Screening for genetic markers of cancer

[Nords]

Does anyone have any experience with genetic screenings for potential cancer markers? My source for this question seems a little too eager to market himself-- Dr. Oz, a recurring guest on "Oprah". He gives the impression that they're almost ready for prime time. I'd like to do some more research.

The question applies to our 15-year-old daughter's potential cancer risk. I'm trying to figure out what the genetic lottery could do to her before she's old enough to have to watch out for it. My mother died of breast cancer that started in 1977 (age 40), through two mastectomies and a lymphectomy, and eventually metastasized to her bones. She gave up the struggle in 1986. I don't know if the vocabulary even existed back then to determine if she passed on anything in her genes, let alone anything useful to my kid's health record. Various other cancers have shown up in three of my mother's four siblings, but there could be many causes other than genetic. My father has survived an aggressive form of prostate cancer so now I've been awarded early membership in the screening club. (Thank goodness for military medical care.) I have no idea if the genetics of a male cancer condition affect the inheritance of a female cancer condition.

However if the genetic lottery is relevant then our kid's already a "winner". My daughter is a spooky imitation of my mother. They look identical in photos taken at the same age and our kid shares way too many of my (and my mother's) habits, preferences, & memory tricks. If there's a genetic component to breast cancer then I sure hope it can't be passed down from grandmothers (through fathers) to their daughters.

I know that I can ask these questions of my father and my surviving aunt, but I don't want to wire-brush old scars for no benefit. Perhaps the best bet would be a consult with our kid's pediatrician and a follow-on to an oncologist, but I want to be ready to hold up my end of that discussion. Does anyone have any knowledge or experience in this area? Any other resources I could consult?

[Letj]

Nords I am not an expert in these matters. Rich will be along shortly to correct me but my understanding is that when it comes to genetic predispositions, it's a better guess to look at the immediate parents and not grand parents. I would think that something like breast cancer would be passed on through the female line and not the male.

[Rich_in_Tampa]

This article is helpful:

http://cms.komen.org/Komen/AboutBrea...s/rfapgenetics

It's a pretty complex area because there are so many false positive and false negatives. But it is true that family history is a factor which is important regardless of BRCA status. The good news is that your young lady doesn't really need to worry about this (other than the very, very rare exception) until she is into her 30s, at which time one can hope the screening tests will be more accurate. First degree relatives have the most effect, BTW, not grandparents.

I hope that genetic testing will lead to real benefits within the decade. Colon, ovarian, breast are promising.

[nphx]

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[ziggy29]

Originally Posted by Rich_in_Tampa

I hope that genetic testing will lead to real benefits within the decade. Colon, ovarian, breast are promising.

Agreed, provided it doesn't result in people being denied insurance (or charged an arm and a leg) simply because of the wrong genes, even when they are otherwise very healthy. This has the potential to save a lot of lives but also the potential of creating a Brave New World.

[Rich_in_Tampa]

Originally Posted by ziggy29

Agreed, provided it doesn't result in people being denied insurance (or charged an arm and a leg) simply because of the wrong genes, even when they are otherwise very healthy. This has the potential to save a lot of lives but also the potential of creating a Brave New World.

You're confusing gene-based diagnostic testing with genetic profiling for congenital and/or hereditary disease.

For the latter, the ethical and societal issues are profound, as you imply. For the former (testing), it is really no different from any diagnostic test like a chest x-ray, colonoscopy, etc. You submit a sample, it gets tested for genetic evidence of colon cancer, and you get a yes or a no.

Just wanted to make sure the distinctions are noted.

[Oldbabe]

Rich,
I understand you were making a distinction between different kinds of genetic testing, but I think what Ziggy was speculating about was the possibility that a genetic marker test that is positive, for breast cancer for example, on a health insurance application might lead the company to decline the applicant. In the current climate, I have no doubt that this would be the case.

[Rich_in_Tampa]

Originally Posted by Oldbabe

Rich,
I understand you were making a distinction between different kinds of genetic testing, but I think what Ziggy was speculating about was the possibility that a genetic marker test that is positive, for breast cancer for example, on a health insurance application might lead the company to decline the applicant. In the current climate, I have no doubt that this would be the case.

I agree with you. I was limiting my comments to diagnostic situations but the scenario you describe certainly could occur. Orwellian.

[Nords]

Originally Posted by Rich_in_Tampa

It's a pretty complex area because there are so many false positive and false negatives. But it is true that family history is a factor which is important regardless of BRCA status. The good news is that your young lady doesn't really need to worry about this (other than the very, very rare exception) until she is into her 30s, at which time one can hope the screening tests will be more accurate. First degree relatives have the most effect, BTW, not grandparents.

Excellent, thanks Rich.

I had no idea that inherited mutations played such a small part. It also seems odd that it'd be carried by the Ashkenazi, who have one of the world's longest lifespans.

But the best news of all is that there's no reason to bring this painful subject up with my elders.

[Rich_in_Tampa]

Originally Posted by Nords

Excellent, thanks Rich.

Nords, many academic centers and cancer centers have genetic screening programs where they review your specific details and then counsel you on whether to proceed with testing, how it might affect risk, and what the implications are. Sounds like something that could put everyone's mind at ease and if there is reason to test, it could be made in a careful manner.

Good that you are aware of these issues, and also that there is no cause for alarm.