Metastatic breast cancer subtypes and central nervous system metastases

BACKGROUND

Breast cancer (BC) subtypes have different survival and response to therapy. We studied predictors of central nervous system metastases (CNS-M) and outcome after CNS-M diagnosis according to tumor subtype.

PATIENTS AND METHODS

488 patients with diagnosis of metastatic BC were retrospectively evaluated. According to the combination of hormone receptors (HR) and HER2 status, tumors were grouped in: Luminal (Lum), Luminal/HER2+, pure HER2-positive (pHER2+) and triple negative (TN). Time to CNS progression, CNS-M free interval and Overall Survival (OS) after CNS-M occurrence were compared by the log-rank test. Cox-proportional hazard models were used to study predictor factors associated with CNS progression, including tumor subtype and all potentially clinical relevant variables.

RESULTS

115 patients (pts) developed CNS-M with a median time to CNS progression of 31 months. The rate of CNS-M by subtype was: Lum 14%, Lum/HER2+ 35%, pHER2+ 49%, TN 22% (p < 0.001). Compared with Lum tumors, Lum/HER2+ (HR 2.514, p < 0.001), pHER2+ (HR 6.799, p < 0.0001) and TN (HR = 3.179, p < 0.001) subtypes were at higher risk of CNS-M. Median OS in months after CNS-M was: Lum 7.4, Lum/HER2+ 19.2, pHER2+ 7, TN 4.9 (p < 0.002). Belonging to the Lum/HER2+ subtype (HR 0.48, p < 0.037) and having isolated CNS (HR 0.37, p < 0.004) predicted significantly reduced risk of death.

CONCLUSIONS

After CNS-M, the Lum/HER2+ subtype appears associated with the longest OS. Prospective clinical trials would be required for evaluating the potential role of screening for asymptomatic CNS lesions and of more aggressive CNS-M treatment in Lum/HER2+ subtype.

Overcoming endocrine resistance in metastatic breast cancer: Current evidence and future directions

About 75% of all breast cancers are estrogen receptor (ER)-positive. They generally have a more favorable clinical behavior, prognosis, and pattern of recurrence, and endocrine therapy forms the backbone of treatment. Anti-estrogens (such as tamoxifen and fulvestrant) and aromatase inhibitors (such as anastrozole, letrozole, and exemestane) can effectively control the disease and induce tumor responses in a large proportion of patients. However, the majority of patients progress during endocrine therapy (acquired resistance) and a proportion of patients may fail to respond to initial therapy (de novo resistance). Endocrine resistance is therefore of clinical concern and there is great interest in strategies that delay or circumvent it. A deeper knowledge of the molecular mechanisms that drive endocrine resistance has recently led to development of new strategies that have the promise to effectively overcome it. Many resistance mechanisms have been described, and the crosstalk between ER and growth factor receptor signaling pathways seems to represent one of the most relevant. Compounds that are able to inhibit key elements of these pathways and restore endocrine sensitivity have been studied and more are currently under development. The aim of this review is to summarize the molecular pathophysiology of endocrine resistance in breast cancer and its impact on current clinical management.

A First-in-Human, Phase I, Dose-Escalation Study of TAK-117, a Selective PI3Kα Isoform Inhibitor, in Patients with Advanced Solid Malignancies

Purpose: To evaluate the safety, MTD, pharmacokinetics, pharmacodynamics, and preliminary antitumor activity of TAK-117 (MLN1117/INK1117), an investigational PI3Kα-selective inhibitor, in patients with advanced solid tumors.Experimental Design: Seventy-one patients received oral TAK-117 once daily [100-300 mg (n = 24)] or 3 days per week [Monday-Wednesday-Friday (MWF), 200-1,200 mg (n = 27); Monday-Tuesday-Wednesday (MTuW), 200-900 mg (n = 20)], in 21-day cycles. Dose escalation proceeded via a 3 + 3 design.Results: TAK-117 once-daily dosing was associated with dose-limiting grade ≥3 alanine/aspartate aminotransferase (ALT/AST) elevations, resulting in a narrow range of tolerable doses (100-150 mg once daily). With MWF/MTuW dosing, no dose-limiting ALT/AST elevations occurred until the MTD of 900 mg; total weekly dose was 2.6-fold that of 150 mg once daily. Drug-related grade ≥3 adverse events occurred in 25%/22%/35% (including hyperglycemia in 0%/7%/15%) of once-daily/MWF/MTuW patients. TAK-117 (100-1,200 mg) exhibited moderately fast oral absorption, a generally dose proportional increase in exposure, and plasma half-life of approximately 11 hours. Total weekly exposures with 900 mg MWF/MTuW dosing were approximately 4 times greater than with 150 mg once daily. Skin pS6 expression was suppressed at ≥200 mg. There were 3/1/0 partial responses (once daily/MWF/MTuW) and 5/7/5 patients had stable disease lasting ≥3 months (all PIK3CA mutated).Conclusions: Intermittent dosing of TAK-117 had an acceptable safety profile and enabled higher doses and total weekly exposures versus once-daily dosing. Although the potential for TAK-117 as single-agent therapy appears limited, further evaluation in combination approaches for advanced solid tumors is warranted. Clin Cancer Res; 23(17); 5015-23. ©2017 AACR.

The neutrophil-lymphocyte ratio and its utilisation for the management of cancer patients in early clinical trials

Background:

Inflammation is critical to the pathogenesis and progression of cancer, with a high neutrophil–lymphocyte ratio (NLR) associated with poor prognosis. The utility of studying NLR in early clinical trials is unknown.

Methods:

This retrospective study evaluated 1300 patients treated in phase 1 clinical trials between July 2004 and February 2014 at the Royal Marsden Hospital (RMH), UK. Data were collected on patient characteristics and baseline laboratory parameters.

Results:

The test cohort recruited 300 patients; 53% were female, 35% ECOG 0 and 64% ECOG 1. RMH score was 0–1 in 66% and 2–3 in 34%. The median NLR was 3.08 (IQR 2.06–4.49). Median OS for the NLR quartiles was 10.5 months for quartile-1, 10.3 months for quartile-2, 7.9 months for quartile-3 and 6.5 months for quartile-4 (P<0.0001). Univariate analysis identified RMH score (HR=0.55, P<0.0001), ECOG (HR=0.62, P=0.002) and neutrophils (HR=0.65, P=0.003) to be associated with OS. In multivariate analysis, adjusting for RMH score, ECOG, neutrophils and tumour type, NLR remained significantly associated with OS (P=0.002), with no association with therapeutic steroid use. These results were validated in a further 1000 cancer patients. In the validation cohort, NLR was able to discriminate for OS (P=0.004), as was the RMH score. This was further improved on in the RMH score+NLR50 and RMH score+Log₁₀NLR models, with an optimal NLR cutoff of 3.0.

Conclusions:

NLR is a validated independent prognostic factor for OS in patients treated in phase 1 trials. Combining the NLR with the RMH score improves the discriminating ability for OS.

Genotyping tumour DNA in cerebrospinal fluid and plasma of a HER2-positive breast cancer patient with brain metastases

BACKGROUND

Central nervous system (CNS) involvement contributes to significant morbidity and mortality in patients with human epidermal growth factor receptor 2 (HER2)-positive metastatic breast cancer (mBC) and represents a major challenge for clinicians. Liquid biopsy of cerebrospinal fluid (CSF)-derived circulating tumour DNA (ctDNA) harbours clinically relevant genomic alterations in patients with CNS metastases and could be effective in tracking tumour evolution.

METHODS

In a HER2-positive mBC patient with brain metastases, we applied droplet digital PCR (ddPCR) and next-generation whole exome sequencing (WES) analysis to measure ctDNA dynamic changes in CSF and plasma collected during treatment.

RESULTS

Baseline CSF-derived ctDNA analysis revealed TP53 and PIK3CA mutations as well as ERBB2 and cMYC amplification. Post-treatment ctDNA analysis showed decreased markers level in plasma, consistent with extra-CNS disease control, while increased in the CSF, confirming poor treatment benefit in the CNS.

DISCUSSION

Analysis of ctDNA in the CSF of HER2-positive mBC is feasible and could represent a useful companion for clinical management of brain metastases.

"Metastatic Cancer of Unknown Primary" or "Primary Metastatic Cancer"?

Cancer of unknown primary (CUP) is an umbrella term used to classify a heterogeneous group of metastatic cancers based on the absence of an identifiable primary tumor. Clinically, CUPs are characterized by a set of distinct features comprising early metastatic dissemination in an atypical pattern, an aggressive clinical course, poor response to empiric chemotherapy and, consequently, a short life expectancy. Two opposing strategies to change the dismal prognosis for the better are pursued. On the one hand, following the traditional tissue-gnostic approach, more and more sophisticated tissue-of-origin (TOO) classifier assays are employed to push identification of the putative primary to its limits with the clear intent of allowing tumor-site specific treatment. However, robust evidence supporting its routine clinical use is still lacking, notably with two recent randomized clinical trials failing to show a patient benefit of TOO-prediction based site-specific treatment over empiric chemotherapy in CUP. On the other hand, with regards to a tissue-agnostic strategy, precision medicine approaches targeting actionable genomic alterations have already transformed the treatment for many known tumor types. Yet, an unmet need remains for well-designed clinical trials to scrutinize its potential role in CUP beyond anecdotal case reports. In the absence of practice changing results, we believe that the emphasis on finding the presumed unknown primary tumor at all costs, implicit in the term CUP, has biased recent research in the field. Focusing on the distinct clinical features shared by all CUPs, we advocate adopting the term primary metastatic cancer (PMC) to denominate a distinct cancer entity instead. In our view, PMC should be considered the archetype of metastatic disease and as such, despite accounting for a mere 2–3% of malignancies, unraveling the mechanisms at play goes beyond improving the prognosis of patients with PMC and promises to greatly enhance our understanding of the metastatic process and carcinogenesis across all cancer types.

Buparlisib , an oral pan-PI3K inhibitor for the treatment of breast cancer

INTRODUCTION

Deregulation of the phosphatidylinositol-3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) intracellular signaling pathway is common in breast cancer (BC) and has been found to be potentially implicated in resistance to endocrine and anti-HER2 therapies. Targeting the PI3K/Akt/mTOR pathway may remove this inhibition and restore sensitivity to these compounds. Buparlisib (BKM120) is a potent oral pan-class I PI3K inhibitor that is being extensively evaluated in multiple tumor types.

AREAS COVERED

This review briefly summarizes the pharmacodynamics and pharmacokinetics of buparlisib, focusing on preclinical and clinical data in BC and on ongoing randomized trials.

EXPERT OPINION

Overall, buparlisib is a safe and tolerable drug and, despite its peculiar toxicity profile, it is suitable for studies in combination with other anticancer agents in BC. Early-phase clinical trials in BC have provided evidence of antitumor activity. Several trials are being conducted in all the biological subsets of BC, including combinations with endocrine therapy, anti-HER2 agents, PARP-inhibitors and chemotherapy. While clinical results are eagerly awaited, biological material suitable for both genomic and non-genomic analyses is being collected. The authors expect an intense investigation of the potential biomarkers that explain response or resistance to buparlisib and inspire strategies to rationally explore the therapeutic potential of this drug.

Higher Risk of Infections with PI3K-AKT-mTOR Pathway Inhibitors in Patients with Advanced Solid Tumors on Phase I Clinical Trials

PURPOSE

Novel antitumor therapies against the PI3K-AKT-mTOR pathway are increasingly used to treat cancer, either as single agents or in combination with chemotherapy or other targeted therapies. Although these agents are not known to be myelosuppressive, an increased risk of infection has been reported with rapamycin analogues. However, the risk of infection with new inhibitors of this pathway such as PI3K, AKT, mTORC 1/2, or multikinase inhibitors is unknown.

EXPERIMENTAL DESIGN

In this retrospective case-control study, we determined the incidence of infection in a group of 432 patients who were treated on 15 phase I clinical trials involving PI3K-AKT-mTOR pathway inhibitors (cases) versus a group of 100 patients on 10 phase I clinical trials of single agent non-PI3K-AKT-mTOR pathway inhibitors (controls) which did not involve conventional cytotoxic agents. We also collected data from 42 patients who were treated with phase I trials of combinations of PI3K-AKT-mTOR inhibitors and MEK inhibitors and 24 patients with combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapies.

RESULTS

The incidence of all grade infection was significantly higher with all single-agent PI3K-AKT-mTOR inhibitors compared with the control group [27% vs. 8%, respectively, OR, 4.26; 95% confidence intervals (CI), 1.9-9.1, P = 0.0001]. The incidence of grade 3 and 4 infection was also significantly higher with PI3K-AKT-mTOR inhibitors compared with the control group (10.3% vs. 3%, OR, 3.74; 95% CI, 1.1-12.4; P = 0.02). Also, the combination of PI3K-AKT-mTOR inhibitors and chemotherapy was associated with a significantly higher incidence of all grade (OR, 4.79; 95% CI, 2.0-11.2; P = 0.0001) and high-grade (OR, 2.87; 95% CI, 1.0-7.6; P = 0.03) infection when compared with single-agent PI3K-AKT-mTOR inhibitors.

CONCLUSIONS

Inhibitors of the PI3K-AKT-mTOR pathway can be associated with a higher risk of infection. Combinations of PI3K-AKT-mTOR inhibitors and cytotoxic chemotherapy significantly increase the risk of infection. This should be taken into consideration during the design and conduct of trials involving PI3K-AKT-mTOR pathway inhibitors, particularly when combined with chemotherapy or myelosuppressive agents.

Self-evaluation of duration of adjuvant chemotherapy side effects in breast cancer patients: A prospective study

Background

We recently reported that self‐evaluation of the incidence and severity of treatment‐related side effects (TSEs) using a National Cancer Institute (NCI) Common Terminology Criteria for Adverse Events (CTCAE) v4.0‐based questionnaire was feasible and more informative than doctor reports in patients undergoing standard adjuvant chemotherapy for operable breast cancer. Here, we compare self‐ and doctor‐evaluated day of onset and duration of TSEs in the same population.

Patients and methods

Six hundred and four patients were enrolled at 11 sites in Italy. CTCAE v4.0 definitions of grade of severity of nausea, vomiting, constipation, anorexia, dysgeusia, diarrhea, fatigue, pain, paresthesia, and dyspnea were translated into Italian and rephrased. Questionnaires were administered after the first and third chemotherapy cycles. At each time‐point, information on TSEs was extracted from the medical charts and compared to patient questionnaires.

Results

A total of 594 and 573 paired patient and doctor questionnaires were collected after cycles one and three, respectively. TSE duration was significantly longer when reported by patients compared to doctors for six and seven of ten items after cycles one and three, respectively. Due to the combined effect of doctor underreporting of TSE incidence and duration, the mean percentages of cycle days with TSEs were significantly higher for all ten items when based on patient reports. Day of onset could not be evaluated because of insufficient numbers of complete records.

Conclusions

Self‐reporting TSE duration is feasible using a CTCAE‐derived questionnaire. As doctors tend to underestimate TSE incidence and duration, patient‐reported outcomes should be incorporated into clinical practice, perhaps using eHealth technologies, to harness their potential to better estimate total TSE burden.

Multiple meningiomas. Report of nine cases

Multiple meningiomas are a seldom encountered neoplasm. Most authors report an incidence ranging from 1 to 3% of all meningiomas. The routine use of CT has resolved diagnostic problems involved with multiple meningiomas; nevertheless, they still present several nosologic problems. In fact, it may be difficult to differentiate "true multiple meningiomas", defined as a distinct entity by Cushing in 1938, from simple recurrences or the special variant (forme fruste) of von Recklinghausen's disease. Our report deals with nine cases of multiple meningiomas selected from a series of 372 meningiomas operated from 1968 to 1981 at our hospital. Cases were divided into a) multiple simultaneous meningiomas (five cases), b) multiple meningiomas successively detected at different localizations (two cases), and c) multiple meningiomas associated with neurofibromatosis (two cases). Only five of these nine cases, four from the first group and one from the second, were true multiple meningiomas. Pathogenetic factors related to true multiple meningiomas are discussed in relation to the literature reports. However, the different hypotheses proposed do not offer a definite explanation of the multicentricity of these tumours.

The Clinical Efficacy and Safety of Neratinib in Combination with Capecitabine for the Treatment of Adult Patients with Advanced or Metastatic HER2-Positive Breast Cancer

Human epidermal growth factor receptor 2 (HER2) positive cancers account for 15–20% of all breast tumors. Several drugs have been approved in the metastatic setting, including monoclonal antibodies, tyrosine kinase inhibitors (TKI) and, more recently, antibody-drug conjugates. Neratinib is a pan-HER, irreversible TKI with potent preclinical activity against trastuzumab-resistant breast cancer models. Based on Phase I and II clinical trials, the combination of neratinib plus capecitabine was compared to lapatinib and capecitabine, an established regimen for trastuzumab-resistant disease, in the randomized, Phase III NALA trial. In this trial, neratinib yielded increased progression-free survival, response duration and a benefit in time to intervention for CNS progression. However, there was no overall survival benefit, no increase in overall response rate and no improvement in QoL. The most frequent adverse event in the neratinib arm was diarrhea, which was manageable with prophylactic treatment with loperamide. Conclusion: Neratinib is a valuable addition to the therapeutic armamentarium to treat metastatic, HER2-positive breast cancer. The current positioning of the combination of neratinib and capecitabine based on the results of the NALA trial needs to consider the rapidly evolving scenario due to the recent introduction of new drugs, like the pure-HER2 TKI tucatinib and the antibody drug-conjugate trastuzumab-deruxtecan.

Potential of afatinib in the treatment of patients with HER2-positive breast cancer

In the absence of treatment, overexpression of the human epidermal growth factor receptor 2 (HER2) predicts a poor prognosis in breast cancer. In the last decade, monoclonal antibodies and small molecule tyrosine kinase inhibitors have significantly improved the outcome of HER2-positive breast cancer patients. However, tumor resistance and toxicities often limit the use of these therapies. For this reason, there is a compelling need for further investigation of new targeted therapies, such as afatinib, an oral irreversible pan inhibitor of the epidermal growth factor receptor (EGFR) family. This compound covalently interacts with tyrosine kinase domains, which are deeply involved in signal transduction leading to cell proliferation and protection from apoptosis. Afatinib has been studied in several Phase I clinical trials in advanced solid tumors. These trials have shown encouraging clinical activity and manageable side effects when afatinib is used either as a single agent or in combination with chemotherapy, with cutaneous adverse events and diarrhea being the most frequently observed toxicities. This review will focus on afatinib's clinical activity and will discuss ongoing clinical studies in HER2-positive breast cancer patients. In the scenario of the different HER2-targeted therapies, it will be important to define the best specific clinical and "molecular" setting for afatinib use, trying to identify predictors of resistance and response. Moreover, afatinib, which has the ability to cross the blood-brain barrier, could play a role in patients with brain metastases from breast cancer.

Circulating Cytokines in Metastatic Breast Cancer Patients Select Different Prognostic Groups and Patients Who Might Benefit from Treatment beyond Progression

Cancer induces immune suppression to overcome its recognition and eradication by the immune system. Cytokines are messengers able to modulate immune response or suppression. There is great interest in the evaluation of their changes during treatment in order to identify their relationship with clinical outcome. We evaluated 18 cytokines in breast cancer patients treated with eribulin before starting treatment (T0) and after four courses of therapy (T1). Longitudinal modifications were considered and cytokine clusters through PCA and HCPC correlated to patients' outcomes were identified. Forty-one metastatic breast cancer patients and fifteen healthy volunteers were included. After clustering, we identified at T0 six patient clusters with different risk of relapse and death. At T1, only four clusters were identified, and three of them accounted for thirty-eight of forty-one patients, suggesting a possible role of treatment in reducing heterogeneity. The cluster with the best survival at T1 was characterized by low levels of IL-4, IL-6, IL-8, IL-10, CCL-2, CCL-4, and TGF-β. The cluster showing the worst survival encompassed high levels of IL-4, IL-6, IL-8, IL-10, CCL-2, and IFN-γ. A subgroup of patients with short progression-free survival (PFS) and long overall survival (OS) was comprised in the cluster characterized by low levels of CCL-2, IL-6, IL-8, IL-10, and IL-12 at T0. Our data support the prognostic significance of longitudinal serum cytokine analysis. This approach may help identify patients for whom early treatment stop avoids needless toxicity or might justify treatment beyond early progression. Further investigations are required to validate this hypothesis.

Exploratory analysis of circulating cytokines in patients with metastatic breast cancer treated with eribulin: the TRANSERI-GONO (Gruppo Oncologico del Nord Ovest) study

Background

Anticancer drugs can interact with the tumour microenvironment and their effects could be exploited to favour anticancer immune response. Eribulin contributes to tumour vasculature remodelling and transforming growth factor β (TGF-β) modulation in experimental models and in humans. We performed a prospective, translational, exploratory analysis of the levels of circulating cytokines at different time points in patients with metastatic breast cancer treated with eribulin.

Methods

TGF-β, tumour necrosis factor α, vascular endothelial growth factor, IL-6, IL-8, IL-10, IL-21 and C-C motif chemokine ligand-2 levels were assessed in peripheral blood samples obtained from seven healthy volunteers and 41 patients at baseline (T₀), after four cycles of eribulin (T₁) and at disease progression (T_PD). Baseline values and longitudinal changes in cytokine levels were then related to clinical outcome.

Results

In the 41 patients, high IL-6 and IL-8 (above the median) at T₀ significantly correlated with worse survival. At T₁, IL-21 significantly decreased in patients with T_PD within the fourth course of treatment, compared with patients without progression. TGF-β and IL-8 above the median and IL-21 below the median at T₁ significantly correlates with worse progression free survival (PFS). Patients exhibiting an increase of TGF-β or a decline of IL-21 between T₀ and T₁ showed a significantly worse PFS. Multivariate Cox regression analysis showed that only plasma TGF-β changes at T₁ correlated with survival. At T_PD, TGF-β significantly increased in all patients.

Conclusions

We observed a significant correlation between TGF-β decline during eribulin treatment and outcome in patients with metastatic breast cancer. Altogether, our data suggest that eribulin treatment might interfere with the tumour microenvironment.

Real-world histopathological approach to malignancy of undefined primary origin (MUO) to diagnose cancers of unknown primary (CUPs)

The aim of this study is to envisage a streamlined pathological workup to rule out CUPs in patients presenting with MUOs. Sixty-four MUOs were classified using standard histopathology. Clinical data, immunocytochemical markers, and results of molecular analysis were recorded. MUOs were histologically subdivided in clear-cut carcinomas (40 adenocarcinomas, 11 squamous, and 3 neuroendocrine carcinomas) and unclear-carcinoma features (5 undifferentiated and 5 sarcomatoid tumors). Cytohistology of 7/40 adenocarcinomas suggested an early metastatic cancer per se. In 33/40 adenocarcinomas, CK7/CK20 expression pattern, gender, and metastasis sites influenced tissue-specific marker selection. In 23/40 adenocarcinomas, a "putative-immunophenotype" of tissue of origin addressed clinical-diagnostic examinations, identifying 9 early metastatic cancers. Cell lineage markers were used to confirm squamous and neuroendocrine differentiation. Pan-cytokeratins were used to confirm the epithelial nature of poorly differentiated tumors, followed by tissue and cell lineage markers, which identified one melanoma. In total, 47/64 MUOs (73.4%) were confirmed CUP. Molecular analysis, feasible in 37/47 CUPs (78.7%), had no diagnostic impact. Twenty CUP patients, mainly with squamous carcinomas and adenocarcinomas with putative-gynecologic-immunophenotypes, presented with only lymph node metastases and had longer median time to progression and overall survival (< 0.001), compared with patients with other metastatic patterns. We propose a simplified histology-driven workup which could efficiently rule out CUPs and identify early metastatic cancer.

New and developing chemical pharmacotherapy for treating hormone receptor-positive/HER2-negative breast cancer

INTRODUCTION

Endocrine therapy is the mainstay of treatment for a substantial proportion of hormone receptor positive (HR+) breast cancer (BC). Indeed, patients with metastatic disease not immediately life threatening may experience long disease control across several lines of endocrine therapy. The major limitation of this therapeutic approach is primary or acquired resistance. A better understanding of endocrine resistance has resulted in newer targeted agents to be added to endocrine therapy. Areas covered: This review highlights new findings in the treatment of HR+/HER2- BC, with a particular focus on new drugs from phase 3 development onwards. Expert opinion: Combining endocrine therapy with agents targeting putative mechanisms of endocrine resistance is a newer treatment paradigm in HR+ BC. Adding a biologically targeted agent to endocrine therapy results in improved response rate, and clinical benefit rate, and prolonged progression-free survival. A clear advantage in overall survival has not yet been reported. Combination therapy allows to delay chemotherapy but increases toxicities and costs, which are critical factors in decision making in the clinical practice. Moreover, identification and validation of biomarkers of response are needed. Ongoing and future trials should elucidate the role of these compounds in the treatment of HR+/HER2- BC.

Cancer of Unknown Primary (CUP): genetic evidence for a novel nosological entity? A case report

Cancer of unknown primary (CUP) is an obscure disease characterized by multiple metastases in the absence of a primary tumor. No consensus has been reached whether CUPs are simply generated from cancers that cannot be detected or whether they are the manifestation of a still unknown nosological entity. Here, we report the complete expression and genetic analysis of multiple synchronous metastases harvested at warm autopsy of a patient with CUP. The expression profiles were remarkably similar and astonishingly singular. The whole exome analysis yielded a high number of mutations present in all metastases (fully shared), additional mutations (partially shared) accumulated one after another in a series, and few private mutations were unique to each metastasis. Surprisingly, the phylogenetic trajectory linking CUP metastases was atypical, depicting a common "stream", sprouting a series of linear "brooks", at variance from the extensive branched evolution observed in metastases from most cancers of known origin. The distinctive genetic and evolutionary features depicted suggest that CUP is a novel nosological entity.

Clinical utility of exemestane in the treatment of breast cancer

Breast cancer is the most prevalent cancer in women, causing a significant mortality worldwide. Different endocrine strategies are available for the treatment of hormone-sensitive breast cancer, including antiestrogen tamoxifen and fulvestrant, as well as third-generation aromatase inhibitors (AIs), such as letrozole, anastrozole, and exemestane. In this review, we will focus on exemestane, its clinical use, and its side effects. Exemestane is a steroidal third-generation AI now used in all treatment settings for breast cancer. In the metastatic disease, it has been extensively investigated as the first-, second-, and further-line treatment and it is now registered for the treatment of postmenopausal women with advanced estrogen-receptor-positive breast cancer whose disease has progressed following antiestrogen therapy. A potential lack of cross-resistance with nonsteroidal AIs has been described, giving additional therapeutic opportunities in sequences of endocrine agents. Exemestane is also approved for the adjuvant treatment of postmenopausal early breast cancer, either as upfront monotherapy for 5 years, as a switch following 2–3 years of tamoxifen, or as extended therapy beyond 5 years of adjuvant treatment. New promising data also showed a beneficial effect in young premenopausal early breast cancer patients, when administered together with ovarian suppression. Interesting results have also emerged when exemestane has been investigated as neodjuvant treatment as well as preventive agent in healthy women at high risk for breast cancer. Exemestane is generally well tolerated, with a side effect profile similar to that of other AIs, including menopausal symptoms, arthralgia, and bone loss. In conclusion, exemestane can be considered an effective and well-tolerated endocrine treatment option for all stages of breast cancer.

Course of intracranial pressure after extirpation of posterior fossa tumours

Forty-seven patients with posterior fossa tumours underwent continuous monitoring of intracranial pressure (ICP) in the early postoperative period by means of an intraventricular catheter. ICP values were very low on the day of operation and subsequently became normal in 37 patients. ICP values were raised in 10 patients. The relationship between the ICP and the clinical course was investigated. Patients were subdivided according to the clinical postoperative course into three groups: good, temporarily deteriorated, poor clinical course. The two first groups showed lower values in the ICP than he third one, nevertheless the relationship between the ICP and the postoperative clinical course is marked but not strict. Our data may have some clinical relevance for the treatment of hydrocephalus before extirpation of posterior fossa tumours.

MiR-100 is a predictor of endocrine responsiveness and prognosis in patients with operable luminal breast cancer

PURPOSE

Overexpression of miR-100 in stem cells derived from basal-like breast cancers causes loss of stemness, induction of luminal breast cancer markers and response to endocrine therapy. We, therefore, explored miR-100 as a novel biomarker in patients with luminal breast cancer.

METHODS

miR-100 expression was studied in 90 patients with oestrogen-receptor-positive/human-epidermal growth factor receptor 2-negative breast cancer enrolled in a prospective study of endocrine therapy given either preoperatively, or for the treatment of de novo metastatic disease. Response was defined as a Ki67 ≤2.7% after 21±3 days of treatment. The prognostic role of miR-100 expression was evaluated in the Molecular Taxonomy of Breast Cancer International Consortium (METABRIC) and The Cancer Genome Atlas (TCGA) breast cancer datasets. Additionally, we explored the correlation between miR-100 and the expression its targets reported as being associated with endocrine resistance. Finally, we evaluated whether a signature based on miR-100 and its target genes could predict the luminal A molecular subtype.

RESULTS

Baseline miR-100 was significantly anticorrelated with baseline and post-treatment Ki67 (p<0.001 and 0.004, respectively), and independently associated with response to treatment (OR 3.329, p=0.047). In the METABRIC dataset, high expression of miR-100 identified women with luminal A tumours treated with adjuvant endocrine therapy with improved overall survival (HR 0.55, p<0.001). miR-100 was negatively correlated with PLK1, FOXA1, mTOR and IGF1R expression, potentially explaining its prognostic effect. Finally, a miR-100-based signature developed in patients enrolled in the prospective study outperformed Ki67 alone in predicting the luminal A phenotype.

CONCLUSIONS

Our findings suggest that miR-100 should be further explored as a biomarker in patients with luminal breast cancer.

Current status and future perspectives in the endocrine treatment of postmenopausal, hormone receptor-positive metastatic breast cancer

INTRODUCTION

Endocrine therapy is a fundamental component of the therapeutic repertoire for treatment of metastatic, hormone receptor-positive breast cancer. Inevitably, however, tumors develop resistance to these compounds, and overcoming this phenomenon is a key motivator of research in this field.

AREAS COVERED

This review summarizes the current status of endocrine therapy for the treatment of metastatic disease, with a main focus on postmenopausal patients. Furthermore, strategies that could potentially sustain endocrine resistance and future perspectives in this direction are also to be described. Relevant references were identified by PubMed searches and from the abstract books of the annual meetings of The European Society of Clinical Oncology (ESMO), The American Society of Clinical Oncology (ASCO) and from the San Antonio Breast Cancer Symposia.

EXPERT OPINION

Combinations of endocrine therapy with HER2 targeting agents, as well as with compounds that can interfere with PI3K/Akt/mTOR signaling, are two promising strategies for delaying or overcoming endocrine resistance, mediated by these relevant biological pathways. Due to increased costs and the burden of toxicity associated with these combination therapies, compared to endocrine therapy alone, it is imperative to concentrate efforts on establishing biomarkers that can predict efficacy.