In some ways it is unimaginable what remains to be discovered in the field of oncology; however, with the amazing pace of research some recent important advances are pointing the way to the future.
An example of this is cancer genomics, the field of studying the genes and mutations of a cancer, has opened our eyes to the complexity of cancers. This complexity is not only evident between individuals, but even within an individual. In other words, it seems easy to understand that two different patients with the same cancer type (for example, two women with colon cancer) may have tumours that are actually quite different at the gene level, after all, the patients are different. However, it is quite astonishing how many differences can be found within tumour cells taken from the same patient (for example, the cells of colon cancer that have travelled to the liver may be quite different from those that travelled to lymph nodes).
Sometimes, differences are even seen between cells that are growing next to each other as part of the same tumour mass, meaning that every cancer nodule or mass has the potential to be a complex soup of different cancer cells. This amazing complexity and genetic diversity helps us to understand how even very good treatments may not succeed if a proportion of cells are always able to survive. I hope that on the horizon are the solutions we need to overcome this major biologic challenge. We can perhaps imagine that by studying many hundreds and thousands of cancers, and using very powerful analytic tools, we may be able to predict the types of genetic changes cancers develop, or at least measure them all simultaneously. With time we may decipher this process or at least be able to monitor it. If this can be achieved, then we can hope for more intelligent treatment approaches that eliminate all the cells efficiently.
There is much to be done, but I always find it inspirational to know that despite what appears to be an insurmountable challenge, researchers have already started with this type of work. But they need our support to keep this work moving forward. Support can come in many forms, including patients participating in studies, and donors generating funds to sustain these important efforts.
The evolving understanding of the role of the immune system in cancer is another fascinating and promising area. I have already mentioned in my earlier blog some of the work that is going into understanding the role of the immune system in controlling cancer. Much like cancer genomes, the interaction of the immune system with cancers is extremely complex.
The immune system is comprised of many different immune cells and hormone signals, all mixed in the complex environment of cancer cells, blood vessels, body organs, etc. Just like our immune systems respond to infections a variety of ways, they respond differently to different cancer types. Some responses are strong and favorable, trying to control cancer, but other responses are weak, allowing cancers to grow unchecked. Much work is going on right now in trying to understand why such different responses are seen.
In addition, there is a lot of interest in figuring out whether we can “turn-on” the immune response even in those cancers that the immune system doesn't recognize. It is particularly interesting that we now know that the cancer genome (the arrangement of genes and gene mutations) can influence how the immune system responds. Cancers that have many genetic mutations, for example, often have stronger immune activation. Cancers with simpler genomes sometimes evade immune detection. Knowing this can help us to better use immunotherapies in those cancers most likely to benefit from them.
As an oncologist, I am keen to have better treatments to offer my patients. However, what I really hope is on the horizon is better methods for early cancer detection and cancer prevention. We may find many good cancer treatments, but at the present time it is difficult to know if those treatments will cure people. Prevention is always better than treatment. I would be happy to be out of work if it meant that people weren’t getting sick with cancer!
Simple prevention strategies like good lifestyle choices remain the corner stone of the best population strategies for keeping the greatest number of people healthy for the longest possible duration of their lives. However, even if every one of us could adhere to a good lifestyle every day of our lives, we would still see cancers arise. A proportion occurs in people who have inherited a faulty gene (hereditary cancers), some may arise as a result of acquiring a cancer causing infection (for example, human papilloma virus which causes cervical, anal and head and neck cancers); however, the majority just occur as a result of being alive and getting older. Better and easier screening tests are needed so that we can detect pre-cancer changes or very early cancers and prevent cancer deaths. This needs to be a major research focus moving forward. The old adage hasn’t changed: and ounce of prevention is worth a pound of cure. If you are reading this blog, ask yourself: Have I spoken to my GP about colon cancer screening? Have I booked my next mammogram? Am I due to have my next Pap smear? Please don’t forget these important methods which are proven to save lives.
Thanks for reading,