Topic: comments requested about Genetic Testing

Jan 31, 2021 07:50AM moth wrote:

In case you haven't seen it yet, BCO has a large section on genetic testing: types, pros, cons & family implications etc https://www.breastcancer.org/symptoms/testing/gene...

I had Color Genomics done when I was diagnosed. https://www.color.com/learn/can-cancer-be-inherite... The test itself is simple - you literally spit in a cup. I had mine done through my cancer treatment center and I had an appointment with a genetics counsellor before and after sending away the kit.

Jan 31, 2021 08:53AM - edited Jan 31, 2021 09:00AM by Beesie

Martha, I'm sorry that your sister has been diagnosed with breast cancer.

A few things to know before you decide what to do next.

First, most breast cancer, as in 85% or more, is NOT genetic. Genetic breast cancers tend to develop at a younger age; a concern about the possibility of a genetic link to breast cancer usually comes up when the person diagnosed is in her 30s or 40s, or if there is a strong family history.

Second, genetic testing, if it is to be done, is always recommended for the patient first, before any family members. It is more logical to look for a possible genetic mutation in the person who already has cancer. If the patient tests positive, then family members can be tested for the one very specific mutation. If the patient tests negative, then there is no need for family members to be tested. Your sister, being 75, is right at the tail end of the prime years in which the average woman, without a genetic predisposition, is at her highest risk develop breast cancer. So unless there is a strong family history of breast cancer, it is unlikely that genetic testing would recommended for your sister and even less likely that insurance will pay.

Third, genetic testing doesn't necessarily provide a clear "yes" or "no" answer. While there are two well known breast cancer genes, BRCA1 and BRCA2, these days most breast cancer genetic testing involves a full panel of genes - possibly as many as 30 - that all could potentially increase risk of breast cancer by varying amounts. But many of these genes increase the risk of other cancers too. And with that many genes being tested, one possible result is a VUS, a variant of uncertain significance, which means that a mutation was found in the gene, but there isn't enough known yet about this mutation to know if it's harmless (most are) or if it increases risk. So sometimes genetic testing results in more questions than answers.

My suggestion is that you talk to a genetic counsellor before you do anything else. Given the age at which your sister has developed breast cancer, the likelihood that her cancer is genetic is probably very low, which would mean that her diagnosis is unlikely to increase your risk by much. That's not to say that you might not also develop breast cancer, as any woman could, particularly during the highest risk years from 60 - mid/late 70s.

If there is a lot of breast cancer in your family, or other related cancers (ovarian and prostate in particular), that would perhaps suggest a greater likelihood that your sister's cancer might be genetic. This is where a discussion with a genetic counsellor will be helpful.

As for my experience, I was diagnosed at 49. My mother was diagnosed just before me at age 80 but one of her sisters had been diagnosed in her late 40s, so that raised a bit of a red flag. According to my genetic counsellor, the bigger concern was all the prostate cancer on my father's side of the family. I had BRCA testing twice and tested negative both times; new mutations continue to be discovered so testing again after a few years is recommended for those with a strong family history who test negative. I had a panel test of another 20 or so genes. All negative. And I participated in a clinical trial in which I was tested for over 150 cancer genes; of those, I had one VUS for a gene that is very weakly linked to a condition that does increase breast cancer and prostate cancer risk - but the link with this gene is so weak that even if I'd tested positive, no additional screening or any other action would have been recommended. So, lots of cancer in my direct family, lots of genes tested, no answers, no action taken.

Jan 31, 2021 11:03AM exbrnxgrl wrote:

Hello,

I am sorry to hear of your sister’s diagnosis. Beesie makes a very good point, in that your sister should, if appropriate, be the one to have genetic testing first. Additionally, it seems that insurance may pay for your sisters testing but would be less likely, or possibly unlikely, to pay for your testing (unless your sister tested positive).

I was diagnosed over 9 years ago. At the time, only BRCA 1 & 2 testing was available. My paternal grandmother had breast cancer and my sister had a uterine sarcoma. I am also of Ashkenazi Jewish descent and we have a higher risk for BRCA. With that personal history, the genetic counselor recommended testing which was fully covered by my insurance. I think it was a Myriad Genetics test and it was negative. About 3 years ago I had the Ambry panel which tested for about 34 genes. Again, this was negative. I have daughters and granddaughters so this was a relief but note that as the patient, I was tested first.

If you have serious concerns about a genetic connection, which is not very common, speaking to a genetic counselor can help you determine whether testing is really warranted. It’s also bound to be cheaper than paying for testing out of pocket if insurance doesn’t cover it. All the best.

Feb 1, 2021 09:49AM - edited Feb 1, 2021 09:49AM by ShetlandPony

Also, it is important to look at all cases of cancer in a family when considering testing, as some different types of cancer may be related to the same genetic mutation. The genetic counselor may recommend a bigger panel than just BRCA or just breast cancer. In my family we see 1 colon, 2 skin, and 2 breast cancers, with a gene other than BRCA implicated. One of the breast cancers was premenopausal but one was postmenopausal, and both women have the genetic mutation. This information is important for our family members. Two others have been found to have the mutation and are following their genetics doctors' advice on appropriate actions and screening.