Readers of this blog will know that I’m undergoing treatment for brain cancer. I’m fortunate enough to be able to access both radiotherapy and chemotherapy, as well as travel to Cologne for some personalised immunotherapy. This latter is interesting enough for a blog post of its own, but the combination of treatments is bringing its own challenges; a blog post covering these challenges needs some setting up, hence this post which is going to try to explain, from my layperson’s perspective, how my treatment is working so that I can explore the challenges in a later post. 

Radio and chemo therapy

The primary aim, of what I think of as my ‘standard’ cancer treatment, is to destroy the cancer cells. In my case this was done in three ways. First through surgery, cutting out as much of the tumour as was accessible. It’s never possible to completely clear all of the tumour cells away, so additional treatment is needed. 

Cancer cells are dangerous because they are dividing rapidly as they attempt to hoover up resources and take over the body. This gives them the disadvantage that they are less able to correct mistakes in DNA replication because they’re dividing so quickly and having to avoid the normal cellular safeguards which prevent mistakes. 

Treatment post surgery exploits the tumour’s disadvantage in two ways. Focused radiotherapy beams bombard the site of tumour, causing breaks in the DNA. Healthy cells which are damaged at the site are better able to repair themselves and carry on as normal. The remaining cancer cells aren’t. As a result the mistakes in the DNA replication get worse and the tumour cells start to die. 

The hope is that the radiotherapy beam is focused effectively on the tumour cells and none can escape. But because some will be able to, the radiotherapy is complemented by a small dose of chemotherapy. These drug molecules are taken up by the tumour cells and have the same effect. They damage the DNA, preventing the cells from replicating effectively and killing them. 

Once the radiotherapy is over, the dose of chemotherapy is increased for six months with the aim of finishing off any remaining tumour cells that hid from the radiotherapy beam and weren’t caught by the lower dose of chemotherapy. We’ll only know how successful all of this has been after an MRI which is going to happen every three months; as I noted in another post, the most positive result is a negative one. 

My treatment path wasn’t smooth sailing, and as the result of an allergic reaction I wasn’t able to finish my course of chemotherapy. This is one of the things I want to explore in a subsequent blog post, but it needs me to describe the immunotherapy I’m also undergoing. 

Immunotherapy

I’m (relatively) lucky to have been diagnosed now rather than five or ten years ago given how rapidly the science underpinning the chemo and radiotherapy has progressed. They are more targeted, and so more effective and less debilitating than they would have been then.

But ongoing advances in personalised medicine are equally exciting scientifically and medically, and I’m fortunate enough to be able to augment the ‘standard’ treatment with some cutting edge, if as yet unproven, medical science. 

So, while the theory behind the chemo and radiotherapy is to use the fragility of the tumour cells against themselves, the immunotherapy takes another approach. The tumour cells are part of me, but they are a mutant part of me. In order to avoid the normal cellular processes which stop excessive growth, they have to express novel proteins both inside and on their surface. Immunotherapy exploits this by priming my immune system to attack these new proteins being expressed by any tumour cells which have survived the radio and chemo therapy. 

The immunotherapy takes place in three phases. I’ve finished phase 1 and am in the middle of phase 2. The new year brings the final phase. 

Immunotherapy phase 1 – priming the immune system

The first phase of immunotherapy takes place in parallel with the radio and chemo therapies. Pam and I have been travelling out to Cologne once a month for a week’s worth of treatment all the way through the chemo phase of the treatment. 

Phase 1 of the immunotherapy is complicated and lasts for at least an hour a day. The first element is localised hyperthermia. This has me lying totally still for the hour, with a water filled pad pressing hard down on my right hand side temple, the site of the tumour. This pad heats up my head and bombards my brain with electromagnetic waves. 

Did I mention that the tumour cells are weak? They aren’t able to cope with the heat and electromagnetism and the aim is to break them up, spreading tumour fragments, including the novel proteins, through my blood. The hope is that the immune system will take notice and start to tackle these new proteins on any cells that remain in the brain. 

While the tumour cells are getting the hyperthermia treatment, I’m also being given a number of infusions to either support the breakdown of the tumour cells, or to augment the immune system. These infusions consist, in turn, of:

• Extracting a volume of my blood, mixing it with ozone to oxygenate it before putting it back into me – again tumour cells can’t cope with highly oxygenated environments in the same way that normal cells can; 
• An infusion of mannitol with the aim of breaking down the blood brain barrier for the next injection of;
• Newcastle’s Disease Virus, a bird flu which is mild in humans, but a challenge for tumour cells. The virus gets into the brain, infects the tumour cells which die spreading cell fragments through my blood for the immune system to pick-up and get to work on; and finally
• A mix of selenium, vitamins and sodium chloride; these strengthen my immune system. 

This phase runs in parallel with the chemo because this also helps to spread tumour fragments through my blood, so they work well together. It also continues through phases 2 and 3 described below. All through this I should be taking a number of drugs which complement the therapy and support the immune system. The allergic reaction I mentioned above means that at the moment I’m not taking most of these, but am slowly trying to bring them back in to try to work out what caused the problems. 

Immunotherapy phase 2 – training the immune system to recognise my tumour

The second phase takes place twice, over two months, eight days at a time. Whereas the first phase has been leaving the immune system to identify the novel proteins by itself and do its own thing, phase two is attempting to give it a leg up and is an example of the kind of personalised medicine that is coming the way of cancer and many other treatments. 

The treatment starts with 200 ml of my blood being taken away to the lab. Here my dendritic cells are extracted. These are the part of the immune system which present antigens, the foreign proteins from invasive bodies (normally things like bacteria and viruses, but in my case the novel tumour proteins) to the part of the immune system which needs to recognise and kill foreign cells. The population of dendritic cells is then increased in the lab over the course of several days. 

At the same time, the novel tumour proteins floating round in my blood sample are extracted, sequenced and then more fragments are manufactured. When the time comes, these manufactured protein fragments are presented to the new population of dendritic cells and my personalised vaccine is ready. 

On day 8, I receive the vaccine. Weirdly I get two (really very painful) injections in each ear and two at the very top of each arm, the aim being to get the primed dendritic cells as close to the lymph system, and the killer T-cells as possible. My immune system is then ready and able to seek out any remaining tumour cells and attack them while leaving my normal cells well alone. 

Immunotherapy phase 3 – training the immune system to recognise standard cancer proteins

Phase 2 is focused on identifying tumour proteins which are unique to me. Phase 3 relies on the fact that although all cancers have novel mutations, some mutations are the same regardless of who has the cancer. This means that in January and February, I’ll be back in Cologne being vaccinated with proteins expressed by all cancers of the type I’ve got. The aim this time is to augment the personalised treatment with a vaccine against standard brain cancer proteins. By the start of spring my immune system should be all guns blazing against any remaining tumour cells. 

As I mentioned, this treatment is as yet unproven. It’s a huge burden on Pam, me and the family, but we’ve got the chance to try it and it seems to me to be worth the roll of the dice given we’re able to do it. We’re continuing to keep our fingers crossed for negative results, but the path isn’t going to be easy as the next post will explore. 

28 November 2023

Top Picture Description: Three white dice with black dots being rolled onto a chessboard. Picture credit.

Body Picture Description: Me lying on a bed with a hyperthermia pad pressing against my right temple. Picture credit: Pam Mason