Cancer and the Immune System

Cancer is able to evade the immune system, and grow within our bodies in a number of ways. Tumours are able to accomplish this feat in hundreds, if not thousands of different ways.

Researchers at USC mentioned that you could then take these “immune signatures” generated by the immune response against a tumour — and target them with whichever drugs or therapy is best suited. This builds on personalized medicine, here’s why: lets say two tumours exist, A + B, where A is a breast tumour and B is a prostate tumour. Generally tumours A + B will have different biochemistry for reasons including: (1) different cell of origin; and (2) different prepotency for specific mutations thus causing cancers in the different cells. Traditionally, drugs have either tries to poison these cells, or hijack an intracellular process associated with a specific mutation found in one cancer. By looking at the immune response signature, you could generate immune-specific drugs that could target tumour illiciting similar immune signatures. Therefore, it could be found for one drug commonly used for tumour A to work perfectly in tumour B if the immune response signatures are in alignment.

In the article, the researchers generated signatures using real-time PCR on 14 pro-immunity genes, and 11 anti-immunity genes from 5 different mouse tumour models. This is merely a start to what seems to be the tip of the iceburg here. It will be excited to see future developments.

Personalized Medicine: Legal Update

Up until now, there has been a big problem in the realm of personalized medicine, with respect to pharmacogenomic analysis, record keeping and access to information. Previously, according to US law, anybody could have access to that information. Meaning: employers and insurance companies could scan your results, or look at your specific genotypes that pre-dispose you to specific illnesses or conditions and discriminate against you for fear of taking on too much risk financially. See my post on ethics of personalized medicine.

As of April 25th, the US House of Representatives voted 420 to 3 in favour of passing the Genetic Information Nondiscrimination Act (GINA), and the senate along with President Bush are expected to approve the act in a few weeks. Undoubtedly, this will be a huge step for the world of personalized medicine. We are already seeing the use of pharmacogenomic markers such as Cytochrome P450 (including the 2C9 and 2D6 variants), warfarin and others that screen for efficacy of drugs such as Herceptin.

It is good timing for this news to come as genotyping is becoming evermore affordable.

Everyone should thank the NHGRI Director Francis Collins for pushing to get this act passed! The act has been shot down twice previously by the senate; hopefully, as the saying goes, the third time will be the charm.

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Ethics in Personalized Medicine

Today, I want to highlight a great article I found on the ethical issues in personalized medicine, which is centered around pharmacogenetic information (your specific DNA genotype for a number of specific genes). Firstly, if you want to get up to speed on pharmacogenomics, check out the US government-run Human Genome Project Information site that has some quick Q&A on this topic!

There was an article recently published online by Reagan Kelly, that discusses some ethical issues of personalized medicine, please see some excerpts below:

“Protecting patient privacy is one of the most important things that must be done before ordinary people will be willing to take advantage of individualized medical care, and just about everyone agrees that patient’s have a right to keep details about their health private from most people (even if not from, say, their insurance company or in some cases state or local governments). But how far does that right extend? Does it cover a person’s genetic makeup? That is something that undeniably influences health, and a fair amount of information about what diseases a person has or is at risk for can be extracted from genotype and gene expression information like what would be collected for personalized medicine services. How do you keep that information private and what uses are OK? … Additionally, what about the privacy of other family members? Families share genetic information, and by knowing something about their risk, a person also learns about their relatives’ risks.”

“One of the issues of privacy is also directly related to patient autonomy – the right of a patient to choose what happens to them. The question of what uses of a patient’s data are permissible is not exclusively a question of privacy but also one of autonomy. Is it OK to require a person to allow their data to be used for risk profiling or diagnosis as a condition of performing the service for them?”

“Cost, just like with the policy issues last time, is a significant ethical issue as well. Something like 46 million people are without health insurance today, and many more have insurance plans that cover only the most basic things. How can we provide access to personalized medicine to everyone? Is access for everyone a reasonable goal? Is it an attainable one?”

Please see the full article for more details.