Abstract LB-177: DNA and RNA from formalin-fixed, paraffin-embedded pancreatic cancer tissue for sequencing: A pilot study of the SEER-linked Virtual Tissue Repository

Author(s):  
Yao Yuan ◽  
Alison Van Dyke ◽  
Valentina Petkov ◽  
Aatur Singhi ◽  
William Hoos ◽  
...  
2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Rafael Parra-Medina ◽  
Sandra Ramírez-Clavijo

AbstractExtraction of DNA and RNA from formalin-fixed paraffin-embedded (FFPE) tissue blocks is a critical process in molecular oncology testing. Using FFPE, it is possible to choose the portion of tissue to study, taking into account the cell morphology, storage stability and storage conditions at room temperature, and make retrospective studies with clinical and pathological information. In prostate cancer tissue, in contrast with macroscopic tumors, it is not easy to identify the tumor; therefore, it is very important to make a microscopic diagnosis. We do not recommend punching this tissue because it can choose normal tissue for molecular analysis. In the present article we review the differences between punch biopsy and microdissection.


2021 ◽  
Vol 10 (11) ◽  
pp. 2304
Author(s):  
Karolina Skubisz ◽  
Joanna Januszkiewicz-Caulier ◽  
Patrycja Cybula ◽  
Elwira Bakuła-Zalewska ◽  
Krzysztof Goryca ◽  
...  

The data demonstrating a correlation between sonographic markers of malignancy of thyroid cancer (TC) and its genetic status are scarce. This study aimed to assess whether the addition of genetic analysis at the preoperative step of TC patients’ stratification could aid their clinical management. The material consisted of formalin-fixed paraffin-embedded tumor fragments of 49 patients who underwent thyroidectomy during the early stages of papillary TC (PTC). Tumor DNA and RNA were subjected to next-generation sequencing (NGS) on Ion Proton using the Oncomine™ Comprehensive Assay panel. We observed a significant correlation between BRAF V600E and a higher EU-TIRADS score (p-value = 0.02) with a correlation between hypoechogenicity and taller-than-wide tumor shape in analysed patients. There were no other significant associations between the identified genetic variants and other clinicopathological features. For TC patient’s stratification, a strong suspicion of BRAF V600E negativity in preoperative management of TC patients could limit the over-treatment of asymptomatic, very low-risk, indolent disease and leave room for active surveillance.


2018 ◽  
Vol 143 (2) ◽  
pp. 183-189 ◽  
Author(s):  
Jing Li ◽  
Stephanie Gan ◽  
Alan Blair ◽  
Kyungji Min ◽  
Taraneh Rehage ◽  
...  

Context.— KRAS Mutation Test v2 is used for the qualitative detection and identification of 28 mutations in exons 2, 3, and 4 of the human KRAS gene. Objective.— To verify the performance of KRAS Mutation Test v2 and to evaluate its accuracy by correlation with a next-generation sequencing method on Illumina MiSeq. Design.— In this study, we used formalin-fixed, paraffin-embedded tissue and plasma specimens from non–small cell lung cancer, colorectal cancer, and pancreatic cancer patients. Results of specificity, precision, analytical sensitivity, and accuracy as compared with a MiSeq method are reported. Results.— The KRAS Mutation Test v2 demonstrated exquisite sensitivity and specificity and broad coverage of KRAS mutations. Precision was 100% (108 of 108) across all samples, operators, and instruments for formalin-fixed, paraffin-embedded tissue and 99.8% (615 of 616) for plasma. Analytical sensitivity was high with detection of 1% mutant sequence in formalin-fixed, paraffin-embedded tissue samples and as low as 25 mutant sequence copies/mL for plasma samples. The test also showed high overall concordance for formalin-fixed, paraffin-embedded tumor tissue as well as for plasma specimens when compared with MiSeq sequencing results. Conclusions.— The KRAS Mutation Test v2 is a highly robust, reproducible, and sensitive test for the qualitative detection of 28 mutations in exons 2, 3, and 4 of the KRAS gene in both solid (tissue) and liquid (plasma) biopsies from colorectal cancer, non–small cell lung cancer, and pancreatic cancer, and is a convenient option for KRAS mutation testing.


2020 ◽  
Vol 19 ◽  
pp. 153303382096076
Author(s):  
Peng Qi ◽  
Qian-ming Bai ◽  
Qian-lan Yao ◽  
Wen-tao Yang ◽  
Xiao-yan Zhou

This study aimed to compare the performance of MilliSect dissection and manual dissection. Twenty-five formalin-fixed paraffin-embedded (FFPE) breast cancer tissue blocks were selected for comparison. Specific areas of interest (AOIs) in invasive carcinoma on tissue sections were transferred to dissection slides by manual macrodissection or the MilliSect instrument. The comparison criteria were 1) the time required for dissection; 2) RNA concentration and purity; 3) RNA quantity of 5 housekeeping genes (by RT-qPCR); and 4) ER, PR, HER2, Ki-67 and recurrence score (RS) values (by the 21-gene assay). Then, tumor-adjacent tissues, including fibrocollagenous and epithelial tissues, from the same selected tissue blocks of 8 of 25 patients were scraped using the mesodissection method, and their RS values were assessed to evaluate the influence of tumor-adjacent tissues on the target AOIs. Ultimately, 4 AOIs of invasive ductal carcinoma (IDC) from 1 tissue block of another 4 patients with lymph node (LN) metastases each, LN tissue and a mixture of IDC and LN tissue from the other tissue block of the same 4 patients were mesodissected to evaluate the influence of infiltrating lymphocyte levels on the RS values of AOIs. In our experience, the MilliSect instrument, which provides process management documentation, required more time than manual macrodissection (on average, approximately 9.1 min per sample versus 5.8 min per sample, respectively). The RNA yield and quality of the dissected tissues were comparable for the 2 methods. However, the tumor-adjacent tissues of the AOIs may influence the RS to some extent. Tumor-infiltrating lymphocytes (TILs) can dramatically increase RSs, far exceeding the influence of tumor-adjacent fibrocollagenous and epithelial tissues. In conclusion, MilliSect mesodissection is comparable to manual dissection. This mesodissection tool may facilitate AOI alignment and the dissection process for the 21-gene RS assay. Samples whose adjacent tissues are intermixed with TILs warrant special attention.


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