Once every year a major event in cancer research takes place somewhere in the United States: the annual meeting of the American Association for Cancer Research (AACR). Some 15,000 basic, translational and clinical researchers from all over the world come together to communicate the latest results in their field of work. Reading this some people must think that it would be a great opportunity to be able to attend an event like this: it was!! In some extraordinary way the AACR got the address of our organization (VOKK) and invited us to propose someone's participation during their 4th Scientist <-> Survivor program. After applying I got invited to come. Being a 19-year-old childhood brain tumor survivor I was by far the youngest, but since I'm a second year medical student I was one of survivors that was able to understand most about the work of cancer researchers.

The purpose of this article is to describe some the vast array of research that is being done to accelerate progress in the fight against cancer. It will be hard though to go into much detail: I'd much rather give you an overview of what might be expected during the next five to ten years.

I think by now many people have heard about the human genome project: a worldwide project to find the sequence of all our genes: our full genome was evaluated by hundreds of laboratories throughout the world. Each of those has been trying to sequence their part of the genome that they had chosen for study (finding the genetic alphabet). These researchers have now almost reached the point at which our whole genome is 'known' (about 95 %, the remaining 5 % will be hard to find out). This gives us the possibility to search for differences in the genetic code between normal (non-cancerous) body cells and cancer cells: specifically, those mutations that cause these cells to grow abnormally fast. Knowledge about the genes that are involved in changing a normal cell to a cancer cell opens the possibility to invent drugs that inhibit or antagonize the gene's abnormal protein. It has hope that this form of drug selection would allow the drugs of the future to act specifically on cancer cells (normal body cells don't have these proteins and aren't affected by the drugs), a process that's called targeted therapy. 

In some cases this theory has proven successful already: a compound called Gleevec has shown to be very effective in the treatment of Chronic Myelogenous Leukemia (CML) which carries a mutation on chromosome 9 and 22 (called the Philadelphia chromosome or the Bcr/ Abl translocation). The drug is now being evaluated in clinical trials on various other diseases that carry the similar mutation. This process may take months or more likely years before the drug is accepted for treatment of larger groups. Many pharmaceutical companies have started developing drugs that attack newly defined molecular targets, hoping to contribute to the treatment of cancerous tumors while reducing the serious side effects that have characterized most forms of cancer treatment in the past.

But there are other things going on too: for some years now, researchers have been experimenting with anti-angiogeneic drugs _ agents that interfere with the development of new blood vessels within a tumor that allow it to grow. Our knowledge about tumors showed us that even potential malignant tumors would not grow any bigger than 0,2 mm if there wasn't enough blood supply (nutrients, oxygen). If there was however, these tumors would expand rapidly and obtain the ability to spread to other sites too (metastasize). The idea suggested here was to prevent blood vessels from forming by inhibiting their growth (anti-angiogenesis). In the beginning researchers hoped to even be able to shrink larger tumors, but nowadays the general view is that these drugs can potentially prevent smaller tumors and distant metastases form growing larger but can't make them disappear. The other problem they are still fighting with in this regard is the variety of ways that tumors seem to be able to recruit blood vessels: the more pathways being used, the harder it is to prevent angiogenesis. In brief, there is still much research to be done, but this field seems less promising than it was initially thought to be.  

Instead of antagonizing or inhibiting the proteins produced by the cancer cell you could also try to repair the genes that are damaged: this process is often called gene therapy. The concept is to insert the right (essential) gene into the tumor cells (often one of the DNA-repair genes) so that the loss of this gene is made up for. The problems have always been to find this essential gene and get it delivered to the cancerous cell. Once delivered it has to be expressed too. Thanks to the many people searching for ways to do this, there are now some promising results by using retro- and other classes of viruses that can carry a gene into a cell. These viruses may also deliver their own genome into the host cell. By deleting the gene that is capable of causing viral illness from the viral genome, the virus won't be able to do any harm but will function as a transport mechanism. It still is hard to get the virus delivered to the tumor and make it infect the tumor cells, but once the gene has been delivered it has shown to have a potential of contributing to the control of disease. One of the problems facing this field of investigation is the recognition that for a normal cell to transform in a cancer, several different mutations must occur. Will the substitution of one gene be enough to change the behavior of a cell? More likely several changes will be required. 

The final new method I wanted to discuss is immunotherapy. Wouldn't it be nice if we could teach our body to recognize the cancerous cells, because they are different, and kill them by itself? Our body has a couple of potentially killing cells such as lymphocytes and other cells of the immune system. If they could recognize the cancer cells as being different and invoke mechanisms that would specifically get rid of these cells based, on the presence of specific recognizing proteins on their cell surface, a major advance in cancer treatment would be achieved. The goals for the coming years is to find the best ways to teach these cells to differentiate between healthy and unhealthy cells, but the work already done looks promising. 

Surveying all the efforts that are taken to tackle this problem, I expect that the next five to ten years might provide us with some significant advances in cancer therapy. It might even include a more specific way of preventing the development of cancer in families who are recognized to be at high risk. There is one thing we should try and keep in mind though: to make it possible for the scientists working in this field to make these steps forward, they'll need time and resources. So while most of us must patiently wait for what future might bring, we could try and support the efforts of the international scientific community in its task to find ways to prevent, diagnose and treat cancer.