The fact that children and young adults with germ cell tumours can sometimes take a very long time to get to the diagnosis is something that is well known amongst specialists that look after those kinds of tumour. What we wanted to do was to look at where the problem was, really, if there was a problem and to do that in some different healthcare systems including the UK, Germany and Canada. We found first of all that the UK has a longer time from first symptom to diagnosis, on average, for its patients compared to both Germany and Canada. If we look at where that delay is occurring it isn’t with the patients, that by and large, there are exceptions to this, most patients seek medical attention within two months of first having symptoms and the delays thereafter are within the healthcare system.
What are the issues once a patient has sought medical advice?
The biggest one, probably, is that for the tumours that have a delay to diagnosis diabetes insipidus is very often the first symptom with patients having polyuria and polydipsia. There is in primary health care and to some extent in secondary health care a difficulty recognising that that’s what is being seen. Many of these patients get tested for diabetes mellitus, the different kind of diabetes, and once that’s excluded there appears to be no further investigation. It’s important for us to find a way to inform our colleagues, possibly via the HeadSmart project, of the implications of diabetes insipidus, particularly in young men but girls as well around the time of puberty where the chance of there being an underlying tumour is really quite high.
From the patients that we looked at there doesn’t appear to be any implication for survival, which is an important one. Most of the relapses actually happen in the patients who had a short time to diagnosis. But in terms of the consequences to the patient I think there are several. First of all it was a slightly unexpected finding that patients are much more likely to have metastases if they have a long symptom interval, a long time to diagnosis. This is something that I think we wouldn’t say for other tumours that we deal with. That means we treat the patients differently and in particular we give more radiotherapy which has its own long-term consequences. We also, because we were able to look at symptoms at first presentation and then symptoms at diagnosis, we were able to say that for about half the patients they had additional hormonal problems by the time they were diagnosed and those we know don’t recover. For a number of patients who didn’t have visual problems with their first symptoms they acquired visual problems, and we know that some of those don’t recover, and there were also cognitive problems.
This is not based on formal cognitive testing so what we know is that there are some patients who, with the bias of recall but at least knowing one of these patients, who develop significant psychomotor retardation by the time they were diagnosed and whose memory was very difficult and certainly hasn’t completely recovered. We know that some patients, about 6 patients of the 23 patients who had delay to diagnosis, developed raised intracranial pressure and we know from other tumours that that can often cause longer term cognitive problems.
Would easier access to MRIs make a difference?
It may well make some difference because once the MRI happened almost all patients moved directly to treatment i.e. the MRI was diagnostic. There were one or two patients in the series where they had more than one MRI before it became diagnostic. It may be that if that MRI had been seen by a specialist in germ cell tumours that they might have made the diagnosis earlier but I think that if the association between diabetes insipidus and the distinct possibility of an intracranial germ cell tumour was made and imaging was requested at that time a lot of these patients would have come to diagnosis earlier.
I would like to talk to Professor Walker about whether there’s any way we can input this into the HeadSmart project and in particular target both primary care and secondary care endocrinologists. There certainly were several patients who a significant portion of their delay time was with secondary care endocrinologists without them gaining imaging. We’d also like to look in more detail at the North American pathway to diagnosis, because we haven’t got as much detail about that, and then publish the work.