VALENCIA. From one of the grey doors lining up in the Medicine department, some musical notes emerge. They come from the office of Rafael Tabarés, professor of Psychiatry in the University of Valencia and main researcher of one of the groups in the Centre for Biomedical Research in the Network for Mental Health (CIBERSAM), who receives us to the sound of Bach, stamping his particular rythm to the morning. «It is the Goldberg Variations played by Glenn Gould», he explains later, holding the music sheet.
Apart from music, he is also a literature lover and, as a sample, he quotes Pessoa in order to discuss knowledge based on paradox. «Things are paradoxes insofar as we do not understand them. When we do, they stop being so. Pessoa said something to the effect that we find things strange at first, but entailing later.» Precisely one of his lines of research, developed alongside professor John Rubenstein in the University of California, is the study of inverse comorbidity between aparently unrelated diseases, such as some neuropsychiatric disorders and cancer. On this topic, inverse comorbidity in cancer, an aticle written by him and Rubenstein has just been released in Nature Reviews Neuroscience, one of the magazines with the most impact in the field.
–Tell us first what inverse comorbidity is. What does it imply?
–Before, it would be interesting to explain what morbidity and the morbidity model are. Usually patients do not have only one illness. Most commonly they have several medical problems at once or one after the other. This, furthermore, worsens with age. For instance, it is frequent for someone with Alzheimer's to develop diabetes, osteoporosis, malnutrition... but the main illness, shall we say, is the dementia. This is the model of morbidity. In the last few years we prefer the term multimorbidity. That is to say, the presence in the same individual of two or more problems or medical conditions without any of them prevailing of being superior to the other.
–It is inevitable to notice comorbidity because symptoms of the illness exist, how can the tendency of an illnes that, ultimately, does not happen, be studied?
–Through observational studies at first. I mean, doctors observe their patients and take notes on how «they die because of this, but not because of this other thing». Given time, some people have tried to see if this was so, doing specific, ad hoc epidemiological studies, using registries of different countries about illnesses, morbidity and death. That is, what do schizophrenic patients die of? That is the reason that really powerful epidemiological studies are published to assess the risk of suffering from cross-illnesses.
And that is when the first publications start to appear at the beginning of the year 2000 pointing, in an absolutely independent manner, that patients with dementia do not die from cancer. Why does that happen? And that is how evidence keeps growing in this regard. We had the boldness to put all of those inverse associations together according to a model, which is the relation between cancer and the nervous system. The whole story started towards the end of 2007 in the USA.
–Is it then that these inquiries started?
–That is when I started thinking about the issue after some research with John Rubenstein about the chromosome 8. Then I found that it is very frequent in that chromosome that, of 484 noted genes, many of them are related to the development of the nervous system from embryogenesis; to mental illnesses such sa schizophrenia and with illnesses of the nervous system such as Parkinson's or Alzheimer's dementia, but also to cancer. And it really caught my attention how it was possible for different groups to find gene variations from the same genes involved in such different morbid processes.
From that moment on, I started to investigate and found that there have been research groups during the last twenty years who published separate articles in relation to this. What we do is notice the association, gather everything and subject it not only to a qualitative analysis, but also to a meta-analytical study of every publication on the same topic and a whole reflection on which molecular bases can be behind it. What the reasons for these positive or negative associations are.
Full text available at Mètode's website.
