Talk

Guest post from Lisa Kessler, DNA Direct’s Senior Genetic Counselor:

A recent article in the New York Times about red flags for hereditary cancer went into detail about specific findings in families. About 5-10% of cancers are thought to be strongly hereditary; for people who worry about their genetic risk, and who have a family history consistent with a hereditary cancer syndrome, genetic counseling and genetic testing can be extremely useful for decisions about personal and family health.

The article emphasizes the need for “intensive professional counseling” for individuals and families concerned about hereditary cancer risk, and I agree completely. I believe that genetic counseling helps people understand whether testing is medically indicated—and why, learn the benefits and limitations of testing, and understand why a certain family member might be the most informative person to test.

At DNA Direct, genetic counseling is required for people considering testing, both before and after hereditary cancer testing. Our counseling model provides people with an opportunity to learn about the testing to determine if it’s right for them — and for their families.

Most people aren’t familiar with the type of information discussed in a genetic counseling session. At DNA Direct, a pre-test genetic counseling session for someone considering BRCA1 and BRCA2 testing (genes for hereditary breast and ovarian cancer risk) includes, but is not limited to:

• discussion of personal medical history related to cancer
• drawing and interpretation of a 3-generation family health history diagram
• discussion of who in the family is the most appropriate member to test first
• background information about genes, chromosomes, and inheritance
• specific cancer risks associated with having a BRCA1/2 mutation
• options for cancer screening and prevention for people at high risk
• discussion of the benefits and limitations of BRCA testing, including psychological impact
• understanding the possible results of testing

If people proceed with testing through DNA Direct, a board-certified genetic counselor discloses the test results over the telephone. Then, clients can access a detailed, 5-chapter Personalized Report that reviews much of the information discussed during the pre- and post-test consultations. Because people often have questions after receiving their results, our genetic counselors are available to answer questions or simply for support, for all who test with us.

Not all patients can see a genetic counselor in person. Providing counseling by telephone gives us at DNA Direct the chance to increase access to genetic services in a responsible way, with a focus on ensuring reliable, easy-to-understand and informative results.

Lisa Kessler, MS, CGC
Senior Genetic Counselor

In the December 6th issue of Journal of the National Cancer Institute, researchers report that BRCA1 and BRCA2 mutations are more common than has been generally thought, and they seem to be associated with a greater risk for a number of cancers.

However, as lead investigator Dr. Harvey A. Risch told Reuters Health,

“For breast and ovarian cancer and perhaps other cancers as well, the lifetime risks for carriers of BRCA1 and BRCA2 mutations are not uniform — they depend on exactly which mutation is carried. Some mutations have higher risks and some have lower risks.”

The risk of cancer also appears to be related to the position of the mutation on the gene.

Abstract: Population BRCA1 and BRCA2 Mutation Frequencies and Cancer Penetrances: A Kin-Cohort Study in Ontario, Canada. Journal of the National Cancer Institute, Vol 98(23), 6 December 2006, pp. 1694-1706(13).

Technorati Tags: cancer, cancer risk, risk factor, brca1, brca2, genes, genetic risk, research news

Yesterday in San Francisco, thousands of people turned out for the Race for the Cure, a fundraising event put on by the Susan G. Koman Foundation for breast cancer awareness. Every year with few exceptions I have raced in honor of my mother, who was first diagnosed with breast cancer at age 35. She is a testament to what it means to be a survivor, zealously pursuing a life defined not by so many surgeries and recoveries but by her love for family, friends and personal interests. My mother has never considered herself a patient or a victim. She is, as my grandmother once put it, “a fireball that descended on Phoenix in 1960 and has been lighting things up ever since!”

As you know from the previous post, it’s also ovarian cancer awareness month. What does breast cancer have to do with ovarian cancer? A small percentage of people have hereditary forms of these cancers, which are caused by inherited changes in the BRCA1 or BRCA2 gene. These gene changes put you at increased risk for both ovarian and breast cancer.

Genetic testing is available, but it’s not for everyone — and it should be done in concert with genetic counseling.

Read more:

• How Breast & Ovarian Cancers Are Inherited
• The BRCA Genes and What They Do
• Considering Genetic Testing for Breast & Ovarian Cancer
• FORCE: Facing Our Risk of Cancer Empowered. FORCE is a nonprofit organization for women with increased risk of cancer due to family history and genetic status, and for members of families in which a BRCA mutation may be present.
• Genetic testing services at DNA Direct

Technorati Tags: breast cancer, ovarian cancer, hereditary cancer, inherited cancer, BRCA1, BRCA2, genetic testing, race for the cure, susan g koman foundation

Ovarian cancer awareness month has begun with good news at the intersection of cancer and genetic research. In the August issue of Oncogene, one of the world’s leading cancer research journals, Canadian researchers published a new model to identify ovarian cancer genes. This marks a big step toward improving treatment for the disease.

In a news release, Dr. Patricia Tonin, a cancer geneticist at McGill University Health Center in Montreal, says:

Our findings now provide tangible targets for effective drug development. Up to now, there has been little in the way of treatment options for this disease, which is one of the most lethal of cancers.

(more…)

Tumor typing - or testing the genetic signature of a cancer - is currently helping doctors distinguish between more aggressive and less agressive cancers. As a result, they can recommend treatment that will be most effective for individual patients. Now, researchers have developed a similar test for lung cancer.

The Lung Metagene Predictor (described in this week’s New England Journal of Medicine) scans non-small cell lung cancer cells’ genetic material for patterns that occur in cancers that are likely to reappear. It is 90 percent accurate, its developers said.

If a patient’s tumor shows such patterns, doctors can prescribe more aggressive treatments that are more likely to prevent a recurrence of cancer.

See Scientific American online for details

Lung cancer is the most common form of cancer, and it’s the number one cancer killer in the States. It also has one of the most easily preventable risk factors: smoking. (More statistics)

I had a fascinating discussion yesterday with geneticist Huijun Ring of UCSF about her current research into the pharmacogenetics and -kinetics of smoking. In the not-so-distant future, there may be a “smoking cessation” genetic panel that will tell us about the way in a person metabolizes nicotine and the medications (such as Zyban) that will be most effective in helping her quit.

Technorati Tags: lung cancer, treatment, genes, genetic test, recurrence, smoking, nicotine, pharmacogenetics, pharmacokinetics, buproprion

Scientists have discovered that a common genetic variant appears to increase the risk of prostate cancer in men who carry it. Specifically, it appears to confer a 60% greater risk of prostate cancer, and may also indicate a more aggressive cancer, when cancer occurs.

This discovery may also explain why African American men have higher rates of prostate cancer than others: This gene variation is about twice as common in blacks than it is in whites.

Kari Stefansson, CEO of deCODE ( www.decode.com) (the Icelandic company conducting the research), sums up why this discovery is so significant:

“This is one of the first genetic variants ever found to confer significant risk of a major cancer among the population in general. Most previously identified cancer genes have their effect on cancer risk only in families with a clear family history of cancer, or are only found mutated in tumors. This discovery is important from a medical standpoint because the only firmly established risk factors for the disease until now have been age, family history and ethnicity. As this variant also appears to be associated with the development of more aggressive prostate tumors, a diagnostic test for the variant may enable doctors to make more informed decisions as to how closely they should monitor those who are at high risk, and how aggressively they should treat the disease once it presents.”

This research is online in Nature Genetics, and will be in print in June

P.S. Interestingly, it’s not clear whether the heightened cancer risk comes from the genetic variant itself or from another that lies nearby on chromosome 8. Sometimes genetic discovery is like that — the gene variant that scientists have discovered may just be a marker that travels along with the gene that’s actually causing the risk. (Prof. John Hawkes offers an evolutionary perspective on this.)

Technorati Tags: prostate cancer, genes, human genome, DNA, risk factors, chromosome 8