By James Brown, Education and Public Engagement Officer, Biochemical Society
Few things can compare to being told that you have cancer. In 2013 there were 352,197 new cases of cancer diagnosed; that’s equivalent to 960 people being given this news every day. This is in part due to improved early detection and screening practices, as well as increased public education about cancer. As we get better at finding cancers early, we are able to offer people treatment at an earlier stage than ever before. This is paying off; Cancer Research UK states that now over half of people diagnosed with cancer survive for ten years or more. However, along with this improvement in outlook comes the problem of over-treatment. Whilst some cancers are aggressive and dangerous, some are slow growing and would not cause a problem in the patient’s life time. Since treatments always contain some level of risk or potential side effects, it may not always be advisable to treat every cancer. But how would you feel if you were told that doctors were not going to treat you?
That was the situation for David Hopkins, who joined the chair Professor Vivienne Harpwood (Cardiff University), Dr Elisabeth Walsby (Cardiff University), Dr Sunil Dolwani (Cardiff University), Professor Howard Kynaston (University Hospital of Wales) at a public panel discussion in Cardiff earlier this month, organised jointly by the Biochemical Society and Cancer Research UK.
David was a member of the ProtecT trial which demonstrated that early prostate cancer detected by screening is usually slow growing and indolent in its behaviour when compared with prostate cancer that presents clinically. David was one of a number of patients who was offered active monitoring rather than treatment. He explained that he made this decision after considering the side effects of chemotherapy and surgery and how they would impact on his life. After getting over the initial shock, he says that being on an active monitoring programme allowed him to forget about the cancer and get on with living normally. Howard presented results from the trail which showed that after 10 years, there was no difference between the monitoring and treatment groups in terms of death rates, although there were greater levels of progression in the monitoring group- about half of whom required some form of treatment. Being able to avoid side effects such as incontinence and erectile dysfunction without an increase in death rates at 10 years suggests active monitoring needs to be seriously considered as an option for those diagnosed with prostate cancer.
In a similar vein, Sunil discussed his work on bowel cancer, in particular the difficulty in choosing treatment options for patients. Like with prostate cancer, polyps in the bowel will not always result in a dangerous cancer. The risks of surgery must be carefully weighed up against the potential benefits, particularly in patients who have other health issues. Sunil gave us a number of examples of patients with other pre-existing conditions and the sorts of considerations that need to be made when deciding on a course of action. These decisions are rarely straight forward and rely on accurate identification of these polyps. Being able to distinguish between fast growing or slow growing polyps will provide patients with a better chance of making the most informed decision.
Elisabeth was able to provide us with an insight into the research that she is carrying out which may make some of these decisions easier to make. Her work on chronic lymphocytic leukaemia (CLL) is identifying the molecular differences between progressive and non-progressive forms of the disease. Elisabeth has developed a novel in vitro model of CLL which lets her investigate the interactions between CLL cells and endothelial cells. As CLL cells flow through the blood vessels, some are able to adhere to the endothelial cells and migrate into the extravascular space. It is these CLL cells which are the most dangerous. By investigating expression of particular cellular markers, Elisabeth is able to identify differences between CLL cells which migrate through the endothelium and those which do not, in particular the increased expression of certain extracellular markers, particularly CD49d, a section of an integral membrane protein.
As research continues into the cellular properties of cancers, we will learn more about what causes some cancers to be fast-growing and aggressive and some cancers to be slow-growing and potentially unnecessary of treatment. The ability to distinguish between these different types on a molecular level, will provide us with better diagnostic tests and the ability to give patients more information about their conditions which will allow them to make better informed decisions and avoid suffering the side effects from unnecessary treatment.
David’s experience on the ProtecT trial was an example of the importance of providing patients with clear information about their options. He cited the support that he received from the doctors and nurses on the trial as a key contributor to his satisfaction with his outcome. As research into cancer biology continues, we will be able to provide individual patients with much more detail about their individual circumstances and treatment options.