How standardization of the pre-analytical phase of both research and diagnostic biomaterials can increase reproducibility of biomedical research and diagnostics.

Comparison of published biomedical studies shows that a large proportion are irreproducible, causing severe damage to society and creating an image of wasted investments. These observations are of course damaging to the biomedical research field, which is currently full of future promise. Precision medicine and disease prevention are successful, but are progressing slowly due to irreproducible study results. Although standardization is mentioned as a possible solution, it is not always clear how this could decrease or prevent irreproducible results in biomedical studies. In this article more insight is given into what quality, norms, standardization, certification, accreditation and optimized infrastructure can accomplish to reveal causes of irreproducibility and increase reproducibility when collecting biomaterials. CEN and ISO standards for the sample pre-analytical phase are currently being developed with the support of the SPIDIA4P project, and their role in increasing reproducibility in both biomedical research and diagnostics is demonstrated. In particular, it is described how standardized methods and quality assurance documentation can be exploited as tools for: 1) recognition and rejection of 'not fit for purpose' samples on the basis of detailed sample metadata, and 2) identification of methods that contribute to irreproducibility which can be adapted or replaced

Tumor-Related Methylated Cell-Free DNA and Circulating Tumor Cells in Melanoma

Solid tumor release into the circulation cell-free DNA (cfDNA) and circulating tumor cells (CTCs) which represent promising biomarkers for cancer diagnosis. Circulating tumor DNA may be studied in plasma from cancer patients by detecting tumor specific alterations, such as genetic or epigenetic modifications. Ras association domain family 1 isoform A (RASSF1A) is a tumor suppressor gene silenced by promoter hypermethylation in a variety of human cancers including melanoma.The aim of the present study was to assess the diagnostic performance of a tumor-related methylated cfDNA marker in melanoma patients and to compare this parameter with the presence of CTCs.RASSF1A promoter methylation was quantified in cfDNA by qPCR in a consecutive series of 84 melanoma patients and 68 healthy controls. In a subset of 68 cases, the presence of CTCs was assessed by a filtration method (Isolation by Size of Epithelial Tumor Cells, ISET) as well as by an indirect method based on the detection of tyrosinase mRNA by RT-qPCR. The distribution of RASSF1A methylated cfDNA was investigated in cases and controls and the predictive capability of this parameter was assessed by means of the area under the ROC curve (AUC).The percentage of cases with methylated RASSF1A promoter in cfDNA was significantly higher in each class of melanoma patients (in situ, invasive and metastatic) than in healthy subjects (Pearson chi-squared test, p<0.001). The concentration of RASSF1A methylated cfDNA in the subjects with a detectable quantity of methylated alleles was significantly higher in melanoma patients than in controls. The biomarker showed a good predictive capability (in terms of AUC) in discriminating between melanoma patients and healthy controls. This epigenetic marker associated to cfDNA did not show a significant correlation with the presence of CTCs, but, when the two parameters are jointly considered, we obtain a higher sensitivity of the detection of positive cases in invasive and metastatic melanomas.Our data suggest that cell-free tumor DNA and CTCs represent two complementary aspects of the liquid biopsy which may improve the diagnosis and the clinical management of melanoma patients

Circulating tumour cells in colorectal cancer

Abstract Background The detection of circulating tumour cells (CTC) in blood sample in patients with early or advanced colorectal cancer has a potential prognostic value. Methods The challenge of CTC detection is related to the requirement of high sensitivity combined with high specificity method. CTCs detection can be distinguished between indirect and direct methods. The former ones are based on the recognition of tissue-, organ- or tumour-specific markers by immuno-histochemistry (indirect immuno-mediated methods) or (real-time) RT-PCR (indirect molecular methods), whilst the latter are related to CTCs selection based on the physical properties of density and sizes. Ongoing and future isolation by size of epithelial tumour cells (ISET) developments concerning automated image analysis on the filter and transmission of high definition images through the web for 'on line' cytopathological consultations are aimed to speed up the work of cytopathologists on CTC/ circulating tumour microemboli (CTM) detection. Conclusions CTC detection in colorectal cancer (CRC) correlates with pathological stage and clinical outcome in particular in those patients with advanced disease. CRC CTC level before and after CT are an independent prognostic factor for progression-free and overall survival. The positive prognostic value of complete clearance CTC after surgery may be useful to select patients for adjuvant chemotherapy

Circulating tumor cells detection and counting in uveal melanomas by a filtration-based method

Uveal melanoma is one of the most deadly diseases in ophthalmology for which markers able to predict the appearance of metastasis are needed. The study investigates the role of circulating tumor cells (CTC) as a prognostic factor in this disease. We report the detection of circulating tumor cells by Isolation by Size of Epithelial Tumor cells (ISET) in a cohort of 31 uveal melanoma patients: we identified single CTCs or clusters of cells in 17 patients, while the control population, subjects with choroidal nevi, showed no CTC in peripheral blood. The presence of CTCs did not correlate with any clinical and pathological parameter, such as tumor larger basal diameter (LBD), tumor height and TNM. By stratifying patients in groups on the basis of the number of CTC (lower or higher than 10 CTC per 10 mL blood) and the presence of CTC clusters we found a significant difference in LBD (p = 0.019), Tumor height (p = 0.048), disease-free and overall survival (p &lt; 0.05). In conclusion, we confirm the role of CTC as a negative prognostic marker in uveal melanoma patients after a long follow-up period. Further characterization of CTC will help understanding uveal melanoma metastasization and improve patient management. © 2014 by the authors; licensee MDPI, Basel, Switzerland