Table 1. NHMRC CRC familial risk categories and screening recommendations (2005).

Risk categories	Category 1: At or slightly above average risk	Category 2: Moderately increased risk	Category 3: Potentially high risk
Definition of family history	• No personal history of CRC, advanced adenoma, or chronic ulcerative colitis • No confirmed close family history of CRC • One FDR or SDR with CRC diagnosed at age 55 or older • Two FDRs or SDRs diagnosed with CRC at age 55 or older but on different sides of the family	• One FDR with CRC diagnosed before age 55 • Two FDRs or 1 FDR and 1 SDR on the same side of the family with CRC diagnosed at any age	• Three or more FDRs or SDRs on the same side of the family diagnosed with CRC • Two or more FDRs or SDRs on the same side of the family diagnosed with CRC plus any of the following features: (multiple CRCs in family member, CRC before age 50, family member with an HPNCC-related cancer)
Screening recommendations	• iFOBT every 2 years from age 50 or • Flexible sigmoidoscopy every 5 years	• Colonoscopy every 5 years from age 50+ or 10 years younger than the age of first CRC in the family, whichever comes first	• Colonoscopy every 1 or 2 years from age 25, or 5 years earlier than the youngest diagnosis in the family

Abbreviations: CRC, colorectal cancer; FDR, first-degree relative; HNPCC, hereditary nonpolyposis colorectal cancer; iFOBT, immunochemical faecal occult blood test; NHMRC, National Health and Medical Research Council; SDR, second-degree relative.