Will we ever get a cure for cancer?

How likely is it you will find a cure for cancer? It’s very unlikely there will ever be a single ‘cure’ because cancer is made up of more than 200 different diseases – like breast, lung, bowel, prostate and blood cancers – and the latest molecular research is breaking these classes down into many more sub-groups. Different targeted treatments are needed for each sub-type – an approach called ‘personalised medicine’. At The Institute of Cancer Research (ICR) we have a relentless focus on making the discoveries that defeat cancer. Our scientists and others worldwide are working incredibly hard to discover better treatments that will cure cancer. On the way to that, we know patients and their families also value therapies that prolong life, for example extending survival in hard-to-treat advanced cancers from a few months to many years.

Which cancers are most effectively treatable? Testicular cancer is now more than 95 per cent curable with drugs. Results in some leukaemias have improved dramatically. Treatments for cancers like breast, bowel, prostate and ovarian cancer have also improved a lot. But other cancers are much tougher to treat. For example, Cancer Research UK has prioritised lung, pancreatic, gullet and brain cancers because the survival rates remain very low.

People should definitely be less afraid of cancer than in the past

Should we be less afraid of cancer? People should definitely be less afraid of cancer than in the past and I think this is happening. Cancer is not now the death sentence it used to be. Survival rates have doubled since the 1970s. Half of patients with cancer now survive for five years or more. People are better informed, are becoming more aware of the symptoms, and realising that research leads to better treatments and outcomes. So we should be less afraid but we still need to improve awareness.

How important is early detection and treatment? Detecting and treating cancer early is really very important. It’s clear that in many cancers early detection and treatment does lead to much better outcomes. Just over half of patients with cancer are diagnosed at a stage when the disease can be successfully treated – but this means that for nearly half of patients the cancer is detected too late. It’s important that people contact their family doctors if they have unusual or worrying symptoms so that tests can be carried out in good time. A recent independent survey confirmed the value of mammography screening for breast cancer. There are new initiatives for early detection in bowel and ovarian cancer.

How big a role does prevention play? Prevention is extremely important. But there is no magic pill. Smoking is still the leading cause of lung and other cancers worldwide and we need to continue to campaign for measures that discourage smoking. Excessive exposure to the sun and sunbed use is the main cause of lethal melanoma skin cancers. The evidence is also clear that a good balanced diet, avoiding obesity and excessive alcohol intake, and taking regular exercise all help in a major way to prevent many cancers; in other words a healthy lifestyle.

How does better understanding of hereditary factors help? Our research at the ICR provided the first evidence that damage to our DNA code is the fundamental cause of cancer at the molecular level. Cancer-causing faults in our DNA code can be inherited from our parents or can be acquired during our lifetime – for example, by smoking. We have now catalogued many inherited genes that can increase the risk of different cancers. Some are powerful on their own – such as the BRCA genes in families at high risk of breast and ovarian cancer – which means that appropriate genetic counselling and testing can be provided and relevant action taken. Other genes have weaker effects and work alongside many additional cancer genes, meaning that counselling is less straightforward. This is a very important area of research.

What have been the biggest advances in research in the last five years? I think the biggest advance in this period has been the dramatic increase in our understanding of the precise faults in the DNA code of our genes that lead to cancer. This was enabled by the sequencing of the human genome, which in turn allowed the DNA code of a cancer to be compared with that of the normal cells and the differences identified. Around 500 cancer genes have been discovered within the 20,000 genes that we all have. And we are not only cataloguing all the cancer genes but also understanding exactly how they act in our cells to cause cancer – by sending signals that force cells to divide uncontrollably and to spread around the body.

We are not only cataloguing all the cancer genes but also understanding exactly how they act in our cells to cause cancer

And in treatment? The most dramatic breakthroughs in treatment over the last few years have followed directly from the genetic and biological understanding. New drugs have been designed to target the defects caused by faulty cancer-causing genes. These are known as personalised medicines because they act specifically in those cancers with the particular gene abnormality, which can be detected in lab tests. Such personalised therapy is more effective and has fewer side-effects than the old one-size-fits-all cytotoxic drugs. This approach has been very effective in the treatment of breast cancer and leukaemia and we have seen recent dramatic progress in tougher cancers like prostate – where our ICR-discovered drug abiraterone has had a huge impact – along with lung and melanoma. This is an area we are focusing on intensely at ICR. The proportion of patients who are eligible for treatments that accurately target their cancer with fewer side-effects – especially using molecularly targeted drugs but also high-precision radiotherapy and minimally invasive surgery – has been increasing steadily.

What might be the next big breakthroughs? In addition to further progress in personalised, targeted therapies there is good evidence that treatments based on improving the immune response to cancer have real potential. A critical area of research will be to understand the mechanisms by which cancers develop resistance to drugs and to devise clever therapeutic approaches to overcome these mechanisms. We are making real progress on this.

What three things would make the biggest difference in prevention and treatment of cancer? First, we need to finish finding all of the cancer genes, understanding how they work and discovering personalised targeted therapies to counteract them. Second, we must understand and counteract drug resistance in cancer cells – often involving further gene changes – which will require carefully designed drug combinations based on regular molecular profiling of the cancer. Transferring such personalised therapy – requiring drugs and companion gene tests – from the setting of clinical research trials into practical, affordable routine care within the NHS will be crucial. Finally, tackling the issues of higher cancer incidence and poor treatment outcomes in low-income communities and poorer regions of the world will be very important. It’s important to stress that funding for cancer research is essential to ensure continued progress towards increasing survival and cures for cancer patients.

Professor Paul Workman is deputy chief executive of The Institute of Cancer Research London