Wednesday 29 February 2012

Bring on the Biomarkers!

I have pinched this title from a slide shown by Charlie Swanton at the First London Cancer Breast Study Day earlier this week! He was one of about a dozen speakers and his session was on a personalised approach to breast cancer treatment. Back to last year's theme of stratified medicine.

He was making the point that predicting drug response and the whole issue of multi-drug resistance are some of the challenges of the personalised approach. The genomics revolution makes it possible to make treatment or trial eligibility decisions fairly quickly based on sequencing from a single biopsy sample. But there is a question as to whether this is the best approach.

Looking at mutations found in samples from primary and secondary tumours shows that while some are ubiquitous, many are not; in fact, the majority are not. Intra-tumour heterogeneity means that drug response can't always be predicted from the sequencing of a single sample.

All this, he suggested, means that the traditional model of linear evolution of cancer is not helpful. Instead, tumours and their evolution are more like trees with branches going off in different directions and then themselves branching. Some tumour-trees have long trunks, while in others the branching starts much lower down. This goes some way to explaining why sometimes we don't see the expected response to a particular drug.

Another reason why stratified medicine is so important.

7 comments:

  1. I had never heard of the term "stratified medicine" before. Thanks for educating your readers on the challenges of developing personalized medicine for breast cancer. We need to delve into how multi-drug resistance and heterogeneity of tumors interplay so we can get to the root of the issue. Thanks for this enlightening post. XX

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    1. Thanks, Jan. maybe it is a European term? We are hearing quite a lot about it at the moment. E xx

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    2. It may well be a European term. Or maybe I've just been out of biotech for too long (almost four years now). XX

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    3. Personalized medicine based on bio-marker status is definitely a way forward in cancer treatment, but perhaps treating the root cause of the issue with the reasons behind increasing incidences would be a better way of tackling. Emphasis on prevention is as important - for instance 95% of breast cancer incidences are sporadic highlights this issue.

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    4. Yes, we need work on causation and prevention, but even there the bio markers are important. Also the sporadic proportion varies from population to population, being lower in some places and populations. So the research has to be (and fortunately is) multifaceted.

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  2. It is strange how can is seen like a tree and its roots.. My mental image was as discribed.. strange really .. keep up the fight Eliza

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  3. Yes, it is odd thinking of it as a tree. The more I learn, the more fascinated I become. Onwards we go, Sarah!

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