This is how it works. You get a form, on which you need to list your whole family history.
- Father’s side: Father, both his parents, and all his brothers and sisters.
- Mother’s side: Mother, both her parents, and all her brothers and sisters.
- All of your siblings (carefully distinguishing through which parent any half-siblings are related).
- Children, if you have any.
- Any other known relatives with relevant illnesses.
The genetic counselor to whom I was referred specializes in genetic counseling related to cancer. All of the questions on the form are geared toward determining whether gynecological cancer patients are likely to have a genetic susceptibility to other cancers, beyond the ones they have already had. You need to give your ethnic background, and then, separately, say whether you have any Ashkenazi Jewish ancestry (since Ashkenazi Jews are more likely to carry BRCA1 and BRCA2 mutations, which can predispose you to breast cancer). You need to say exactly which cancer each family member had, and at exactly what age the diagnosis came. And you need to say whether anyone has had more than a certain number of colon polyps. There’s also a space where you can add information. I filled in, here, all the relevant information I had from 23andme. (I don’t have the specific BRCA1/BRCA2 variants for which they test, but can’t rule out the possibility that I have others, and, for specific genes that they test, I’m at average risk for breast cancer and colon cancer. I specified the genes. 23andme reports exploratory research that I’m at elevated risk for ovarian cancer, and Promethease, fed 23andme data, says that I’m at elevated risk for endometrial cancer, probably also exploratory rather than well replicated and established research. In any case, endometrial cancer is what I’ve already had, and both my uterus and my ovaries are gone.)
The form needs to be sent in at least a week before your appointment. It will be converted to a family tree of circles and squares (to distinguish men from women), with shading for the ones who have had cancer.
You can bring a family member to your appointment, but, the hospital being at the other end of the county from where we live, Joel wound up not going.
The genetic counselor made short work of the question of whether my family might carry BRCA1 or BRCA2 genes. It’s unlikely. Absolutely no one shows up on my tree with breast cancer or ovarian cancer (since the cancer that spread to my ovaries started as endometrial cancer, it’s not so likely to be related to BRCA1/BRCA2), and I have no known Ashkenazi Jewish ancestry (some possible Sephardic Jewish ancestry doesn’t count).
It took more time to discuss whether I have Lynch Syndrome. Most endometrial cancer isn’t genetic, but, when it is, the most common cause is Lynch Syndrome, a genetic disorder that greatly increases your risk both of colon cancer and of endometrial cancer. There are three ways to test for Lynch Syndrome. First, there are the Amsterdam criteria, drawn from your family history. Second, there is a blood test, sometimes covered by insurance, that you can get from a company called Myriad. Third, they can test my tumor, which, it turns out, is still preserved at the hospital where it was removed, and will be kept there for years. Depending on what proteins are found in the tumor, I may or may not be likely to have a mutation of one of the four genes that, if mutated, can cause Lynch Syndrome.
Probably I don’t. Of all of my known relatives, only one uncle, besides myself, has a cancer that could possibly be related to Lynch Syndrome. Both of us were over 50 when diagnosed. The other family cancers (all occurring over the age of 50, and scattered among a set of people not all of whom are all that closely related to me) involve things like prostate cancer after the age of 85 and lung cancer in smokers over the age of 60, none of which is particularly significant if you’re looking for Lynch Syndrome. Dad’s multiple myeloma is probably not genetic. My family does not meet the Amsterdam criteria for being likely to have Lynch Syndrome.
Since testing the tumor is cheaper than taking the blood test, we’ve ruled out the blood test, and I get to take time to decide whether I want the test ordered on the tumor. I am putting that decision off until I have gotten my colonoscopy (as well as the written report from the genetic counselor). It may depend on how reassuring my colonoscopy results are.