13 July 2008 - Questions and Answers

Correspondence with Fred Berki, Macmillan Clinical Nurse Specialist Neuro Oncology, Queen Elizabeth Hospital, Birmingham

Deb’s Brain Tumour

Correspondence with Fred Berki, Macmillan Clinical Nurse Specialist Neuro Oncology, Queen Elizabeth Hospital, Birmingham

Questions and Answers


Brain Tumour
For general information on brain tumours see Annex 1

Q1 What is the likelihood that the malignant cells will spread to other areas of the brain? Does their location and/or size may make this more or less likely to happen?

A1 Spread from GBM outside of the nervous system is very, very rare, and even into the spine is rare. It can however spread within brain matter and is said to infiltrate along 'white matter tracts'. This can happen despite the treatments mentioned above. Hence the need for regular scans. I wouldn't be able to say at this stage whether this is likely or not, and it does not necessarily depend on tumour size or location

Q2 Does the 30 - 40 % of the tumour that Mr Kay said he would be able to remove include the 'active' areas of the grade 4 tumour? If this is so, doesn't it make surgery a more attractive option?

A2 High grade glioma -type tumours often are not uniform in their makeup - the cells can have elements of Grade 3 and 4 activity i.e. different levels of activity and a single biopsy only gives a snap-shot of that part of the tumour. Also, if this is a tumour that has been there for a long time then much of the active elements will around the outer part, and the middle can be composed of necrotic (dead) or calcified cells. The tumour is also bi-frontal, deep, and up against the ventricles (the fluid-filled spaces in the centre of the brain) which makes surgery complicated. I think, therefore, that if Mr Kay did remove 30-40% of the tumour it would be from the area where it is most accessible, least likely to cause disability, but at the same time least likely to reduce possibility of symptoms - I think if the benefits of surgery clearly outweighed any risks then it would have been offered more emphatically.

Q3 I am still not sure what it is about the tumour that kills you. I asked Mr Kay this question yesterday and I think he said it wasn't the 'mass effect' but the 'pathology' of the tumour. Can you clarify what this means?

A3 These tumours have several detrimental effects; they create a shell of fluid around them (oedema) which causes pressure effects on the brain, which is usually 'generalised' (as opposed to 'localised') and usually causes headache or drowsiness/confusion - localised effects are usually speech problems or limb weaknesses and are associated with more discrete areas of the brain. If not controlled then the increasing oedema compresses the brain and function is gradually impaired and eventually fails - this is controlled by the use of steroids. Similarly as the tumour itself grows, 'mass-effect', it causes rising pressure with the same results as the oedema, but this is minimally responsive to steroids. Finally, the cells of the tumour, which split and multiply rapidly (the pathology) aggressively infiltrate surrounding brain tissue destroying function gradually. It is the action of these processes combined that have the detrimental effect.

Q4 Mr Kay described the tumour as being diffuse and not having clear boundaries. He said parts of the tumour not visible on the scan were extending into other parts of the brain. Will the radio/chemotherapy deal with this?

A4 High grade gliomas do not have a distinct border - although they may appear to be clearly defined on a scan, the edge of the tumour merges with healthy brain. During surgery the surgeon attempts 'macroscopic' removal, i.e. they take as much as they can see, but although we know there are 'fingers' of tumour extending beyond the visible margin, by trying to remove tissue beyond this margin would result in disability - therefore 'microscopic removal is not possible. In contrast radiotherapy is designed to extend beyond the visible margins of the tumour and thereby catch as many active cells as possible. However, if even a small number of tumour cells escape the radiation then the process of tumour growth continues. Prof Jones says that each treatment of the planned 30 kills about 80% of cells, which means there is a decreasing number at each treatment, but there is never total eradication. Prof will, very occasionally, give a second course of radiotherapy, after one year from the first course. Chemotherapy can be used as necessary, and as tolerated, and alternative drugs are available.

Q5 If the tumour does not respond to treatment and continues to grow do we have any idea what the next phase will be like? Deb's previous symptoms - headache, dizziness - appear to be due to the 'mass effect' i.e. the tumour pressing on other parts of the brain. Am I correct in understanding that this glioblastoma could spread to other parts of the brain and produce different symptoms?

A5 People respond differently to the treatments and it is very difficult to predict an individual's response, although radiation is considered to be pretty effective. We would expect to do a scan roughly 3 months after completion of the radiotherapy to give a baseline, and subsequent scans then enable comparison. Radiation can distort the images of brain tissue on scan in the early period which can lead to assumptions that the tumour has not responded, whereas in fact the images are of 'radiation effects' Both Mr Kay and the Prof suggested that surgery may become more feasible in the future, if there is significant tumour shrinkage following the treatment.

Q6 I understand that in the age group 45 - 59 about 160 men and 70 women are diagnosed with brain tumours per year in the UK. So very rare in this age group. Prof Jones also said that Debs was not a 'classical' GBM because it was largely benign with aggressive 'hot-spots'. Does this make what Deb has very rare? How much experience do we have in treating this type/size of tumour?

A6 I think it is unhelpful to think in terms of 'hot spots' in the tumour. While there may be areas of varying activity, this must be treated as a GBM. The radio- and chemotherapy is most effective approach in high-grade tumours - i.e. the most rapidly growing (and therefore most susceptible) cells are most likely to be damaged; however, they are also most likely to recur. There are approximately 4000 new cases of primary malignant brain tumour (including GBM) in England and Wales each year. As you know these are graded, and it is the high grade tumours (3-4) that require treatment - the more aggressive the tumour, the more aggressive the treatment. Radiotherapy is the standard approach, and radio/chemotherapy is the 'gold standard in GBM. These tumours make up less than 2% of all new cancer diagnoses, so they are already rare. The term Glioblastoma Multiforme does not refer to a discrete form of tumour. Rather it is a histological description of the cell activity seen in a tumour. So, oligodendrogliomas, astrocytomas, and ependymomas are reclassified as GBM when they reach Grade 4. I don't think that within our patient population it is particularly unusual to have a tumour with areas of mixed activity. Choices of treatment are not influenced by what the tumour has arisen from, but by what it is classified as now.

Q7 What is the likelihood that the malignant cells will spread to other areas of the brain? Does their location and/or size may make this more or less likely to happen?

A7 Spread from GBM outside of the nervous system is very, very rare, and even into the spine is rare. It can however spread within brain matter and is said to infiltrate along 'white matter tracts'. This can happen despite the treatments mentioned above. Hence the need for regular scans. I wouldn't be able to say at this stage whether this is likely or not, and it does not necessarily depend on tumour size or location

Radiotherapy
For general information on radiotherapy see Annex 2

Q8 Please could you clarify the overall purpose of the radiotherapy? Is the aim of the treatment to shrink the overall tumour or focus on the hot spots? How deep are these malignant cells – can radiotherapy reach these areas effectively? `

A8 Radiotherapy is most effective on rapidly dividing cells i.e. tumour cells. As 'brain cells' do not divide - we have a set number from early infancy, then the radiation kills cancerous cells rather than the brain cells. However, it will still cause irritation and inflammation to non-cancerous cells. The effects of the radiotherapy usually start about half way into the treatment and can still be effective for several weeks after completion of the 6 weeks. Radiotherapy is effective on active cells, but cells have a life cycle. This means they have resting/dormant phases and active phases - the therapy acts on cells in their active phase. However, not all cells are active or resting at the same time. So, some dormant cells can become active after treatment effects have ended, and hence tumour recurrence. In addition, not everyone is susceptible to the effects of Temodal and will only get reduced beneficial effects.

Chemotherapy
For general information on chemotherapy see Annex 3

Q9 How does the temozolimide actually work?

A9 Temozolomide is a 'methylating' agent, and acts by blocking the repair mechanism of DNA. The effect of radiotherapy, and many cytotoxic drugs is to kill tumour cells by damaging their DNA - then as they split to duplicate the new ones are damaged and die. So, the radiotherapy damages the DNA of tumour cells, which then cannot repair themselves due to the action of the Temodal, and die.

Q10 I understand that although originally GBM was not thought to be very sensitive to chemotherapy, there is now a lot of evidence from randomised trials showing that temozolimide, taken together with radiotherapy, improves survival time and delays disease progression, compared with radio alone (by about 15%). But the treatment toxicity of a combined regimen can be substantial. Can you tell me what the likely impact on quality of life will be during treatment and how long can you expect it to last i.e. is there a bit more information as to what is to be expected in the next 6 months when having chemo, radio and steroids together?

A10 Temodal is much better tolerated than the older drugs. It is taken orally, and therefore has less of a systemic effect - less nausea and hair loss. But it can increase risk of infection and bruising/bleeding because of its effects on the immune system and bone marrow production.

Q11 If we do not get the funding for chemo, is there another drug Deb can take? If so what are the success rates for this?

A11 If the request for Temodal is turned down then we can appeal and have it reconsidered. However, if it looks as if this will drag on we would not delay starting the radiotherapy without it. There are other chemotherapy agents that are still commonly used for high-grade tumours and they are effective. But, as you say, Temodal has been shown to influence outcome, by on average two and a half months - but it's impossible to equate this to an individual. We would normally use Temodal as first line and if there were to be tumour recurrence then we would consider the older drugs. I could write reams on protocols and side effects for these drugs, but can we leave this until or if the eventuality arises.

Q12 Are there any ongoing clinical trials we could participate in? Are there newer chemo drugs that are not yet approved but are being assessed in trials?

A12 Drug trials are one way of gaining access to newer treatments. However, randomised controlled trials, by their nature mean the person has a 50/50 chance of getting the new treatment or the established standard treatment. We have been recruiting ourselves under Prof Cruikshank (for the Herpes simplex virus) but this is currently on hold. There are of course trials elsewhere in the country and you can enquire yourself whether Deb may be eligible.