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Rex, Douglas K.

https://orcid.org/0000-0002-9836-4309

A5083845259 | I4394709130

Mayo Clinic

Indiana University School of Medicine

Citations 22

Stool DNA and Occult Blood Testing for Screen Detection of Colorectal Neoplasia

Annals of Internal Medicine | April 12, 2013 | Volume: 149 | Issue: 7 | Pages: 441-450

10.7326/0003-4819-149-7-200810070-00004 | PMID 18838724

Improved Marker Combination for Detection of De Novo Genetic Variation and Aberrant DNA in Colorectal Neoplasia

Clinical Chemistry | November 2, 2006 | Volume: 52 | Issue: 12 | Pages: 2299-2302

10.1373/clinchem.2007.070896 | PMID 17082247

Abstract Background: The genetic heterogeneity of sporadic colorectal cancer (CRC) makes the choice of genetic markers and sequence variation–detection technologies critical to the performance of screening assays. We have previously described the effectiveness of a CRC assay composed of 22 known variants in KRAS, APC, TP53, and BAT-26 (V1). We introduce a new marker formulation (V2) that includes detection of de novo variation in APC, PIK3CA, and CTNNB1, hypermethylated sequences within SMARCA3 and VIM, and a single-base variation within BRAF. We compared the abilities of the V1 and V2 markers to detect aberrant DNA in colorectal neoplasias. Methods: V1 and V2 marker formulations were used to analyze 144 colorectal tissue samples comprising 50 precancerous adenomas, 94 carcinomas, and 11 nonpathologic tissues. V1 analysis consisted of single-base extension analysis of the 22 V1 variants. V2 analysis consisted of DNA scanning of the APC mutation cluster region, PIK3CA exons 9 and 20, CTNNB1 exon 3, analysis for the BRAF Val600Glu substitution, and methylation-specific PCR analysis of VIM and SMARCA3. Results: The V2 marker formulation had significantly higher sensitivity than the V1 markers for carcinomas (93.6% and 72.3%, respectively; P = 0.0002) and adenomas (92.0% and 62.0%, respectively; P = 0.0006). None of the nonpathologic samples were positive for any marker. Conclusions: We demonstrate improved sensitivity of a new marker formulation (V2) to detect aberrant DNA in CRC and precancerous adenoma tumor tissues.