Collecting Blood and Stool Samples to Detect Colorectal Cancer or Advanced Neoplasia in Lynch Syndrome Patients

Who May Qualify: - Patients at least 18 years of age - Individuals diagnosed with Lynch syndrome (mutation in MLH1, MSH2, MSH6, PMS2, EPCAM) or suspected Lynch syndrome or individuals diagnosed with early onset colorectal cancer (CRC) (\< 50 years old) - Colonoscopy/flexible sigmoidoscopy (flex sig) scheduled +/- 90 days from sample collection - Patient has agreed to participate and has signed the study consent form Who Should NOT Join This Trial: - Patient has known cancer (stage I-IV) 5 years prior to current sample collection (not including basal cell or squamous cell skin cancers; if patient has not been seen or if information is not available, the patient is eligible) - Patient has received chemotherapy class drugs for the treatment of cancer in the 5 years prior to current sample collection - Patient has had any abdominal radiation therapy prior to current sample collection - Patient had therapy to the target lesion with intent to completely remove or debulk the lesion prior to sample collection \[examples include snare polypectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), surgical resection, trans anal excision\] - Patient has prior diagnosis of non-lynch hereditary colon cancer syndrome \[familial adenomatous polyposis (FAP), MUTYH-associated polyposis (MAP), Peutz-Jeghers syndrome (PJS), juvenile polyposis syndrome (JPS), PTEN, POL\] - ADDITIONAL STOOL EXCLUSIONS: - Bowel prep \< 7 days prior to stool collection - Oral or rectal contrast given within 7 days prior to stool collection - Removal of more than 50% of colon or presence of ileostomy - Enteral feeds or total parenteral nutrition (TPN) - Diagnosis of inflammatory bowel disease Always talk to your doctor about whether this trial is right for you.