why so much uncertainty?

Well, I woke up and thought, That's why there is no more definite answer! Sure, it's 4am.... but what better time to post to this blog?!

The question is: Why is there so much uncertainty about my current life expectancy?

I have GBM -- glioblastoma multiforme. This is a form of brain cancer, I have had a tumour removed from my brain. According to Wikipedia, "The most common length of survival following diagnosis is 12 to 15 months, with fewer than 3% to 5% of people surviving longer than five years."

Okay, I've set a personal planning horizon to three years plus one calendar month plus an unknown number of days... This works better -- for me & for Deb -- than simply saying, I'm gonna die!

But why are doctors not telling me, You're gonna die!

Incidentally: I misread that Wikipedia article. I must have looked at the image of a tumour -- my type of tumour -- in a "15-year-old male". I had the impression that GBM should hit early in life. That I'm lucky that it hit me so late... Well, no: "It most often begins around 64 years of age and occurs more commonly in males than females." 64, 65? Close enough... I'm right in the target zone :-)

Anyway, why are doctors not being specific about my life expectancy? Is there so much uncertainty? I hope they are not simply glossing over the truth. Bad enough that *I* do that...

Then I woke up and thought, Perhaps it needs a second look?

So here are my thoughts... today... right or wrong. Supported by an analogy, of course:

You come home from holiday and find that couch grass has invaded your garden. (Couch grass... that's the analogy for my brain tumour. In the "garden" of my brain.)

You pull up as much of the couch grass as you can see. (Brain surgery to remove the visible tumour.) You would like to clear the entire garden with a back-hoe -- but that would kill every other living plant as well. (Too much surgical cutting would destroy my brain.) You pull out as much couch as you can -- without damaging the surrounding non-couch plants.

Will the couch grass return? Probably, yes. How soon before your garden will, again, be overgrown with couch? Hard to tell... It all depends on how many couch grass runners are still hidden in the garden. There may be lots of runners near where you have been digging -- but hidden, deeper in the soil. There may be runners scattered round the garden -- away from your digging -- just waiting for the opportunity to start growing.

(See the analogy? There could be lots of GBM cells hidden, or too small to see, near the now-removed tumour. Other cancerous GBM cells could be scattered round the brain. In unexpected places.)

Then there's the weather... and the soil... and other unknown factors. Birds? worms? insects? wellington boots? seeds amongst the more-visible runners? It's hard to know exactly what spreads couch grass, or why it suddenly decides to grow very quickly in one area. (And, yes, it's the same with GBM. There are a lot of unknowns in its causes and reasons for growth.)

It's very hard to predict -- just from the one observation -- just where and when the couch grass will grow back. It's hard to predict just when your garden will be overgrown. Overgrown again, that is. So you do your best -- you start spraying. Selectively... You don't really want to kill every other plant in your garden.

(This is where I'm at now: spraying... Except that the GBM version is radiation and chemotherapy. Very careful targeting of known areas of GBM. Very selective application of the GBM "weedicide". Still not sure where or when a tumour will reappear.)

Six weeks' later... and you take another, very careful look around your garden. Is there another couch invasion? How quickly has it appeared? Where is it? in an isolated corner or near your most valuable, most delicate flowering plants? And that is what I am waiting on...

(Six weeks' later, I am waiting on another brain scan. My brain is out of sight, a scan is needed to look for tumours. What will be found? After six weeks' of treatment -- will a tumour have regrown? will new tumours be popping up all over my brain? how close to essential and valuable areas of brain will new tumours be appearing?! End of analogy...)

A GBM tumour grew in my brain. It has been surgically removed. Will it regrow? quickly or slowly? in the same location or somewhere else? One look inside the brain is not enough to tell, not with any certainty.

Chemoradiotherapy is intended to slow down regrowth. To prevent spreading, to limit the growth of new cancerous tumours. Is it working? Can't tell -- not without looking.

So, I'm having six weeks' of chemoradiotherapy. Then there will be a brain scan. What will it show?

If there are new tumours popping up all over the place -- then I'm doomed. If my brain looks all clear of tumours -- then something is working and I will continue with preventative chemoradiotherapy. What will be the actual situation? All will be revealed -- by the next brain scan... And at that point -- there will be more certainty.

At least, that's the way that I now understand it!

A bit of looking inside my brain, a few scans offering various views of my brain -- not enough to know what will happen over time. I -- the doctors -- need a second set of scans:

What is changing over time? Is it fast or slow? Localised or widespread? The six-week *rate of change* will indicate the future rate of change. Which will, in turn, indicate the rate at which my GBM will be attacking my brain.

A period of treatment... a second snapshot... then a better understanding of the future. With more certainty in my prognosis, in my (still statistical but more certain) life expectancy.

That is my new & current understanding. Right or wrong :-)

Another four weeks' of chemoradiotherapy, another brain scan... and I will know more.

Till then... Keep spraying for weeds. And be glad that the rest of the garden is still growing as well as ever :-)

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Dr Nick Lethbridge / Consulting Dexitroboper
Agamedes Consulting / Problems ? Solved
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​"No one said they wanted faster horses, they wanted less horseshit." … no, not said by Henry Ford

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