Paul Cottu

Comparison of Low-Molecular-Weight Heparin and Warfarin for the Secondary Prevention of Venous Thromboembolism in Patients With Cancer: A Randomized Controlled Study

Venous thromboembolism occurs in about 10% of patients with cancer. In this setting, vitamin K antagonists have been associated with a high risk of recurrent disease and major bleeding. Low-molecular-weight heparin allows reducing by 50% the rate of recurrent venous thromboembolism as compared to vitamin K antagonists. Even with low-molecular-weight heparin, recurrent venous thromboembolism occurs in up to 6% of the patients. In this case it has been suggested to increase the dosage of low-molecular-weight heparin. Vena cava filtration probably plays a minor role in setting. After the sixth month, prolongation of low-molecular-weight-heparin or switch to vitamin K antagonist should be discussed on a case by case basis.

Adjuvant bevacizumab-containing therapy in triple-negative breast cancer (BEATRICE): primary results of a randomised, phase 3 trial

BACKGROUND The addition of bevacizumab to chemotherapy improves progression-free survival in metastatic breast cancer and pathological complete response rates in the neoadjuvant setting. Micrometastases are dependent on angiogenesis, suggesting that patients might benefit from anti-angiogenic strategies in the adjuvant setting. We therefore assessed the addition of bevacizumab to chemotherapy in the adjuvant setting for women with triple-negative breast cancer. METHODS For this open-label, randomised phase 3 trial we recruited patients with centrally confirmed triple-negative operable primary invasive breast cancer from 360 sites in 37 countries. We randomly allocated patients aged 18 years or older (1:1 with block randomisation; stratified by nodal status, chemotherapy [with an anthracycline, taxane, or both], hormone receptor status [negative vs low], and type of surgery) to receive a minimum of four cycles of chemotherapy either alone or with bevacizumab (equivalent of 5 mg/kg every week for 1 year). The primary endpoint was invasive disease-free survival (IDFS). Efficacy analyses were based on the intention-to-treat population, safety analyses were done on all patients who received at least one dose of study drug, and plasma biomarker analyses were done on all treated patients consenting to biomarker analyses and providing a measurable baseline plasma sample. This trial is registered with ClinicalTrials.gov, number NCT00528567. FINDINGS Between Dec 3, 2007, and March 8, 2010, we randomly assigned 1290 patients to receive chemotherapy alone and 1301 to receive bevacizumab plus chemotherapy. Most patients received anthracycline-containing therapy; 1638 (63%) of the 2591 patients had node-negative disease. At the time of analysis of IDFS, median follow-up was 31·5 months (IQR 25·6-36·8) in the chemotherapy-alone group and 32·0 months (27·5-36·9) in the bevacizumab group. At the time of the primary analysis, IDFS events had been reported in 205 patients (16%) in the chemotherapy-alone group and in 188 patients (14%) in the bevacizumab group (hazard ratio [HR] in stratified log-rank analysis 0·87, 95% CI 0·72-1·07; p=0·18). 3-year IDFS was 82·7% (95% CI 80·5-85·0) with chemotherapy alone and 83·7% (81·4-86·0) with bevacizumab and chemotherapy. After 200 deaths, no difference in overall survival was noted between the groups (HR 0·84, 95% CI 0·64-1·12; p=0·23). Exploratory biomarker assessment suggests that patients with high pre-treatment plasma VEGFR-2 might benefit from the addition of bevacizumab (Cox interaction test p=0·029). Use of bevacizumab versus chemotherapy alone was associated with increased incidences of grade 3 or worse hypertension (154 patients [12%] vs eight patients [1%]), severe cardiac events occurring at any point during the 18-month safety reporting period (19 [1%] vs two [<0·5%]), and treatment discontinuation (bevacizumab, chemotherapy, or both; 256 [20%] vs 30 [2%]); we recorded no increase in fatal adverse events with bevacizumab (four [<0·5%] vs three [<0·5%]). INTERPRETATION Bevacizumab cannot be recommended as adjuvant treatment in unselected patients with triple-negative breast cancer. Further follow-up is needed to assess the potential effect of bevacizumab on overall survival.

miR-141 and miR-200a act on ovarian tumorigenesis by controlling oxidative stress response

Although there is evidence that redox regulation has an essential role in malignancies, its impact on tumor prognosis remains unclear. Here we show crosstalk between oxidative stress and the miR-200 family of microRNAs that affects tumorigenesis and chemosensitivity. miR-141 and miR-200a target p38α and modulate the oxidative stress response. Enhanced expression of these microRNAs mimics p38α deficiency and increases tumor growth in mouse models, but it also improves the response to chemotherapeutic agents. High-grade human ovarian adenocarcinomas that accumulate miR-200a have low concentrations of p38α and an associated oxidative stress signature. The miR200a-dependent stress signature correlates with improved survival of patients in response to treatment. Therefore, the role of miR-200a in stress could be a predictive marker for clinical outcome in ovarian cancer. In addition, although oxidative stress promotes tumor growth, it also sensitizes tumors to treatment, which could account for the limited success of antioxidants in clinical trials.

Extensive characterization of genetic alterations in a series of human colorectal cancer cell lines

A number of genetic alterations have been described in colorectal cancers. They include allelic losses on specific chromosomal arms, mutations of oncogenes, tumor suppressor genes and mismatch repair genes, microsatellite instability in coding repeat sequences of target genes and methylation defects in gene promoters. Since these alterations have been reported by different groups on different tumors and cell lines, the complete repertoire of genetic alterations for any given tumor sample remains unknown. In the present study, we analysed a series of 22 colorectal cancer cell lines for 31 different genetic alterations. We found significant correlations between mutational profiles in these colorectal cell lines associated with differences in mismatch repair status. This panel of colon cancer cell lines is representative of the genetic heterogeneity occurring in sporadic colorectal carcinoma. Our results may prove to be very useful for understanding the different biological pathways involved in the development of colon cancer, and for groups studying cellular biology and pharmacology on the same cell lines.

Allelic profiles of mononucleotide repeat microsatellites in control individuals and in colorectal tumors with and without replication errors.

We have recently shown that analysis of BAT-26, was sufficient to establish the Replication Error status of colorectal tumors and cell lines without the need for matching normal DNA. BAT-26, a poly(A) tract in the 5th intron of the hMSH2 gene, does not present significant size variation either between the allleles of one individual or between alleles of different individuals. In colorectal tumors without defects in the replication error system (RER− phenotype), BAT-26 is also quasi-monomorphic. On the contrary, in RER+ colorectal tumors, BAT-26 shows unstable shortened alleles. In order to see whether this behaviour was specific for BAT-26, or was a more general phenomenon for mononucleotide repeat microsatellites, we analysed eight other mononucleotide repeats. In control individuals (72 samples) and in RER− colorectal tumors and cell lines (55 samples), these microsatellites were polymorphic, dimorphic, quasi-monomorphic or monomorphic, indicating that the quasi-monomorphic nature of BAT-26 was not a general rule. All of them showed a tendency to be shorter in RER+ colorectal tumors and cell lines (19 samples), but only quasi-monomorphic and monomorphic mononucleotide repeats could be used to determine the RER status of tumors without matching normal DNA, although with a lower efficiency than BAT-26 due to either a smaller range of shortening in RER+ tumors or to a larger number of false negative cases.

Molecular profiling of patient-derived breast cancer xenografts

IntroductionIdentification of new therapeutic agents for breast cancer (BC) requires preclinical models that reproduce the molecular characteristics of their respective clinical tumors. In this work, we analyzed the genomic and gene expression profiles of human BC xenografts and the corresponding patient tumors.MethodsEighteen BC xenografts were obtained by grafting tumor fragments from patients into Swiss nude mice. Molecular characterization of patient tumors and xenografts was performed by DNA copy number analysis and gene expression analysis using Affymetrix Microarrays.ResultsComparison analysis showed that 14/18 pairs of tumors shared more than 56% of copy number alterations (CNA). Unsupervised hierarchical clustering analysis showed that 16/18 pairs segregated together, confirming the similarity between tumor pairs. Analysis of recurrent CNA changes between patient tumors and xenografts showed losses in 176 chromosomal regions and gains in 202 chromosomal regions. Gene expression profile analysis showed that less than 5% of genes had recurrent variations between patient tumors and their respective xenografts; these genes largely corresponded to human stromal compartment genes. Finally, analysis of different passages of the same tumor showed that sequential mouse-to-mouse tumor grafts did not affect genomic rearrangements or gene expression profiles, suggesting genetic stability of these models over time.ConclusionsThis panel of human BC xenografts maintains the overall genomic and gene expression profile of the corresponding patient tumors and remains stable throughout sequential in vivo generations. The observed genomic profile and gene expression differences appear to be due to the loss of human stromal genes. These xenografts, therefore, represent a validated model for preclinical investigation of new therapeutic agents.

Distinct tumor protein p53 mutants in breast cancer subgroups.

Tumor protein p53 (TP53) is mutated in approximately 30% of breast cancers, but this frequency fluctuates widely between subclasses. We investigated the p53 mutation status in 572 breast tumors, classified into luminal, basal and molecular apocrine subgroups. As expected, the lowest mutation frequency was observed in luminal (26%), and the highest in basal (88%) tumors. Luminal tumors showed significantly higher frequency of substitutions (82 vs. 65%), notably A/T to G/C transitions (31 vs. 15%), whereas molecular apocrine and basal tumors presented much higher frequencies of complex mutations (deletions/insertions) (36 and 33%, respectively, vs. 18%). Accordingly, missense mutations were significantly more frequent in luminal tumors (75 vs. 54%), whereas basal tumors displayed significantly increased rates of TP53 truncations (43 vs. 25%), resulting in loss of function and/or expression. Interestingly, as basal tumors, molecular apocrine tumors presented with a high rate of complex mutations, but paradoxically, these were not associated with increased frequency of p53 truncation. As in luminal tumors, this could reflect a selective pressure for p53 gain of function, possibly through P63/P73 inactivation. Collectively, these observations point not only to different mechanisms of TP53 alterations, but also to different functional consequences in the different breast cancer subtypes.

Frequent genomic structural alterations at HPV insertion sites in cervical carcinoma

To investigate whether integration of HPV DNA in cervical carcinoma is responsible for structural alterations of the host genome at the insertion site, a series of 34 primary cervical carcinomas and eight cervical cancer‐derived cell lines were analysed. DNA copy number profiles were assessed using the Affymetrix GeneChip Human Mapping 250K Sty array. HPV 16, 18 or 45 integration sites were determined using the DIPS‐PCR technique. The genome status at integration sites was classified as follows: no change, amplification, transition normal/gain, normal/loss or gain/LOH. A single HPV integration site was found in 34 cases; two sites were found in seven cases; and three sites in one case (51 sites). Comparison between integration sites and DNA copy number profiles showed that the genome status was altered at 17/51 (33%) integration sites, corresponding to 16/42 cases (38%). Alterations detected were amplification in nine cases, transition normal/loss in four cases, normal/gain in three cases, and gain/LOH in one case. A highly significant association was found between genomic rearrangement and integration of HPV DNA (p < 10−10). Activation of the replication origin located in viral integrated sequences in a cell line derived from one of the primary cervical carcinomas induced an increase of the amplification level of both viral and cellular DNA sequences flanking the integration locus. This mechanism may be implicated in the triggering of genome amplification at the HPV integration site in cervical carcinoma. Structural alterations of the host genome are frequently observed at the integration site of HPV DNA in cervical cancer and may act in oncogenesis. Copyright

Lobular invasive carcinoma of the breast is a molecular entity distinct from luminal invasive ductal carcinoma

In order to get insight into the molecular alterations of invasive lobular carcinoma (ILC), comparative genomic hybridisation array and transcriptomic analyses of a series of 62 oestrogens-positive (ER) invasive tumours [21 ILC and 41 invasive ductal carcinomas (IDC)] were performed. ILC and IDC shared highly recurrent regions of gains (1q12-q44(+) in more than 60% of the cases, 16pter-p11.2(+) in 45% and 63% of ILC and IDC, respectively) and losses (16q11.2-q24.2(-) in 84% of ILC and 67.5% of IDC and 17pter-p12(-) in 50% of ILC and IDC). However, ILC genomic signature was characterised by significantly more frequent losses of 13q21.33-q31.3 region (46.5%) and 22q11.23-q12.1 region (50%) whereas IDC showed significantly more frequent losses of 11q23.1-q23.2 region (in 44% of IDC). Nine different regions of high level amplifications were found in 38% of ILC (8/21 cases). Localised on chromosome 11 (11q13.2 region), the most frequent region of amplification encompassing the CCND1 and FGF3 genes was observed in five different ILC. Unsupervised hierarchical clustering of transcriptomic data showed that ILC and IDC clustered apart. Genes involved in cell adhesion, cell communication and trafficking, extra cellular matrix-interaction pathways or cell mobility contributed to this clustering. Despite these differences, the overall clinical outcome of ILC was identical to that of IDC. This molecular study highlights that lobular and oestrogens-positive ductal invasive carcinomas share common genomic alterations but that ILC present some specific molecular alterations. These molecular specificities should help with the identification of new therapeutic targets for ILC patients.

Assessment of circulating tumor cells and serum markers for progression-free survival prediction in metastatic breast cancer: a prospective observational study

IntroductionCirculating tumor cells (CTC) have been recently proposed as a new dynamic blood marker whose positivity at baseline is a prognostic factor and whose changes under treatment are correlated with progression-free survival (PFS) in metastatic breast cancer patients. However, serum marker levels are also used for the same purpose, and no clear comparison has been reported to date.MethodsThe IC 2006-04 enrolled prospectively 267 metastatic breast cancer patients treated by first line chemotherapy and confirmed that CTC levels are an independent prognostic factor for PFS and overall survival (OS). A secondary pre-planned endpoint was to compare prospectively the positivity rates and the value of CTC (CellSearch®), of serum tumor markers (carcinoembryonic antigen (CEA), cancer antigen 15.3 (CA 15-3), CYFRA 21-1), and of serum non-tumor markers (lactate deshydrogenase (LDH), alkaline phosphatase (ALP)) at baseline and under treatment for PFS prediction, independently from the other known prognostic factors, using univariate analyses and concordance indexes.ResultsA total of 90% of the patients had at least one elevated blood marker. Blood markers were correlated with poor performance status, high number of metastatic sites and with each other. In particular, CYFRA 21-1, a marker usually used in lung cancer, was elevated in 65% of patients. A total of 86% of patients had either CA 15-3 and/or CYFRA 21-1 elevated at baseline. Each serum marker was associated, when elevated at baseline, with a significantly shorter PFS. Serum marker changes during treatment, assessed either between baseline and week 3 or between baseline and weeks 6 to 9, were significantly associated with PFS, as reported for CTC. Concordance indexes comparison showed no clear superiority of any of the serum marker or CTC for PFS prediction.ConclusionsFor the purpose of PFS prediction by measuring blood marker changes during treatment, currently available blood-derived markers (CTC and serum markers) had globally similar performances. Besides CEA and CA 15-3, CYFRA 21-1 is commonly elevated in metastatic breast cancer and has a strong prognostic value.