An exploration of the impact of ethanol diluent on breath alcohol concentration in patients receiving paclitaxel chemotherapy.

PURPOSE: This study aimed to provide a better understanding of the impact of paclitaxel chemotherapy on breath alcohol in an Irish population. METHODS: Patients attending the Oncology Day Unit at Beaumont Hospital were invited to participate on the day of their treatment. The brand of paclitaxel used was Actavis Pharma Inc and contained 6 mg/mL paclitaxel in 50% Ethanol/ 50% Cremophor EL. Breath alcohol concentration was measured using the AlcoSense ™ Breathalyser on three separate visits. The primary end-point was the number of patients who were above the legal threshold for drink driving in Ireland. RESULTS: In total, 50 patients were recruited. 36 (68%) were female. The most common diagnosis was breast cancer (56%). Ten (20%) patients had metastatic disease and 4 (8%) had liver metastases. The mean paclitaxel dose administered was 118 mg. The mean amount of ethanol infused was 7.7 g. 27 patients had a detectable breath alcohol level on at least one visit. The mean breath alcohol concentration was 2 mcg/100 mL or 0.02 mg/L of breath. The maximum concentration of ethanol in exhaled breath was 11 mcg/100 mL or 0.11 mg/L which is 50% of the statutory limit for drink driving in Ireland. A weak correlation was observed between ethanol concentration in exhaled breath and the total amount of ethanol administered. Although no patient exceeded the general limit for drink driving in Ireland, three (6%) participants had a breath alcohol concentration above the threshold for professional, learner or novice drivers. CONCLUSION: Although definitive conclusions are limited by relatively small numbers, it seems unlikely that weekly paclitaxel infusions pose any significant risk to patients driving.

The role of infiltrating lymphocytes in the neo-adjuvant treatment of women with HER2-positive breast cancer.

BACKGROUND: Pre-treatment tumour-associated lymphocytes (TILs) and stromal lymphocytes (SLs) are independent predictive markers of future pathological complete response (pCR) in HER2-positive breast cancer. Whilst studies have correlated baseline lymphocyte levels with subsequent pCR, few have studied the impact of neoadjuvant therapy on the immune environment. METHODS: We performed TIL analysis and T-cell analysis by IHC on the pretreatment and 'On-treatment' samples from patients recruited on the Phase-II TCHL (NCT01485926) clinical trial. Data were analysed using the Wilcoxon signed-rank test and the Spearman rank correlation. RESULTS: In our sample cohort (n = 66), patients who achieved a pCR at surgery, post-chemotherapy, had significantly higher counts of TILs (p = 0.05) but not SLs (p = 0.08) in their pre-treatment tumour samples. Patients who achieved a subsequent pCR after completing neo-adjuvant chemotherapy had significantly higher SLs (p = 9.09 × 10-3) but not TILs (p = 0.1) in their 'On-treatment' tumour biopsies. In a small cohort of samples (n = 16), infiltrating lymphocyte counts increased after 1 cycle of neo-adjuvant chemotherapy only in those tumours of patients who did not achieve a subsequent pCR. Finally, reduced CD3 + (p = 0.04, rho = 0.60) and CD4 + (p = 0.01, rho = 0.72) T-cell counts in 'On-treatment' biopsies were associated with decreased residual tumour content post-1 cycle of treatment; the latter being significantly associated with increased likelihood of subsequent pCR (p < 0.01). CONCLUSIONS: The immune system may be 'primed' prior to neoadjuvant treatment in those patients who subsequently achieve a pCR. In those patients who achieve a pCR, their immune response may return to baseline after only 1 cycle of treatment. However, in those who did not achieve a pCR, neo-adjuvant treatment may stimulate lymphocyte influx into the tumour.

Vaccine-induced thrombosis and thrombocytopenia (VITT) in Ireland: A review of cases and current practices.

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) virus pandemic, several highly effective and safe vaccines have been produced at remarkable speed. Following global implementation of vaccination programmes, cases of thrombosis with thrombocytopenia following administration of adenoviral vector-based vaccines started being reported. In this review we discuss the known pathogenesis and epidemiology of so-called vaccine induced thrombocytopenia and thrombosis (VITT). We consider the available guidelines, diagnostic laboratory tests and management options for these patients. Finally, we discuss important unanswered questions and areas for future research in this novel pathoclinical entity.

A randomized phase II study evaluating different maintenance schedules of nab-paclitaxel in the first-line treatment of metastatic breast cancer: final results of the IBCSG 42-12/BIG 2-12 SNAP trial.

Background: The phase II SNAP trial was designed to evaluate the efficacy of alternative chemotherapy schedules for prolonged administration in HER2-negative metastatic breast cancer (MBC), after a short induction at conventional doses. Patients and methods: Between April 2013 and August 2015, 258 women untreated with chemotherapy for MBC were randomly assigned to receive three different maintenance chemotherapy schedules after three cycles of identical induction chemotherapy: arm A, nab-paclitaxel 150 mg/m2 days 1 and 15 Q28; arm B, nab-paclitaxel 100 mg/m2 days 1, 8 and 15 Q28; arm C, nab-paclitaxel 75 mg/m2 days 1, 8, 15 and 22 Q28. Induction was three cycles nab-paclitaxel 150/125 mg/m2, days 1, 8 and 15 Q28. The primary objective was to evaluate the efficacy of each maintenance schedule, in terms of progression-free survival (PFS), as compared with the historical reference of 7-month median PFS reported by previous studies with first-line docetaxel. One-sample, one-sided log-rank tests were utilized. Quality-of-life (QoL) evaluation was carried out, and the global indicator for physical well-being was defined as the primary QoL end point; completion rates of QoL forms were >90%. Results: In total, 255 patients were assessable for the primary end point. After 18.2-month median follow-up, 182 PFS events were observed. Median PFS was 7.9 months [90% confidence interval CI 6.8-8.4] in arm A, 9.0 months (90% CI 8.1-10.9) in arm B and 8.5 months (90% CI 6.7-9.5) in arm C. PFS in arm B was significantly longer than the historical reference of first-line docetaxel (P = 0.03). Grade ≥2 sensory neuropathy was reported in 37.9%, 36.1% and 31.2% of the patients in arm A, B and C, respectively (Grade ≥3 in 9.1%, 5.6% and 6.6% of the patients, respectively). Noteworthy, the QoL scores for sensory neuropathy did not worsen with prolonged nab-paclitaxel administration in any of the maintenance arms. Conclusion: The SNAP trial demonstrated that alternative nab-paclitaxel maintenance schedules with reduced dosages after a short induction at conventional doses are feasible and active in the first-line treatment of MBC. Registration: ClinicalTrials.gov NCT01746225.

ICORG 10-14: NEOadjuvant trial in Adenocarcinoma of the oEsophagus and oesophagoGastric junction International Study (Neo-AEGIS).

BACKGROUND: Neoadjuvant therapy is increasingly the standard of care in the management of locally advanced adenocarcinoma of the oesophagus and junction (AEG). In randomised controlled trials (RCTs), the MAGIC regimen of pre- and postoperative chemotherapy, and the CROSS regimen of preoperative chemotherapy combined with radiation, were superior to surgery only in RCTs that included AEG but were not powered on this cohort. No completed RCT has directly compared neoadjuvant or perioperative chemotherapy and neoadjuvant chemoradiation. The Neo-AEGIS trial, uniquely powered on AEG, and including comprehensive modern staging, compares both these regimens. METHODS: This open label, multicentre, phase III RCT randomises patients (cT2-3, N0-3, M0) in a 1:1 fashion to receive CROSS protocol (Carboplatin and Paclitaxel with concurrent radiotherapy, 41.4Gy/23Fr, over 5 weeks). The power calculation is a 10% difference in favour of CROSS, powered at 80%, two-sided alpha level of 0.05, requiring 540 patients to be evaluable, 594 to be recruited if a 10% dropout is included (297 in each group). The primary endpoint is overall survival, with a minimum 3-year follow up. Secondary endpoints include: disease free survival, recurrence rates, clinical and pathological response rates, toxicities of induction regimens, post-operative pathology and tumour regression grade, operative in-hospital complications, and health-related quality of life. The trial also affords opportunities for establishing a bio-resource of pre-treatment and resected tumour, and translational research. DISCUSSION: This RCT directly compares two established treatment regimens, and addresses whether radiation therapy positively impacts on overall survival compared with a standard perioperative chemotherapy regimen Sponsor: Irish Clinical Research Group (ICORG). TRIAL REGISTRATION: NCT01726452 . Protocol 10-14. Date of registration 06/11/2012.

The impact of outpatient systemic anti-cancer treatment on patient costs and work practices.

BACKGROUND: There is extensive focus on the rising costs of healthcare. However, for patients undergoing cancer treatment, there are additional personal costs, which are poorly characterised. AIM: To qualify indirect costs during anti-cancer therapy in a designated Irish cancer centre. METHODS: An anonymous questionnaire collected demographic data, current work practice, and personal expenditure on regular and non-regular indirect costs during treatment. Differences between groups of interest were compared using the Mann-Whitney U test. RESULTS: In total, there were 151 responders of median age 58 years; 60 % were female and 74 % were not working. Breast cancer (29 %) was the most frequent diagnosis. Indirect costs totalled a median of €1138 (range €21.60-€7089.84) per patient, with median monthly outgoings of €354. The greatest median monthly costs were hair accessories (€400), transportation (€65), and complementary therapies (€55). The majority (74 %) of patients used a car and median monthly fuel expenditure was €31 (range €1.44-€463.32). Women spent more money during treatment (€1617) than men (€974, p = 0.00128). In addition, median monthly expenditure was greater for those less than 50 years old (€1621 vs €1105; p = 0.04236), those who lived greater than 25 km away (€2015 vs €1078; p = 0.00008) and those without a medical card (€2023 vs €961; p = 0.00024). CONCLUSION: This study highlights the need for greater awareness of indirect expenditures associated with systemic anti-cancer therapy in Ireland.

Burkitt leukaemia/lymphoma: R-CODOX-M/R-IVAC remains gold standard treatment in BL.

BACKGROUND: Sporadic Burkitt lymphoma (BL), characterised by translocation-associated C-MYC upregulation is a rare, aggressive lymphoma with a cure rate up to 90 % using the R-CODOX-M/R-IVAC (RCRI) protocol. RCRI is active in HIV-associated BL in combination with HAART. The WHO classification system defines lymphomas intermediate between DLBCL and BL, in which lymphomas with t(14;18)(q32;q21) and C-MYC-carrying translocation, i.e. 'double-hit' are included (BL-DH), and these patients are conventionally treated with RCRI. RESULT: We describe the SJH experience of 25 patients with BL, BL + HIV and BL-DH treated with RCRI between 2002 and 2011. Twelve BL patients (8M/4F), median age 49.1 years (range 20-73 years); of whom 9 had extensive disease, including 8 with marrow and 2 with CNS involvement. Eleven patients remain in remission at 80.5 months (range 37-147 months) from completion of treatment and one died of progressive BL giving an OS of 91.6 % at 1 year with no late relapses. Eight patients with BL + HIV were treated (6M/2F) with a median age 40.25 years (range 24-64). Five remain in complete remission (CR) at 65 months (range 13-109 months), three patients died, two of progressive disease and one of treatment-associated hepatotoxicity in CR. Five patients with BL-DH were included; (3M/2F), age 47.8 years (range 42-55 years); and all patients died of progressive disease, 4 on RCRI therapy and a further patient despite an allogeneic transplantation. CONCLUSION: These results confirm that RCRI is an effective treatment in adults with BL and BL + HIV and remains the gold standard against which other regimens should be compared. We confirm the poor prognosis found in BL-DH, indicating new treatment approaches are needed for this sub-group which should be identified at diagnosis by FISH analysis.

BCL2 protein signalling determines acute responses to neoadjuvant chemoradiotherapy in rectal cancer.

UNLABELLED: In locally advanced rectal cancer, neoadjuvant chemoradiotherapy is performed prior to surgery to downstage the tumour. Thirty to 40 % of patients do not respond. Defects in apoptotic machinery lead to therapy resistance; however, to date, no study quantitatively assessed whether B cell lymphoma 2 (BCL2)-dependent regulation of mitochondrial apoptosis, effector caspase activation downstream of mitochondria or a combination of both predicts patient responses. In a cohort of 20 rectal cancer patients, we performed protein profiling of tumour tissue and employed validated ordinary differential equation-based systems models of apoptosis signalling to calculate the ability of cancer cells to undergo apoptosis. Model outputs were compared to clinical responses. Systems modelling of BCL2-signalling predicted patients in the poor response group (p = 0.0049). Systems modelling also demonstrated that rectal cancers depended on BCL2 rather than B cell lymphoma-extra large (BCL(X)L) or myeloid cell leukemia 1 (MCL1) for survival, suggesting that poor responders may benefit from therapy with selective BCL2 antagonists. Dynamic modelling of effector caspase activation could not stratify patients with poor response and did not further improve predictive power. We deliver a powerful patient stratification tool identifying patients who will likely not benefit from neoadjuvant chemoradiotherapy and should be prioritised for surgical resection or treatment with BCL2 antagonists. KEY MESSAGES: Modelling BCL2-family proteins identifies patients unresponsive to therapy. Caspase activation downstream of mitochondria cannot identify these patients. Rectal tumours of poor responders are BCL2- but not BCL-XL-dependent. DR_MOMP allows clinicians to identify patients who would not benefit from therapy. DR_MOMP is also a useful patient stratification tool for BCL2 antagonists.

HER2-family signalling mechanisms, clinical implications and targeting in breast cancer.

Approximately 20 % of human breast cancers (BC) overexpress HER2 protein, and HER2-positivity is associated with a worse prognosis. Although HER2-targeted therapies have significantly improved outcomes for HER2-positive BC patients, resistance to trastuzumab-based therapy remains a clinical problem. In order to better understand resistance to HER2-targeted therapies in HER2-positive BC, it is necessary to examine HER family signalling as a whole. An extensive literature search was carried out to critically assess the current knowledge of HER family signalling in HER2-positive BC and response to HER2-targeted therapy. Known mechanisms of trastuzumab resistance include reduced receptor-antibody binding (MUC4, p95HER2), increased signalling through alternative HER family receptor tyrosine kinases (RTK), altered intracellular signalling involving loss of PTEN, reduced p27kip1, or increased PI3K/AKT activity and altered signalling via non-HER family RTKs such as IGF1R. Emerging strategies to circumvent resistance to HER2-targeted therapies in HER2-positive BC include co-targeting HER2/PI3K, pan-HER family inhibition, and novel therapies such as T-DM1. There is evidence that immunity plays a key role in the efficacy of HER-targeted therapy, and efforts are being made to exploit the immune system in order to improve the efficacy of current anti-HER therapies. With our rapidly expanding understanding of HER2 signalling mechanisms along with the repertoire of HER family and other targeted therapies, it is likely that the near future holds further dramatic improvements to the prognosis of women with HER2-positive BC.

A preclinical evaluation of the PI3K alpha/delta dominant inhibitor BAY 80-6946 in HER2-positive breast cancer models with acquired resistance to the HER2-targeted therapies trastuzumab and lapatinib.

The PI3K pathway is a key mechanism of trastuzumab resistance, but early attempts to indirectly target this pathway with mTOR inhibitors have had limited success. We present the results of a preclinical study of the selective alpha/delta isoform dominant PI3K inhibitor BAY 80-6946 tested alone and in combination with HER2-targeted therapies in HER2-positive cell lines, including models with acquired resistance to trastuzumab and/or lapatinib. A panel of HER2-positive breast cancer cells were profiled for their mutational status using Sequenom MassARRAY, PTEN status by Western blot, and anti-proliferative response to BAY 80-6946 alone and in combination with the HER2-targeted therapies trastuzumab, lapatinib and afatinib. Reverse phase protein array was used to determine the effect of BAY 80-6946 on expression and phosphorylation of 68 proteins including members of the PI3K and MAPK pathways. The Boyden chamber method was used to determine if BAY 80-6946 affected cellular invasion and migration. BAY 80-6946 has anti-proliferative and anti-invasive effects when used alone in our panel of cell lines (IC50s 3.9-29.4 nM). BAY 80-6946 inhibited PI3K signalling and was effective in cells regardless of their PI3K, P53 or PTEN status. The combination of HER2-targeted therapies and BAY 80-6946 inhibited growth more effectively than either therapy used alone (with clear synergism in many cases), and can restore sensitivity to trastuzumab and lapatinib in cells with acquired resistance to either trastuzumab and/or lapatinib. The addition of BAY 80-6946 to HER2-targeted therapy could represent an improved treatment strategy for patients with refractory metastatic HER2-positive breast cancer, and should be considered for clinical trial evaluation.

Growth factor receptor/steroid receptor cross talk in trastuzumab-treated breast cancer.

Treatment with tyrosine kinase inhibitors (TKIs) including trastuzumab has revolutionized the management of HER2-positive breast cancer. Recent evaluation of clinical trial data suggests that a subset of HER2/ER double-positive cancers may not receive significant benefit from the TKI therapy. Here we investigate the cross talk between HER2 and ER in breast cancer and monitor the effect of trastuzumab on the tyrosine kinase effector transcription factor Myc. In HER2-positive breast cancer patients treated with neoadjuvant trastuzumab, steroid receptor-negative status (ER and PR negative) of pre-treatment biopsies predicted pathological complete response (pCR) (n=31 patients, P=0.0486), whereas elevated Myc protein inversely associated with pCR (P=0.0446). Liquid chromatography mass spectrometry identified the corepressor SMRT as a novel Myc-interacting protein. Trastuzumab treatment enhanced Myc-SMRT interactions in HER2-overexpressing breast cancer cells (LCC1) and inhibited expression of the Myc target gene survivin. In HER2-low, ER-positive steroid-dominant cells (MCF7), trastuzumab therapy repressed Myc-SMRT interactions and upregulated survivin expression. Trastuzumab treatment induced ER-CBP interactions, enhanced ER transcriptional activity and upregulated expression of the ER target gene pS2. The absence of pS2 expression in pre-treatment biopsies predicted pCR to neoadjuvant trastuzumab in breast cancer patients (n=25, P=0.0089) and pS2 expression associated with residual cancer burden (P=0.0196). Furthermore, metastatic tissues from patients who had failed trastuzumab therapy were pS2 positive. In HER2-overexpressing cells, trastuzumab treatment can repress Myc transcriptional activity and clinical response is favorable. However, with co-expression of the steroid pathway, this inhibition is lost and response to treatment is often poor.

The prognostic value of tumour regression grade following neoadjuvant chemoradiation therapy for rectal cancer.

AIM: To date, there is no uniform consensus on whether tumour regression grade (TRG) is predictive of outcome in rectal cancer. Furthermore, the lack of standardization of TRG grading is a major source of variability in published studies. The aim of this study was to evaluate the prognostic impact of TRG in a cohort of patients with locally advanced rectal cancer treated with neoadjuvant chemoradiation therapy (CRT). In addition to the Mandard TRG, we utilized four TRG systems modified from the Mandard TRG system and applied them to the cohort to assess which TRG system is most informative. METHOD: One-hundred and fifty-three patients with a T3/T4 and/or a node-positive rectal cancer underwent neoadjuvant 5-fluorouracil-based CRT followed by surgical resection. RESULTS: Thirty-six (23.5%) patients achieving complete pathological response (ypCR) had a 5-year disease-free survival (DFS) rate of 100% compared with a DFS rate of 74% for 117 (76.5%) patients without ypCR (P = 0.003). The Royal College of Pathologists (RCPath) TRG best condenses the Mandard five-point TRG by stratifying patients into three groups with distinct 5-year DFS rates of 100%, 86% and 67%, respectively (P = 0.001). In multivariate analysis, pathological nodal status and circumferential resection margin (CRM) status, but not TRG, remained significant predictors of DFS (P = 0.002, P = 0.035 and P = 0.310, respectively). CONCLUSION: Our findings support the notion that ypCR status, nodal status after neoadjuvant CRT and CRM status, but not TRG, are predictors of long-term survival in patients with locally advanced rectal cancer.

Dual diagnosis of sarcoidosis and lymphoma.

BACKGROUND: Sarcoidosis is a multisystem granulomatous disease of unknown origin with pulmonary and extrapulmonary manifestations. Worldwide it is most often diagnosed in the third and fourth decades and most often affects Swedish, Danish and black patients. The association between malignancy and sarcoidosis has not been conclusively proven. Cancer can eventually occur in patients who have an established diagnosis of sarcoidosis for example, in sarcoidosis-lymphoma syndrome. Sarcoidosis can also subsequently develop in an oncology patient. There are multiple obstacles to confirming epidemiologically the linkage between sarcoidosis and malignancy. Histological verification and clinical acumen are needed to avoid misdiagnosis. The 18 fluorodeoxyglucose (18-FDG) PET has failed to provide a non invasive diagnostic method to differentiate neoplasia from benign sarcoid lesions and tissue diagnosis is essential before commencing a new therapeutic intervention in patients with lymphoma. METHODS: We report 3 cases of co-diagnosis of sarcoidosis and lymphoma that were seen in an oncology unit in Drogheda, Co. Louth. RESULTS: Our patients varied in the temporal association between the diagnosis of sarcoidosis and lymphoma as well as their demographic characteristics. CONCLUSION: These cases help to demonstrate the need for careful clinical, histological and radiological assessment.

Molecular subclasses of breast cancer: how do we define them? The IMPAKT 2012 Working Group Statement.

The 2012 IMPAKT task force investigated the medical usefulness of current methods for the classification of breast cancer into the 'intrinsic' molecular subtypes (luminal A, luminal B, basal-like and HER2). A panel of breast cancer and/or gene expression profiling experts evaluated the analytical validity, clinical validity and clinical utility of two approaches for molecular subtyping of breast cancer: the prediction analysis of microarray (PAM)50 assay and an immuno-histochemical (IHC) surrogate panel including oestrogen receptor (ER), HER2 and Ki67. The panel found the currently available evidence on the analytical validity and clinical utility of Ki67 based on a 14% cut-off and PAM50 to be inadequate. The majority of the working group members found the available evidence on the analytical validity, clinical validity and clinical utility of ER/HER2 to be convincing. The panel concluded that breast cancer classification into molecular subtypes based on the IHC assessment of ER, HER2 and Ki67 with a 14% cut-off and on the PAM50 test does not provide sufficiently robust information to modify systemic treatment decisions, and recommended the use IHC for ER and HER2 for the identification of clinically relevant subtypes of breast cancers. Methods for breast cancer classification into molecular subtypes should, however, be incorporated into clinical trial design.

Patterns of genomic loss of heterozygosity predict homologous recombination repair defects in epithelial ovarian cancer.

BACKGROUND: Defects in BRCA1, BRCA2, and other members of the homologous recombination pathway have potential therapeutic relevance when used to support agents that introduce or exploit double-stranded DNA breaks. This study examines the association between homologous recombination defects and genomic patterns of loss of heterozygosity (LOH). METHODS: Ovarian tumours from two independent data sets were characterised for defects in BRCA1, BRCA2, and RAD51C, and LOH profiles were generated. Publically available data were downloaded for a third independent data set. The same analyses were performed on 57 cancer cell lines. RESULTS: Loss of heterozygosity regions of intermediate size were observed more frequently in tumours with defective BRCA1 or BRCA2 (P=10(-11)). The homologous recombination deficiency (HRD) score was defined as the number of these regions observed in a tumour sample. The association between HRD score and BRCA deficiency was validated in two independent ovarian cancer data sets (P=10(-5) and 10(-29)), and identified breast and pancreatic cell lines with BRCA defects. CONCLUSION: The HRD score appears capable of detecting homologous recombination defects regardless of aetiology or mechanism. This score could facilitate the use of PARP inhibitors and platinum in breast, ovarian, and other cancers.

Overcoming resistance and restoring sensitivity to HER2-targeted therapies in breast cancer.

BACKGROUND: Approximately 15%-23% of breast cancers overexpress human epidermal growth factor receptor 2 (HER2), which leads to the activation of signaling pathways that stimulate cell proliferation and survival. HER2-targeted therapy has substantially improved outcomes in patients with HER2-positive breast cancer. However, both de novo and acquired resistance are observed. DESIGN: A literature search was performed to identify proposed mechanisms of resistance to HER2-targeted therapy and identified novel targets in clinical development for treating HER2-resistant disease. RESULTS: Proposed HER2-resistance mechanisms include impediments to HER2-inhibitor binding, signaling through alternative pathways, upregulation of signaling pathways downstream of HER2, and failure to elicit an appropriate immune response. Although continuing HER2 inhibition beyond progression may provide an additional clinical benefit, the availability of novel therapies targeting different mechanisms of action could improve outcomes. The developmental strategy with the most available data is targeting the phosphatidylinositol 3-kinase/protein kinase B/mammalian target of rapamycin (mTOR) pathway. The oral mTOR inhibitor everolimus has shown promising activity in combination with chemotherapy and trastuzumab in trastuzumab-refractory, advanced breast cancer. CONCLUSIONS: Non-HER2-targeted therapy is a promising means of overcoming resistance to HER2-targeted treatment. Ongoing clinical studies will provide additional information on the efficacy and safety of novel targeted therapies in HER2-resistant advanced breast cancer.

Cyclin G1 regulates the outcome of taxane-induced mitotic checkpoint arrest.

Anti-mitotic chemotherapeutic agents such as taxanes activate the spindle assembly checkpoint (SAC) to arrest anaphase onset, but taxane-exposed cells eventually undergo slippage to exit mitosis. The therapeutic efficacy of taxanes depends on whether slippage after SAC arrest culminates in continued cell survival, or in death by apoptosis. However, the mechanisms that determine these outcomes remain unclear. Here, we identify a novel role for cyclin G1 (CCNG1), an atypical cyclin. Increased CCNG1 expression accompanies paclitaxel-induced, SAC-mediated mitotic arrest, independent of p53 integrity or signaling through the SAC component, BUBR1. CCNG1 overexpression promotes cell survival after paclitaxel exposure. Conversely, CCNG1 depletion by RNA interference delays slippage and enhances paclitaxel-induced apoptosis. Consistent with these observations, CCNG1 amplification is associated with significantly shorter post-surgical survival in patients with ovarian cancer who have received adjuvant chemotherapy with taxanes and platinum compounds. Collectively, our findings implicate CCNG1 in regulating slippage and the outcome of taxane-induced mitotic arrest, with potential implications for cancer therapy.

Modeling ductal carcinoma in situ: a HER2-Notch3 collaboration enables luminal filling.

A large fraction of ductal carcinoma in situ (DCIS), a non-invasive precursor lesion of invasive breast cancer, overexpresses the HER2/neu oncogene. The ducts of DCIS are abnormally filled with cells that evade apoptosis, but the underlying mechanisms remain incompletely understood. We overexpressed HER2 in mammary epithelial cells and observed growth factor-independent proliferation. When grown in extracellular matrix as three-dimensional spheroids, control cells developed a hollow lumen, but HER2-overexpressing cells populated the lumen by evading apoptosis. We demonstrate that HER2 overexpression in this cellular model of DCIS drives transcriptional upregulation of multiple components of the Notch survival pathway. Importantly, luminal filling required upregulation of a signaling pathway comprising Notch3, its cleaved intracellular domain and the transcriptional regulator HES1, resulting in elevated levels of c-MYC and cyclin D1. In line with HER2-Notch3 collaboration, drugs intercepting either arm reverted the DCIS-like phenotype. In addition, we report upregulation of Notch3 in hyperplastic lesions of HER2 transgenic animals, as well as an association between HER2 levels and expression levels of components of the Notch pathway in tumor specimens of breast cancer patients. Therefore, it is conceivable that the integration of the Notch and HER2 signaling pathways contributes to the pathophysiology of DCIS.