tag:blogger.com,1999:blog-5424255638293718915.post2761924065223688313..comments2024-03-18T01:10:51.745-05:00Comments on neuropathology blog: MGMT status of glioblastomas: Is PCR or IHC better?Brian E. Moore, MD, MEdhttp://www.blogger.com/profile/17503916201692804693noreply@blogger.comBlogger8125tag:blogger.com,1999:blog-5424255638293718915.post-27118782329773971542010-05-27T11:19:20.957-05:002010-05-27T11:19:20.957-05:00This post is very nice and informative dude. I saw...This post is very nice and informative dude. I saw this site while browsing and think it may be relevant <a href="http://www.zell-arazim.com/" rel="nofollow">Psoriasis Treatments</a> . Keep up the good work!Psoriasis Treatmentshttp://www.zell-arazim.com/noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-65687432567834656982010-05-22T05:37:01.461-05:002010-05-22T05:37:01.461-05:00This just made my day much brighter. Thanks a lot...This just made my day much brighter. Thanks a lot. Something else I across was this http://www.imgenex.com . Take a look!<br /><br /><a href="http://www.imgenex.com" rel="nofollow">DNA Methyl transferase 3B</a>DNA Methyl transferase 3Bhttp://www.imgenex.comnoreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-29604882746469806962009-07-13T16:02:27.279-05:002009-07-13T16:02:27.279-05:00To Harold,
EGFR is another genetic test that can b...To Harold,<br />EGFR is another genetic test that can be done on brain tumor specimens, but it is not related to MGMT status per se. Although not mechanistically related, I am not sure if there is a statistical correlation between a patient's MGMT status and the same patient's EGFR status. I'll look into this issue and publish it as a separate blog post. Stay tuned... Regarding your second question, methylation is the most common way (but not the only way) that MGMT is inactivated.Brian E. Moore, MD, MEdhttps://www.blogger.com/profile/17503916201692804693noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-59859174243251252712009-07-13T00:22:54.732-05:002009-07-13T00:22:54.732-05:00Dr. Moore,
I'm sorry - I have a couple more -...Dr. Moore,<br /><br />I'm sorry - I have a couple more - I think related - questions.<br /><br />Is there a correlation between having the MGMT expression and being EGFRvIII positive?<br /><br />As is either of the two related to the "unmethalyated status" (if I'm using the term correctly?)haroldhttps://www.blogger.com/profile/10501191218266502054noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-85725537290289405342009-07-11T17:01:52.803-05:002009-07-11T17:01:52.803-05:00To Harold:
You have it exactly right. MGMT inactiv...To Harold:<br />You have it exactly right. MGMT inactivity is a good thing since MGMT would otherwise act to mitigate the effects of alkylating chemotherapeutic agents.<br />Best to you,<br />BEMBrian E. Moore, MD, MEdhttps://www.blogger.com/profile/17503916201692804693noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-80497663037419367322009-07-11T12:07:05.138-05:002009-07-11T12:07:05.138-05:00Hi, Dr. Moore,
I'm a GBM patient, not a docto...Hi, Dr. Moore,<br /><br />I'm a GBM patient, not a doctor.<br /><br />But, I have a question, if you don't mind answering it.<br /><br />Are you saying that when MGMT is not active in a tumor cell, it is good because, when the MGMT is active, it acts to removes the toxic methylguanine (whatever that is)?<br /><br />And this is one the benefits of Temodar - introducting the toxic methylguanine to the tumor cell?haroldhttps://www.blogger.com/profile/10501191218266502054noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-12657354450053533412009-07-06T10:04:29.422-05:002009-07-06T10:04:29.422-05:00All good points, Shipcolldoc. I should note that i...All good points, Shipcolldoc. I should note that infiltrating microglia do stain positively for MGMT on immunohistochemistry. Of course, rather than a reliable internal positve control, they are more likely to serve as a source of confusion. I know that the lab at Duke is working on this issue to see if it can be resolved.Brian E. Moore, MD, MEdhttps://www.blogger.com/profile/17503916201692804693noreply@blogger.comtag:blogger.com,1999:blog-5424255638293718915.post-11444538840301829352009-07-04T11:34:28.787-05:002009-07-04T11:34:28.787-05:00This is an interesting problem. There is no doubt ...This is an interesting problem. There is no doubt that the absence of MGMT expression in a high grade glioma connotes a better response to alkylating agent chemotherapy, especially Temozolomide, and probably a better long-term survival, but the published data also show that patients survive longer after radiation and chemotherapy even if their tumors express MGMT. So denial of treatment based on this test is not currently justifiable. That being the case, why do the test? Just for prognostic purposes? If we had better alternative treatments for high grade gliomas, I could see doing the test, but the current state of treatment doesn't support a clinical use of this test, whether IHC or PCR. As for the choice of tests, a negative IHC test could imply no MGMT expression OR failure of the test...one needs a reliable internal positive control, and that isn't always so easy either. So this remains a thorny ethical as well as practical clinical-pathological problem.--DCMshipcolldochttps://www.blogger.com/profile/09565353468786579592noreply@blogger.com