Helpful Poisons

Cancer Research UK runs the Race For Life events, in which thousands of people from all walks of life, young and old, go out and run/walk to collect sponsorship money that’s donated to CRUK.

My supervisor [at the time of writing] – known in the building as one of the many PIs (Principal Investigators) who head the lab groups in the Institute we work in – went along with her 6 year-old daughter to go up on stage and thank people for participating.

I spoke to her about it a while ago and she told me how moved she was to see so many people come out to do their best on a Sunday morning, raising what money they can so enthusiastically. That she was very emotional surveying the sea of people in pink who had turned up to support each other and by raising that money, the scientists whose work aims to improve the treatments we have for cancer. That includes our lab. Plus the patients and their families who have to go through all of it.

Her daughter asked “why are all these people getting cancer?” – because they’re ill, she replied. I know I wouldn’t have understood such a concept at that age either so her determination is admirable.

What treatments we currently have are by no means ideal, although curing people of cancer does happen, contrary to popular belief. Sadly, googling that kind of thing will lead to lots of alt-med scam sites trying to tell people if they just eat raw peppers or rub hemp oil on themselves, their tumours will disappear. This is incredibly damaging for hopefully obvious reasons.

Tough Love

Some liver cells under the microscope, via wikipedia

Many chemotherapeutic drugs do cause horrific side-effects that make people feel very ill (of course, they are already seriously ill, but often we don’t feel it just from the disease itself). That’s because chemo, generally, is a form of poison. Alt-med proponents will often try to use that fact to make medicine sound bad to people they want to convince to use alternative products instead – sadly, people fall for it sometimes and this of course can have the worst consequence.

It is designed to kill living cells – the cancer cells. Anything that’s capable of doing that is likely to be unpleasant – remember that awful hangover? Your liver cells weren’t happy about that night, certainly. Fortunately most of us drink sensible amounts and don’t end up causing liver cancer when we’re enjoying the effects of alcohol.

Therein lies the important element – sensible amounts. The thing about drugs is that dose is everything – we’re finding this more and more in our research and perhaps I’ll write something about that at a later date.

Chemo drugs are carefully researched so that doctors know how much to give – how much should kill off the cancer most efficiently, while doing as little damage to the rest of the person as possible. The reason it often makes people feel ill is that there will be some damage – off-target effects, as they’re known – to normal tissues.

Much cancer research currently focuses on developing different drugs that will be entirely tumour-specific, eliminating or at least drastically reducing side-effects.

The thing about cancer cells is that they grow too quickly, they’ve gotten around the normal checks and barriers cells have that tell them to stop growing. Most cells don’t grow and divide in adults, they’re stable – with obvious exceptions like the lining of the gut, which is constantly replacing itself, the womb lining during the menstrual cycle, hair follicles…

And this is where the chemo side-effects come in. We target cancer cells’ ability to grow and divide a lot with these drugs, which unfortunately also go for some normal, non-cancerous dividing cells. Hence the hair loss effect that’s commonly seen (not with all drugs) and other painful/unpleasant things.

Now we have other treatments, for example radiotherapy targeted very specifically at the tumour with highly-specialised machines designed to minimise off-target exposure. Since the radiation used is also what can cause cancer (by damaging normal DNA – this is why you need to wear sun cream!), you don’t want to hit normal tissues with it any more than you absolutely have to. This is another alt-med favourite, ‘Cancer treatment gives you cancer! They want you to come back for more!!’ – it’s conspiracy theory at its best. There’s truth in it, but it’s been distorted away from reality.

Cause, simplified

If you can damage cancer cell DNA to the point where controls do kick in to destroy the cells, that’s a good way to kill tumours. But also, as I said, DNA damage is what causes cancer in the first place – it can come from various sources; hereditary cancers are mainly or entirely (example) due to mutations, that are passed down from previous generations, in particular genes that usually control cell growth.

Sporadic cases of cancer occur when there’s too much exposure to environmental carcinogens – be it sunlight (UV), cigarette smoke, alcohol or a combination of many subtle things – in that case the normal DNA is damaged in places that are important for maintaining cells’ in-built anti-cancer controls.

These two distinctions and the explanations are extremely simplified but hopefully making sense (?).

That’s why it’s still a numbers game – you’re not 100% certain to develop cancer even if you do things that do involve carcinogens and they may well have damaged your DNA, the point is that particular damage may not have occurred in places that affect the cells’ anti-cancer controls. Only if it occurs in genes that regulate cell growth in some way will it then possibly lead to cancer. Even then a number of other changes will need to occur in that population of cells that are now growing more for cancer to take hold.

Thing is, once you have some damaged cells that are growing more frequently, there are more chances for further DNA damage to happen as cells replicate. As the population gets bigger, the likelihood of the changes occurring in ‘bad’ places (i.e. further reducing the barriers and promoting growth) only increases.

So it’s a question of risk. It’s a gamble, if you want to smoke, for example. For me it’s absolutely not worth it – why spend money on something that does nothing but make you a drug addict (sorry, but that’s the case, for those who don’t insist it’s just a social thing and I can quit whenever I want) and increases the chance of your lung cells becoming irreparably damaged to the point where you may well lose a lung, or indeed your life? ‘Cool’ is very subjective, and those things don’t fall within my list.

At least the liver has alcohol dehydrogenase – but it’s still a question of dose, and ADH doesn’t apply in oesophageal, pancreatic or other cancer types.

Everything in moderation

Sure, we can’t obsess about everything every minute of the day – but there are sensible and easy things to be done to protect yourself and your family – for me, that’s completely worth it. Once you’ve watched a loved one die of cancer, whatever form, whether they had a hand in its occurrence or not – well, I don’t need to say more.

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The people who get up and raise money for institutes like ours all over the country, and the world, do contribute to the medical establishment’s ability to treat cancer. They deserve all our thanks.

Cancer is immensely complicated, we don’t fully understand it yet, but the more everyone does know, the better we can cope with it.

Maybe one day we’ll look back in wonder that so many lost their lives to such a thing; as we look now at little cuts and grazes when bacteria killed so readily, before we understood their existence and found (relatively) simple ways of dealing with them.

This seems a nice future to hope for.