1. Genetic Testing for Inherited Cancers
Cancer Genetics Service for Wales

2. Genetics in the Media

4. Sugar phosphate backbone
The DNA Double Helix
Sugar phosphate backbone
Base pair
Bases
Adenine (A)
Thymine (T)
Cytosine (C)
Guanine (G)
ASCO

5. There are two types of genetic changes or mutations:
those that are passed down from generation to generation (germ line mutations)
those that happen during the lifetime of a person and are not passed on to the next generation (somatic mutations).

6. Cancers that can be inherited:
Breast
Ovarian
Colorectal
Other cancers:
Single gene cancer syndromes (e.g. von Hippel-Lindau disease, retinoblastoma)
Rare cancer syndromes (e.g. Li Fraumeni syndrome, Cowden syndrome) where a variety of different cancers occur in the same family.

7. What other factors influence cancer?
Environment
Diet
Exercise
Availability of healthcare services (e.g. screening)
Sun protection
Safe sex
Only a minority (5-10%) of cancers are caused by a genetic mutation.

9. BRCA1-Associated Cancers: Lifetime Risk
Breast cancer 50%85% (often early age at onset)
Second primary breast cancer 40%60%
Ovarian cancer 15%45%
Possible increased risk of other cancers (e.g. prostate, colon)
ASCO

10. Decision Aids Decision Aids
GREEN: Breast Cancer Risk and Genetic Testing
Green M, Fost N, Becker J, Biesecker B, Laxova R, Cambone P, Newcomb P, and Newcomb P, Breast Cancer Risk and Genetic Testing (CD ROM). 1997, Wisconsin Alumni Research Foundation: Wisconsin.

11. Decision Aids
PREDICT
Bromberg J, Schneider KA, Patenaude A, Simmons J, and Corsini E, Predisposition risk education and Information about cancer testing PREDICT (CD ROM). 2003, inflexxion: Newton, MA.

12. Some common questions How is cancer inherited?
Can inherited cancers skip a generation?
If I look like my parent with cancer, does this make it more likely that I will get cancer too?
What does a genetic test actually involve?
I want a genetic test but have been told I cannot have one. What options do I have?