Therapeutic Potential of EVs: Targeting Cardiovascular Diseases

Due to their different biological functions, extracellular vesicles (EVs) have great potential from a therapeutic point of view. They are released by all cell types, carrying and delivering different kinds of biologically functional cargo. Under pathological events, cells can increase their secretion of EVs and can release different amounts of cargo, thus making EVs great biomarkers as indicators of pathological progression. Moreover, EVs are also known to be able to transport and deliver cargo to different recipient cells, having an important role in cellular communication. Interestingly, EVs have recently been explored as biological alternatives for the delivery of therapeutics, being considered natural drug delivery carriers. Because cardiovascular disorders (CVDs) are the leading cause of death worldwide, in this review, we will discuss the up-to-date knowledge regarding the biophysical properties and biological components of EVs, focusing on myocardial infarction, diabetic cardiomyopathy, and sepsis-induced cardiomyopathy, three very different types of CVDs.

Genomic characterisation of hormone receptor-positive breast cancer arising in very young women

BACKGROUND

Very young premenopausal women diagnosed with hormone receptor-positive, human epidermal growth factor receptor 2-negative (HR+HER2-) early breast cancer (EBC) have higher rates of recurrence and death for reasons that remain largely unexplained.

PATIENTS AND METHODS

Genomic sequencing was applied to HR+HER2- tumours from patients enrolled in the Suppression of Ovarian Function Trial (SOFT) to determine genomic drivers that are enriched in young premenopausal women. Genomic alterations were characterised using next-generation sequencing from a subset of 1276 patients (deep targeted sequencing, n = 1258; whole-exome sequencing in a young-age, case-control subsample, n = 82). We defined copy number (CN) subgroups and assessed for features suggestive of homologous recombination deficiency (HRD). Genomic alteration frequencies were compared between young premenopausal women (<40 years) and older premenopausal women (≥40 years), and assessed for associations with distant recurrence-free interval (DRFI) and overall survival (OS).

RESULTS

Younger women (<40 years, n = 359) compared with older women (≥40 years, n = 917) had significantly higher frequencies of mutations in GATA3 (19% versus 16%) and CN amplifications (CNAs) (47% versus 26%), but significantly lower frequencies of mutations in PIK3CA (32% versus 47%), CDH1 (3% versus 9%), and MAP3K1 (7% versus 12%). Additionally, they had significantly higher frequencies of features suggestive of HRD (27% versus 21%) and a higher proportion of PIK3CA mutations with concurrent CNAs (23% versus 11%). Genomic features suggestive of HRD, PIK3CA mutations with CNAs, and CNAs were associated with significantly worse DRFI and OS compared with those without these features. These poor prognostic features were enriched in younger patients: present in 72% of patients aged <35 years, 54% aged 35-39 years, and 40% aged ≥40 years. Poor prognostic features [n = 584 (46%)] versus none [n = 692 (54%)] had an 8-year DRFI of 84% versus 94% and OS of 88% versus 96%. Younger women (<40 years) had the poorest outcomes: 8-year DRFI 74% versus 85% and OS 80% versus 93%, respectively.

CONCLUSION

These results provide insights into genomic alterations that are enriched in young women with HR+HER2- EBC, provide rationale for genomic subgrouping, and highlight priority molecular targets for future clinical trials.

The epigenetic enzyme DOT1L orchestrates vascular smooth muscle cell-monocyte crosstalk and protects against atherosclerosis via the NF-κB pathway

AIMS

Histone H3 dimethylation at lysine 79 is a key epigenetic mark uniquely induced by methyltransferase disruptor of telomeric silencing 1-like (DOT1L). We aimed to determine whether DOT1L modulates vascular smooth muscle cell (VSMC) phenotype and how it might affect atherosclerosis in vitro and in vivo, unravelling the related mechanism.

METHODS AND RESULTS

Gene expression screening of VSMCs stimulated with the BB isoform of platelet-derived growth factor led us to identify Dot1l as an early up-regulated epigenetic factor. Mouse and human atherosclerotic lesions were assessed for Dot1l expression, which resulted specifically localized in the VSMC compartment. The relevance of Dot1l to atherosclerosis pathogenesis was assessed through deletion of its gene in the VSMCs via an inducible, tissue-specific knock-out mouse model crossed with the ApoE-/- high-fat diet model of atherosclerosis. We found that the inactivation of Dot1l significantly reduced the progression of the disease. By combining RNA- and H3K79me2-chromatin immunoprecipitation-sequencing, we found that DOT1L and its induced H3K79me2 mark directly regulate the transcription of Nf-κB-1 and -2, master modulators of inflammation, which in turn induce the expression of CCL5 and CXCL10, cytokines fundamentally involved in atherosclerosis development. Finally, a correlation between coronary artery disease and genetic variations in the DOT1L gene was found because specific polymorphisms are associated with increased mRNA expression.

CONCLUSION

DOT1L plays a key role in the epigenetic control of VSMC gene expression, leading to atherosclerosis development. Results identify DOT1L as a potential therapeutic target for vascular diseases.

rs41291957 controls miR-143 and miR-145 expression and impacts coronary artery disease risk

The role of single nucleotide polymorphisms (SNPs) in the etiopathogenesis of cardiovascular diseases is well known. The effect of SNPs on disease predisposition has been established not only for protein coding genes but also for genes encoding microRNAs (miRNAs). The miR-143/145 cluster is smooth muscle cell-specific and implicated in the pathogenesis of atherosclerosis. Whether SNPs within the genomic sequence of the miR-143/145 cluster are involved in cardiovascular disease development is not known. We thus searched annotated sequence databases for possible SNPs associated with miR-143/145. We identified one SNP, rs41291957 (G > A), located -91 bp from the mature miR-143 sequence, as the nearest genetic variation to this miRNA cluster, with a minor allele frequency > 10%. In silico and in vitro approaches determined that rs41291957 (A) upregulates miR-143 and miR-145, modulating phenotypic switching of vascular smooth cells towards a differentiated/contractile phenotype. Finally, we analysed association between rs41291957 and CAD in two cohorts of patients, finding that the SNP was a protective factor. In conclusion, our study links a genetic variation to a pathological outcome through involvement of miRNAs.

MicroRNA and ROS Crosstalk in Cardiac and Pulmonary Diseases

Reactive oxygen species (ROS) affect many cellular functions and the proper redox balance between ROS and antioxidants contributes substantially to the physiological welfare of the cell. During pathological conditions, an altered redox equilibrium leads to increased production of ROS that in turn may cause oxidative damage. MicroRNAs (miRNAs) regulate gene expression at the post-transcriptional level contributing to all major cellular processes, including oxidative stress and cell death. Several miRNAs are expressed in response to ROS to mediate oxidative stress. Conversely, oxidative stress may lead to the upregulation of miRNAs that control mechanisms to buffer the damage induced by ROS. This review focuses on the complex crosstalk between miRNAs and ROS in diseases of the cardiac (i.e., cardiac hypertrophy, heart failure, myocardial infarction, ischemia/reperfusion injury, diabetic cardiomyopathy) and pulmonary (i.e., idiopathic pulmonary fibrosis, acute lung injury/acute respiratory distress syndrome, asthma, chronic obstructive pulmonary disease, lung cancer) compartments. Of note, miR-34a, miR-144, miR-421, miR-129, miR-181c, miR-16, miR-31, miR-155, miR-21, and miR-1/206 were found to play a role during oxidative stress in both heart and lung pathologies. This review comprehensively summarizes current knowledge in the field.

miR-128-3p Is a Novel Regulator of Vascular Smooth Muscle Cell Phenotypic Switch and Vascular Diseases

RATIONALE

MicroRNAs (miRNAs, miRs) are small noncoding RNAs that modulate gene expression by negatively regulating translation of target genes. Although the role of several miRNAs in vascular smooth muscle cells (VSMCs) has been extensively characterized, the function of miRNA-128-3p (miR-128) is still unknown.

OBJECTIVE

To determine if miR-128 modulates VSMC phenotype and to define the underlying mechanisms.

METHODS AND RESULTS

We screened for miRNAs whose expression is modulated by an altered DNA methylation status in VSMCs, and among the hits, we selected miR-128. We found that miR-128 was expressed in various tissues, primary murine cells, and pathological murine and human vascular specimens. Through gain- and loss-of-function approaches, we determined that miR-128 affects VSMC proliferation, migration, differentiation, and contractility. The alterations of those properties were dependent upon epigenetic regulation of key VSMC differentiation genes; notably, Kruppel-like factor 4 was found to be a direct target of miR-128 and able to modulate the methylation status of the pivotal VSMC gene myosin heavy chain 11 (Myh11). Finally, in vivo lentiviral delivery of miR-128 prevented intimal hyperplasia in a mouse model of carotid restenosis without modifying vital cardiovascular parameters.

CONCLUSION

miR-128 is a critical modulator of VSMCs and is regulated by epigenetic modifications upon stress. Its modulation in the context of disease could be exploited for therapeutic purposes.

Delivery of biologically active miR-34a in normal and cancer mammary epithelial cells by synthetic nanoparticles

Functional RNAs, such as microRNAs, are emerging as innovative tools in the treatment of aggressive and incurable cancers. In this study, we explore the potential of silica dioxide nanoparticles (SiO₂NPs) in the delivery of biologically active miRNAs. Focusing on the tumor-suppressor miR-34a, we evaluated miRNAs delivery by SiO₂NPs into the mammary gland, using in vitro as well as in vivo model systems. We showed that silica nanoparticles can efficiently deliver miR-34a into normal and cancer epithelial cells grown in culture without major signs of toxicity. Delivered miRNA retained the ability to silence artificial as well endogenous targets and can reduce the growth of mammospheres in 3D culture. Finally, miR-34a delivery through intra-tumor administration of SiO₂NPs leads to a reduced mammary tumor growth. In conclusion, our studies suggest that silica nanoparticles can mediate the delivery of miR-34a directly into mammary tumors while preserving its molecular and biological activity.

Circ_Lrp6, a Circular RNA Enriched in Vascular Smooth Muscle Cells, Acts as a Sponge Regulating miRNA-145 Function

RATIONALE

microRNAs (miRNAs) modulate gene expression by repressing translation of targeted genes. Previous work has established a role for miRNAs in regulating vascular smooth muscle cell (VSMC) activity. Whether circular RNAs are involved in the modulation of miRNA activity in VSMCs is unknown.

OBJECTIVE

We aimed to identify circular RNAs interacting with miRNAs enriched in VSMCs and modulating the cells' activity.

METHODS AND RESULTS

RNA sequencing and bioinformatics identified several circular RNAs enriched in VSMCs; however, only one, possessing multiple putative binding sites for miR-145, was highly conserved between mouse and man. This circular RNA gemmed from alternative splicing of Lrp6 (lipoprotein receptor 6), a gene highly expressed in vessels and implicated in vascular pathologies and was thus named circ_Lrp6. Its role as a miR-145 sponge was confirmed by determining reciprocal interaction through RNA immunoprecipitation, stimulated emission depletion microscopy, and competitive luciferase assays; functional inhibition of miR-145 was assessed by measuring expression of the target genes ITGβ8 (integrin-β8), FASCIN (fascin actin-bundling protein 1), KLF4 (Kruppel-like factor 4), Yes1 (YES proto-oncogene 1), and Lox (lysyl oxidase). The interaction was preferentially localized to P-bodies, sites of mRNA degradation. Using loss- and gain-of-function approaches, we found that circ_Lrp6 hindered miR-145-mediated regulation of VSMC migration, proliferation, and differentiation. Differential expression of miR-145 and circ_Lrp6 in murine and human vascular diseases suggests that the ratio of circ_Lrp6 bound to miR-145 versus unbound could play a role in vascular pathogenesis. Viral delivery of circ_Lrp6 shRNA prevented intimal hyperplasia in mouse carotids.

CONCLUSIONS

circ_Lrp6 is an intracellular modulator and a natural sponge for miR-145, counterbalancing the functions of the miRNA in VSMCs.

Abstract 4410: miRNA-34a sensitizes triple-negative breast cancer cells to paclitaxel reducing cancer stem cell population and lung colonization

Background: Cancer stem cells (CSCs) have inherent or developed drug resistance for which chemotherapy fails to eliminate all tumor cells, a property that is critically contributing to recurrence and metastasis. Here, we combine miR-34a, a well-known tumor suppressor miRNA that controls proliferation, apoptosis and self-renewal, with Paclitaxel (PTX), a commonly used first-line chemotherapy drug. Based on our preliminary observations (Bonetti et al., manuscript under revision), we hypothesized a combinatorial approach, coupling miRNA- and chemo- treatment, aimed at reducing CSCs in vitro and recurrence in vivo using triple-negative breast cancer (TNBC) as a model. Methodology: As a model, we exploited SUM159pt cells (TNBC mesenchymal-like, with CSC features) to mimic aggressive breast cancer, which harbor a vector for pLUC, which is induced by luciferin in vivo, to monitor tumor growth in real time. Furthermore, we used i) pSlik34a, with tunable expression of miR-34a by doxycycline; ii) treatment with PTX to select for resistant cells (RC); and combined the two, by treating RC with doxycycline. CSC content was evaluated by ALDH (Aldehyde Dehydrogenase) activity, sphere-forming efficiency (SFE) and qRT-PCR of known markers. A similar approach was followed for in vivo studies, with NSG female injected through tail vein injection with 500,000 SUM159/pLUC/pSlik34a cells, and separated into three groups: not treated (NT), PTX alone, and PTX+34a. Results: As observed for aggressive breast cancer, treatment of SUM159 with PTX generated resistant cells (RC) with increased CSC content (ALDH activity and spheres forming ability). When miR-34a was induced in the RC, cells changed morphology, slowed proliferation rate, and decreased CSC content (ALDH activity and spheres). Moreover, a second PTX treatment almost completely abolished the ALDH activity and SFE. The combined effect was evaluated in vivo, following by luminescence the growth of metastases after lung colonization, with PTX+34a mice reducing lung colonization than the PTX treatment or miR-34a treatment alone. Conclusions: Overall, these results indicate that miR-34a sensitize PTX-resistant cells reducing cancer stem-cell capacities, and in this preclinical setting limited the aggressive phenotype of breast cancer, including proliferation, drug resistance, relapse and metastasis causing in delay of lung colonization in vivo.

Citation Format: Montserrat Climent, Paola Bonetti, Francesco Nicassio. miRNA-34a sensitizes triple-negative breast cancer cells to paclitaxel reducing cancer stem cell population and lung colonization [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4410.

Weight loss and quality of life in patients surviving 2 years after gastric cancer resection

BACKGROUND

Malnutrition is common in patients undergoing gastric cancer resection, leading to weight loss, although little is known about how this impacts on health-related quality of life (HRQL). This study aimed to explore the association between HRQL and weight loss in patients 2 years after curative gastric cancer resection.

METHODS

Consecutive patients undergoing curative gastric cancer resection and surviving at least 2 years without disease recurrence were recruited. Patients completed the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ-C30) and the specific module for gastric cancer (STO22) before and 2 years postoperatively and associations between HRQL scores and patients with and without ≥ 10% body weight loss (BWL) were examined.

RESULTS

A total of 76 patients were included, of whom 51 (67%) had BWL ≥10%. At 2 years postoperatively, BWL ≥10% was associated with deterioration of all functional aspects of quality of life, with persistent pain (21.6%), diarrhoea (13.7%) and nausea/vomiting (13.7%). By contrast, none of the patients with BWL <10% experienced severe nausea/vomiting, pain or diarrhoea.

CONCLUSIONS

Disabling symptoms occurred more frequently in patients with ≥10% BWL than in those with <10% BWL, with a relevant negative impact on HRQL. A cause-effect relationship between weight loss and postoperative outcome remains unsolved.

Postoperative complications do not impact on recurrence and survival after curative resection of gastric cancer

BACKGROUND

We assessed the impact of complications on recurrence and survival after curative gastric cancer resection.

METHODS

Patients undergoing R0 resections between 1990 and 2009 were identified in a prospectively maintained database and were categorized by presence of any complication Clavien-Dindo (CD) ≥ II, sepsis or intra-abdominal sepsis. Cox regression analyses to relate complications and clinico-pathological variables to time to recurrence (TTR) and overall survival (OS) were performed.

RESULTS

A total of 271 patients were included with a median follow-up of 149.9 months (range 140.1-159.9). Complications CD ≥ II occurred in 162 (59.8%) patients, sepsis in 66 (22.5%), and intra-abdominal sepsis in 37 (13.6%). Recurrence developed in 88 (32.4%) patients. Independent predictors of short TTR were pTNM stage (IIIB-IIIC vs. IA-IIA) (hazard ratio [HR] = 37.55, 95% confidence interval [CI] 17.57-80.24; p < 0.001), D1 lymphadenectomy (HR = 3.14, 95% CI 1.94-5.07; p < 0.001), and male gender (HR = 1.65, 95% CI 1.06-2.57; p = 0.026). pTNM stage (IIIB-IIIC vs. IA-IIA, HR = 10.28, 95% CI 6.51-16.23; p < 0.001), male gender (HR = 1.64, 95% CI 1.17-2.31; p = 0.005), age (HR = 1.03, 95% CI 1.02-1.05; p < 0.001), and adjuvant therapy (HR = 0.55, 95% CI 0.37-0.83; p = 0.004) were identified as independent predictors of OS..

CONCLUSIONS

Evidence provided by this study does not support a negative impact of postoperative complications CD ≥ II, sepsis, and intra-abdominal sepsis on the oncologic outcome after curative gastric cancer resection.

TGFβ Triggers miR-143/145 Transfer From Smooth Muscle Cells to Endothelial Cells, Thereby Modulating Vessel Stabilization

RATIONALE

The miR-143/145 cluster is highly expressed in smooth muscle cells (SMCs), where it regulates phenotypic switch and vascular homeostasis. Whether it plays a role in neighboring endothelial cells (ECs) is still unknown.

OBJECTIVE

To determine whether SMCs control EC functions through passage of miR-143 and miR-145.

METHODS AND RESULTS

We used cocultures of SMCs and ECs under different conditions, as well as intact vessels to assess the transfer of miR-143 and miR-145 from one cell type to another. Imaging of cocultured cells transduced with fluorescent miRNAs suggested that miRNA transfer involves membrane protrusions known as tunneling nanotubes. Furthermore, we show that miRNA passage is modulated by the transforming growth factor (TGF) β pathway because both a specific transforming growth factor-β (TGFβ) inhibitor (SB431542) and an shRNA against TGFβRII suppressed the passage of miR-143/145 from SMCs to ECs. Moreover, miR-143 and miR-145 modulated angiogenesis by reducing the proliferation index of ECs and their capacity to form vessel-like structures when cultured on matrigel. We also identified hexokinase II (HKII) and integrin β 8 (ITGβ8)-2 genes essential for the angiogenic potential of ECs-as targets of miR-143 and miR-145, respectively. The inhibition of these genes modulated EC phenotype, similarly to miR-143 and miR-145 overexpression in ECs. These findings were confirmed by ex vivo and in vivo approaches, in which it was shown that TGFβ and vessel stress, respectively, triggered miR-143/145 transfer from SMCs to ECs.

CONCLUSIONS

Our results demonstrate that miR-143 and miR-145 act as communication molecules between SMCs and ECs to modulate the angiogenic and vessel stabilization properties of ECs.

Expression of endogenous retroviruses is negatively regulated by the pluripotency marker Rex1/Zfp42

Rex1/Zfp42 is a Yy1-related zinc-finger protein whose expression is frequently used to identify pluripotent stem cells. We show that depletion of Rex1 levels notably affected self-renewal of mouse embryonic stem (ES) cells in clonal assays, in the absence of evident differences in expression of marker genes for pluripotency or differentiation. By contrast, marked differences in expression of several endogenous retroviral elements (ERVs) were evident upon Rex1 depletion. We demonstrate association of REX1 to specific elements in chromatin-immunoprecipitation assays, most strongly to muERV-L and to a lower extent to IAP and musD elements. Rex1 regulates muERV-L expression in vivo, as we show altered levels upon transient gain-and-loss of Rex1 function in pre-implantation embryos. We also find REX1 can associate with the lysine-demethylase LSD1/KDM1A, suggesting they act in concert. Similar to REX1 binding to retrotransposable elements (REs) in ES cells, we also detected binding of the REX1 related proteins YY1 and YY2 to REs, although the binding preferences of the two proteins were slightly different. Altogether, we show that Rex1 regulates ERV expression in mouse ES cells and during pre-implantation development and suggest that Rex1 and its relatives have evolved as regulators of endogenous retroviral transcription.

Association of Rex-1 to target genes supports its interaction with Polycomb function

Rex-1/Zfp42 displays a remarkably restricted pattern of expression in preimplantation embryos, primary spermatocytes, and undifferentiated mouse embryonic stem (ES) cells and is frequently used as a marker gene for pluripotent stem cells. To understand the role of Rex-1 in selfrenewal and pluripotency, we used Rex-1 association as a measure to identify potential target genes, and carried out chromatin-immunoprecipitation assays in combination with gene specific primers to identify genomic targets Rex-1 associates with. We find association of Rex-1 to several genes described previously as bivalently marked regulators of differentiation and development, whose repression in mouse embryonic stem (ES) cells is Polycomb Group-mediated, and controlled directly by Ring1A/B. To substantiate the hypothesis that Rex-1 contributes to gene regulation by PcG, we demonstrate interactions of Rex-1 and YY2 (a close relative of YY1) with Ring1 proteins and the PcG-associated proteins RYBP and YAF2, in line with interactions reported previously for YY1. We also demonstrate the presence of Rex-1 protein in both trophectoderm and Inner Cell Mass of the mouse blastocyst and in both ES and in trophectoderm stem (TS) cells. In TS cells, we were unable to demonstrate association of Rex-1 to the genes it associates with in ES cells, suggesting that association may be cell-type specific. Rex-1 might fine-tune pluripotency in ES cells by modulating Polycomb-mediated gene regulation.

Impact on Survival of Primary Tumor Resection in Women with Metastatic Breast Cancer at Initial Diagnosis. The Alamo Project

Background: Recent medical and scientific reports suggest that surgery of the primary tumor (PT) could be taken into account, although far from the current standard of care, in metastatic breast cancer (MBC) patients. The mechanistic basis for these findings stem from crosstalk between the PT and metastatic foci, immunosuppressive effects, and/or the avoidance of metastatic re-seeding from the primary source. We have focused on implementing surgical excision of the PT in certain settings and tumor types in order to ascertain whether this aggressive treatment modality can be justified in a classic palliative setting. Methods: The ALAMO Project (A) is a retrospective analysis of patients (pts) diagnosed with BC between 1990 and 1997 across 43 GEICAM hospitals. Patterns of BC presentation (tumor and host characteristics), treatment and survival were recorded in 2 cohorts, AI (1990-93, 4532 pts, closed by 2000) and AII (1994-97, 10849 pts, closed by 2003). Only MBC pts at first diagnosis were included, excluding those with secondary tumors, without a minimum of 2 months follow-up at the same institution, and without complete information regarding their PT surgery. Descriptive, Kaplan-Meier and Cox regression analyses were carried out. Results: 6.12% of the ALAMO database pts were initially diagnosed with MBC (605 fulfilled the present analysis criteria), with a medium age of 61.6 years (yrs). 54.2% had single-organ metastasis, anatomically distributed in skin/soft tissue (18.8%), bone (35.9%), lung (9.8%), and other viscera (35.5%). 26.3% of pts had surgery of the PT (83.7% of them radical procedures, 73.3% of them axillary dissected and 5.6% received radiotherapy). Chemotherapy (30.7%), endocrine therapy (23.1%) or both (41.7%) were the systemic approaches, and 4.5% received supportive care. Women in the surgery (S) group (159 pts) were younger, with skin/soft tissue or bone metastasis and oligometastatic disease. 5-yr overall survival (OS) was 18.84%, 2.94 yrs median OS in the S-group versus 1.83 yrs in the nS-group (p&lt;0.001). A stratified analysis by organ showed relevant effects of surgery for pts with skin/soft tissue metastasis, 4.52 yrs versus 1.77 yrs median OS in the S and nS arms respectively. The multi-adjusted HR for surgery in this subgroup was 0.30 (p&lt;0.001), which was not significantly modified considering a propensity score (PS) factor (HR 0.29, p&lt;0.001). Surgery (p&lt;0.001), systemic treatment (p&lt;0.001), and the interaction between surgery and metastatic location (p&lt;0.004) were included in the multivariate predictive model of survival for the whole series. Discussion: Local surgery of the PT is associated with an increase in OS for pts with skin/soft tissue metastasis and is maintained in multi-adjusted models. These analyses suggest that loco-regional control of the PT should be considered for the treatment of advanced disease in selected patients, but must be further investigated in randomized controlled trials in MBC at first diagnosis.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 3104.

Gemcitabine and oxaliplatin combination: a multicenter phase II trial in unfit patients with locally advanced or metastatic urothelial cancer

BACKGROUND

Up to 50% of patients with bladder cancer cannot be treated with cisplatin because they are considered unfit due to poor renal function. Gemcitabine and oxaliplatin are active, nonnephrotoxic therapies with nonoverlapping toxicity profiles that provide an alternative therapy for this group of patients.

PATIENTS AND METHODS

In a multicenter study, patients received gemcitabine 1200 mg/m(2) on days 1 and 8 and oxaliplatin 100 mg/m(2) on day 8 every 21 days. Eligible criteria were creatinine clearance >30 ml/min and/or Eastern Cooperative Oncology Group (ECOG) performance status of two or less.

RESULTS

Forty-six patients were assessable for response and toxicity. Median age was 69 years (range 52-85), median ECOG two (range 0-2). Median number of metastatic sites was 2 (range 1-6). Median creatinine clearance was 50.73 ml/min (range 30-87). A total of 187 cycles were given with a median of 5 (range 1-6). Hematological toxicity was mild with grade 3-4 peripherical neuropathy occurring in 4% of patients. Overall response rate was 48% (three complete response, 19 partial response, seven stable disease and 17 progressive disease). Median time to disease progression was 5 months.

CONCLUSION

Gemcitabine-oxaliplatin is an active and tolerable combination with response rate that merits further study in patients with impaired renal function but good performance status.

Objective response rate in a phase II multicenter trial of pertuzumab (P), a HER2 dimerization inhibiting monoclonal antibody, in combination with trastuzumab (T) in patients (pts) with HER2-positive metastatic breast cancer (MBC) which has progressed during treatment with T

1004

Background: T and P bind to different epitopes on the extra cellular domain of HER2. Unlike T, P binds to the dimerization domain and blocks homo- and hetero-dimerization of HER2 with other HER kinase family members. Xenograft models support the hypothesis that the complementary mechanisms of action could result in augmented efficacy when T and P are combined. Methods: Two-stage design, criteria to proceed to the 2nd stage were: ≥ 2 partial responses (PR) or 1 PR and 12 stable disease (SDs) or 13 SDs. Eligibility included: measurable, centrally-tested HER2 positive breast cancer; up to 3 lines of prior chemotherapy plus T (including adjuvant chemotherapy plus T); disease progression during T as most recent treatment for metastatic disease; baseline left ventricular ejection fraction (LVEF) ≥ 55% and no decrease of LVEF to below 50% during prior T treatment. Consenting Pts received T i.v. weekly or every 3 weeks at 2 mg/kg or 6 mg/kg respectively (with re-loading dose if required) plus 420mg fixed dose of P i.v. every 3 weeks following loading dose 840mg. Study treatment was initiated within 9 weeks of the last dose of T given as most recent therapy. An independent data safety monitoring board has overseen the 1st stage safety data. Results: Recruitment into 1st stage is complete. The main adverse events were diarrhea (71%), fatigue (46%), nausea/vomiting (38%) and rash (25%). Most AE’s were mild to moderate (there was 1 case of Grade 3 diarrhea) and none was treatment-limiting. There were no clinical cardiac events, and central review revealed no case of fall in LVEF of ≥10% and to ≤50%. Response status: 5 confirmed PR (21%); 12 SD (50%). Responses have been observed in lymph node and liver metastases. Recruitment into the 2nd stage of the trial has commenced. Conclusions: The combination of the P and T is active and well tolerated in patients with pre-treated HER2 positive breast cancer which has progressed during treatment with T.

No significant financial relationships to disclose.

Prognostic factors for relapse in stage I seminoma managed by surveillance or adjuvant carboplatin: A multivariate analysis on 588 cases

4552

Background: The availability of reliable prognostic factors for relapse in stage I seminoma would allow a better patient stratification for individually tailored therapies. We performed a pooled analysis of patients included in two consecutive risk-adapted protocols. Methods: Between 1994 and 2004, 588 cases were prospectively registered. Median patient age was 33 years, median tumor size was 45 mm, serum BHCG levels were elevated preoperatively in 14.6%, and rete testis invasion was present in 26.9%. Three hundred and four patients (51.7%) with risk factors received two courses of adjuvant carboplatin, whereas 284 (48.3%) without these criteria were managed by surveillance. After a median follow-up of 48 months (range, 12–144), 43 relapses (7.3%) have occurred. Five-year disease-free survival was 92.3%. Univariate (log rank) and multivariate (Cox regression) analyses of prognostic factors for relapse were performed. Results: Relapses were less frequent after carboplatin treatment (3% vs 12%, p < 0.0001). Statistically significant, independent predictors of relapse were: 1) rete testis invasion and age (<30 years) in the whole series; 2) rete testis invasion for patients treated with adjuvant chemotherapy; and 3) tumor invasion beyond the albuginea and microvessel neoplastic invasion (defining 1997 AJCC pT2–4 staging) for patients managed by surveillance. In contrast, tumor size, histologic subtype (anaplastic), and serum preoperative BHCG levels were not associated with prognosis. Conclusions: Invasion of the rete testis and age (<30 years) represent high-risk factors for patients with clinical stage I testis seminoma, independently of the treatment selected. These two features, in combination with pathologic T2–4 staging, could improve patient selection for risk-adapted therapies.

No significant financial relationships to disclose.