Monday, June 3, 2013

Cancer Bombs: Drunken Genes

[Note: The first of the genetic testing and prophylactic mastectomy series can be found here. All previous (and subsequent) installments of this series can be found here.]


As I’m sure you can garner from the mission of this post series that the family history questionnaire I’d filled out passed whatever sundry requirements The Geneticists (yes, capitalized) had, and they called me in for a meeting.

An intake meeting.

Meaning: my family history was such that I was likely to be carrying a gene mutation that caused cancer, and they wanted to see me... (dun dun DUN!)

October 31st, 2011.

The first half of this meeting was a group session. It was a Power Point presentation by one of the genetic counsellors, teaching a mini lesson on genetics (a concise review of high school biology) and explaining the possible results that could be expected from the analysis of your DNA.

So here’s my mini, slapdash, completely non-canon-and-should-not-be-taken-as-gospel-or-medical-intelligence rundown...

DNA is a complex set of instructions that tells every cell in our body what it should do. The individual commands in that DNA are genes.

Everyone has two copies of each gene in their DNA. They inherit one from each biological parent. What those parents carry dictates what the offspring receives—unless something mutates along the way, the only possible DNA for the offspring is what their parents carry (but we’re not falling down the rabbit hole of chance mutations here—admittedly that falls into the realm of Darwinism and it’s actually pretty fun to hang out there... uh... unless you’re a Creationist.)

Geneticists have isolated the gene that can be the cause of breast cancer. This means that the organization of the gene’s code needs to be exact in order to function properly, and certain variations of that code have been proven through research to alter the function of the gene.

If that gene doesn’t do its job? Voil√†: Breast cancer.

They’ve isolated two genes related to breast cancer, actually. Their names are BRCA1 and BRCA2 (super creative, right? heh).

Now, remember learning about mitosis in high school? No? (No shame, I don't judge.)

Every cell in your body replicates itself as you age (seems to me skin cells regenerate themselves every three weeks—but my memory, she’s not the greatest). The four stages of cell division are prophase, metaphase, anaphase, and telophase.

Then there’s interphase (that’s the only one important in this post). It’s that sneaky phase that encompasses all other cell activity except actual cell division (growth, uh, and whatever else it is that cells do when they’re not busy dividing), and therefore is considered the “resting phase." There's still lots of activity going on, just not division, so it's a misleading term, for sure.

Anyhow. All cells are supposed to have a resting phase after division (mitosis). Geneticists have found two genes, BRCA1 and BRCA2, that tell mammary cells to have that rest after dividing (there may be more, we don’t know yet).

So guess what happens if you have a mammary cell with a gene that doesn’t properly tell that cell to rest after dividing?

It divides and divides and divides and divides... until you have a lump of irregular cells (read: cancerous tumor).

Makes total sense, right? So simple. Mind = blown.

Good news is that since we get two of these genes (one from each biological parent) as long as each cell has one gene that isn’t broken, then those cells know what to do and don’t divide and divide on their way to cancer central, tumor town, breast cancer.

But the thing is: cell DNA breaks down naturally over time. It’s called aging.

And many things can speed up that aging and breakdown: unhealthy lifestyle, hormone fluctuation, exposure to chemicals, environmental factors... those damn carcinogens you hear about everywhere...

(My personal favourite shit sandwich here is the hormones—try and find a woman whose hormones don't rage through a spectrum... unless she's had a hysterectomy, well, good luck. Heh.)

Geneticists figure a good mammary gene lasts 30-40 years before it breaks down through the aging process. So you’re all good if you’ve inherited two good genes and have a healthy backup gene sitting in the wings ready to take over.

Then that second unbroken gene will last another 30-40 years before it breaks, so we see a lot of naturally occurring (non-inherited) breast cancer in the age range of 60-80 years (30-40 years per good gene).

But you see, if you’ve inherited one good gene and one broken gene, you have no backup for those mammary cells when your only good gene breaks down due to age, hormones, carcinogens, environment, unhealthy lifestyle, whatever... a breakdown that will happen around that 30-40 year mark... or possibly earlier, if you’ve been exposed to a particularly toxic cocktail of environmental factors, lifestyle choices, overabundant hormones, carcinogens, and, um, aging (try and avoid THAT, I dare you. HaHA!).

This is why it’s considered inherited cancer—you haven’t received the needed backup like everyone else... instead you've inherited a death trap.

Whee...

But WAIT! It gets worse...

Consider that each mammary cell has its own genetic code, its own chance to break and malfunction.

These cells act independently of each other, and cannot rely on a different cell's DNA to tell them what to do. If their own gene has the wrong instructions, then they fail and function improperly, regardless of the fact that the cells around it are fine.

Now multiply this chance for failure by the number of mammary cells in the body... Everyone has millions, billions, fuck me if I know but it’s a huge number of mammary cells.

And each cell has those two genes (BRCA1 and BRCA2) with the capability of breaking down over time and becoming cancer...

Sweet, right? Riiiight...

So in the midst of this Power Point presentation that was designed to scare the living shit educate the dozen or so candidates in the room, I couldn't avoid the fact that I—very literally—had cancer bombs strapped to my chest.

Tick tick tick...

But I always knew this. I wasn’t fooled. I always knew I was doomed had inherited one of those goddamn broken genes, even before I understood the details.

I caught Mr Lannis’ eye and knew we were thinking the same thing...

Ka-boom.





The second half of the Power Point presentation was about the science behind genetic testing and what the answers would mean to us individually, case by case.

In order to do the gene sequencing and determine our genetic makeup, we needed to undergo a blood test.

Yes, that's all it takes.

The team of geneticists would map our DNA (perform gene sequencing), find our BRCA1 and BRCA2 genes, and compare them to how those genes should look.


There were three possible responses we’d receive from the test:

1. Negative. This sounds great, but really it’s the worst possible response for someone like me who is certain she’s carrying the defective gene. It means you’re negative for what they know causes cancer, and your BRCA1 and BRCA2 genes appear to be normal. Sound great, right? But here’s the catch: there’s a huge chance that scientists haven’t discovered other genes that affect breast cancer. Which means you might be carrying something they haven’t researched yet...

Just because you look fine (genetically) doesn’t mean you are fine. You have no proof you aren't a walking time bomb, and worst still: there's absolutely nothing they can do to help you.


2. Positive. Your genetic code matches what they know causes breast cancer. Sounds horrible at first, but it’s in fact the best outcome, as it means all the proactive treatment doors are flung wide open with promise. Sure, you might want to rethink what you’re passing on to offspring, but it’s the result with the longest possible lifespan ahead of you, since you can opt to fight proactively.


3. Negative with unknown variants. This is the messy result. This would mean the genetic code you carry doesn’t match what The Geneticists know causes cancer (yay!), but it doesn’t look anything the way it should, either (boo!). Your gene might be missing pieces of code, or the sequence might be mixed up, or duplicated, or reversed. Basically drunk.

This particular result of the test is... iffy... your messed up gene could be completely innocent and harmless (think: happy drunk!) or it might mean cancer down the road (think: that mean drunk who punches a hole in the drywall and then you wonder why you invited him to the party who is that guy and why is he wrecking my house?!).

The thing is: The Geneticists can't tell you which type of drunk your gene might be, because they haven’t researched it yet.

So your result would be put on file, and every 6-12 months you get to call back for updates on whether there’s been any breakthroughs concerning your drunken genes. Fun, right?


As soon as I heard about possibility #3, I caught Mr Lannis’ eye again (and may have snorted loud enough for everyone in the room to turn and look at me).

I’ve kind of sort of always fallen into the “medical exception” category my entire goddamn life (more on that in another post). If there was a fucked up weirdo result option, I knew where I'd land. I needed no blood test to tell me.

Mr Lannis squeezed my hand, because he knew, too, and we were in it together.

Drunken genes and cancer bombs.

Ka-boom.



[The next installment of this series can be found here.]

1 comment:

  1. Ah, yes, the "old (and possibly degenerative) eggs" spiel. Ugh. I don't envy you, Jane...

    ReplyDelete