endpoint was progression-free survival. Secondary endpoints included patients' characterization, overall survival and post-progression survival. Univariate and multivariate analyses were carried out. All tests were two-sided and a P ≤ 0.05 was considered statistically significant. RESULTS: Among 1252 screened patients, 75 met the inclusion criteria. Forty-four (58.7%) received P + T + taxane and 31 (41.3%) received T-DM1. The two cohorts showed similar characteristics of aggressiveness and no significant differences in treatment history. T-DM1, compared with P + T + taxane was associated with worse progression-free survival (adjusted hazard ratio: 2.26, 95% confidence interval: 1.13-4.52, P = 0.021) and overall survival (adjusted hazard ratio: 3.95, 95% confidence interval: 1.38-11.32, P = 0.010), irrespective of previous (neo)adjuvant treatment, age, hormone receptors status, time-to-relapse (≤6 months or within 6-12 months) and presence of visceral/brain metastases. No differences were observed in post-progression survival (P = 0.095). CONCLUSIONS: Our study suggests superiority for P + T + taxane over T-DM1 as up-front treatment of early-relapsing HER2+ metastatic breast cancer, which merits further assessment in larger and prospective trials.

Eribulin in combination with bevacizumab as second-line treatment for HER2-negative metastatic breast cancer progressing after first-line therapy with paclitaxel and bevacizumab: a multicenter, phase II, single arm trial (GIM11-BERGI).

BACKGROUND: We evaluated the efficacy and safety of the nontaxane microtubule dynamics inhibitor eribulin plus the humanized anti-VEGF monoclonal antibody bevacizumab in a novel second-line chemotherapy scheme in HER2-negative metastatic breast cancer (MBC) patients progressing after first-line paclitaxel and bevacizumab. PATIENTS AND METHODS: This is a multicenter, single-arm, Simon's two-stage, phase II study. The primary endpoint was the overall response rate, considered as the sum of partial and complete response based on the best overall response rate (BORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and clinical benefit rate. RESULTS: A total of 58 of the 61 patients enrolled in the study were evaluable for efficacy. The BORR was 24.6% (95% CI 14.5-37.3). The clinical benefit rate was 32.8% (95% CI 21.3-46.0). The median PFS was 6.2 months (95% CI 4.0-7.8), and median OS was 14.8 months (95% CI 12.6-22.8). Overall, adverse events (AEs) were clinically manageable and the most common AEs were fatigue, paresthesia, and neutropenia. Quality of life was well preserved in most patients. CONCLUSIONS: The results of this study suggest that second-line therapy with bevacizumab in combination with eribulin has a meaningful clinical activity and may represent a potential therapeutic option for patients with HER2-negative MBC.

Palbociclib as single agent or in combination with the endocrine therapy received before disease progression for estrogen receptor-positive, HER2-negative metastatic breast cancer: TREnd trial.

Background: The activity of palbociclib as a single agent in advanced breast cancer has not been extensively studied, with the only available clinical data limited to heavily pretreated patients. Preclinical data suggests palbociclib may partially reverse endocrine resistance, though this hypothesis has not been evaluated in previous clinical studies. This phase II, open-label, multicenter study examined the activity of palbociclib monotherapy, as well as palbociclib given in combination with the same endocrine therapy (ET) that was received prior to disease progression, in postmenopausal women with moderately pretreated, estrogen receptor-positive, HER2 negative advanced breast cancer. Patients and methods: Eligible women with advanced disease which had progressed on one or two prior ETs were randomized 1 : 1 to receive either palbociclib alone, or palbociclib in combination with the ET as previously received. Primary end point was clinical benefit rate (CBR); secondary end points included progression-free survival (PFS). Results: Between October 2012 and July 2016, a total of 115 patients were randomized. The CBR was 54% [95% confidence interval (CI): 41.5-63.7] for combination therapy, and 60% (95% CI: 47.8-72.9) for monotherapy. Median PFS was 10.8 months (95% CI: 5.6-12.7) for combination therapy, and 6.5 months (95% CI: 5.4-8.5) for monotherapy [hazard ratio (HR) 0.69; 95% CI: 0.4-1.1, exploratory P-value = 0.12]. Exploratory analyses revealed the PFS advantage for combination therapy was seen in the subgroup of patients who received prior ET for >6 months (HR 0.53; 95% CI: 0.3-0.9, exploratory P-value = 0.02), but not in those who received prior ET for ≤6 months. Conclusion: Palbociclib has clinical activity as a single agent in women with moderately pretreated, oestrogen receptor-positive, HER2-negative advanced breast cancer. Palbociclib may have potential to reverse endocrine resistance in patients with a history of previous durable response to ET. Clinical trial information: NCT02549430.

Androgen receptor in triple negative breast cancer: A potential target for the targetless subtype.

Triple negative breast cancer (TNBC) represents the 15-20% of all breast cancers (BC) and is characterized by a very aggressive behavior. Recent data suggest that TNBC is not a single disease, but it is rather an umbrella for different ontology-profiles such as basal like 1 and 2, mesenchymal, and the luminal androgen receptor (LAR). The LAR subtype is characterized by the expression of the Androgen Receptor (AR) and its downstream effects. Notwithstanding the role of the AR in several signaling pathways, its impact on a biological and clinical standpoint is still controversial. The LAR subtype has been associated with better prognosis, less chemotherapy responsiveness and lower pathologic complete response after neoadjuvant treatment. Clinical evidence suggests a role for anti-androgen therapies such as bicalutamide, enzalutamide and abiraterone, offering an interesting chemo-free alternative for chemo-unresponsive patients, and therefore potentially shifting current treatment strategies.

Imaging tests in staging and surveillance of non-metastatic breast cancer: changes in routine clinical practice and cost implications.

BACKGROUND: Although guidelines do not recommend computerised tomography (CT), positron emission tomography (PET) or magnetic resonance imaging (MRI) for the staging or follow-up of asymptomatic patients with non-metastatic breast cancer, they are often requested in routine clinical practice. The aim of this study was to determine the staging and follow-up patterns, and relative costs in a large population of breast cancer patients living and treated in a Southern Italian region. METHODS: We analysed the clinical computerised information recorded by 567 primary-care physicians assisting about 650 000 inhabitants in the Campania region. Patients with non-metastatic breast cancer were identified and divided into calendar years from 2001 to 2010. The number of diagnostic tests prescribed per 100 patients (N/Pts) and the mean cost per patient was determined 3 months before diagnosis and up to 1 year after diagnosis. Costs are expressed in constant 2011 euros. RESULTS: We identified 4680 newly diagnosed cases of asymptomatic non-metastatic breast cancer. N/Pts increased significantly (P<0.0001) from 2001 to 2010. The mean number of prescribed mammograms, bone scans, abdominal ultrasound and chest X-rays ('routine tests'), and costs was unchanged. However, the number of CT, PET scans and MRI ('new tests')prescriptions almost quadrupled and the mean cost per patient related to these procedures significantly increased from [euro ]357 in 2001 to [euro ]830 in 2010 (P<0.0001). CONCLUSIONS: New test prescriptions and relative costs significantly and steadily increased throughout the study period. At present there is no evidence that the delivery of new tests to asymptomatic patients improves breast cancer outcome. Well-designed clinical trials are urgently needed to shed light on the impact of these tests on clinical outcome and overall survival.

Tumor characteristics and prognosis in familial breast cancer.

BACKGROUND: Approximately 5-10% of breast cancers are hereditary and their biology and prognosis appear to differ from those of sporadic breast cancers. In this study we compared the biological features and clinical characteristics of non metastatic breast cancer in patients with BRCA mutations versus patients with a family history suggesting hereditary breast cancer but without BRCA mutations (BRCA wild type) versus patients with sporadic disease, and correlated these findings with clinical outcome. METHODS: We retrieved the clinical and biological data of 33 BRCA-positive, 66 BRCA-wild type and 1826 sporadic breast cancer patients contained in a single institution clinical database between 1980 and 2012. Specifically, we recorded age, tumor size, nodal status, treatment type, pattern of relapse, second primary incidence, outcome (disease-free survival and overall survival), and biological features (estrogen receptor [ER], progesterone receptor [PgR], tumor grade, proliferation and c-erbB2 status). Median follow-up was 70 months. RESULTS: BRCA-positive patients were significantly younger than sporadic breast cancer patients, and less likely to be ER-, PgR- or c-erbB2-positive than women with BRCA-wild type or sporadic breast cancer. Tumor size and grade, nodal status and proliferation did not differ among the three groups. Rates of radical mastectomy were 58, 42 and 37%, and those of conservative surgery were 42, 58 and 63% in women with BRCA-positive, BRCA-wild type and sporadic breast cancer (p = 0.03), respectively. The incidence of contralateral breast cancer was 12, 14 and 0% (p <0.0001) and the incidence of second primary tumors (non breast) was 9, 1 and 2% (p <0.0001) in BRCA-positive, BRCA-wild type and sporadic breast cancer, respectively. Median disease-free survival in years was 29 in BRCA-wild type, 19 in BRCA-positive and 14 in sporadic breast cancer patients (log-rank = 0.007). Median overall survival in years was not reached for BRCA-wild type, 19 for BRCA-positive and 13 for sporadic breast cancer patients (log-rank <0.0001). At multivariate analyses only BRCA-wild type status was related to a significant improvement in overall survival versus the sporadic breast cancer group (HR = 0,51; 95% CI (0,28-0,93) p = 0.028). CONCLUSIONS: The biology and outcome of breast cancer differ between patients with BRCA mutations, patients with a family history but no BRCA mutations and patients with sporadic breast cancer.

Body weight and risk of molecular breast cancer subtypes among postmenopausal Mediterranean women.

Breast cancer (BC) is the most common malignant tumor in women, obesity is associated with increased BC incidence and mortality and high levels of circulating insulin may negatively impact on cancer incidence. In the present study, we investigated whether the strength of several anthropometric and metabolic parameters varies between BC molecular subtypes. Eligible cases were 991 non-metastatic BC patients recruited between January 2009 and December 2013. Anthropometric, clinical and immunohistochemical features were measured. Multivariate logistic regression models were built to assess HER2 positive BC risk, comparing (a) triple positive (TP) with luminal A, luminal B and triple negative (TN) and (b) HER2-enriched group with luminal A, luminal B and TN. We stratified patients in pre- and post-menopause: significant differences emerged for luminal A in relation to age: they were more likely to be older compared to other groups. Among postmenopausal patients, the adjusted multivariate analysis showed that high BMI and high waist circumference were inversely correlated to TP subtype when compared to luminal B (OR=0.48 and OR=0.49, respectively). Conversely, HOMA-IR was a risk factor for TP when compared to luminal A and TN (OR=2.47 and OR=3.15, respectively). Our findings suggest a potential role of higher abdominal fat in the development of specific BC molecular subtypes in postmenopausal women. Moreover, they support a potential role of insulin resistance in the development of HER2 positive BC, although this role appears to be stronger when hormone receptors are co-expressed, suggesting a difference in the etiology of these two BC subtypes.

Tailoring the dosing schedule of nab-paclitaxel in metastatic breast cancer according to patient and disease characteristics: Recommendations from a panel of experts.

The choice of chemotherapy for patients with metastatic breast cancer (MBC) depends on disease- and patient-related factors, but there is little guidance on dosing modifications for patients unable to receive the licensed dose. Nab-paclitaxel is a solvent-free form of paclitaxel that uses albumin as a drug carrier and exploits endogenous albumin transport pathways to achieve enhanced drug targeting and tumour penetration with reduced toxicity. It is approved for use at a dose of 260 mg/m(2) every three weeks in adults who have failed first-line treatment for MBC and for whom standard anthracycline-based therapy is not indicated. Emerging data suggest that weekly dosing schedules of nab-paclitaxel may provide clinical benefit in some patients, but the utility of these alternative dosing schedules remains unclear. A panel of breast cancer experts convened to review available literature for nab-paclitaxel in MBC and, taking into account their clinical experience, recommended that alternative dosing schedules may be considered according to the aggressiveness of disease and patient condition as follows: 125 mg/m(2) QW 3/4 (aggressive disease and fit), 100mg/m(2) QW 3/4 (aggressive or indolent disease and unfit). All dosing schedules were considered acceptable for fit patients with indolent disease. These recommendations are based on current evidence, and emerging data from ongoing trials may reinforce or modify the recommendations provided.

Surgery of the primary tumor in de novo metastatic breast cancer: To do or not to do?

Approximately five percent of all breast cancer patients in developed countries present with distant metastases at initial diagnosis. Due to its incurability, metastatic breast cancer is generally treated with systemic therapies to achieve disease control and reduce tumor-related symptoms. Primary treatments for metastatic breast cancer are chemotherapy, endocrine- and biologic therapy, whereas surgery with or without radiotherapy is usually performed to treat impending wound issues. Since 2002, several retrospective non-randomized clinical studies have shown that extirpation of the primary tumor correlates with a significantly improved survival in patients with primary metastatic breast cancer. Others have argued that this survival benefit associated with surgery may be due to selection biases. Therefore, in the absence of published results from randomized controlled trials carried out in India and Turkey and completion of a trial in the United States, there is no clear conclusion on whether surgical excision of the primary breast cancer translates into a survival benefit for patients with de novo metastatic disease. Furthermore, timing and type of surgical procedure, as well as selection of patients who could benefit the most from this approach, represent additional points of uncertainty. Despite the epidemiological burden of this condition, there are no guidelines on how to manage breast cancer patients presenting with de novo metastatic breast cancer; and decisions are often left to provider and patient preferences. Here, we present a critical overview of the literature focusing on the rationale and potential role of primary tumour excision in patients with de novo metastatic breast cancer.

Role of vesicular nucleotide transporter VNUT (SLC17A9) in release of ATP from AR42J cells and mouse pancreatic acinar cells.

ATP is released from cells in response to various stimuli. Our previous studies on pancreas indicated that pancreatic acini could be major stores of secreted ATP. In the present study, our aim was to establish the role of the vesicular nucleotide transporter (VNUT), SLC17A9, in storage and release of ATP. Freshly prepared acini from mice and AR42J rat acinar cells were used in this study. We illustrate that in AR42J cells, quinacrine (an ATP store marker) and Bodipy ATP (a fluorescent ATP analog) co-localized with VNUT-mCherry to vesicles/granules. Furthermore, in acini and AR42J cells, a marker of the zymogen granule membranes, Rab3D, and VNUT co-localized. Dexamethasone treatment of AR42J cells promoted formation of acinar structures, paralleled by increased amylase and VNUT expression, and increased ATP release in response to cholinergic stimulation. Mechanical stimulus (pressure) and cell swelling also induced ATP release, but this was not influenced by dexamethasone, most likely indicating different non-zymogen-related release mechanism. In conclusion, we propose that VNUT-dependent ATP release pathway is associated with agonist-induced secretion process and downstream purinergic signalling in pancreatic ducts.

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.

Clinical and biologic features of triple-negative breast cancers in a large cohort of patients with long-term follow-up.

Studies on well characterized, large populations of estrogen receptor (ER)/progesterone receptor (PgR)/HER2-negative [triple-negative (TN)] breast cancer (BC) patients with long-term follow-up are lacking. In this study, we analyze clinical outcomes of TN BC and implications of epidermal growth factor receptor (EGFR) expression. Clinical and biologic features, time to first recurrence (TTFR), and overall survival (OS) were compared in 253 TN versus 1,036 ER positive, PgR positive, HER2-negative [estrogen-driven (ED)] BC. Compared to ED, TN tumors were larger (p = 0.02), more proliferative (high S-phase 54 vs. 17 %, p < 0.0001), more aneuploid (64 vs. 43 %, p < 0.0001) and more likely EGFR positive (≥10 fmol/mg by radioligand-binding assay, 49 vs. 7 %, p < 0.0001). Among TN, EGFR-positive BC were larger (p = 0.0018), more proliferative (p < 0.0001), and more aneuploid, (p < 0.0001) than EGFR-negative BC. Adjuvant-treated TN patients had shorter TTFR (p = 0.0003), and OS (p = 0.0017), than ED patients. However, in untreated patients, no differences in TTFR and OS were observed at 8 years median follow-up. Among TN patients, EGFR expression was not associated with worse outcome. TN tumors have a worse outcome in systemically treated patients but not in untreated patients. EGFR expression, does not predict for worse long-term survival.

Circulating tumor cells in immunohistochemical subtypes of metastatic breast cancer: lack of prediction in HER2-positive disease treated with targeted therapy.

BACKGROUND: Circulating tumor cells (CTCs) are associated with inferior prognosis in metastatic breast cancer (MBC). We hypothesized that the relationship between CTCs and disease subtype would provide a better understanding of the clinical and biologic behavior of MBC. PATIENTS AND METHODS: We retrospectively analyzed 517 MBC patients treated at a single institution. Subtypes of primary tumors were analyzed by immunohistochemical (IHC) or fluorescent in situ hybridization analyses and CTCs were enumerated by CellSearch(®) at starting a new therapy. Overall survival (OS) and progression-free survival durations for each IHC subtype were determined. RESULTS: At a median follow-up of 24.6 months, 276 of 517 (53%) patients had died. The median OS for patients with <5 and ≥ 5 CTCs were 32.4 and 18.3 months, respectively (P < 0.001). Except in HER2+ patients, the prognostic value of CTCs was independent of disease subtype and disease site. CONCLUSIONS: In this large retrospective study, CTCs were strongly predictive of survival in all MBC subtypes except HER2+ patients who had been treated with targeted therapy. Our results clearly demonstrate the value of enumerating CTCs in MBC and strongly suggest an interesting biological implication in the HER2+ subset of patients that need to be further explored.

Treatment of triple negative breast cancer (TNBC): current options and future perspectives.

Breast cancer is not considered anymore a unique disease. Microarray gene expression analysis led to the identification of 4 major breast cancer "intrinsic" subtypes, including hormone receptor (HR)-positive luminal A and B, human epidermal growth receptor 2 (HER2)-positive and basal-like breast cancer (BLBC). These subtypes have distinct phenotypes, molecular profiles, clinical behaviour and response to therapy, with the BLBC carrying the worst outcome. Microarray analysis is not feasible in routine practice and therefore oncologists rely on a simpler immunohistochemical (IHC) classification to identify relevant breast cancer subtypes. Triple negative breast cancer (TNBC) is defined by the absence of oestrogen receptor, progesterone receptor and HER2 expression at IHC analysis. TNBC is strictly related to BLBC and, given the lack of common therapeutic targets, represent a major challenge for breast oncologist. In this review we will summarize the updated knowledge on TNBC, with emphasis on its current treatment and on the new therapeutic options under development.