Sarcoma: concordance between initial diagnosis and centralized expert review in a population-based study within three European regions.

BACKGROUND: Sarcomas represent a heterogeneous group of tumors. Accurate determination of histological diagnosis and prognostic factors is critical for the delineation of treatment strategies. The contribution of second opinion (SO) to improve diagnostic accuracy has been suggested for sarcoma but has never been established in population-based studies. METHODS: Histological data of patients diagnosed with sarcoma in Rhone-Alpes (France), Veneto (Italy) and Aquitaine (France) over a 2-year period were collected. Initial diagnoses were systematically compared with SO from regional and national experts. RESULTS: Of 2016 selected patients, 1463 (73%) matched the inclusion criteria and were analyzed. Full concordance between primary diagnosis and SO (the first pathologist and the expert reached identical conclusions) was observed in 824 (56%) cases, partial concordance (identical diagnosis of connective tumor but different grade or histological subtype) in 518 (35%) cases and complete discordance (benign versus malignant, different histological type or invalidation of the diagnosis of sarcoma) in 121 (8%) cases. The major discrepancies were related to histological grade (n = 274, 43%), histological type (n = 144, 24%), subtype (n = 18, 3%) and grade plus subtype or grade plus histological type (n = 178, 29%). CONCLUSION: More than 40% of first histological diagnoses were modified at second reading, possibly resulting in different treatment decisions.

A large-scale candidate gene approach identifies SNPs in SOD2 and IL13 as predictive markers of response to preoperative chemoradiation in rectal cancer.

Neoadjuvant radiochemotherapy followed by total mesorectal excision is now the standard treatment for locally advanced rectal cancer. However, tumor response to chemoradiation varies widely among individuals and cannot be determined before the final pathologic evaluation. The aim of this study was to identify germline genetic markers that could predict sensitivity or resistance to preoperative radiochemotherapy (RT-CT) in rectal cancer. We evaluated the predictive value of 128 single-nucleotide polymorphisms (SNPs) in 71 patients preoperatively treated by RT-CT. The selected SNPs were distributed over 76 genes that are involved in various cellular processes such as DNA repair, apoptosis, proliferation or immune response. The SNPs superoxide dismutase 2 (SOD2) rs4880 (P=0.005) and interleukin-13 (IL13) rs1800925 (P=0.0008) were significantly associated with tumor response to chemoradiation. These results reinforce the idea of using germline polymorphisms for personalized treatment.

A prospective epidemiological study of new incident GISTs during two consecutive years in Rhône Alpes region: incidence and molecular distribution of GIST in a European region.

BACKGROUND: Preliminary data indicate that the molecular epidemiology of localised gastrointestinal stromal tumour (GIST) may be different from that of advanced GIST. We sought to investigate the molecular epidemiology of sarcomas, including GIST, in the Rhone-Alpes region in France. PATIENTS AND METHODS: A prospective and exhaustive study in the Rhone-Alpes Region in France to assess the precise incidence of primary sarcomas with systematic centralised pathological review and molecular analysis was conducted for 2 consecutive years. RESULTS: Among 760 patients with a confirmed diagnosis of sarcoma, 131 (17%) had a GIST. The majority of patients had gastric primaries (61%). Mutational analysis could be performed in 106 tumour samples (74%), and 71 (67%) had exon 11 mutations. PDGFRA mutations were found in 16% of cases, which is twice as high as previously reported for advanced GIST. CONCLUSION: Data indicate that PDGFRA mutations in localised GIST may be twice as high as what was previously reported in patients with advanced disease. This finding may have important consequences for patients offered adjuvant imatinib, although most of these tumours are in the low-risk group.

[Incidence rate, epidemiology of sarcoma and molecular biology. Preliminary results from EMS study in the Rhône-Alpes region]. / Incidence, épidémiologie des sarcomes et biologie moléculaire. Résultats préliminaires de l'étude EMS en Rhône-Alpes.

Sarcomas comprise a heterogeneous group of mesenchymal neoplasms. They can be grouped into 3 general categories, soft tissue sarcoma, visceral and primary bone sarcoma, which have different staging and treatment approaches. Soft tissue sarcomas are typically classified on the basis of genetic alterations and light-microscopic examination of hematoxylin-eosin-stained tissue, in which recognizable morphological characteristics of normal tissues are identified. Sarcomas are further characterized by histologic grade. The 3 most important prognostic variables are grade, size, and location of the primary tumor. This review includes a discussion of both soft tissue sarcomas (unclassified sarcoma, liposarcoma, leiomyosarcoma, synovial sarcoma, dermatofibrosarcoma protuberans, angiosarcoma, Kaposi sarcoma, gastrointestinal stromal tumor, rhabdomyosarcoma, ...) and primary bone sarcomas (osteosarcoma, Ewing sarcoma and chondrosarcoma). The approach to a patient with a sarcoma begins with a biopsy that obtains adequate tissue for diagnosis without interfering with subsequent optimal definitive surgery. Subsequent treatment depends on the specific type of sarcoma. Due to the absence of clear knowledge for incidence rate, we conducted in 2005 and 2006 an exhaustive analysis of all diagnosed cases in the Rhône-Alpes region. Because sarcomas are relatively uncommon yet comprise a wide variety of different entities, second opinion was systematically performed for all included cases.

[Considerations for normalisation of RT-qPCR in oncology]. / La RT-qPCR en oncologie: considérations pour la normalisation.

Gene expression analysis has many applications in the management of cancer, including diagnosis, prognosis, and therapeutic care. In this context, the reverse transcription quantitative polymerase chain reaction (RT-qPCR) has become the "gold standard" for mRNA quantification. However, this technique involves several critical steps such as RNA extraction, cDNA synthesis, quantitative PCR, and analysis, which all can be source of variation. To obtain biologically meaningful results, data normalisation is required to correct sample-to-sample variations that may be introduced during this multistage process. Normalisation can be carried out against a housekeeping gene, total RNA mass, or cell number. Careful choice of the normalization method is crucial, as any variation in the reference will introduce errors in the quantification of mRNA transcripts. By reviewing the different methods available and their related problems, the aim of this article is to provide recommendations for the set up of an appropriate normalisation strategy for RT-qPCR data in oncology.