David Downs discovers first-hand the surprising past and innovative future of chemotherapy
I vividly remember the first Gulf war in the early 1990s. It was tragic, yet entrancing. I recall sitting at home watching on TV as US cruise missiles were launched and then, with pinpoint accuracy, they hit targets hundreds of miles away. TV viewers the world over were turned into voyeurs, watching on from the safety of our living rooms as we saw grainy green footage of tomahawks going through the window of what we were told was a military facility, then a flash of white light as it destroyed its target.
That was over 25 years ago, and the technology in the military sector has only gotten more accurate. Not always for the most noble of purposes, sure, but one has to marvel at the engineering and science behind the destructive power and pinpoint accuracy.
I was reminded of all this as I researched cancer drugs. Over the last few months I have had the misfortune of being quite ill with a large, cancerous tumour in my abdomen, which has meant I’ve been off work, and also had a bit of time on my hands. It’s exposed me to a lot of new things, one of the main ones being the chemotherapy drugs I’ve been prescribed.
Like the cruise missiles of the 1990s, these chemo drugs are amazing in their targeting abilities – and like the military hardware of a quarter century ago, they appear to only be getting more accurate.
I’m not an oncologist (or a haematologist – the cancer doctor for my particular type of cancer), so this is a layman’s perspective. I was very ignorant before my diagnosis about what chemotherapy was, and so too were many of my friends, as we’ve since sheepishly admitted to each other. No surprise though, just as there are hundreds of different types of cancer, all with their own nuances, so too are there many different treatment regimens all collectively called ‘chemotherapy’. The ‘chemo’ bit simply means ‘treated with chemicals’ – i.e. drugs.
I wanted to find out more than my previously uninformed view that chemotherapy is basically poisoning yourself, as some people and many internet-based naysayers would claim. Yes, there are some nasty side effects, but I wanted to understand more about how the underlying science worked. Was it really a scorched earth treatment, or something with more finesse? I was amazed to learn how exact the treatment really is.
Many of the chemo therapy regimens involve a combination of different drugs designed to work in concert with each other. Like a military operation, the drugs each attack the cancer cells in slightly different ways to achieve overall victory.
My particular regime is called ‘DA-EPOCH-R’, which stands for a Dose Adjusted (they change the dose regularly) mix of chemicals whose initials spell EPOCH-R. Etopiside, Prednisone, Oncovin) or Vincristine) Cyclophosphamide, Hydroxydaunorubicin (or doxorubicin), and Rituximab, if you must know.
Researching the science behind how these drugs are formed made me admire the clever scientists and physicians who designed them, and who continue to work in this area – my treatment is relatively new.
Some of the drugs interrupt the process of mitosis (cell division) – by either ‘getting in the way’ of the DNA as it breaks apart and then comes back together, or by stopping it breaking apart at all. Some ‘mark’ the cell so that the body’s own defences attack it. Others trigger the process of apoptosis – cell death – causing the cell to implode. They have also added an accelerant (in this case, a steroid) to make the whole process work faster. And they design the drugs to only work on the fast-growing cells in the body, which cancer definitely is. All of this is orchestrated to work in unison as different weapons for a common foe.
This isn’t indiscriminate poisoning, this is tomahawk missile-like targeting of the enemy base.
The origins of the drugs themselves vary also, in interesting ways – some are the results of experiments with mustard gas in World War II, one is derived from the wild mandrake plant (which I though was made up for Harry Potter, but is a real thing) and another came about after botanists noticed a red clay from a particular castle in the south of Italy seemed to kill local wildlife.
As good as all this is, it’s still not enough. The side effects of chemotherapy can be severe, as the drugs attack other fast-growing cells in the body. For some patients, this impact is too great, and they can’t tolerate treatment. Again, like the military, the search is always on for better treatments.
New Zealand is at the forefront of this work, with Kiwis working on cancer research and looking for cures and for better treatments. Professor Mike Berridge of the Malaghan Institute in Auckland, and his team do research into cancer cell energy metabolism and gene transfer. Berridge recently showed through his research that at least some sorts of cancer cells transfer information between cells using mitochondrial DNA (mtDNA) and if blocked, tumours don’t develop.
The mtDNA sits outside the core nucleus of the cell and only has 37 genes, as opposed to the tens of thousands in the main DNA of the nucleus. Mitochondria are the powerhouse of the cell, controlling most of the cell’s energy as well as its growth and death, and up until now scientists had believed that these genes stayed within cells, except during reproduction. It now seems that they can move between cells, and that this process is required for the growth of some sorts of cancer.
This previously unknown phenomenon is a major breakthrough. It opens up new areas of research and new therapies, utilising the new knowledge. Interrupting the cell messaging pathways is a yet-more targeted way of attacking cancer and while it’s not mainstream medicine yet, it shows great promise of becoming another advanced weapon in the medical arsenal for attacking a common enemy: cancer.
In the meantime, the trusty missiles of the current generation of weaponry seem to be doing a great job fighting my particular tumour. Notwithstanding the ‘collateral damage’ to my hair follicles, my particular tumour foe is being battled into submission by the targeted DA-EPOCH-R missiles my amazing doctors keep firing at it. Like the second Gulf War, it’s not quite mission accomplished, but it’s getting close.
David is a regular contributor to Idealog, currently battling cancer and preparing for the release of the upcoming book he has written with Dr Michelle Dickinson on New Zealand Technology called ‘No.8 Recharged’, to be published by Penguin books later this year.