Colorectal Cancer (CRC)

Epidemiology and risk factors (CA Cancer J Clin 2018;68:7)

  • 4th most common cancer in U.S. men & women; 2nd leading cause of all cancer death
  • 90% of cases occur after age 50. ~75% are sporadic.
Genetic Risk Factors
Disorder CRC risk Pathophysiology Assoc Cancers
Hereditary nonpolyposis colorectal cancer (HNPCC or Lynch) ~80%
Most common hered. CRC (~3%). Mismatch repair mut (eg MSH2, MLH1). Dx: ≥3 family HNPCC cancer, 1 dx before 50 y, involves 2 gen. Typically right-sided. Endometrial, ovarian, stomach, urothelial, small wel & pancreas