The impact of complete resection most important for IDH-mut astrocytoma

There is an important new study, just published as an early preliminary manuscript online in Neuro-Oncology, called "The impact of surgery in molecularly defined low-grade glioma: an
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 also shows outcomes for IDH-mutant low grade astrocytoma, by various amounts of residual tumor post-resection.  (My snip only shows the first 3 images in the series). 

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.

The abstract is available here.  I can email the full study if anyone wants it.

Oligo 2 meeting with Patrick Wen

Hello,

I met with my NO Dr. Patrick Wen who is director of Dana Farber NO department yesterday. While I 'm stilling awaiting surgery, and therefore pathology, Dr. Wen feels my tumour is most likely an Oligo 2. It is 3cm in left left frontal lobe. I'm 35.

Dr. Wen told me most of these will recur around 10 years (for this location, size, my age, and depending on resection, etc). He also said he believes it's not unrealistic to think that by then there'll be an effective therapy to stop IDH mutant tumours from growing, essentially turning it into a chronic condition. He has a low grade patient (or more) who he was meeting with before me who has been on and IDH inhibitor for a year and a half now. Those seemed to be most promising to him.  He also mentioned PARP inhibitors and a number of other promising agents. He named about 6, including demethylating agents which seemed like a new idea.

I thought I'd share, because it was really helpful to me. He is very optimistic. He said that all of NO is focused on this mutation right now.


I know that's not useful to others without the mutation. Sorry.


I also thought I'd share his video addressing the recent WHO reclassification of these tumours. Most people on here  probably know this but on other blogs it seems a lot of people do not. Their type of tumour may have been essentially misdiagnosed all along.

http://www.practiceupdate.com/content/new-classification-scheme-for-low-grade-gliomas-clinical-implications/33428

It's my understanding that there is no longer a grey area. You must have co-deletions and IDH mutation to have an Oligo. Without the co-deletions it's an Astrocytoma and without IDH mutation it's a glioblastoma. I often see things that read "80% of Oligos have co-deletions (or IDH mutation)" but you can no longer be diagnosed with an Oligo if it doesn't have these characteristics. Grading is then related to not yet malignant (low grade) or malignant (high grade). I also believe they can lose their co-deletions, progressing to and Astrocytoma but are not likely to lose the IDH mutation. Maybe Stephen, or others, will be gracious enough to let me know if I have this correct.

I'm curious to know how likely Pligos are to lose their co-deletions upon first recurrence. I'm not sure this information is available.


Maria