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Cologuard. Where It Fits In. Cologuard. Screening test for colorectal cancer FIT-DNA : composite of tests :(1) hemoglobin (2) molecular assays for DNA mutations (3) methylation biomarkers. Colorectal Neoplasms. DNA shed into stool may reveal genetic mutations (KRAS) and epigenetic changes.
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Cologuard Where It Fits In
Cologuard • Screening test for colorectal cancer • FIT-DNA : composite of tests :(1) hemoglobin (2) molecular assays for DNA mutations (3) methylation biomarkers
Colorectal Neoplasms DNA shed into stool may reveal genetic mutations (KRAS) and epigenetic changes
Test Procedure • Patient collects a stool sample in a special collection kit • No dietary or medication restrictions • Kit mailed back in 72 hours or less • Repeat testing every 3 years (if negative) • If positive, refer for colonoscopy
Who is a Candidate? • Average risk patients • Should not be used if: (1) history of colonic adenomas or cancer (2) history of IBD (3) family history of colon cancer/ Lynch Syndrome/FAP
Effectiveness • Sensitivity (confirmed by colonoscopy) for CRC 92% • Not affected by CRC stage or location of lesion • Specificity for CRC was 87% • Significance of a (+) Cologuard followed by a (-) colonoscopy is unknown
Colonoscopy • “Gold Standard”-but not a perfect test • prep needed and complications possible • “Miss rate” of 2% with large adenomas (>10mm), 25% <5 mm
Positive Cologuard Changes screening colonoscopy to diagnostic colonoscopy
Potential Risks of PPI’s • Proton pump inhibitors have been used on millions of patients since Prilosec was introduced in the USA in 1989
Mechanism of Action • Binds to the H-K-ATPase on the luminal surface of the parietal cell • Most effective after a prolonged fast and when the parietal cell is stimulated after a meal
Clinical Uses • GERD-especially erosive esophagitis • Peptic ulcer disease • Eradication of H. pylori • Zollinger-Ellison syndrome • Prevention NSAID ulcers
Potential Adverse Effects • Increased risk of Clostridium difficile infection • Calcium malabsorption and fracture risk • Pneumonia • Dementia • Death
Kidney Disease and PPI’s • PPI’s can cause acute interstitial nephritis • Weak association with PPI’s and chronic kidney disease (CKD)
Potential Malabsorption • Iron malabsorption • Magnesium malabsorption • Vitamin B12 malabsorption
Why Use PPI’s • Inhibit gastric acid secretion much more effectively than H2 RA’s • Once-daily dosing decreases gastric acid secretion by 66%
Any Clinical Difference? • rabeprazole • omeprazole • esomeprazole • lansoprazole • pantoprazole
PPI’s and H2 Blockers • H2RA’s suppress acid much less effectively, but work more quickly-better for prn use • Taking them at the same time renders the PPI less effective