WIN Symposium 2013
Challenges and opportunities for implementing personalized medicine in Brazil
Dr Rui Reis - Barretos Cancer Hospital, Barretos, Brazil
At Barretos Cancer Hospital we have a huge tumour bank. Currently we have more than 90,000 samples from approximately 80,000 patients so we know that all patients are different and the disease has a different outcome. So having this huge number of cases and being in Brazil, having a Brazilian background that in fact is European with African with Asian, the idea is to identify some genetic alterations that are present on the tumours and that can be associated with different outcomes of disease or a better prognosis or a better response to some therapeutic regimen. So we are doing a lot of genetic tests on human samples from our patients. Some of the projects we are trying to replicate other biomarkers that were discovered in other populations like North American and European, that most of the studies are done on those populations, but for that genetic alteration to become a biomarker we have to validate in other populations. So our purpose is first to validate those markers in our population and to see if in our population that potential biomarker can really be used as a biomarker because it leads to a different clinical response of the patient.
You said, just in passing, we have a tumour bank of 80,000 people.
That’s amazing because in Europe they’re just starting to do tumour banks at a lot of hospitals. Now this is quite well established.
Yes, the tumour bank has twelve years now and started before the institution was planning to do research in the future. It is an institutional tumour bank and that means that all surgeries that are performed in the hospital, we take blood, tumour tissue and normal tissue whenever is possible and this material is cryopreserved and its purpose is for future studies. Of course we also take the tissue for pathology diagnosis, this is taking care, of course, that first is to take care of patients and then to do research but when you have material we have this tumour bank. As I was saying, since it’s an institution tumour bank it’s mandatory. So what happens in many hospitals is that the physician is interested in doing research and then starts to have his own tumour bank. Then the other physicians start this as well as it’s not a centralised structure. In our hospital we started the other way around, we started with the structure centralised where everybody has to do those procedures and we have staff that were hired specifically for that. So we started in an organised way and our Barretos Cancer Hospital, it’s one of the biggest cancer hospitals in Latin America. We attend currently more than 12,000 new cancer patients per year so it’s huge numbers. Since it’s centralised, all this tumour collection or sample collection, we have this organised way then this constitutes a stream rich resource for future studies and to identify new markers.
What we are performing also in terms of research, we know it’s well-known that the ethnical background of each patient can influence the disease, the course of disease. In Brazil the research is not as well developed as in Western countries and it’s a very mixed indigenous population. So every time we have some different results we say, ‘Oh, because there’s a mix of population of European, African, Amerindian,’ and what we are trying to dissect also the influence of this ethnical background, we are for each patient using genetic markers we are determining exactly what is the proportion of their ancestry. So we are trying also to analyse the disease not only by the size of the disease, of the tumour itself, but also the patient, what is his genetic background and if his genetic background can influence also the course of the disease.
So have you been able to identify any new mutations or new alterations?
We are not identifying new mutations, what we are observing is that the proportion of the mutations that are known, published in North American and European populations, they are rather different in Brazilian populations. This has an important impact because some of these genetic alterations, they are predictive for a specific drug and we know that if this frequency is different the number of patients that will be treated will be rather different. So this frequency of mutations are rather important for health strategy and health planning for therapeutic decisions, for example.
How does this implement on treatment?
To have a specific case, for example lung cancer, we know that today if a patient has a mutation in a particular gene that is the EGFR, epidermal growth factor receptor, it’s a protein that is very important. If this protein is mutated, if this gene is mutated, there’s a drug that works very well in the presence of this mutation. If the patient doesn’t have the mutation the drug doesn’t work at all. So the frequency of this mutation is much more frequent in the Asian population than European, for example. In the Brazilian population nobody knew what was the impact of this mutation. So not knowing the frequency we don’t know how many patients will need to be treated. So having access to a huge tumour bank we can do a retrospective study, try to identify the presence of this mutation, the frequency and then we can plan ahead what would be the best strategy for dealing with this, in this case particular with lung cancer.