Eric RosenthalUCSD Cancer Center
Is My Family At Risk?Genetic Counseling for
Familial Prostate Cancer
• What is genetic counseling?• What do we know about inherited risks for
cancer in general, and how does this apply to prostate cancer?
• What is an inherited cancer syndrome?• How do we diagnose and treat inherited
cancer syndromes?• What do we know about inherited cancer
syndromes that include prostate cancer?
Goals of Today’s Presentation
What is Genetic Counseling?Genetic Counseling as a Profession
• Health professionals with specialized graduate degrees and experience in the areas of medical genetics and counseling.
• Members of a health care team, providing information and support to families who have members with birth defects or genetic disorders and to families who may be at risk for a variety of inherited conditions. They identify families at risk, investigate the problem present in the family, interpret information about the disorder, analyze inheritance patterns and risks of recurrence and review available options with the family.
• Providers of supportive counseling to families, serving as patient advocates and refer individuals and families to community or state support services. They serve as educators and resource people for other health care professionals and for the general public.
• Participants in research activities related to the field of medical genetics and genetic counseling.
Adapted from the definition adopted by the National Society of Genetic Counselors, Inc. 1983
What are the components of the genetic counseling process?
• Determine patient concerns and pre-existing knowledge.
• Collect the family history.• Interpret the family history and explain the
relevant medical issues.• Suggest possible diagnoses and testing
options.• Discuss pros and cons of testing.• Arrange testing, if appropriate.• Interpret results.• Assist with arranging follow-up.
Prostate Cancer
1/3 of all newly diagnosed cancers in US men
2nd most common cause of cancer death
Overall lifetime risk is 16.7% (1:6)
Risk Factors for Prostate Cancer
Age
Over 70% of all prostate cancers are diagnosed over age 65
Risks for men at various ages:Less than 39 years old - .005%40 to 59 years old - 2.2%60 to 79 years old - 13.7%
Risk Factors for Prostate Cancer
Nationality
Prostate cancer is more common in North AmericaAnd Northwestern Europe than it is in Asia, Africa,
Central and South America
When men from Japan, where prostate cancer is relatively rare, move to the U.S., their rate increases. This is more pronounced for men who move when young, or who have spent more time in the U.S.
Risk Factors for Prostate Cancer
Race
In the US:AA > Caucasian > Hispanic > Asian/Pacific Islander
African-American men are diagnosed with prostate cancer 70% more often than men of other races and are more likely to be diagnosed at more advanced stages. Rates are also high in men of African descent in other countries, but data on prostate cancer in Africa is poor.
Risk Factors for Prostate Cancer
Family History
Men with a father or brother who has had prostate cancer have an increased risk. This
risk is higher when there are two or more affected relatives and if relatives have been
diagnosed at younger ages.
An identical twin of a man with prostate cancer has a higher risk than a non-identical twin.
Risk Factors for Prostate Cancer
Diet?Physical activity?
Ejaculation frequency?Vasectomy?
Environmental Exposures?
What do we know about how family history affects your risk
for cancer?
Most cancers are “sporadic”, meaning that they occur in people who do have any close relatives who have had that same kind of cancer.
Approximately 30% of cancers are thought to be “familial”. Cancer “runs in families” due to shared genes, environments and lifestyles
In general, a person who has a 1st degree relative with any cancer has a 2 to 3 fold increased risk for developing that cancer themselves. (Melanoma – 10 fold increase)
A subset of “familial cancer” is due to inherited cancer syndromes, thought to be responsible for 5 to 10% of all cancers.
What is an inherited cancer syndrome?
• A genetic condition causing a high risk for cancer.• Inherited cancer syndromes are caused by mutations in a
single gene. Most inherited cancer genes are tumor suppressors.
• Usually, the increased risk is for more than one type of cancer. Sometimes there other physical signs of the syndrome in addition to cancer.
• Most inherited cancer syndromes are inherited as dominant conditions. This means that the condition is inherited from a single parent, who is likely (but not certain) to have some signs of the condition himself or herself.
• Inherited cancer syndromes increase the risk for cancer. The environment still must contribute to the event that actually causes a cancer to develop.
Inherited Cancer Syndromes are Caused by Mutations in Tumor
Suppressor Genes
What are the signs that a family is affected by an inherited cancer
syndrome?• Multiple individuals in different generations affected by the
same cancer, or cancers that are known to be related.• Individuals diagnosed with cancer at unusually young ages.• Individuals who have had more than one kind of cancer, or
multiple primary cancers in the same organ.• Unusual or rare cancers.• Unusual numbers of precancerous lesions.• Other clinical features known to be part of an inherited
cancer syndrome.• Membership in an ethnic group known to have a higher
likelihood of having a specific inherited cancer syndrome.
Examples of some inherited cancer syndromes:
Hereditary Breast and Ovarian Cancer Syndrome – breast, ovaryCowden Syndrome – breast, thyroidHereditary Diffuse Gastric Cancer – stomach, breastRetinoblastoma – retinoblastoma, osteosarcomaHereditary Non-polyposis Colon Cancer – colon, uterus, ovary, ureterFamilial Adenomatous Polyposis – colon, stomach, thyroid, stomachMultiple Endocrine Neoplasia I – adrenal, pancreas, parathyroidMultiple Endocrine Neoplasia II – thyroid, parathyroid,
pheochromocytomaLi-Fraumeni syndrome – breast, osteosarcoma, leukemia, adrenalvon Hippel Landau – kidney, pheochromocytoma, brainGorlin Syndrome – skin, brainBloom Syndrome – leukemia, lymphoma, tongue, larynx, esophagus
Examples of inherited cancer syndromes with prostate cancer as a
major feature:
?
Hereditary Breast and Ovarian Cancer (HBOC) and Prostate Cancer
Mutations in the genes BRCA1 and BRCA2.More common in some ethnic groups than other.
Especially common in Ashkenazi Jews (2% of population).
For women, there is an 85% lifetime risk of breast cancer, and a 25 to 40% lifetime risk for ovarian cancer.
For men and women, there may be increased risks for stomach and colon cancer, and with BRCA2 mutations there is an increased risk for pancreas cancer and melanoma.
For men, there is a 6% risk for breast cancer with BRCA2 mutations.
Hereditary Breast and Ovarian Cancer and Prostate Cancer, cont
Generally accepted that men with BRCA1 and BRCA2 mutations have an increased risk for prostate cancer, particularly at younger ages. However, this has not been supported by all studies.
Various studies have found relative risks ranging from 0.39 to 4.6.
Recent study from Memorial Sloan-Kettering found no increased risk for prostate cancer in men with BRCA1 mutations, and a 4.8 fold increased risk with BRCA2 mutations.
Discrepancies between studies could be due to:• Different populations studied.• Different methods for the studies.• Actual risks probably vary depending on the family.
How do we find inherited cancer syndrome genes?
Through the cooperation of families (the bigger the better) with
multiple affected and unaffected individuals.
So, why don’t we have any genes for familial prostate cancer?
Prostate cancer is so common that it’s hard to distinguish between the sporadic and familial cases, even within the same family.
For a disease that is more likely to strike when people are older, it’s hard to find families with affected individuals in multiple generations.
If there are many different genes that are involved, it’s hard to know how to “pool” families that you suspect have the same genetic basis for their disease.
Candidate genes for familial prostate cancer
• HPC1 – May be the RNASEL gene (involved in interferon activity)
• HPC2 – Also known as ELAC2 • HPCX• CAPZB – Prostate and brain cancer• ELAC2 • PSA (prostate specific antigen)• AR (androgen receptor)• SRD5A2 – Steroid 5 alpha-reductase• CDKN1B – Also known as p27
Examples of ongoing research looking for familial prostate cancer
genesLinkage Analysis of Hereditary Prostate Cancer Families (Moffitt CC)
Studying the importance of HPC1 in families with more than one individual with prostate cancer. Recruiting men with prostate cancer diagnosed under age 55, with at least one other affected family member.
Genetic Epidemiology of Prostate Cancer (U Chicago)Collecting blood and tissue from members of high-risk families.
Familial Prostate Cancer (Mayo Clinic) Collecting blood and tissue from members of high-risk families.
Prostate Cancer, Longevity , Ancestry and Lifestyle (Albert Einstein)Blood and tumor samples from Ashkenazi Jewish men over 50 with and without prostate cancer.
The Search for Hereditary Prostate Cancer Genes (Wake Forest)Blood, questionnaires and medical records from Ashkenazi Jewish families with at least 3 1st-degree relatives with prostate cancer
Things to think about if you are being recruited for a genetics study
Is the study approved by an Institutional Review Board?
What is the purpose of the study?Who will profit from the results of the study?What am I expected to contribute as a participant?What are the possible risks and/or costs of
participating?Will I be informed of results from the research?Will I get my own personal lab results?Who do I talk to if I have questions?
If I could use genetic testing to find out if I had an inherited cancer
syndrome, would I want to know?
Provides information about risks for cancer in the future.
• More, and earlier, screening for early detection.• Prevention with drugs.• Prevention with lifestyle changes.• Prevention with prophylactic surgeries.• Resolution of uncertainty.
Other possible benefits of genetic testing for an inherited cancer
syndrome• Explanation for “Why me?”• May influence reproductive
decisions.• Helps identify people for clinical
trials.• May help improve treatment.
Risks of genetic testing
Risks of genetic testing
Can create excessive anxiety.
Can disrupt family relationships.
Could lead to discrimination in health insurance, life insurance, employment, or social relationships.
Summary
1. Family history is a significant risk factor for prostate cancer.
2. Progress in finding genes that are important in familial prostate cancer has been slow. This may be because there may be many genes involved, each contributing to a fraction of familial cases.
3. At this time, there is no genetic testing available clinically that can provide information about a man’s risk for prostate cancer.
4. It is almost certain that genes will eventually be found and clinical testing will be available. The availability of this testing will pose the same dilemmas we have encountered in genetic testing for other inherited cancer syndromes.