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Saturday, November 27, 2010

Why We Haven't Cured Cancer

I’m going to try to give everyone a brief overview as to why researchers have been unable to cure cancer for the last twenty years and I would love anyone who has additional feedback to comment. Let's get right into it. DNA is our genetic material found in every single human being. DNA consists of 4 nucleotides(A,T,C,G). Many nucleotides can form a gene and this gene can make a protein. These proteins are critical for our survival and play many important functions. In DNA the A nucleotides pair up with the T’s and the C’s pair up with the G’s. It should be stated that many of our nucleotides don’t form proteins and we still don't have a good grasp on what these nucleotides actually do. Most researchers believe these nucleotides play a role in structure. Cancer results when random mutations form in our DNA everytime we replicate our cells. For example, a T nucleotide will mistakenly base pair with a C instead of an A. One big potential problem with this inaccurate basepairing is that we no longer form the proteins that need to be made from that specific gene. Also, we could potentially form abnormal proteins that can lead to cancer forming. Clever scientists decided that it was time to sequence all the genes in cancer cells they isolated from the tumors of cancer patients and compare these with normal cells in the same area. These scientists eventually noticed similar patterns of mutations occurring in various types of cancer in different patients. As a result, these doctors attempted to inhibit these genes that were accumulating mutations shown in many patients with similar forms of cancer by using drugs. Unfortunately, our bodies are constantly changing and new mutations are always forming so eventually resistance forms against the drugs given to block these genes. Now, the next question most of you probably are asking is “why don’t we find the form of resistance and target a drug to stop this”? The overwhelming problem is that it is very hard to specifically find what mutations are causing the resistance and there are many mechanisms of resistance possible to the drugs used to treat cancer. Furthermore, while one drug might block a long sequence of one gene, all it may take is a single nucleotide mutation to cause the cells to become resistant to the drug given. By the way, these drugs(herceptin, gleevec) are pretty expensive(averaging around 60000 dollars a year). Most of the time these drugs are combined with chemotherapy to give an enhanced affect to try to kill the malignant cells and they tend to add about an extra two months to lifespan on average for some individuals. Bottom line, even a small tumor contains tens of billions of cancer cells which are constantly evolving. It is impossible for us to try to target one specific gene or try to identify one protein that could be the sole cause of cancer occurring. We can not predict the evolution that is constantly taking place in our bodies. Instead we need to focus on the simpler models of cancer and try to solve the problem on a larger scale. All cancerous cells require normal cell machinery to function. Also, all cancerous cells need to be able to proliferate and be invasive(cross the basement membrane and enter new sites of the body) in order to cause damage. Researcher needs to focus more on the mechanisms that are found in the normal machinery that are allowing all cancerous cells to do their job. If we can inhibit proteins needed for invasiveness and stop replication of cancerous cells we will be able to solve the problems of cancer. On that note, I have come to the realization that being healthy both on a physical, dietary, and mental level is of key importance. It has been shown in many studies that microtumors are unable to develop into large scale tumors unless our environment triggers this effect. Also, it has been shown that eating right and being less stressed(practicing breathing exercises, meditating) can actually change expression of genes in a positive manner and can help fight cancer. If you need evidence for this, just look at the fact that most Japanese men do not develop cancer in their own countries; however, when they migrate to America and start eating a western diet cancer rates skyrocket. Also, although i’m very new to this field of research, after reading many books I feel every cancer patient should realize that they have a choice. Cancer patients should always get a second opinion and not resort to the first form of treatment justified by their doctors. Many times surgery is not the answer and active surveillance can be used instead. Also, a cancer patients outlook on life and belief that they will win this fight is of utmost importance. With that said I will continue to find information about many questions people might have(Can biopsies spread cancer? Which foods are good for fighting certain types of cancer?). I will also continue to highlight relevant research and find out any new forms of conventional treatment proven to be helpful. For more information on why cancer is so difficult to cure, check out this excellent talk by Carlo Maley in which he gives an in depth look at all the mechanisms involved in causing cancerous lesions to form and what we want to do in the future to look at tumor evolution.

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