Dr. Lea Velsher's presentation from the 2013 Regional Oncology Conference

1. Genomics and Cancer
2013
How Genomics is
Changing Cancer Care

2. Faculty/Presenter Disclosure
Faculty: Dr. Lea Velsher
Advisor for Thunder Bay Genetics, NRGP
Physician at North York General Hospital, Genetics
Consultant in Genetics for Medcan Clinic
No conflicts of interest to declare

3. Learning
• Explain how the genetics of sporadic and
hereditary cancers differ
• Review features that suggest an inherited
cancer risk
• Discuss how genomics is being integrated
into cancer diagnosis and treatment

4. • Somatic Cells
• Germ Cells

5. Epigenomics
• Method for turning genes
‘off’ or ‘on’
• Reversible changes to
chromosomes
• No mutations in the DNA
code itself
• Environment may alter
epigenomics in cells
5

6. Epigenomics: regulating
expression of genes

7. Cancer is a genetic disease:
accumulation of mutations and
epigenomic changes in somatic cells
7

10. What patterns make us think of a
hereditary risk?
• Family history
• Personal history
• Pathology
• Unusual features

11. Family History
• 3 or more close
relatives with
cancer
• Cancer < 50 years
old
• Clusters of certain
cancer types
• Person has >1
primary cancer

12. 52 y.o. woman
Ductal Breast Cancer
Breast 60
Breast 75
Breast 38
3
2

13. Personal history
Colon cancer
29 years old

14. Pathology of the tumour
• Medullary Breast Cancer:
– Triple negative in premenopausal woman
– Consider BRCA1 testing
• Right sided mucinous undifferentiated
colon cancer
– Consider doing Immunohistochemistry for
Lynch (HNPCC)
• Medullary thyroid cancer
– Consider genetic testing for MEN2

15. Unusual findings
Multiple polyps on colonoscopy

16. Sebaceous Adenoma
• A benign neoplasm
of sebaceous
tissue, with a
predominance of
mature secretory
sebaceous cells.

17. Most cancer is sporadic

18. We can use the genomic changes
unique to the cancer for:
•Prognosis
•Therapy
•Screening

19. Genomic analysis of the tumour
cells
19

20. For ER +, Node - tumours

21. Screening for cancer using
cancer biomarkers

22. Genetic biomarkers as a screen
• Methylated Septin 9
test
– Blood test
– Looks at a gene that is
methylated in colon
cancer
– Sensitivity and specificity
maybe 60 - 85%

23. Targeted Therapy
Altered genome leads to
altered protein products
Target the cancer cells
based on their altered
genotype and phenotype

24. Pharmacogenomics
• Germ line polymorphisms
• Alter pharmacokinetics/dynamics of
chemotherapy agents
• UGT1A1 – homozygous SNP reduces
activity
– Increases toxicity of Irinotecan
24

25. E.G. CYP2D6 and Tamoxifen

26. What will the future hold?
• Cheaper, simpler, faster testing
• Incorporation of genomic markers into
risk algorithms
• Targeted ‘personalized’ treatment
based on genomic information
• Pharmacogenomic testing at point of
care

27. Summary Points
• All cancer is ‘genetic’ but only a small
number of cases are ‘hereditary’
• Genomic and epigenomic changes within
the cancer (somatic mutations) can be
used in screening and treatment
• A person’s genomic (germ line variations)
make up may influence treatment

28. Thank You