Why Haven’t we Cured Cancer Yet? [Becky + Em]
[Em’s note: This legitimately happened to Becky – I was somewhere in Lounge too but was apparently otherwise occupied at the time.]
Lizard Lounge, Bristol, on a Saturday night. (Don’t judge me – this is going somewhere I promise!)
I’m pretty merry by this point, chatting away to people I’d just met, and the inevitable question of what we do in life comes up. So I say I’m a scientist.
Now, this tends to gets varying responses, but upon explaining I was a Biochemist I received a response I wasn’t prepared for…
“So why haven’t we cured cancer yet?”
Perhaps not the ideal situation for science communication – I’m fuzzy at best and Carly Rae Jepsen’s “Call Me Maybe” is threatening to tear holes in my ear drums, but I take a stab at it.
Definitely was not expecting that conversation in Lizard Lounge of all places, but then I guess as scientists we need to be prepared to do the occasional impromptu bit of sci-comm!
The next morning I reflected on this particular conversation. This person most likely isn’t alone in wondering why we haven’t solved the cancer mystery yet. Cancer is undoubtedly one of the most well-funded research areas in medical science – a lot of the scientific workforce is dedicated to working out a cancer cell’s every move and mutation and the media seems to tell us about “breakthroughs” in the field of cancer research every day. So why haven’t we completely nuked cancer yet? Here’s a few reasons…
Cancer isn’t like a bacterial infection where it’s “them vs. us”, where “they” are cell types completely different to our own which respond to the same drug very differently. You go down with tonsillitis and all you need to do is pop some pills for a week or so, feel a bit rubbishy for while and then carry on with your life. The antibiotics you were prescribed will wreak all kinds of havoc on the bacterial cells (assuming they aren’t a resistant sort…) but your mammalian cells will be barely affected.
In a similar way, we cannot eradicate cancer the way we eradicated smallpox in the 1970s because the threat comes from within and isn’t something you can immunise yourself against (see NOTE 1)
We often catch it too late:
When you’re checking for lumps (which you should!), the smallest you’ll probably notice is a 1cm3 sphere. This doesn’t seem too big but this sphere will already contain a billion cells and may already have acquired multiple mutations. For internal cancers like bowel and pancreatic, checking for lumps just isn’t possible so it’s usually only caught when you display symptoms, which may be too late.
There are lots of different types:
The five-year survival rate for cancers in general is 51%, but this figure for different types of cancer varies wildly. Each cancer is as individual as the person suffering from it, because of the interplay of genetics, lifestyle and pure bad luck.
There’s a childhood eye cancer called retinoblastoma for which treatment has a remarkably high success rate, with 98% of sufferers surviving it. It’s straightforward to diagnose and simple to treat because it’s pretty much always caused by the same mutation – that of a gene called Rb1 (see NOTE 2). For most cancers this is simply not the case and every mutation requires a different specific drug to work on.
There are many, many different genes that when mutated support uncontrolled growth and turn a cell cancerous. A cancer cell will generally have a few different mutations too. So treating cancer with targeted therapies can be less straightforward than it seems.
Awareness and funding:
This is important for the simple reason that people prefer to give money to things they know about. Cancer overall is an incredibly high profile disease (compare to dengue fever, which half a million people are dying of right now but few people seem to know about), but all cancers are not equal in this regard. 2006 statistics from the National Cancer Institute shows that breast cancer research received $13,452 per cancer death whereas lung cancer received only $1,630 per death. Research councils care about what the public cares about and this influences where the money for research goes.
What’s next – is there hope?
The truth is, I don’t know. While I hesitate to say this, I don’t think it’s realistic to think that we will have a wonder drug that will cure all cancer. The only “Achilles’ heel” of all cancer cells that we know about is the fact that they divide very rapidly when compared to normal cells (with a few exceptions like hair root cells and those in your gut lining, which explains why chemotherapy can cause severe nausea and hair loss). To move forward, we must start treating each cancer differently.
As we are living longer and longer, cancer is an inevitable part of people’s lives, either directly or indirectly. We all have the image of the scientist with the light bulb above their head saying “Eureka!”, but the reality is that science can be slow. The time between a lab making a cool discovery and a useful drug based on that discovery may span years, even decades. Just because a drug looks promising in the laboratory, doesn’t mean it will work when we eventually try it out in a human patient (see my earlier post).
But it’s not all doom and gloom. Think about the progress we have made. Survival rates for many different types of cancer have increased dramatically, thanks to many improvements in the treatment and diagnosis of cancer. We may well reach a stage in the future where we are very much on top of it.
There are also a lot of interesting things in the research pipeline, which I will talk about in another blog post (watch this space!). But for now, prevention and early diagnosis remain extremely important in our battle against cancer.
This article was a joint effort by Becky and Em
NOTE 1: If you’re wondering about the new cervical cancer jab – this works by immunising against a virus called HPV which mutates cells in a specific way which causes the cancer. So in this, and a few other cases, cancer is an indirectly contagious disease.
NOTE 2: The reason retinoblastoma is so rare is that both of your Rb1 genes must have the same mutation to get the disease – a very unlikely occurrence. Children who do suffer with retinoblastoma almost always have inherited one faulty copy from one of their parents so it only takes one more random mutation to bring about this form of cancer.