20 July - Treatment and prognosis

I finally felt brave enough to do a bit of online research into my brain tumour, which is described as a Glioblastoma Multiforme Grade 4. According to Wikipedia it is the most common and most aggressive type of malignant brain tumour. Despite this, it occurs in only 2 to 3 in every 100,000 people in Europe and North America. So it seems that I, who normally never even wins the club raffle, really hit the jackpot with this one.

The treatment I am receiving - craniotomy to remove as much of the tumour as possible, followed by a combined course of conformal radiotherapy and temozolomide chemotherapy - is the most common and generally regarded as most effective form of treatment. Nevertheless prognosis is poor. In a clinical trial of 575 patients receiving this treatment the median survival rate was 14.6 months. (Without chemotherapy this was reduced to 12 months.)

The most important factor determining the survival period would seem to be how much of the tumour was removed during the craniotomy. A typical tumour contains 10^11 cancerous cells. This is reduced to 10^9 if the surgeons remove 98% of it. Radiotherapy can kill 98% of those, reducing the number to 10^9. But that is still a lot of cells that will eventually multiply, grow the tumour and kill the patient.

There are reasons to be optimistic. Olga saw the surgeon as I came out of the operating theatre. She says he looked pleased, was smiling and said the operation went very well and I would be OK. So perhaps he got more than 98% of the bugger. Time will tell.

Temozolomide is a chemotherapy drug that is used to treat newly diagnosed glioblastoma in patients that are fit enough to look after themselves. It can be taken orally as it has the ability to penetrate the barrier to the brain so that it can reach the cells it is designed to treat. It works by blocking the ability of the cancerous cells to make DNA so they are unable to replicate. It also increases the effectiveness of the radiotherapy.

Although temozolomide has side effects, including nausea and a weakening of the immune system, it is not as bad as some chemotherapy drugs according to some sources. If I can avoid picking up any bugs hopefully it will not be too bad.

The reason it takes a long time to start the actual radiotherapy is apparently that the planning is very time consuming. A lot of precise calculations have to be made in order to target the X-rays on the cancerous cells in the brain while avoiding everything else. The nurse technician yesterday said "the maths can be complicated." I had visions of teams of people slaving over calculators but I presume they use computer modelling.

Given how I feel right now and what I now know about the treatment, I'm hopeful that I can beat that 14.6 months prognosis by a significant margin.