Robert Malafosse

Evaluation of predictive models in daily practice for the identification of patients with Lynch syndrome.

The optimal strategy for identifying patients with Lynch syndrome among patients with newly diagnosed colorectal cancer (CRC) is still debated. Several predictive models (e.g., MMRpredict, PREMM1,2 and MMRpro) combining personal and familial data have recently been developed to quantify the risk that a given patient with CRC carries a Lynch syndrome‐causing mutation. Their clinical applicability to patients with CRC from the general population requires evaluation. We studied a consecutive series of 214 patients with newly diagnosed CRC characterized for tumor microsatellite instability (MSI), somatic BRAF mutation, MLH1 promoter methylation and mismatch repair (MMR) gene germline mutation status. The performances of the models for identifying MMR mutation carriers (8/214, 3.7%) were evaluated and compared to the revised Bethesda guidelines and a molecular strategy based on MSI testing in all patients followed by the exclusion of MSI‐positive sporadic cases from mutational testing by screening for BRAF mutation and MLH1 promoter methylation. The sensitivities of the three models, at the lowest thresholds proposed, were identical (75%), with similar numbers of probands eligible for further MSI testing (almost half the patients). In our dataset, the prediction models gave no better discrimination than the revised Bethesda guidelines. Both approaches failed to identify two of the eight mutation carriers (the same two patients, aged 67 and 81 years, both with no family history). Thus, like the revised Bethesda guidelines, predictive models did not identify all patients with Lynch syndrome in our series of consecutive CRC. Our results support systematic screening for MMR deficiency in all new CRC cases.

Linear quantification of lymphoid infiltration of the tumor margin: a reproducible method, developed with colorectal cancer tissues, for assessing a highly variable prognostic factor

BackgroundLymphoid infiltration is a prognostic marker in solid tumors, such as colorectal, breast and lung carcinomas. However, lymphoid infiltration is heterogeneous and the reproducibility of quantification based on single counts within a tumor is very low. We aimed to develop a reproducible method for evaluating lymphoid infiltration in tumors.MethodsVirtual slides were obtained from tissue sections from the localized colorectal carcinomas of 117 patients, stained for CD3 and CD45R0. We assessed the variation of lymphoid cell density by automatic counts in 1 mm-wide, 5 μm-long segments of the invasive front, along an axis 4 mm in length running perpendicular to the invasive front of the tumor.ResultsWe plotted curves of the variation of lymphocyte density across the tumor front. Three distinct patterns emerged from this linear quantification of lymphocyte (LQLI). In pattern 1, there was a high density of lymphocytes within the tumor. In pattern 2, lymphocyte density peaked close to the invasive margin. In pattern 3, lymphocytes were diffusely distributed, at low density. It was possible to classify all the tumors studied, and interobserver reproducibility was excellent (kappa =0.9). By contrast, single counts of CD3+ cells on tissue microarrays were highly variable for a given LQLI pattern, confirming the heterogeneity of lymphoid infiltration within individual tumors. In univariate analysis, all pathologic features (stage, metastatic lymph node ratio (LNR), vascular embolism, perineural invasion), CD3+ cell density, LQLI patterns for CD3+ and CD45R0+ cells) were found to have a significant effect on disease-free survival (DFS). In multivariate analysis, only the LQLI pattern for CD3+ cells (HR: 6.02; 95% CI: 2.74-13.18) and metastatic lymph node ratio (HR: 6.14; 95% CI: 2.32-16.2) were associated with DFS.ConclusionLQLI is an automated, reproducible method for the assessment of lymphoid infiltration. However, validation of its prognostic value in larger series is required before its introduction into routine practice for prognostic evaluation in patients with colorectal carcinomas.Virtual slidesThe virtual slide(s) for this article can be found here:http://www.diagnosticpathology.diagnomx.eu/vs/9861460717895880

Improved retroviral suicide gene transfer in colon cancer cell lines after cell synchronization with methotrexate.

BackgroundCancer gene therapy by retroviral vectors is mainly limited by the level of transduction. Retroviral gene transfer requires target cell division. Cell synchronization, obtained by drugs inducing a reversible inhibition of DNA synthesis, could therefore be proposed to precondition target cells to retroviral gene transfer. We tested whether drug-mediated cell synchronization could enhance the transfer efficiency of a retroviral-mediated gene encoding herpes simplex virus thymidine kinase (HSV-tk) in two colon cancer cell lines, DHDK12 and HT29.MethodsSynchronization was induced by methotrexate (MTX), aracytin (ara-C) or aphidicolin. Gene transfer efficiency was assessed by the level of HSV-TK expression. Transduced cells were driven by ganciclovir (GCV) towards apoptosis that was assessed using annexin V labeling by quantitative flow cytometry.ResultsDHDK12 and HT29 cells were synchronized in S phase with MTX but not ara-C or aphidicolin. In synchronized DHDK12 and HT29 cells, the HSV-TK transduction rates were 2 and 1.5-fold higher than those obtained in control cells, respectively. Furthermore, the rate of apoptosis was increased two-fold in MTX-treated DHDK12 cells after treatment with GCV.ConclusionsOur findings indicate that MTX-mediated synchronization of target cells allowed a significant improvement of retroviral HSV-tk gene transfer, resulting in an increased cell apoptosis in response to GCV. Pharmacological control of cell cycle may thus be a useful strategy to optimize the efficiency of retroviral-mediated cancer gene therapy.

Management of patients over 80 years of age treated with resection for localised colon cancer: Results from a French referral centre

BACKGROUND Few data are available on management of very elderly colon cancer patients, especially concerning the parameters of therapeutic decisions and the role of geriatricians. METHODS We retrospectively reviewed the charts of patients over 80 years of age who underwent surgery for a localised colon cancer in a French academic hospital. RESULTS A total of 176 patients underwent surgery (postoperative morbidity and mortality rates: 25% and 6.7%). Adjuvant chemotherapy was discussed at a multidisciplinary team meeting for 91% of stage III patients, but only 13.5% of them were treated. Twenty-five patients relapsed: 19 were discussed at the multidisciplinary meeting and 16 were treated (5 had a metastasectomy). Despite their increase with time, geriatric assessments were infrequent, 17% (33% after 2006), and had no impact on postoperative morbi-mortality. Median overall survival and recurrence-free survival were 65.3 months and 65.1 months, respectively. Age, emergency surgery, and Charlson comorbidity index were independent prognostic factors. CONCLUSION Selected elderly colon cancer patients have significant access to surgery. However, postoperative morbi-mortality rates remain high and adjuvant chemotherapy rarely prescribed. Perioperative geriatric assessment, especially before surgery, should be routinely proposed to these patients to evaluate its impact on postoperative morbi-mortality and prescription of adjuvant treatment.

LETHAL FECALOMA: LETTERS TO THE EDITOR

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La résection anastomose colorectale protégée n’est-elle pas finalement la meilleure option thérapeutique en cas de péritonite par perforation diverticulaire Hinchey III ?

But Le traitement chirurgical optimal des peritonites purulentes (Hinchey III) par perforation diverticulaire (PPPD) reste debattu. Le but de cette etude etait de comparer les resultats postoperatoires du lavage-drainage laparoscopique (LDL) a ceux de la resectionanastomose colorectale protegee (RAP) pour PPPD. Methodes De 2010 a 2015, tous les malades operes pour PPPD ont ete inclus. Le choix entre LDL et RAP etait laisse a l’appreciation du chirurgien. Resultats 24 malades ont eu une RAP et 15 un LDL. La proportion de malades ASA>2 etait superieure dans le groupe RAP (12/24 vs 1/15, p vs 67 %, N S ; 8.3 % vs 6.7 %, NS). Les taux de complications chirurgicales et de reoperations etaient plus eleves apres LDL qu’apres RAP (53 % vs 17 %, p=0.03 ; 47 % vs 4 %, p Conclusion En cas de PPPD, pres de la moitie des malades ayant un LDL sont reoperes pour avoir une stomie. La RAP est une alternative fiable, elle limite le risque de reintervention pour complication grave sans augmenter le risque de stomie definitive. Declaration d’interet Les auteurs n’ont pas transmis de conflits d’interets.