Genetics and Scan

Scan

I was expecting nice clean lines and a cavity, maybe even no hole at all. All of the pot resection scans I’ve seen are removal of outlying tumours near or on the surface, they always seem to be very neat and tidy. Mine was nothing like that. Hopefully one day I can get a copy to show. It hasn’t been reported on yet so I don’t know the official verdict but it looked a mess to me. The cavity held different density fluids and there were some areas of uptake that were hopefully scar tissue rather than residual tumour. But I wouldn’t be able to tell the difference. They might not either. If it doesn’t grow it means its just scar tissue, if it does it’s tumour. I’ll have to update when I have an official report

Genetics

There are a couple important genetic factors to look for that affect prognosis.

Positive for IDH1 – most Gliomas that are grade 2-3 contain this gene, it is beneficial to survival to have it as not having it people tend to be classed as pre-glioblastoma. However in numerous studies I’ve read IDH mutation didn’t show survival benefits until treatment was present, so although I’m glad I’m not what would be termed pre-glioblastoma, I’m not sure what benefits I’ll see from this.

'IDH1 mutations are associated with a Janus headlike phenomenon; unfavorable prognostic influence on PFS turns into favorable impact on postrecurrence survival. A similar pattern of influence might exist for MGMT methylation. Cancer 2011;. © 2011 American Cancer Society.'

Negative for 1p19q co-deletion

This is the one I really wanted going into the meeting as it shows a longer survival curve to have it.

In a study published in clinical pathology journal last year, it is stated that it indicates longer survival and differentiates between oligo tumour from astrocytomas and ‘oligo mimickers’ and is probably the reason for oligos having improved survival over astrocytomas. However even 20% of oligos don’t have this gene deletion. In one study the difference in survival between grade 3 oligos with/without this gene deletion was 2 years and 12 years respectively, so a 6-fold increase in survival.

Not having this co-deletion means I think i have to accept that having the word oligo in front of my astrocytoma doesn’t really mean much in terms of prognosis. At least in my understanding that is limited to a few recent studies.

LOH in 10q

Loss of heterzygosity in 10q is normally associated with high grade tumours.

This is an extract from neuro-oncology 2010

The loss of chromosomes 1p–19q is the only prognostic molecular alteration identified in low-grade gliomas (LGGs) to date. Search for loss of heterozygosity (LOH) on chromosomes 1p, 9p, 10q, and 19q was performed in a series of 231 LGGs. Loss of chromosomes 1p–19q was strongly correlated with prolonged progression-free survival (PFS) and overall survival (OS) in univariate and multivariate analyses. LOH on 9p and 10q were associated with shortened PFS (P = .01 and .03, respectively) on univariate analysis. On multivariate analysis, LOH on 9p remained significant for PFS (P = .05), whereas LOH on 10q had a significant effect on OS (P = .02). Search for LOH 9p and 10q appears to be a useful complement to analysis of chromosomes 1p–19q in LGGs.

So loss of heterozygosity is good is great for 1p and 19q which didn’t happen for me

Loss of heterozygosity in 10q is bad a predictor of short survival time, my results say I have lost 10q.

Summary

I went into genetics full of hope. Believing I’d have one of the lucky genetic tumours, studies I’ve read suggested I had at least a 50% chance of this. But unless I’ve extremely misunderstood everything, it’s one of the worst. I’ve gone weak at the knees to say the least. This is easily the worst news I’ve had since being diagnosed. To be honest I think its hitting me harder than when I was diagnosed. My survival prognostics are not good. the opposite of all the genetics that i wanted happened.

the way i've mentally coped with having a brain tumour is telling myself it will be okay your young you'll have a favourable outcome compared to the averages. but when you find out your well below average in terms of prognosis, then they become an optimistic goal