Colorectal Cancer

  • Diagnosis
  • Screening
  • Monitoring
  • Pharmacogenetics
  • Background
  • Lab Tests
  • References
  • Related Topics
  • Videos

Indications for Testing

  • Colorectal bleeding
  • Family history of colorectal cancer (CRC)
  • Clinical symptoms consistent with genetic/hereditary CRC (eg, MUTYH-associated polyposis (MAP), familial adenomatous polyposis (FAP), Turcot syndrome, Gardner syndrome)

Histology

  • All polyps removed should have histologic examination
  • Tissue is gold standard for tumor classification and further testing
    • KRAS, NRAS, BRAF, PIK3CA, PTEN  genes for prognostication and therapy decisions
      • PTEN by IHC is adequate testing
    • Microsatellite instability (MSI)
    • Mismatch repair (MMR) genes
  • Immunohistochemistry (IHC) – identifies MMR genes to guide MMR gene variant testing
    • All tumors should be tested – ~15% of sporadic CRC will have MSI
    • MLH1, MSH2, MSH6, PMS2 – MMR genes to test based on IHC results

Genetic Testing

  • MMR genes – should be considered for patients with newly diagnosed CRC
  • Gene testing for other more rare syndromes should be based on clinical presentation and family history, and in conjunction with genetic consultation (see NCCN guidelines – Genetic Familial High Risk Assessment: Colorectal, 2016; ACMG, 2015)

Prognosis

  • Anatomic location of tumor within colon appears to make a difference in overall survival as well as treatment response (Venook, 2016)
    • Left-sided tumors have better prognosis than right-sided tumors
  • MMR-deficient tumors – generally more favorable prognosis
  • Chromosomal alterations in 8p, 17p, 18p – associated with poor prognosis
  • Serum markers
    • Carcinoembryonic antigen (CEA) – measure prior to surgery (ASCO, 2006)
    • Other potential but not validated serum markers – carbohydrate antigen (CA) 19-9, CA242, circulating tumor cells (CTC), and tissue inhibitor of metalloproteinase-1 (TIMP-1)
      • CTC – independent predictor of progression-free and overall survival

Differential Diagnosis

  • Direct evidence from clinical trials concludes that fecal occult blood testing and flexible sigmoidoscopy reduces mortality from colorectal cancer (CRC); however, National Comprehensive Cancer Network recommends colonoscopy as the preferred screening method (NCCN, 2015)
  • Fecal occult blood testing
    • 50% of confirmed colon cancer cases have a negative fecal occult blood test (FOBT)
      • If patient is at risk, consider sigmoidoscopy or colonoscopy even in the presence of a negative FOBT
    • Positive FOBT mandates further evaluation (eg, colonoscopy)
  • Flexible sigmoidoscopy/colonoscopy – negative result does not rule out CRC
    • 90% sensitivity for lesions ≥10 mm
  • Septin 9
    • Biomarker for presence of CRC – high negative predictive values
    • Indicated for individuals ≥50 years who have an average risk and no family history of CRC
    • Not recommended for individuals with
      • History of previous CRC
      • Above-average risk (eg, family history of early onset CRC, hereditary CRC)
      • Previous polyp removal
    • Not intended as substitute for colonoscopy – may be useful as a complement to colonoscopy or for those who are unwilling or unable to have a colonoscopy (Choosing Wisely: 5 Things Physicians and Patients Should Question, American Society of Clinical Pathology, 2015)
      • Patients with elevated level should undergo colonoscopy to rule out CRC
    • Has been shown to detect cancers in cecum, ascending colon, transverse colon, splenic flexure, descending colon, sigmoid, recto-sigmoid junction, and rectum
  • Multi-targeted stool-based DNA testing
    • Emerging screening strategy that combines a fecal immunochemical test (FIT) with testing for altered DNA biomarkers in cells shed into the stool
    • Multi-targeted stool DNA testing has increased single-test sensitivity for detecting CRC compared with FIT alone
    • Reasonable alternative to other stool-based and visualization-based tests (USPSTF, 2016)
  • Serum carcinoembryonic antigen (CEA)
    • Elevated postoperative titer predicts tumor recurrence
    • Preoperative and postoperative monitoring for changes in concentration
      • Stage II or III tumors – measure every 3 months post operation, continuing for 3 years
    • Patient with metastatic disease – monitoring may help evaluate treatment response
  • Serum circulating tumor cell count (CTC) – in metastatic tumors, monitor disease progression and response to therapy
  • Others
    • Serum CA 19-9
    • Deletion 18q – not enough data to recommend use
    • 9q22.2-31.2 – promising new marker for hereditary colorectal cancers
  • UGT1A1 genotyping
    • Uridine diphosphate glucuronosyl transferase (UGT1A1) is responsible for clearance of irinotecan, a camptothecin analogue used in treatment of advanced colon cancer
    • Decreased gene expression may lead to drug toxicity (development of severe neutropenia)
      • Two gene variants responsible for 98-99% of genotypes in the Caucasian population – *1  and *28 (repeat TA sequence)
    • Routine reduction of dose in *28 homozygous is not recommended (Evaluation of Genomic Applications in Practice Working Group, 2014), but may identify patients at risk for adverse events and in need of closer monitoring
      • Selective genotyping based on patient preferences and predicted dosing
        • Higher doses associated with increased risk for certain genotypes that may not occur with lower dosing
        • Patients homozygous for *1 may tolerate aggressive treatment better than patients with the *28 variant
        • Patients homozygous for *28 may require a dose reduction to minimize dose-related adverse events
  • 5-fluorouracil (5-FU) sensitivity – genotyping of DYPD and TYMS
    • 5-FU is a fluoropyrimidine drug used in the treatment of colorectal cancer and other solid tumors
    • Pharmacogenetic variations in genes such as DPYD and TYMS may contribute to risk of toxicity or altered therapeutic benefits
      • DPYD variant or TYMS variant detected – most variants or mutations are associated with increased risk for 5-FU toxicity
        • Alternative chemotherapeutic agents, therapeutic drug monitoring, altered 5-FU doses, or increased surveillance for adverse drug reactions may be indicated

Colorectal cancer (CRC) is the third most common form of cancer in the U.S. It can be roughly divided into sporadic and hereditary types.

Epidemiology

  • Incidence – 43.7/100,000 (2012 U.S. SEER data)
    • Sporadic – most common form (~80%)
    • Hereditary CRCs
      • Hereditary nonpolyposis colorectal cancer (HNPCC), or Lynch syndrome – accounts for 2-4% of CRC cases in the U.S. (NCCN, 2015)
      • Familial adenomatous polyposis (FAP) – occurs in 1/10,000 live births
        • ~0.5% of total CRC cases
      • MUTYH (formerly MYH)-associated polyposis (MAP) – ~1% of Caucasians are predicted to carry an MUTYH gene variant
      • Other inherited syndromes
        • Peutz-Jeghers syndrome (PJS) – 1/200,000
        • Juvenile polyposis syndrome (JPS) – 1/100,000
        • Hereditary diffuse gastric cancer – rare
        • Serrated polyposis syndrome – uncommon
        • Cowden syndrome (multiple hamartoma syndrome)
        • Li Fraumeni syndrome –  rare
  • Age
    • Sporadic – median is 70 years
    • Hereditary – usually <60 years
  • Sex – M>F

Genetics

  • Sporadic
    • TP53 gene – mutated in ~75% of sporadic tumors
    • DCC gene – mutated in ~70% of CRCs
    • DNA mismatch repair (MMR) genes – variant or modification found in 15% of sporadic tumor

Risk Factors

  • Diet high in animal fats (Western diet)
  • Patients with metabolic syndrome
  • Inflammatory bowel disease (eg, Crohn disease, ulcerative colitis)
  • Adenoma/sessile serrated polyp (SSP)
  • First-degree relative with colorectal adenoma or invasive CRC
  • Ureterosigmoidostomy – carcinoma can develop ≥15 years post procedure

Pathophysiology

  • Most CRCs arise from adenomatous polyps
    • Villous adenomas transform into adenocarcinomas more frequently than tubular adenomas
    • Subset of adenocarcinomas develop from hyperplastic-appearing polyps, especially large, right-sided polyps
    • Adenocarcinoma arising in a polyp is considered malignant when it penetrates into the submucosa
  • Other less-common tumors can occur (lymphomasendocrinemesenchymal)

Clinical Presentation

  • Symptoms vary with tumor location – most are located in sigmoid colon and rectum
    • Cecum and ascending colon – tumors may be very large without causing obstruction
      • Anemia – a common presenting symptom
    • Descending and transverse colon – tumors tend to obstruct and cause annular lesions (apple core or napkin ring) with abdominal pain and bloating
    • Rectosigmoid – hematochezia, tenesmus, and narrowing of stool caliber
  • Sporadic tumors – usually single tumors
Tests generally appear in the order most useful for common clinical situations. Click on number for test-specific information in the ARUP Laboratory Test Directory.

Mismatch Repair by Immunohistochemistry 0049302
Method: Qualitative Immunohistochemistry

Limitations 

~10% of individuals with LS will have IHC tests that show normal staining of the MMR proteins

Because the correlation of MSI with IHC is not 100%, direct testing of MSI by PCR may be helpful

Occult Blood, Fecal by Immunoassay 2007190
Method: Quantitative Immunoassay

Limitations 

Less sensitive than colonoscopy

Microsatellite Instability (MSI), HNPCC/Lynch Syndrome, by PCR 0051740
Method: Polymerase Chain Reaction/Fragment Analysis

Limitations 

15% of sporadic CRCs are also MSI-H

Preoperative chemoradiation of rectal cancer may complicate IHC interpretation and/or decrease tumor mass and make MSI testing difficult

Evaluation of pretreatment biopsies will avoid this limitation

Epi proColon 2013906
Method: Polymerase Chain Reaction

Follow-up 

The Epi proColon test results should be used in combination with physician's assessment and individual risk factors in guiding patient management

Patients with a positive Epi proColon test result should be referred for diagnostic colonoscopy

Colon Cancer Gene Panel, Somatic 2011616
Method: Mass Spectrometry

Limitations 

Limit of detection – ~10% mutant alleles

Variants outside of codons tested will not be detected

KRAS Mutation Detection with Reflex to BRAF Codon 600 Mutation Detection 2001932
Method: Polymerase Chain Reaction/Pyrosequencing

Limitations 

Limit of detection – 10% mutant alleles

Oncogenic variants outside of codons tested will not be detected

A substantial portion of individuals with wild-type KRAS still fail to respond to anti-EGFR agents, implicating downstream variants

KRAS Mutation Detection 0040248
Method: Polymerase Chain Reaction/Pyrosequencing

Limitations 

Limit of detection – 10% mutant alleles

Oncogenic variants outside of codons tested will not be detected

 A substantial portion of individuals with wild type KRAS still fail to respond to anti-EGFR agents, implicating downstream variants

BRAF Codon 600 Mutation Detection by Pyrosequencing 2002498
Method: Polymerase Chain Reaction/Pyrosequencing

Limitations 

Limit of detection – 10% mutant alleles

Oncogenic variants outside of codon tested will not be detected

NRAS Mutation Detection by Pyrosequencing 2003123
Method: Polymerase Chain Reaction/Pyrosequencing

Limitations 

Limit of detection – 10% mutant alleles

Oncogenic variants outside of codons tested are not detected

Presence or absence of variants does not guarantee a positive response to anti-EGFR therapies

PTEN by Immunohistochemistry 2004115
Method: Immunohistochemistry

PTEN with Interpretation by Immunohistochemistry 2007031
Method: Immunohistochemistry

PIK3CA Mutation Detection 2004510
Method: Polymerase Chain Reaction/Pyrosequencing

Limitations 

Limit of detection – 10% mutant alleles

Oncogenic variants outside of codons tested will not be detected

Presence or absence of variants does not guarantee a response or lack of response to anti-EGFR therapy

Familial Mutation, Targeted Sequencing 2001961
Method: Polymerase Chain Reaction/Sequencing

Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations 2004915
Method: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Limitations 

APC gene

  • Deep intronic or regulatory region variants will not be identified
  • Breakpoints of large deletions/duplications will not be determined

Only two pathogenic MUTYH  gene variants will be tested – Y165C and G382D

Diagnostic errors can occur due to rare sequence variations

Negative result does not rule out FAP, APC-associated polyposis, or MAP due to the possibility of an undetectable variant in the specific gene(s) analyzed or a variant in another gene

Carcinoembryonic Antigen 0080080
Method: Quantitative Electrochemiluminescent Immunoassay

Limitations 

Not sensitive or specific enough for screening in the general population

MUTYH-Associated Polyposis (MUTYH) 2 Mutations 2004911
Method: Polymerase Chain Reaction/Sequencing

Limitations 

Not detected – large deletions or duplications; deep intronic, regulatory region, or promoter pathogenic variants

Only two pathogenic MUTYH  gene variants are tested – Y165C and G382D

Diagnostic errors can occur due to rare sequence variations

MUTYH gene variants of unknown significance may be detected

Circulating Tumor Cell Count 0093399
Method: Immunomagnetic Separation/Immunofluorescent Stain/Computer Assisted Analysis

Limitations 

CTC test is not as accurate as imaging in assessing whether a patient has progressive disease

Doxorubicin therapy patients – allow at least 7 days following administration of dose before testing

Not detected – CTCs that do not express EpCAM; CTCs that express EpCAM but not cytokeratins 8, 18, and 19

Serial CTCs should be performed in the same laboratory

MUTYH-Associated Polyposis (MUTYH) 2 Mutations with Reflex to Sequencing 2006307
Method: Polymerase Chain Reaction/Sequencing

Gastrointestinal Hereditary Cancer Panel, Sequencing and Deletion/Duplication, 16 Genes 2013449
Method: Massively Parallel Sequencing/Exonic Oligonucleotide-based CGH Microarray/Sequencing/Multiplex Ligation-dDependent Probe Amplification

Limitations 

Diagnostic errors can occur due to rare sequence variations

Not determined or evaluated – Variants in genes not included on the panel; deep intronic and regulatory region variants; breakpoints for large deletions/duplications; sequence changes in EPCAM gene

Deletions/duplications may not be detected in exon 9 in BMPR1A gene; exon 1 in CDH1 and MSH2 genes; exon 8 in PMS2 gene; exons 4, 6, and 7 in STK11 gene

Individuals with hematological malignancy and/or a previous allogenic bone marrow transplant should not undergo molecular genetic testing on peripheral blood specimen; testing of cultured fibroblasts or buccal specimen is required for accurate interpretation of test results; not all predisposing genes are analyzed

Guidelines

Allegra CJ, Jessup M, Somerfield MR, Hamilton SR, Hammond EH, Hayes DF, McAllister PK, Morton RF, Schilsky RL. American Society of Clinical Oncology provisional clinical opinion: testing for KRAS gene mutations in patients with metastatic colorectal carcinoma to predict response to anti-epidermal growth factor receptor monoclonal antibody therapy. J Clin Oncol. 2009; 27(12): 2091-6. PubMed

Allegra CJ, Rumble B, Schilsky RL. Extended RAS Gene Mutation Testing in Metastatic Colorectal Carcinoma to Predict Response to Anti-Epidermal Growth Factor Receptor Monoclonal Antibody Therapy: American Society of Clinical Oncology Provisional Clinical Opinion Update 2015 Summary. J Oncol Pract. 2016; 12(2): 180-1. PubMed

American Cancer Society Guidelines for the Early Detection of Cancer. American Cancer Society. Atlanta, GA [Accessed: June 2014]

American Society for Clinical Pathology. Choosing Wisely - Five Things Physicians and Patients Should Question. An initiative of the ABIM Foundation. [Last revision Feb 2015; Accessed: Jan 2016]

Duffy MJ, van Dalen A, Haglund C, Hansson L, Holinski-Feder E, Klapdor R, Lamerz R, Peltomaki P, Sturgeon C, Topolcan O. Tumour markers in colorectal cancer: European Group on Tumour Markers (EGTM) guidelines for clinical use. Eur J Cancer. 2007; 43(9): 1348-60. PubMed

Evaluation of Genomic Applications in Practice and Prevention (EGAPP) Working Group. Recommendations from the EGAPP Working Group: can UGT1A1 genotyping reduce morbidity and mortality in patients with metastatic colorectal cancer treated with irinotecan? Genet Med. 2009; 11(1): 15-20. PubMed

Hampel H, Bennett RL, Buchanan A, Pearlman R, Wiesner GL, Guideline Development Group, American College of Medical Genetics and Genomics Professional Practice and Guidelines Committee and National Society of Genetic Counselors Practice Guidelines Committee. A practice guideline from the American College of Medical Genetics and Genomics and the National Society of Genetic Counselors: referral indications for cancer predisposition assessment. Genet Med. 2015; 17(1): 70-87. PubMed

Lin JS, Piper MA, Perdue LA, Rutter CM, Webber EM, O'Connor E, Smith N, Whitlock EP. Screening for Colorectal Cancer: Updated Evidence Report and Systematic Review for the US Preventive Services Task Force JAMA. 2016; 315(23): 2576-94. PubMed

Locker GY, Hamilton S, Harris J, Jessup JM, Kemeny N, Macdonald JS, Somerfield MR, Hayes DF, Bast RC, ASCO. ASCO 2006 update of recommendations for the use of tumor markers in gastrointestinal cancer. J Clin Oncol. 2006; 24(33): 5313-27. PubMed

NCCN Clinical Practice Guidelines in Oncology, Colon Cancer. National Comprehensive Cancer Network. Fort Washington, PA [Accessed: Nov 2015]

NCCN Clinical Practice Guidelines in Oncology, Colorectal Cancer Screening. National Comprehensive Cancer Network. Fort Washington, PA [Accessed: Nov 2015]

NCCN Clinical Practice Guidelines in Oncology, Genetic/Familial High-Risk Assessment: Colorectal. National Comprehensive Cancer Network. Fort Washington, PA [Accessed: Jan 2016]

NCCN Clinical Practice Guidelines in Oncology, Rectal Cancer. National Comprehensive Cancer Network. Fort Washington, PA [Accessed: Nov 2015]

Protocol for the Examination of Specimens from Patients with Primary Carcinoma of the Colon and Rectum. Based on AJCC/UICC TNM, 7th ed. Protocol web posting date: Jan 2016. College of American Pathologists (CAP). Northfield, IL [Accessed: Nov 2015]

Schmoll HJ, Van Cutsem E, Stein A, Valentini V, Glimelius B, Haustermans K, Nordlinger B, van de Velde CJ, Balmana J, Regula J, Nagtegaal ID, Beets-Tan RG, Arnold D, Ciardiello F, Hoff P, Kerr D, Köhne CH, Labianca R, Price T, Scheithauer W, Sobrero A, Tabernero J, Aderka D, Barroso S, Bodoky G, Douillard JY, Ghazaly E, Gallardo J, Garin A, Glynne-Jones R, Jordan K, Meshcheryakov A, Papamichail D, Pfeiffer P, Souglakos I, Turhal S, Cervantes A. ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making. Ann Oncol. 2012; 23(10): 2479-516. PubMed

Stoffel EM, Mangu PB, Gruber SB, Hamilton SR, Kalady MF, Lau MW, Lu KH, Roach N, Limburg PJ, American Society of Clinical Oncology, European Society of Clinical Oncology. Hereditary colorectal cancer syndromes: American Society of Clinical Oncology Clinical Practice Guideline endorsement of the familial risk-colorectal cancer: European Society for Medical Oncology Clinical Practice Guidelines. J Clin Oncol. 2015; 33(2): 209-17. PubMed

Van Cutsem E, Cervantes A, Nordlinger B, Arnold D, ESMO Guidelines Working Group. Metastatic colorectal cancer: ESMO Clinical Practice Guidelines for diagnosis, treatment and follow-up. Ann Oncol. 2014; 25 Suppl 3: iii1-9. PubMed

General References

Bedeir A, Krasinskas AM. Molecular diagnostics of colorectal cancer. Arch Pathol Lab Med. 2011; 135(5): 578-87. PubMed

Chua W, Moore MM, Charles KA, Clarke SJ. Predictive biomarkers of clinical response to targeted antibodies in colorectal cancer. Curr Opin Mol Ther. 2009; 11(6): 611-22. PubMed

Cunningham D, Atkin W, Lenz H, Lynch HT, Minsky B, Nordlinger B, Starling N. Colorectal cancer. Lancet. 2010; 375(9719): 1030-47. PubMed

deVos T, Tetzner R, Model F, Weiss G, Schuster M, Distler J, Steiger KV, Grützmann R, Pilarsky C, Habermann JK, Fleshner PR, Oubre BM, Day R, Sledziewski AZ, Lofton-Day C. Circulating methylated SEPT9 DNA in plasma is a biomarker for colorectal cancer. Clin Chem. 2009; 55(7): 1337-46. PubMed

Fearon ER. Molecular genetics of colorectal cancer. Annu Rev Pathol. 2011; 6: 479-507. PubMed

Impact of primary (1º) tumor location on overall survival (OS) and progression-free survival (PFS) in patients (pts) with metastatic colorectal cancer (mCRC): Analysis of CALGB/SWOG 80405 (Alliance). J Clin Oncol. 34, 2016 (suppl; abstr 3504) [Accessed: Jul 2016]

Newton KF, Newman W, Hill J. Review of biomarkers in colorectal cancer. Colorectal Dis. 2012; 14(1): 3-17. PubMed

Ross JS. Clinical implementation of KRAS testing in metastatic colorectal carcinoma: the pathologist's perspective. Arch Pathol Lab Med. 2012; 136(10): 1298-307. PubMed

Sharma SG, Gulley ML. BRAF mutation testing in colorectal cancer. Arch Pathol Lab Med. 2010; 134(8): 1225-8. PubMed

Song L, Li Y. SEPT9: A Specific Circulating Biomarker for Colorectal Cancer. Adv Clin Chem. 2015; 72: 171-204. PubMed

Venook AP. Metastatic Colorectal Cancer: Lessons Learned, Future Possibilities J Natl Compr Canc Netw. 2016; 14(5 Suppl): 666-8. PubMed

Wilkins T, Reynolds PL. Colorectal cancer: a summary of the evidence for screening and prevention. Am Fam Physician. 2008; 78(12): 1385-92. PubMed

Yurgelun MB, Goel A, Hornick JL, Sen A, Turgeon DK, Ruffin MT, Marcon NE, Baron JA, Bresalier RS, Syngal S, Brenner DE, Boland R, Stoffel EM. Microsatellite instability and DNA mismatch repair protein deficiency in Lynch syndrome colorectal polyps. Cancer Prev Res (Phila). 2012; 5(4): 574-82. PubMed

References from the ARUP Institute for Clinical and Experimental Pathology®

Affolter K, Samowitz W, Tripp S, Bronner MP. BRAF V600E mutation detection by immunohistochemistry in colorectal carcinoma. Genes Chromosomes Cancer. 2013; 52(8): 748-52. PubMed

Burt RW, Leppert MF, Slattery ML, Samowitz WS, Spirio LN, Kerber RA, Kuwada SK, Neklason DW, Disario JA, Lyon E, Hughes P, Chey WY, White RL. Genetic testing and phenotype in a large kindred with attenuated familial adenomatous polyposis. Gastroenterology. 2004; 127(2): 444-51. PubMed

Campbell PT, Curtin K, Ulrich CM, Samowitz WS, Bigler J, Velicer CM, Caan B, Potter JD, Slattery ML. Mismatch repair polymorphisms and risk of colon cancer, tumour microsatellite instability and interactions with lifestyle factors. Gut. 2009; 58(5): 661-7. PubMed

Curtin K, Samowitz WS, Wolff RK, Caan BJ, Ulrich CM, Potter JD, Slattery ML. MSH6 G39E polymorphism and CpG island methylator phenotype in colon cancer. Mol Carcinog. 2009; 48(11): 989-94. PubMed

Curtin K, Samowitz WS, Wolff RK, Ulrich CM, Caan BJ, Potter JD, Slattery ML. Assessing tumor mutations to gain insight into base excision repair sequence polymorphisms and smoking in colon cancer. Cancer Epidemiol Biomarkers Prev. 2009; 18(12): 3384-8. PubMed

Curtin K, Slattery ML, Ulrich CM, Bigler J, Levin TR, Wolff RK, Albertsen H, Potter JD, Samowitz WS. Genetic polymorphisms in one-carbon metabolism: associations with CpG island methylator phenotype (CIMP) in colon cancer and the modifying effects of diet. Carcinogenesis. 2007; 28(8): 1672-9. PubMed

Curtin K, Ulrich CM, Samowitz WS, Bigler J, Caan B, Potter JD, Slattery ML. Thymidylate synthase polymorphisms and colon cancer: associations with tumor stage, tumor characteristics and survival. Int J Cancer. 2007; 120(10): 2226-32. PubMed

Eliason K, Hendrickson BC, Judkins T, Norton M, Leclair B, Lyon E, Ward B, Noll W, Scholl T. The potential for increased clinical sensitivity in genetic testing for polyposis colorectal cancer through the analysis of MYH mutations in North American patients. J Med Genet. 2005; 42(1): 95-6. PubMed

Ferrández A, Pho L, Solomon C, Samowitz WS, Kuwada SK, Knecht TP, Gilfeather M, Burt RW. An evidence-based, multidisciplinary approach to the clinical considerations, management, and surveillance of adrenal lesions in familial adenomatous polyposis: report of three cases. Dis Colon Rectum. 2006; 49(11): 1781-90. PubMed

Neklason DW, Thorpe BL, Ferrández A, Tumbapura A, Boucher K, Garibotti G, Kerber RA, Solomon CH, Samowitz WS, Fang JC, Mineau GP, Leppert MF, Burt RW, Kuwada SK. Colonic adenoma risk in familial colorectal cancer--a study of six extended kindreds. Am J Gastroenterol. 2008; 103(10): 2577-84. PubMed

Patil DT, Bronner MP, Portier BP, Fraser CR, Plesec TP, Liu X. A five-marker panel in a multiplex PCR accurately detects microsatellite instability-high colorectal tumors without control DNA. Diagn Mol Pathol. 2012; 21(3): 127-33. PubMed

Rowe LR, Bentz BG, Bentz JS. Detection of BRAF V600E activating mutation in papillary thyroid carcinoma using PCR with allele-specific fluorescent probe melting curve analysis. J Clin Pathol. 2007; 60(11): 1211-5. PubMed

Salk JJ, Bansal A, Lai LA, Crispin DA, Ussakli CH, Horwitz MS, Bronner MP, Brentnall TA, Loeb LA, Rabinovitch PS, Risques RA. Clonal expansions and short telomeres are associated with neoplasia in early-onset, but not late-onset, ulcerative colitis. Inflamm Bowel Dis. 2013; 19(12): 2593-602. PubMed

Samadder J, Neklason DW, Boucher KM, Byrne KR, Kanth P, Samowitz W, Jones D, Tavtigian SV, Done MW, Berry T, Jasperson K, Pappas L, Smith L, Sample D, Davis R, Topham MK, Lynch P, Strait E, McKinnon W, Burt RW, Kuwada SK. Effect of Sulindac and Erlotinib vs Placebo on Duodenal Neoplasia in Familial Adenomatous Polyposis: A Randomized Clinical Trial. JAMA. 2016; 315(12): 1266-75. PubMed

Samowitz WS, Albertsen H, Sweeney C, Herrick J, Caan BJ, Anderson KE, Wolff RK, Slattery ML. Association of smoking, CpG island methylator phenotype, and V600E BRAF mutations in colon cancer. J Natl Cancer Inst. 2006; 98(23): 1731-8. PubMed

Samowitz WS, Broaddus R, Iacopetta B, Goldblatt J. PCR versus immunohistochemistry for microsatellite instability. J Mol Diagn. 2008; 10(2): 181-2; author reply 181. PubMed

Samowitz WS, Curtin K, Wolff RK, Albertsen H, Sweeney C, Caan BJ, Ulrich CM, Potter JD, Slattery ML. The MLH1 -93 G>A promoter polymorphism and genetic and epigenetic alterations in colon cancer. Genes Chromosomes Cancer. 2008; 47(10): 835-44. PubMed

Samowitz WS, Curtin K, Wolff RK, Tripp SR, Caan BJ, Slattery ML. Microsatellite instability and survival in rectal cancer. Cancer Causes Control. 2009; 20(9): 1763-8. PubMed

Samowitz WS, Ogino S. DNA methylation in breast and colorectal cancers. Mod Pathol. 2008; 21(8): 1054; author reply 1054-5. PubMed

Samowitz WS, Slattery ML, Sweeney C, Herrick J, Wolff RK, Albertsen H. APC mutations and other genetic and epigenetic changes in colon cancer. Mol Cancer Res. 2007; 5(2): 165-70. PubMed

Samowitz WS, Wolff RK, Curtin K, Sweeney C, Ma K, Andersen K, Levin TR, Slattery ML. Interactions between CYP2C9 and UGT1A6 polymorphisms and nonsteroidal anti-inflammatory drugs in colorectal cancer prevention. Clin Gastroenterol Hepatol. 2006; 4(7): 894-901. PubMed

Samowitz WS, Wolff RK, Ma KN, Andersen K, Caan B, Slattery ML. Polymorphisms in insulin-related genes predispose to specific KRAS2 and TP53 mutations in colon cancer. Mutat Res. 2006; 595(1-2): 117-24. PubMed

Samowitz WS. Genetic and epigenetic changes in colon cancer. Exp Mol Pathol. 2008; 85(1): 64-7. PubMed

Samowitz WS. The CpG island methylator phenotype in colorectal cancer. J Mol Diagn. 2007; 9(3): 281-3. PubMed

Slattery ML, Curtin K, Sweeney C, Levin TR, Potter J, Wolff RK, Albertsen H, Samowitz WS. Diet and lifestyle factor associations with CpG island methylator phenotype and BRAF mutations in colon cancer. Int J Cancer. 2007; 120(3): 656-63. PubMed

Slattery ML, Curtin K, Wolff R, Ma KN, Sweeney C, Murtaugh M, Potter JD, Levin TR, Samowitz W. PPARgamma and colon and rectal cancer: associations with specific tumor mutations, aspirin, ibuprofen and insulin-related genes (United States). Cancer Causes Control. 2006; 17(3): 239-49. PubMed

Slattery ML, Curtin K, Wolff RK, Boucher KM, Sweeney C, Edwards S, Caan BJ, Samowitz W. A comparison of colon and rectal somatic DNA alterations. Dis Colon Rectum. 2009; 52(7): 1304-11. PubMed

Slattery ML, Herrick JS, Mullany LE, Valeri N, Stevens J, Caan BJ, Samowitz W, Wolff RK. An evaluation and replication of miRNAs with disease stage and colorectal cancer-specific mortality Int J Cancer. 2015; 137(2): 428-38. PubMed

Slattery ML, Wolff RK, Curtin K, Fitzpatrick F, Herrick J, Potter JD, Caan BJ, Samowitz WS. Colon tumor mutations and epigenetic changes associated with genetic polymorphism: insight into disease pathways. Mutat Res. 2009; 660(1-2): 12-21. PubMed

Sweeney C, Boucher KM, Samowitz WS, Wolff RK, Albertsen H, Curtin K, Caan BJ, Slattery ML. Oncogenetic tree model of somatic mutations and DNA methylation in colon tumors. Genes Chromosomes Cancer. 2009; 48(1): 1-9. PubMed

Szankasi P, Reading S, Vaughn CP, Prchal JT, Bahler DW, Kelley TW. A quantitative allele-specific PCR test for the BRAF V600E mutation using a single heterozygous control plasmid for quantitation: a model for qPCR testing without standard curves. J Mol Diagn. 2013; 15(2): 248-54. PubMed

Tomsic J, Senter L, Liyanarachchi S, Clendenning M, Vaughn CP, Jenkins MA, Hopper JL, Young J, Samowitz W, de la Chapelle A. Recurrent and founder mutations in the PMS2 gene. Clin Genet. 2013; 83(3): 238-43. PubMed

Vaughn CP, Baker CL, Samowitz WS, Swensen JJ. The frequency of previously undetectable deletions involving 3' Exons of the PMS2 gene. Genes Chromosomes Cancer. 2013; 52(1): 107-12. PubMed

Vaughn CP, Lyon E, Samowitz WS. Confirmation of single exon deletions in MLH1 and MSH2 using quantitative polymerase chain reaction. J Mol Diagn. 2008; 10(4): 355-60. PubMed

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Last Update: September 2016