Family History Crucial In Determining Cancer Risks
Family History Crucial In Determining Cancer Risks
By Nancy K. Crevier
Although the title of her talk, Tuesday, July 12, at Heritage Village was âWhat Every Jewish Woman Should Know About Hereditary Breast And Ovarian Cancer,â Ellen T. Matloff, director of cancer genetic counseling at Yale Cancer Center in New Haven, told the Hadassah Womenâs Chapter members and guests in attendance that the information was pertinent to every man and woman, no matter what his or her ethnic background.
Her talk focused on the ten percent of people diagnosed with a cancer that is passed down through family lines, called germline mutations; who is most at risk for these cancers; the use of genetic counseling; and who should consider counseling.
These cancers can be passed from either the mother or father to either the son or daughter, she said. âEven breast and ovarian cancers can be passed from fathers, and to sons as well as daughters,â Ms Matloff stressed. Adoption poses another problem, said Ms Matloff. People tend to forget, she said, that while their adoptive families may not show a history of cancer, if they do not have access to their bloodline relativesâ family histories, there is no way to know the actual risk factors. Genetic counseling and testing can be extremely beneficial in those instances.
Understanding risk factors and family history are vital in determining whether a person is a candidate for genetic counseling. Risk factors include:
*Early age onset of a cancer. For instance, the occurrence of breast cancer in a person under the age of 45.
*Multiple family members with cancer.
*Related cancers in a family; these may be caused by the same genetic mutation.
*Multiple primary cancers. Has one person had more than one cancer â breast, ovarian, pancreatic, etc?
*An unusual presentation of cancer. An example would be breast cancer in a man.
*Ethnicity. Those of Jewish ancestry have an increased risk over the general population for breast and ovarian cancers, although no ethnic background is clear.
*Pathology. When certain types of cancer are overrepresented in the family.
Using diagrams, Ms Matloff showed the group how cancer is passed down a family tree. Take down the medical histories of all family members, urged Ms Matloff, and draw a family history. That family history can be important when determining if genetic counseling is a good idea, and which family members should be tested first.
Two genes in particular are of concern to those of Jewish ancestry, Ms Matloff said. The BRCA-1, on chromosome 17, increases the risk of breast, ovarian, and prostate cancers. âThere are hundreds of mutations of BRCA-1,â said Ms Matloff.
A completely different gene on chromosome 13, BRCA-2 increases the risk of breast, ovarian, prostate, and pancreatic cancers. Three mutations on these genes, called the Jewish Ashkenazi mutations, increase those risks still more.
âOne in 43 American Jews carries a mutation, and those three mutations trace back to just three families in Eastern Europe,â she said. âIf you are of Jewish ancestry and have cancer or have cancer in your family, you are a candidate for testing,â said Ms Matloff.
âThe early onset breast cancer in the Jewish population is two times that of the general population,â said Ms Matloff. Eleven to 13 percent of the general population will be affected each year, for all breast cancers. For those carrying the BRCA-1 gene, that number rises dramatically, to 55 to 85 percent; for those with the BRCA-2 gene, 50 to 80 percents will be affected.
Only one to two percent of the general population gets ovarian cancer, a relatively rare cancer, Ms Matloff said, but those with BRCA-1 increase that risk to 15 to 60 percent, and with BRCA-2, 15 to 40 percent.
From a low of less than one percent of the population of males getting breast cancer in the general population, a person with the BRCA-1 or 2 gene ups the risk to five or ten percent.
Genetic counseling is important for a number of reasons, said Ms Matloff, including understanding family history. âSmall families with no history of cancer may still be carriers,â she noted. âIf there are not enough siblings, the mutation just may not be apparent.â Particularly, though, counseling serves as a means for the management of cancers.
âSurveillance, beginning in the early 20s for women, rather than waiting until the first mammogram at age 40, can begin. There is a much better success rate for treating cancer found in the early stage,â she said.
Those tested and found to have the genetic mutations can consider treatments to prevent cancer.
âChemoprevention, which is not the same as chemotherapy, means that healthy, high risk people can take medications to reduce the chance of getting cancer. One drug, Tamoxifen, can reduce that risk by 50 percent,â she said. Birth control pills, taken for up to seven years, are the most effective chemoprevention available for those at high risk of ovarian cancer, for which there is no good test.
Prophylactic surgery is a radical approach to ensuring that cancer will not occur. âSome people who know they carry mutations opt to have both breasts surgically removed,â Ms Matloff said. While it may seem a desperate measure, Ms Matloff said that she has witnessed instances in which the benefit to the patient was clear to her.
âI had a patient, a 35-year-old highly educated Jewish woman who tested BRCA-1 positive,â she told the group. While Ms Matloff struggled to share the news with the patient, she found the woman reassuring her, instead.
âShe suspected the test would be positive and had already set up surgery for a bilateral mastectomy. She told me it was the easiest decision she had ever made. Her grandmother had missed her motherâs wedding; her own mother had missed her graduation. âIâm going to be at my girlsâ graduations and weddings,ââ she said.
A few months later, the same woman opted to have her ovaries an fallopian tubes removed, as well. âFor some,â said Ms Matloff, âprophylactic surgery is the answer.â
There are many myths in the field of genetic testing that make people reticent to pursue it, said Ms Matloff.
âThe first myth is that if you have genetic testing, your health insurance will discriminate against you. I have never found this to be true,â she said.
Another myth is that insurance will not cover the cost of genetic testing, but that is far less common today.
âThere is a myth that only Ashkenazi Jews are at risk for the BRCA mutations, and that is not true,â said Ms Matloff.
Only if you would consider prophylactic mastectomy should you consider genetic counseling is another myth, she said, stressing again the positive points of managing high risk cancer patients through surveillance and chemoprevention.
âPeople think that if they have already had cancer, testing wonât help. It is as important for men as it is for women to be tested. It can help. It can help you, and it can help other family members,â Ms Matloff said.
âThere is a myth that the fatherâs history does not count. There is a myth that there is a need for genetic counseling only if you test positive for a mutation, and it is a myth that if you test negative for mutations, you are at the same general population risk for cancer,â she said.
There are many cancer genetic tests available, said Ms Matloff, dispelling yet another myth.
To determine if a person is a good candidate for genetic testing, Ms Matloff said that there are several good programs in Connecticut and New York City. To find an area counselor, she recommended visiting www.nsgc.org, or contacting Yale Cancer Genetic Counseling at yalecancercenter.org.
âIf I have one take home message for you,â Ms Matloff wrapped up her talk, âit is to try to have genetic counseling before surgery or before radiation treatment. Know your family history.â