Direct evidence from clinical trials concludes that fecal occult blood testing and flexible sigmoidoscopy reduces mortality from colorectal cancer; however, NCCN recommends colonoscopy as the preferred screening method (NCCN, 2012)
Colorectal cancer is the third most common form of cancer in the U.S. and can be roughly divided into sporadic, familial and hereditary types.
Tests generally appear in the order most useful for common clinical situations
| Test name: Occult Blood, Fecal by Immunoassay |
| ARUP #: 2007190 |
| Methodology: Quantitative Immunoassay |
| Use: Screening test of choice for colorectal cancer |
| Test name: Septin 9 (SEPT9), Methylated DNA Detection by Real-Time PCR |
| ARUP #: 2003243 |
| Methodology: Polymerase Chain Reaction |
| Use: Screen for colorectal cancer; positive result indicates increased risk |
| Limitations: Do not use as screening in patients with previous history of colorectal cancer or in patients with family history of early onset colorectal or hereditary colorectal cancer Overall sensitivity (all stages) - 90% Sensitivity (stage I-II) - 87% Specificity - 89% |
| Test name: Mismatch Repair by Immunohistochemistry |
| ARUP #: 0049302 |
| Methodology: Qualitative Immunohistochemistry |
| Use: First-line screening test for Lynch Syndrome (LS) Use to determine mismatch repair deficiency and to direct additional molecular diagnostic testing for LS |
| Test name: KRAS Mutation Detection with Reflex to BRAF Codon 600 Mutation Detection |
| ARUP #: 2001932 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Use: Preferred test for determining anti-EGFR therapy eligibility Test detects mutations in codons 12, 13, and 61 If KRAS is not detected, BRAF codon 600 mutation detection will be performed |
| Test name: BRAF Codon 600 Mutation Detection by Pyrosequencing |
| ARUP #: 2002498 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Use: Detects activating BRAF mutations associated with anti-EGFR therapy resistance |
| Test name: NRAS Mutation Detection by Pyrosequencing |
| ARUP #: 2003123 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Use: Detects rare NRAS mutations associated with relative resistance to anti-EGFR therapy |
| Test name: PTEN by Immunohistochemistry |
| ARUP #: 2004115 |
| Methodology: Immunohistochemistry |
| Use: Detects loss of PTEN expression in tumor tissue Possibly associated with relative resistance to anti-EGFR therapy |
| Test name: PIK3CA Mutation Detection |
| ARUP #: 2004510 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Use: Detects activating PIK3CA mutations in exons 9 and 20 Exon 20 mutations may be associated with relative resistance to anti-EGFR therapy Exons 9 and 20 activating mutations indicate possible response to therapies targeting genes downstream of PI3K in the AKT/mTOR-signaling cascade |
| Test name: Familial Mutation, Targeted Sequencing |
| ARUP #: 2001961 |
| Methodology: Polymerase Chain Reaction/Sequencing |
| Use: Evaluate family members for a known family mutation A copy of a relative's laboratory test report documenting the gene and specific mutation(s) for which testing is requested must be submitted with the test order |
| Test name: HNPCC/Lynch Syndrome Deletion/Duplication |
| ARUP #: 2001728 |
| Methodology: Polymerase Chain Reaction/Multiplex Ligation-dependent Probe Amplification |
| Use: Evaluate family members for a known family mutation Detect mutations and large deletions in MLH1, MSH2, MSH6 or PMS2 genes |
| Limitations: For PMS2 testing, suspected deletions or duplication in exons 12-15 require sequencing to exclude pseudogene copy number variants |
| Test name: Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations |
| ARUP #: 2004915 |
| Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification |
| Use: Determine genetic basis for FAP Test at-risk family members with family history but no known familial mutation |
| Limitations: Do not use for identification of a known familial mutation |
| Test name: Familial Adenomatous Polyposis (APC) Sequencing |
| ARUP #: 2004863 |
| Methodology: Polymerase Chain Reaction/Sequencing |
| Use: Detect gene mutations related to APC-associated FAP Detects ~90% of APC gene mutations |
| Test name: Familial Adenomatous Polyposis (APC) Deletion/Duplication |
| ARUP #: 2004920 |
| Methodology: Polymerase Chain Reaction/Multiplex Ligation-dependent Probe Amplification |
| Use: Detect APC deletions and duplications related to APC-associated FAP |
| Limitations: Detects only APC gene mutations not identified by sequencing |
| Test name: MUTYH-Associated Polyposis (MUTYH) 2 Mutations |
| ARUP #: 2004911 |
| Methodology: Polymerase Chain Reaction/Sequencing |
| Use: Diagnostic or presymptomatic testing for MAP and MUTYH-associated polyposis |
| Limitations: Uncertain result means that a gene mutation was detected; it may be pathogenic or benign; clinician should rely on clinical findings and family history |
| Test name: Carcinoembryonic Antigen |
| ARUP #: 0080080 |
| Methodology: Quantitative Electrochemiluminescent Immunoassay |
| Use: Monitor tumor recurrence |
| Limitations: Not sensitive or specific enough for screening in the general population |
| Test name: Circulating Tumor Cell Count |
| ARUP #: 0093399 |
| Methodology: Immunomagnetic Separation/Immunofluorescent Stain/Computer Assisted Analysis |
| Use: Use in metastatic tumors in conjunction with clinical data and imaging Monitor disease progression and response to therapy when comparing baseline values to serially monitor response and assess prognosis Prognostic marker that provides information about progression-free survival and overall survival |
| Limitations: Results should be interpreted with caution if specimens drawn within 7 days of doxorubicin therapy |
| Test name: Microsatellite Instability (MSI), HNPCC/Lynch Syndrome, by PCR |
| ARUP #: 0051740 |
| Methodology: Polymerase Chain Reaction/Fragment Analysis |
| Comments: First-line screening test for LS |
| Test name: HNPCC/Lynch Syndrome (MLH1) Sequencing and Deletion/Duplication |
| ARUP #: 0051650 |
| Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification |
| Comments: Use in MSI carcinoma with suggestive IHC (loss of MLH1 and PMS2 proteins), absence of BRAF codon 600 mutation, and normal MLH1 methylation studies |
| Test name: HNPCC/Lynch Syndrome (MSH2) Sequencing and Deletion/Duplication |
| ARUP #: 0051654 |
| Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification |
| Comments: Use in MSI carcinoma with suggestive IHC (loss of MSH2 and MSH6 proteins) |
| Test name: HNPCC/Lynch Syndrome (MSH6) Sequencing and Deletion/Duplication |
| ARUP #: 0051656 |
| Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification |
| Comments: Use in MSI carcinoma with suggestive IHC (isolated loss of MSH6 protein) |
| Test name: HNPCC/Lynch Syndrome (PMS2) Sequencing and Deletion/Duplication |
| ARUP #: 0051737 |
| Methodology: Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification |
| Comments: Use in MSI carcinoma with suggestive IHC (isolated loss of PMS2 protein) Suspected deletions or duplications in exons 12-5 require additional sequencing to exclude pseudogene copy number variants |
| Test name: BRAF Codon 600 Mutation Detection with Reflex to MLH1 Promoter Methylation |
| ARUP #: 0051750 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Comments: Recommended reflex test for differentiating between LS and sporadic CRC in tumors showing loss of MLH1 If no BRAF mutation is detected, MLH1 promoter methylation is evaluated; evaluation can also help determine whether further workup for HNPCC is indicated |
| Test name: KRAS Mutation Detection |
| ARUP #: 0040248 |
| Methodology: Polymerase Chain Reaction/Pyrosequencing |
| Comments: Detects most activating KRAS mutations associated with anti-EGFR therapy resistance |
| Test name: 5-Fluorouracil (5-FU) Toxicity and Chemotherapeutic Response, 7 Mutations |
| ARUP #: 2007228 |
| Methodology: Polymerase Chain Reaction/Single Nucleotide Extensions/Fragment Analysis |
| Comments: Detect genetic variants influencing metabolism and action of 5-FU to identify people who may be at risk for drug toxicity |
| Test name: UDP Glucuronosyltransferase 1A1 (UGT1A1) Genotyping |
| ARUP #: 0051332 |
| Methodology: Polymerase Chain Reaction/Fragment Analysis |
| Comments: Detect irinotecan sensitivity in patients who will be administered these compounds |
| Test name: Solid Tumor Mutation Panel by Next Generation Sequencing |
| ARUP #: 2007991 |
| Methodology: Massively Parallel Sequencing |
| Comments: Prognosis/treatment of individuals with solid tumor cancers at initial diagnosis or with refractory disease |