Gene deletions?

connsteele
connsteele Member Posts: 232
in Brain Cancer #1
I've been trying to find older posts that included the term "gene deletions" and how it works with Temodar. Our son's doc has never mentioned that to us (son age 34, dx 4-13-11 AA3, inoperable) but I don't know enough about it to even ask the question. Does the test to determine this deletion have to be done at time of biopsy? Do I understand it right that if the patient has this certain gene deletion, that it means better response to Temodar? Would appreciate any info anyone can pass along.

Comments

  • mighty6
    mighty6 Member Posts: 47
    #2
    1p/19q gene deletion
    As far as I know,
    The 1p/19q gene deletion only predicts how well the tumor respond to chemotherapy. If one does not have that deletion, he/she is slightly less likely to have a positive response to chemo.

    Another important biomarker in brain tumor is MGMT methylation. This is from Wikipedia:
    MGMT methylation are associated with longer survival.A DNA test can be conducted on glioblastomas to determine whether or not the promoter of the MGMT gene is methylated. ... This DNA characteristic is intrinsic to the patient and currently cannot be altered externally.

    Both tests can be done with the tumor section taken by the surgery. I don't think checking those two are standard practice. You have to push your Dr. to order those. However, keep in mind, human body are so complicated, so do not lose your hope just because your son does not have preferred results with those two above.

    Take care!
    Jane
  • connsteele
    connsteele Member Posts: 232
    #3
    mighty6 said:

    1p/19q gene deletion
    As far as I know,
    The 1p/19q gene deletion only predicts how well the tumor respond to chemotherapy. If one does not have that deletion, he/she is slightly less likely to have a positive response to chemo.

    Another important biomarker in brain tumor is MGMT methylation. This is from Wikipedia:
    MGMT methylation are associated with longer survival.A DNA test can be conducted on glioblastomas to determine whether or not the promoter of the MGMT gene is methylated. ... This DNA characteristic is intrinsic to the patient and currently cannot be altered externally.

    Both tests can be done with the tumor section taken by the surgery. I don't think checking those two are standard practice. You have to push your Dr. to order those. However, keep in mind, human body are so complicated, so do not lose your hope just because your son does not have preferred results with those two above.

    Take care!
    Jane

    Benefit of knowing?
    Thanks for the reply. I wonder: what is the benefit of knowing if our son has these genetic markers. Would it change his treatment regimen? I will ask his doc about it, but I have a feeling that he will say it won't change his current treatment plan. His NO has been very vague about prognosis. Just says that he doesn't make projections.

    My husband's oncologist (my husband was dx with prostate cancer in 2003). A chest xray showed some "hot spots" in his lungs. The doc said it could be mets or could be scar tissue from exposure to histoplasmosis, which is endemic here in the Ohio. The only way to know for sure is to do a lung biopsy, which is invasive. And the results wouldn't change treatment plan, so why go through that. On one hand, I see his point. On another, we'd just like to know.

    So, we have a similar situation with our son. I have a strong feeling that his NO will say the same: knowing his genetic signature won't change treatment plan.

    I have conflicting feelings about knowing specifics re: prognosis and survival time. Is it really worth having a statistic thrown out there? Apparently, our son's NO doesn't think so. But from reading posts on this site, I see that others have had a timeframe given by their NO.
  • mighty6
    mighty6 Member Posts: 47
    #4
    connsteele said:

    Benefit of knowing?
    Thanks for the reply. I wonder: what is the benefit of knowing if our son has these genetic markers. Would it change his treatment regimen? I will ask his doc about it, but I have a feeling that he will say it won't change his current treatment plan. His NO has been very vague about prognosis. Just says that he doesn't make projections.

    My husband's oncologist (my husband was dx with prostate cancer in 2003). A chest xray showed some "hot spots" in his lungs. The doc said it could be mets or could be scar tissue from exposure to histoplasmosis, which is endemic here in the Ohio. The only way to know for sure is to do a lung biopsy, which is invasive. And the results wouldn't change treatment plan, so why go through that. On one hand, I see his point. On another, we'd just like to know.

    So, we have a similar situation with our son. I have a strong feeling that his NO will say the same: knowing his genetic signature won't change treatment plan.

    I have conflicting feelings about knowing specifics re: prognosis and survival time. Is it really worth having a statistic thrown out there? Apparently, our son's NO doesn't think so. But from reading posts on this site, I see that others have had a timeframe given by their NO.

    what is the best
    I understand your feeling totally. I, too had the same thinking before. Here is how I think now:

    . knowing the worst: get a general idea (from Dr. or anywhere you are conformable with) about stat. on prognosis, etc.
    . target for the best: Go for the more aggressive cocktail chemo treatments if the patient can take.Go for the most promising trials, especially the ones in immuno-therapy

    For the second one, you will need to know all the important bio-markers to be able to sort out the right options. yes, Drs do not agree among themselves regarding those issues.But I do know Drs. adjust their treatment plans based on those information.If our Dr. decide not to do so, we need to know why and if she/he made decision after lots of thinking.

    I am so sorry to hear about your husband is fighting too. it must be really hard for you, as a wife and a mom. With disease like this, nobody (even Drs.) knows for sure what is the best treatment plan for each individual. However, I know, just being there for them, is for sure one of the BEST ways.

    All the best to all the moms/wives/sisters/daughters/girl-friends on this sites. I've found tremendous love/care/strength among you all. I am proud to be one of you. I'm sure our loved ones know it and, God knows.

    Jane

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