integrated clinical, radiological and molecular analysis". This was a large retrospective study including 228 adult low-grade glioma patients undergoing resection since 2003. The tumors were classed as A) IDH-mutant oligodendroglioma (with complete 1p/19q codeletion), B) IDH-mutant astrocytoma (no 1p/19q codeletion) and C) IDH wild-type (GBM-like).
The most important finding of this study was that complete resection (0 residual tumor), was most critical in the IDH-mutant astrocytoma group, as seen in the following figures. In the first figure shown below, even a small amount of residual tumor post-resection negatively affected survival for IDH-mutant low grade astrocytoma.
The next figure shows that complete resection also improves survival in low grade IDH-mutant oligodendroglioma, but the difference in survival between 0 residual tumor and small amounts of residual tumor is not a large as for the astrocytoma group as we saw in the first figure.
Wonder if this would have the same prognostic value for AA and GBM for that matter. There seems to be a major difference between DA and AA in survival rates/studies even though they are very similar in pathology and molecular diagniostics. The borderline or greyzone between high end DAs and low end AAs is very hard to distinguish. Off-topic: I find this blog and astrocytoma options one of the most valuable sources of information regarding my wifes newly diagnosed AA - In that process we get to meet and talk to the surgeon and the oncologist, but never the pathologist who does the actual diagnosis. Have some questions regarding the pathology report and interpetation of it. But how do I make a post, like I see other users do? - can only comment on exisiting posts and it feels a little like hijacking threads. BR Troels R
ReplyDeleteI think Stephen W (admin of this blog) has to add you on some sort of list so you can be able to post. I'm sure he will do so when he'll see your message.
DeleteAnd thanks for the study Stephen :)
Hello Troels, I need your email address to add you to the author list so you can start a new post. My email is on the User Information page at the top of the blog.
DeleteIn reply to your comment, IDH1 status is more informative of prognosis than tumor grade. For anaplastic astrocytoma grade 3, IDH non-mutant (wild-type) survival averages are similar to glioblastoma. For AA3 with mutated IDH, survival averages are similar to grade 2 astrocytoma, IDHmut. Conversely for grade 2 astrocytoma with non-mutant IDH (these are called "GBM like" in some studies), survival tends to be closer to GBM.
DeleteSo IDH (usually IDH1, only rarely is IDH2 mutated in gliomas) status is of paramount importance.
Unlike in grade 2 astrocytoma where the majority are IDH1 mutant, it is nearly half and half for grade 3 astrocytoma (almost half are IDH1 wild-type), and that is why the outcomes might seem significantly different for grade 3 versus grade 2, when IDH1 mutant and wild-type are not analyzed separately. The 2016 official tumor classification now recognizes IDH-mutant and non-mutant gliomas as being biologically distinct entities. Which means "anaplastic astrocytoma" is no longer a sufficient diagnosis - IDH status must be determined as well.
Please do post your questions on the pathology report.