Network News - Winter/Spring 2010 - Canadian Breast Cancer ...

Other Risks
Rare families with BRCA1/2 mutations
may report an increased incidence of
pancreatic cancer and melanoma.
Inheritance
BRCA1 or BRCA2 mutations are
inherited in an autosomal dominant
pattern. That is, an individual who
carries one of these mutations has a
50% risk of passing it on to any child,
whether the child is male or female.
Monitoring in Individuals with a
BRCA1 or BRCA2 mutation
Note: May be modified for previous
surgery/treatment and current health
status
1. Monthly self-breast exam
(including males), from age 18
2. Twice yearly physician breast
exam (including males), from age
25
3. Yearly mammogram, from age
25-30. This can also be done on
males with breast enlargement
(gynecomastia). Based on the
mammogram, the radiologist
may recommend ultrasound
and/or MRI to some individuals
4. Twice yearly pelvic exam
with CA-125 measurement
and transvaginal ultrasound
for females, from age 35.
Unfortunately, this screening has
many false positives and false
negatives
5. Yearly digital rectal exam and
PSA measurement for males,
from age 50
6. Other screening as indicated by
family history
Prevention –
Surgery and Chemoprevention
The program is designed to offer cancer risk assessment,
genetic counselling and, when appropriate, arrange genetic
testing in patients at high risk for hereditary cancer (cancer
associated with mutations in known cancer susceptibility genes).
Contact:
By Phone: (780) 407-7333
By Fax: (780) 407-6845
By Mail: Medical Genetics Clinic
University of Alberta
8-53 Medical Sciences Building
Edmonton, Alberta T6G 2H7
Consideration of preventive
(prophylactic) bilateral total
mastectomy, with or without
reconstruction, may be considered
by women with BRCA1 or BRCA2
mutations. This reduces the risk
of breast cancer by up to 90%.
Prophylactic oophorectomy (removal
of the ovaries) should be considered
by women with BRCA1 or BRCA2
mutations, ideally between the
ages of 35-40, or upon completion
of child-bearing. The risk for
breast cancer is reduced by up to
50% by oophorectomy in the 30’s.
Oophorectomy, at any age, reduces
the risk for ovarian cancer by up to
95%. The remaining risk is for primary
peritoneal carcinomatosis (cancer of
the lining of the pelvic cavity).
As most BRCA1 tumours are hormone
receptor negative, it is unlikely that
the prophylactic use of Tamoxifen or
Raloxifene would be of benefit. Most
BRCA2 tumours are estrogen receptor
positive. Therefore, the prophylactic
use of Tamoxifen or Raloxifene may
be of benefit to carriers of BRCA2
mutations, particularly if they are post-
menopausal. This should be discussed
with the family doctor, gynecologist or
oncologist. •
References
National Comprehensive Cancer Network
(www.nccn.org).
Meta-Analysis of BRCA1 and BRCA2
Penetrance. J Clin Onc 25(11):
1329-1333, 2007.
Dr. Dawna M. Gilchrist, M.D., FRCPC,
FCCMG, DHMSA; has been on staff with
the Faculty of Medicine and Dentistry at
the University of Alberta (UofA) since
1990. Currently, she is a Clinician-
Teacher for UofA’s Department of Medical
Genetics and is an Adjunct Professor for
both the Department of Medicine and
the Department of Pediatrics. She also
serves as the Director for the university’s
History of Medicine Program. Dr.
Gilchrist first attended the University of
Alberta, graduating in 1972 in Biology,
and then continued there to obtain her
BSc. Specialization in Genetics (1979) and
M.D. (1983). Additionally, she received
her diploma in the history of medicine from
the Society of Apothecaries in London, UK
(2002). Dr. Gilchrist’s areas of expertise
include genetic disorders of adult onset;
particularly, genetic cancer, inherited
disorders of connective tissue and inherited
neurodegenerative disorders. She is a
fellow of the Canadian College of Medical
Geneticists.
In Edmonton, How to Obtain Referral to the
Edmonton Cancer Genetics Clinic
Clinic Protocol
1. Referral (letter preferred) by specialist or primary
care physician to the Cancer Genetics Clinic.
2. Preliminary workup by us – pedigree construction
and obtaining/reviewing medical records.
3. Appointment made with patient/family.
4. First appointment. Contents to include: assessment of
hereditary cancer risk in patient/family; discussion of
potential molecular testing including risks/benefits/
limitations; recommendations for clinical management.
Letter sent to patient(s), referring physician, and other
physician(s) as designated by patient.
12 Network News Winter/Spring 2010