Introduction

Question 1

What is the cumulative lifetime risk of developing CRC in the US?

Answer 1

Approx 6%

Question 2

A family history of CRC increases an individual’s risk of developing CRC by how much/

Answer 2

Four fold

Question 3

What percentage of CRC cases occur in patients with inherited predisposition syndromes?

Answer 3

Fewer than 5%

Question 4

Most CRC cases are considered …………., although ….. to ….. percent of cases might have a familial basis despite the absence of a known …………. …….. .

Answer 4

Sporadic
20-30%
germline defect

Question 5

……………… studies reveal at least 20 ………. that elevate the risk of developing CRCs

Answer 5

GWA (genome wide association studies)

alleles

Question 6

List four subgroups of genetic factors that promote the development of CRC

Answer 6

1. Characteristic somatic mutations
2. DNA repair defects
3. Chromosomal instability
4. Epigenetic alterations