Wednesday, 8 January 2014

A mystery solved?

"when you have eliminated the impossible, whatever remains, however improbable, must be the truth", Sherlock Holmes.
My cancer story began back in February 2011 when I developed obstructive hydrocephalus. This is a condition in which inflammation blocks the drainage of the fluid that surrounds the brain resulting in increasing fluid pressure inside the skull, something which can ultimately be fatal. In my case a CT scan allowed the doctors to make a timely diagnosis and I underwent emergency surgery to fit a pressure relieving drain. I was prescribed a short course of high dose steroids and these quickly reduced the brain inflammation. In fact the steroids were so successful that further CT scans very soon showed that my brain had returned to normal.
The neurologist and neurosurgeon treating me wanted to find out what had triggered my problem in the first place. They gave me a battery of tests all of which proved negative until they performed a CT scan on my abdomen. It was this scan that found the tumours that were later discovered through biopsy to be Leiomyosarcoma. At the time of my LMS diagnosis I remember the neurologist and neurosurgeon both being very surprised. They had thought that the tumours were caused by a lymphoma because lymphomas can cause hydrocephalus and often respond extremely well to steroid treatment. LMS, on the other hand, does not typically cause hydrocephalus.
The LMS diagnosis left us with no explanation for the hydrocephalus, however the brain is so complex that sometimes these things can occur without a clear cause being identified. My oncologists were aware of this part of my case history and their view was that, in the absence of any further evidence of lymphoma, we should focus on treating the LMS as this was the more immediate danger to me. 
You may be wondering why I'm recapping this history here, well the reason is related to the 'stroke' that I had last week. Before we had the radiology report on the brain MRI last Friday my oncologist told Katie and I that he thought the scan could be showing a lymphoma. When the consultant radiologist indicated that the scan was showing a stroke my oncologist had to go along with this, however he was not entirely comfortable so he arranged for the scan to be reviewed at the neuro-MDT meeting today. This is a meeting of specialists in neurology and neurosurgery and is intended to provide opinions on cases in which there is difficulty making a diagnosis or selecting a treatment. The verdict of the MDT meeting was that the brain MRI does not show a stroke, instead it shows inflammation and damage related to a cerebral lymphoma or to an as yet unidentified inflammatory condition.
Given that my problems started with an event consistent with lymphoma this new information strongly suggests that I do indeed have this form of cancer in addition to LMS. An interesting characteristic of some lymphoma's is that they can go into long lasting remission when treated with steroids. Since my initial diagnosis I've been receiving a high dose of steroids each time I've had chemotherapy - roughly once a month. This could explain why the lymphoma has been a 'sleeping partner' in my illness to date. Interestingly before tonight I hadn't had any steroids since November (my last chemotherapy treatment), so perhaps the break from chemotherapy explains why the lymphoma has 'woken up' and caused the stroke like event of last week.
I looked at cancer incidence rates in the UK tonight and I found that the odds of a specific individual in the UK population being diagnosed with LMS and primary cerebral lymphoma in any one year are just under nineteen billion to one. For context if that same individual were to enter the national lottery just once in that year the odds of them winning would be fourteen million to one, i.e. they would be more than a thousand times more likely to win the lottery than to be diagnosed with these two rare cancers!
You have to be careful with statistics however as the calculation above gives the odds for a person who has an average risk of developing each of these two conditions. In my case there is a reason to think that my chances of developing both of these cancers is unusually high - that's my Li-Fraumeni Syndrome. This very rare genetic condition predisposes me to certain cancers. Sarcoma is closely associated with this syndrome, someone with Li-Fraumeni is known to be at much higher risk of sarcoma than the general population. Whilst not as closely associated with the syndrome as sarcoma, there is also an increased risk of developing non-Hodgkin's Lymphoma.
So we now have a much tidier hypothesis for my complex cancer history. My Li-Fraumeni syndrome facilitated the development of two otherwise very rare cancers simultaneously. The lymphoma caused the hydrocephalus and was then sent into a long lasting remission by the continued exposure to steroids. Meanwhile, in investigating the cause of the hydrocephalus my LMS was discovered. When my last treatment for LMS failed I went onto a treatment break for a couple of months allowing the lymphoma to resurface and to cause the brain problem I had last week.
In terms of treatment for the lymphoma the initial step is to try a course of steroids and then to check via brain MRI if these are working. I've had the first of the steroids tonight and I'm hoping that these will put the lymphoma back into remission.
That's the theory then, of course nothing is certain - hence that lingering question mark in the title of this post.

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