Gérard-Yves Perret

Procalcitonin as a diagnostic test for sepsis in critically ill adults and after surgery or trauma: a systematic review and meta-analysis.

Objective:To quantify the accuracy of serum procalcitonin as a diagnostic test for sepsis, severe sepsis, or septic shock in adults in intensive care units or after surgery or trauma, alone and compared with C-reactive protein. To draw and compare the summary receiver operating characteristics curves for procalcitonin and C-reactive protein from the literature. Data Source:MEDLINE (keywords: procalcitonin, intensive care, sepsis, postoperative sepsis, trauma); screening of the literature. Study Selection:Meta-analysis of all 49 published studies in medical, surgical, or polyvalent intensive care units or postoperative wards. Children, medical patients, and immunocompromised patients were excluded. Data Extraction:Thirty-three studies fulfilled inclusion criteria (3,943 patients, 1,828 males, 922 females; mean age: 56.1 yrs; 1,825 patients with sepsis, severe sepsis, or septic shock; 1,545 with only systemic inflammatory response syndrome); eight studies could not be analyzed statistically. Global mortality rate was 29.3%. Data Synthesis:Global odds ratios for diagnosis of infection complicated by systemic inflammation were 15.7 for the 25 studies (2,966 patients) using procalcitonin (95% confidence interval, 9.1–27.1) and 5.4 for the 15 studies (1,322 patients) using C-reactive protein (95% confidence interval, 3.2–9.2). The summary receiver operating characteristics curve for procalcitonin was better than for C-reactive protein. In the 15 studies using both markers, the Q* value (intersection of summary receiver operating characteristics curve with the diagonal line where sensitivity equals specificity) was significantly higher for procalcitonin than for C-reactive protein (0.78 vs. 0.71, p = .02), the former test showing better accuracy. Conclusions:Procalcitonin represents a good biological diagnostic marker for sepsis, severe sepsis, or septic shock, difficult diagnoses in critically ill patients. Procalcitonin is superior to C-reactive protein. Procalcitonin should be included in diagnostic guidelines for sepsis and in clinical practice in intensive care units.

Microvessel Density as a Prognostic Factor in Women with Breast Cancer: A Systematic Review of the Literature and Meta-Analysis

We performed a meta-analysis of all 87 published studies linking intratumoral microvessel density (MVD), reflecting angiogenesis, to relapse-free survival (RFS) and overall survival (OS). With median MVD as cutoff, MVD impact was measured by risk ratio (RR) between the two survival distributions. Seventeen studies did not mention survival data or fit inclusion criteria. Twenty-two were multiple publications of the same series, leaving 43 independent studies (8936 patients). MVD was assessed by immunohistochemistry, using antibodies against factor VIII (27 studies; n = 5262), CD31 (10 studies; n = 2296), or CD34 (8 studies; n = 1726). MVD might be a better prognostic factor when assessed by CD31 or CD34 versus factor VIII (P = 0.11). For RFS, statistical calculations were performed in 25 studies (6501 patients). High MVD significantly predicted poor survival [RR = 1.54 for RFS and OS with the same 95% confidence interval (CI), 1.29-1.84]. Twenty-two studies analyzed separately lymph node-negative patients (n = 3580), for whom predictors of poor survival are requested. This latter meta-analysis included 15 studies for RFS (2727 patients) and 11 for OS (1926 patients). High MVD significantly predicted poor survival [RR = 1.99 for RFS (95% CI, 1.33-2.98) and RR = 1.54 for OS (95% CI, 1.01-2.33)]. Between-study variations could result from patient selection criteria, techniques to stain and count microvessels, and cutoff selection. MVD was a significant although weak prognostic factor in women with breast cancer. Standardization of MVD assessment is needed.

Microvessel density and VEGF expression are prognostic factors in colorectal cancer. Meta-analysis of the literature

We performed a meta-analysis of all published studies relating intratumoural microvessel density (MVD) (45 studies) or vascular endothelial growth factor (VEGF) expression (27 studies), both reflecting angiogenesis, to relapse free (RFS) and overall survival (OS) in colorectal cancer (CRC). For each study, MVD impact was measured by risk ratio between the two survival distributions with median MVD as cutoff. Eleven studies did not mention survival data or fit inclusion criteria, six were multiple publications of same series, leaving 32 independent studies for MVD (3496 patients) and 18 for VEGF (2050 patients). Microvessel density was assessed by immunohistochemistry, using antibodies against factor VIII (16 studies), CD31 (10 studies) or CD34 (seven studies). Vascular endothelial growth factor expression was mostly assessed by immunohistochemistry. Statistics were performed for MVD in 22 studies (the others lacking survival statistics) including nine studies (n=957) for RFS and 18 for OS (n=2383) and for VEGF in 17 studies, including nine studies for RFS (n=1064) and 10 for OS (n=1301). High MVD significantly predicted poor RFS (RR=2.32 95% CI: 1.39–3.90; P<0.001) and OS (RR=1.44; 95% CI: 1.08–1.92; P=0.01). Using CD31 or CD34, MVD was inversely related to survival, whereas it was not using factor VIII. Vascular endothelial growth factor expression significantly predicted poor RFS (RR=2.84; 95% CI: 1.95–4.16) and OS (RR=1.65; 95% CI: 1.27–2.14). To strengthen our findings, future prospective studies should explore the relation between MVD or VEGF expression and survival or response to therapy (e.g. antiangiogenic therapy). Assessment of these angiogenic markers should be better standardised in future studies.

Does microsatellite instability predict the efficacy of adjuvant chemotherapy in colorectal cancer? A systematic review with meta-analysis

BACKGROUND Microsatellite instability (MSI) status in predicting the efficacy of adjuvant chemotherapy in colorectal cancer remains controversial. MATERIALS AND METHODS Studies were identified through PubMed, Embase and ASCO proceedings with a combination of keywords (colorectal cancer, chemotherapy and MSI). RESULTS A MA was performed for treated and non-treated MSI population on seven studies. Statistical calculations were performed on 7 studies representing 3690 patients; mean age: 65.5 years; 810 stage II and 2444 stage III (75%). MSI-high (MSI-H) was found in 454 patients (14% of the global population), and microsatellite stable (MSS) in 2871. A total of 1444 patients received 5-fluorouracil (5FU)-based chemotherapy, whereas 1518 patients did not. For MSI-H patients, there was no statistically significant difference for RFS whether or not they received chemotherapy (5 studies); HR RFS: 0.96 (95% confidence interval (CI): 0.62-1.49); HR OS (6 studies): 0.70 (95% CI: 0.44-1.09; p=0.12). Elsewhere, we found a significant interaction between MSI status (MSI-H or MSS) and therapeutic status suggesting a lesser benefit for MSI-H than for MSS patients (HR interaction RFS: 0.77 (95% CI: 0.67-0.87)). CONCLUSION We found similar RFS for treated and untreated MSI-H patients, showing that MSI-H status, in addition to being a good prognostic factor is also a predictive factor of non response.

Does delaying adjuvant chemotherapy after curative surgery for colorectal cancer impair survival? A meta-analysis

BACKGROUND In stage III colorectal cancer (CRC), adjuvant chemotherapy (CT) is usually prescribed within two months after curative surgery. Whether or not delaying initiation of CT affects survival is still debated. MATERIAL AND METHODS We performed a meta-analysis (MA) of all published studies (full papers or abstracts) comparing delayed CT with standard care. Studies were obtained from a PubMed query (keywords: CRC, adjuvant treatment, delay of CT), a review (Chau et al., 2006), cross-checking references and abstracts from the proceedings of ASCO, ASCO GI and WCGI annual meetings. We chose a cutoff delay of 8 weeks. Risk Ratios (RRs) were calculated from the recorded events (deaths, relapses). We used EasyMA software (fixed-effect model). RESULTS Fourteen studies (including four abstracts) were identified (17,645 patients; 5,952 males, 5,151 females, mean age 70 years). Of these, three could not be statistically analysed and three used another cutoff (4, 5 or 6 weeks), leaving 8 studies for main MA (13,158 patients; 3,932 males, 3,644 females, 5,942 missing data; 5,576 colon cancers, 6,677 rectal, 1,265 missing data). Delaying CT more than 8 weeks was associated to worse Overall Survival (OS) (RR: 1.20; 95% Confidence Interval (CI) 1.15-1.26). In the MA including all studies whatever their cutoff, longer delay was similarly associated to a worse OS but not a worse Relapse-Free Survival (RFS) (five studies). CONCLUSION Adjuvant chemotherapy should be started within 8 weeks after surgery. Delaying the initiation of adjuvant CT for more than 8 weeks after surgery significantly decreased OS but not RFS. This discrepancy might be due to factors not directly related to cancer (post-operative complications, social status) or to a more accurate appraisal of death.

Transient Hypocalcemia after Thyroidectomy

The causes of transient hypocalcemia after thyroid surgery are not fully understood. In 95 consecutive patients undergoing total thyroidectomy (n = 30), subtotal thyroidectomy (n = 14), or hemithyroidectomy (n = 51), we serially measured total calcium, parathyroid hormone (PTH), and proteins before surgery and 6, 24, 48, 72, and 96 hours after surgery, and we calculated the corresponding ionized calcium levels. In the whole population, there was a statistically significant decrease of PTH, total calcium, and proteins at nearly every time of blood withdrawal, when compared with the preoperative levels. The PTH decreased earlier and total calcium levels were significantly lower after total thyroidectomy than after hemithyroidectomy (at 48, 72, and 96 hours). Ten patients had on 2 occasions serum calcium levels below or equal to 2 mmol/L and were defined as having severe hypocalcemia. Severe hypocalcemia was found in 8 patients after total thyroidectomy, compared with 2 after hemithyroidectomy (p < .05), and was present in 3 of the 5 patients with thyroid carcinoma, compared with 7 of the 90 patients with nonmalignant thyroid diseases (p < .01). Despite careful preservation of the parathyroid glands and their blood supply, thyroidectomy was often followed by transient hypocalcemia, the determinants of which are hypoparathyroidism and hemodilution. No patients had persistent symptoms of hypocalcemia from 2 to 3 months after surgery.

Glycosaminoglycan mimetics inhibit SDF-1/CXCL12-mediated migration and invasion of human hepatoma cells

We have recently reported that the CXC-chemokine stromal cell-derived factor-1 (SDF-1)/CXCL12 induces proliferation, migration, and invasion of the Huh7 human hepatoma cells through its G-protein-coupled receptor CXCR4 and that glycosaminoglycans (GAGs) are involved in these events. Here, we demonstrate by surface plasmon resonance that the chemokine binds to GAG mimetics obtained by grafting carboxylate, sulfate or acetate groups onto a dextran backbone. We also demonstrate that chemically modified dextrans inhibit SDF-1/CXCL12-mediated in vitro chemotaxis and anchorage-independent cell growth in a dose-dependent manner. The binding of GAG mimetics to the chemokine and their effects in modulating the SDF-1/CXCL12 biological activities are mainly related to the presence of sulfate groups. Furthermore, the mRNA expression of enzymes involved in heparan sulfate biosynthesis, such as exostosin-1 and -2 or N-deacetylase N-sulfotransferases remained unchanged, but heparanase mRNA and protein expressions in Huh7 cells were decreased upon GAG mimetic treatment. Moreover, decreasing heparanase-1 mRNA levels by RNA interference significantly reduced SDF-1/CXCL12-induced extracellular signal-regulated kinase 1/2 (ERK 1/2) phosphorylation. Therefore, we suggest that GAG mimetic effects on SDF-1/CXCL12-mediated hepatoma cell chemotaxis may rely on decreased heparanase expression, which impairs SDF-1/CXCL12s signaling. Altogether, these data suggest that GAG mimetics may compete with cellular heparan sulfate chains for the binding to SDF-1/CXCL12 and may affect heparanase expression, leading to reduced SDF-1/CXCL12 mediated in vitro chemotaxis and growth of hepatoma cells.

Invading Basement Membrane Matrix Is Sufficient for MDA-MB-231 Breast Cancer Cells to Develop a Stable In Vivo Metastatic Phenotype

Introduction The poor efficacy of various anti-cancer treatments against metastatic cells has focused attention on the role of tumor microenvironment in cancer progression. To understand the contribution of the extracellular matrix (ECM) environment to this phenomenon, we isolated ECM surrogate invading cell populations from MDA-MB-231 breast cancer cells and studied their genotype and malignant phenotype. Methods We isolated invasive subpopulations (INV) from non invasive populations (REF) using a 2D-Matrigel assay, a surrogate of basal membrane passage. INV and REF populations were investigated by microarray assay and for their capacities to adhere, invade and transmigrate in vitro, and to form metastases in nude mice. Results REF and INV subpopulations were stable in culture and present different transcriptome profiles. INV cells were characterized by reduced expression of cell adhesion and cell-cell junction genes (44% of down regulated genes) and by a gain in expression of anti-apoptotic and pro-angiogenic gene sets. In line with this observation, in vitro INV cells showed reduced adhesion and increased motility through endothelial monolayers and fibronectin. When injected into the circulation, INV cells induced metastases formation, and reduced injected mice survival by up to 80% as compared to REF cells. In nude mice, INV xenografts grew rapidly inducing vessel formation and displaying resistance to apoptosis. Conclusion Our findings reveal that the in vitro ECM microenvironment per se was sufficient to select for tumor cells with a stable metastatic phenotype in vivo characterized by loss of adhesion molecules expression and induction of pro-angiogenic and survival factors.

New pharmacological strategies against metastatic spread

Although metastatic spread is the most frequent cause of death in cancer patients, there are very few drugs specifically targeting this process. Bases for a new antimetastatic drug discovery strategy are weak because a great number of unknowns characterize the complete understanding of the metastatic cascade mechanisms. Moreover, the current experimental models are too simplistic and do not account for the complexity of the phenomenon. Some targets have been identified but too few are validated. Among them, the metastasis suppressor genes seem to be the most promising. In spite of this, during recent years, a dozen of molecules, which fulfil the definition of a specific metastatic drug that inhibits the metastases without altering the growth of the primary tumour (which can be eradicated by surgery), have been identified and assessed for the proof of the concept. The continuation of this effort would benefit in terms of efficiency, if the objectives were defined more precisely. It is particularly important to distinguish molecules that prevent spread of the metastatic cells of the early‐stage primary tumour from the ones which induce a regression of the established metastases or to inhibit the transition from disseminated occult tumour cells to dormant micrometastasis. This second goal is a priori more relevant in the current clinical setting where the detection of early metastatic spread is very difficult, and therefore would call for greater effort on the part of the scientific community.

Inhibition of epidermoid carcinoma A431 cell growth and angiogenesis in nude mice by early and late treatment with a novel dextran derivative.

We investigated the effect of a new dextran derivative, phenylacetate carboxymethyl benzylamide dextran (NaPaC), on epidermoid carcinoma A431 cells secreting a large quantity of angiogenic factor, vascular endothelial growth factor (VEGF). In vitro, NaPaC inhibited the proliferation of A431 cells (IC50=5 μM). Also, NaPaC decreased the binding of radiolabelled VEGF165 to endothelial cells (IC50=0.2 μM). In vivo, we explored the effects of NaPaC (15 mg kg−1) on A431 xenograft growth starting the drug administration at the time of tumour cell inoculation (early treatment) and 1 week later, when tumours were well established (late treatment). Early treatment was more efficient on tumour inhibition (70% vs control) than late treatment (50% vs control). Early and late NaPaC-treatment increased the aponecrosis in tumour by 70 and 30%, respectively. Whatever treatment, NaPaC inhibited the intratumour endothelial cell density in the same manner. In contrast, vessel area was decreased only when NaPaC was injected early (35%). These results show that NaPaC has a potent inhibitory effect, dependent on treatment outset, on epidermoid carcinoma growth associated with an intratumour microvascular network diminution and an aponecrosis increase. As this drug is nontoxic at efficient dose, it offers interesting perspectives for the therapy of malignant lesions.