My Prognosis

What the Numbers Say, And What They Don’t

After surgery comes the waiting. The tests. The pathology reports. The meetings where doctors sit across from you with papers full of words you have to learn on the fly.

This is my attempt to share what I’ve learned about my specific diagnosis what the tumour actually is, what the treatment looks like, and what the statistics say. I’m sharing it openly because I think people who are going through something similar deserve real information, and because pretending the numbers don’t exist doesn’t make them go away.

What They Found

My tumour has a full name: Diffuse Astrocytoma, IDH1 R132H mutant, WHO grade 3.

That’s a mouthful, so let me break it down into what actually matters.

IDH-mutant is the most important part of that name, and it’s good news. IDH is a genetic mutation that changes how the tumour behaves — IDH-mutant tumours are generally slower growing and more responsive to treatment than their IDH-wildtype counterparts. It’s one of the key reasons my prognosis is meaningfully better than someone with a grade 3 or 4 tumour of a different type.

MGMT promoter methylated this one matters because temozolomide, the chemotherapy drug I’m on, works by damaging tumour DNA. MGMT is a repair enzyme that some tumours use to undo that damage. Mine is methylated, which means that repair mechanism is switched off. The chemo is more likely to do its job.

CDKN2A/B not detected this was a relief. The absence of CDKN2A/B deletion is significant because its presence would have automatically upgraded my tumour to grade 4. It wasn’t there. Grade 3 stands.

1p/19q not co-deleted this one confirmed the tumour type. A co-deletion would have indicated a different kind of tumour called an oligodendroglioma. Mine is an astrocytoma. Not better or worse, just different — and it means the treatment approach is different too.

The less straightforward part: the tumour was only partially removed. There is residual tumour, and it crosses the midline of my brain via the corpus callosum. That’s the unfavourable part of my picture, and I’m not going to gloss over it.

The Treatment

I’m currently on the CATNON protocol the current standard of care for my tumour type, and one that has shown clear survival benefit over radiation alone.

Here’s what that looks like in practice:

33 fractions of radiotherapy to the right hemisphere, with left hippocampal sparing. The hippocampus is the part of the brain most involved in forming new memories. By sparing it as much as possible during radiation, the aim is to reduce long-term cognitive and memory decline. That’s not a small thing.

Temozolomide (140mg daily) for 6 weeks, running concurrently with radiation. This is standard dosing — roughly 75mg per square metre of body surface area per day.

Then 12 months of adjuvant temozolomide at a higher dose — 150–200mg/m² for 5 days out of every 28, for 12 cycles. This is the long haul. A year of chemotherapy after radiation ends.

It’s a lot. But it’s also the treatment that gives me the best chance, and I’d rather know that than not.

The Statistics

I promised to be honest about this, so here it is.

For IDH-mutant grade 3 astrocytoma treated with the CATNON regimen:

5-year survival: approximately 70–75%
10-year survival: approximately 50–55%

My specific profile puts me in the better half of that range. The IDH mutation, the MGMT methylation, the absence of CDKN2A/B deletion, my age, and my functional recovery after surgery are all factors that work in my favour. The subtotal resection and the tumour crossing the midline work against me.

I want to be clear about what “median survival” means, because it’s easy to misread. It doesn’t mean everyone lives exactly that long. It means half of people in that group lived longer, and half lived less. Medians are population-level statistics. They don’t know me. They don’t know my surgeon, my treatment team, or what the next decade of research is going to produce.

Brain tumour research is moving. IDH-mutant tumours in particular are an active area — there are targeted therapies in trial right now specifically because of mutations like mine. The numbers I’ve been given reflect current data. That data will keep changing.

My specialists have told me though that I can expect 2 – 4 years as a general rule.

How I’m Holding This

I won’t pretend the statistics are easy to read. They’re not. There’s something deeply strange about sitting with numbers that describe your own survival probability as a percentage.

But here’s what I keep coming back to: I have a diagnosis with a known profile, a treatment plan backed by trial data, a surgical team I trust, and a set of favourable factors on my side. That’s not nothing. That’s actually quite a lot.

I’m not naive about what I’m facing. But I’m also not defined by it.

I’m still me. I’m still here. And I intend to stay that way for as long as possible.

I started rewatching Scrubs recently and Dr Cox said something that stuck with me

“Who cares, what statistics show? I mean, look at medicine. 80% of people with pancreatic cancer die within five years. 95% of appendectomies occur with zero complications. But we both know pancreatic cancer patients that lived, and appendix patients that, unfortunately, passed. Statistics mean nothing to the individual”