Colorectal Cancer Overview (Screening, Diagnosis, and Treatment)
Colorectal cancer management should follow stage-appropriate treatment with molecular testing for metastatic disease and evidence-based screening starting at age 45 for average-risk adults. [1]
Evidence-Based Screening and Early Detection
Average-risk adults should begin colorectal cancer screening at age 45. [1]
Screening should continue through age 75. [1]
For ages 76 to 85, screening should be individualized. [1]
Diagnostic Workup and Staging Principles
Initial evaluation should use colonoscopy with biopsy to confirm diagnosis. American Cancer Society: Stages
Staging should be performed using TNM criteria. American Cancer Society: Stages
Staging typically requires cross-sectional imaging to assess for metastatic disease. RadiologyInfo: Staging of Colorectal Cancer
Molecular Testing for Treatment Selection in Metastatic Disease
For metastatic colorectal cancer, treatment selection should incorporate MSI-H/dMMR status, RAS mutation status, and BRAF V600E status. ASCO: Treatment of Metastatic Colorectal Cancer guideline
RAS wild-type status is required for use of anti-EGFR therapy in appropriate clinical settings. ASCO: Molecular biomarker considerations (RAS/BRAF/MSI testing context)
Metastatic Colorectal Cancer Treatment Algorithm
First-line systemic therapy should be selected by molecular subtype and primary tumor sidedness. ASCO: Treatment of Metastatic Colorectal Cancer guideline
Pembrolizumab is recommended for metastatic colorectal cancer with MSI-H or dMMR tumors. ASCO: Treatment of Metastatic Colorectal Cancer guideline
For metastatic colorectal cancer with microsatellite stable (MSS) / proficient mismatch repair (pMMR) tumors, chemotherapy plus targeted therapy is recommended based on mutation status and sidedness. ASCO: Treatment of Metastatic Colorectal Cancer guideline
For previously treated BRAF V600E–mutant metastatic colorectal cancer, encorafenib plus cetuximab is recommended after progression following at least one prior line of therapy. ASCO: Treatment of Metastatic Colorectal Cancer guideline
Adjuvant Therapy After Curative Resection (Stage II–III Colon)
Adjuvant chemotherapy is not routinely recommended for stage II colon cancer patients without high-risk features. ASCO guideline update: Adjuvant Therapy for Stage II Colon Cancer
Adjuvant therapy decisions for stage II colon cancer should use shared decision-making in risk-stratified settings. ASCO guideline update: Adjuvant Therapy for Stage II Colon Cancer
For completely resected stage III colon cancer, adjuvant chemotherapy duration with a fluoropyrimidine plus oxaliplatin should follow ASCO duration recommendations based on risk category. ASCO: Duration of Oxaliplatin-Containing Adjuvant Therapy for Stage III Colon Cancer
Oxaliplatin duration decisions are guided by disease-free survival and adverse-event risk, including peripheral neuropathy. ASCO: Duration of Oxaliplatin-Containing Adjuvant Therapy for Stage III Colon Cancer
Surveillance After Curative Treatment
A structured surveillance approach after curative treatment is recommended for colon and rectal cancer survivors. [2]
Surveillance colonoscopy is recommended at 1 year after initial surgery. [2]
Carcinoembryonic antigen (CEA) monitoring is optional when CT imaging is performed. [2]
Common “Latest” Pitfalls in Contemporary Practice
Anti-EGFR therapy should not be selected without appropriate molecular criteria, particularly RAS status. ASCO: Molecular biomarker considerations (RAS/BRAF/MSI testing context)
Immunotherapy selection in metastatic disease should not be made without MSI-H/dMMR evaluation. ASCO: Treatment of Metastatic Colorectal Cancer guideline
Overtreatment in stage II colon cancer should be avoided when adjuvant chemotherapy is not routinely recommended. ASCO guideline update: Adjuvant Therapy for Stage II Colon Cancer