In 1971, US President Richard Nixon signed the National Cancer Act, kick-starting what has become known as the War on Cancer. In the following four decades, cancer diagnosis, prevention and treatment has changed significantly in many developed countries. But until relatively recently, these advances had failed to translate into meaningful improvements in survival for many types of cancer.
In the mid-1980s, a statistician named John Bailar published a damning and much-publicised report looking at cancer survival rates in the US, concluding that – with the exception of certain diseases such as leukaemia – Nixon’s War on Cancer was a “qualified failure”. This poor public perception still persists today in many quarters, with some people claiming that “nothing has changed” and that “millions of research dollars have achieved nothing”. Yet things have improved – albeit not as fast as all of us would like, and certainly not on a global scale.
From losing to gaining
When Bailar revisited his analysis of the War on Cancer in 1997, the conclusions were still grim. Although survival for more types of cancer was starting to improve measurably in the US, any gains were overwhelmed by surging lung cancer rates, thanks to the smoking boom earlier in the 20th century. But again, the picture has changed over recent years, and survival has climbed consistently in many countries since the mid-1990s. In many parts of the world, your chances of beating cancer today are better than they have ever been.
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This improvement has been driven by researchers all over the globe, finding new ways of diagnosing cancer earlier, visualising it within the body, and treating it with surgery, radiotherapy, chemotherapy and other approaches. In the UK alone, advances in research have saved more than half a million lives over recent decades.
Despite this progress, the statistics are stark. More than 12 million people are diagnosed with cancer every year worldwide and the disease accounts for more than 15 percent of annual global deaths, claiming more than 7.5 million lives. And, ironically, while advances in public health have helped to reduce deaths from infectious diseases in poorer countries, cancer is a growing spectre in these parts of the world.
Global problem, global action
Although cancer is a global problem, there are significant variations from country to country and few “one size fits all” solutions. In Western Europe and the US, cancer incidence is dominated by the “big four” – lung, breast, prostate and bowel cancers. Stomach and liver cancers are a much bigger problem in Asia and Eastern Europe than in the west, while cervical cancer and non-Hodgkin lymphoma (caused by infection with the Epstein-Barr virus, or EBV) are major players in Africa. And malignant melanoma, the most dangerous form of skin cancer, is the fourth-most common cancer in Australia due to overexposure to UV rays from the sun.
These differences are underpinned by a range of things including genetics, lifestyle and the environment. In addition, cancer is just one of the health problems affecting us all. Heart and lung diseases, infections including HIV/AIDS and malaria, diabetes, famine and drought, malnutrition and war are all pressing problems in different parts of the world. And there’s also huge variation in the availability of money and political will to fix them.
To try to pull together a co-ordinated effort to tackle cancer across the globe, research and health leaders from 15 countries – representing more than half the world’s population, including low- and middle-income countries – met in November 2012. Led by the US National Cancer Institute’s director and Nobel laureate Dr Harold Varmus and Cancer Research UK’s chief executive Dr Harpal Kumar, they identified a number of key areas to focus on, which will collectively benefit millions of people. Here are a few of the really big ones.
Number crunching: In order to fix a problem, you need to know what you’re dealing with. One of the major problems in understanding cancer in many countries is a lack of good data on the number of cases (incidence), deaths (mortality) and how long people survive (survival). The latest research suggests that global cancer figures are estimated from data taken from only around one-third of 184 countries. So building better cancer registries to collect and crunch the numbers, as well as providing better pathology services to analyse tumours, are a key priority. Health services and governments can’t tackle what they can’t measure.
Prevention is better than cure: As everyone knows, prevention is better than cure, yet preventable causes of cancer still continue to claim a huge death toll around the world. Smoking remains the leading cause of cancer death in the world, and though the introduction of smoke-free legislation in many countries has loosened the grip of the tobacco industry in the West, it has taken its trade elsewhere. China and Africa are the industry’s main targets, priming a tobacco time-bomb that will explode into millions of lung cancer cases over the coming decades. Governments and health organisations must do more to control tobacco use and save millions of lives, despite the lobbying from tobacco companies.
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One in five cancers globally is caused by viruses and bacteria, which could be prevented by vaccination and antibiotics, respectively. In particular, the existing vaccines against hepatitis B virus (HBV, which causes liver cancer) and human papilloma virus (HPV, causing cervical cancer) have the capacity to save many lives, and should be rolled out as widely as possible. Vaccination programmes in Africa and Asia have shown that HBV jabs can cut liver cancer rates. But there’s been less success with HPV vaccination, due to low uptake in many countries and the cost of the vaccine (covered in some places by the GAVI Alliance). And there’s also an urgent need to develop vaccines against other cancer-causing infections, such as hepatitis C (liver cancer) and Epstein-Barr virus (lymphoma and naso-pharyngeal cancer).
The modern plagues of obesity and excessive alcohol consumption are having a significant impact on cancer rates in richer countries – and are a growing threat as poorer countries develop and become more westernised – posing the challenge of balancing personal responsibility with public policy. There’s also more work to be done on drugs to prevent cancer, known as chemoprevention. For example, there’s growing evidence that regular low doses of aspirin may help to cut cancer risk in some people, while hormone-blocking drugs can cut the chances of breast cancer in those at high risk.
Finally, screening is also vital for spotting cancers at an early stage, or – in the case of bowel and cervical screening – before any suspicious cells get the chance to develop into full-blown disease. However, some of the available tests – notably breast screening through mammograms – suffer the problem of over-diagnosis, which still needs to be resolved through more detailed research and analysis. And, of course, screening tests that we take for granted in the west simply aren’t available in many parts of the world, although innovative thinking – such as a vinegar-based test for cervical cancer – could make a big difference.
Improving treatment: Treating cancer effectively is still difficult, especially once it has spread through the body. Surgery is still the mainstay of treatment, and cures more people than any other therapy. Yet access to even basic cancer surgery is scarce in many poorer countries. Programmes to send surgeons from wealthier countries to carry out operations and train up locals are making a difference, but more could be done. Radiotherapy is also a “forgotten” treatment, yet it too cures more patients than chemotherapy. Again, access to radiotherapy technology and trained operators varies hugely around the world.
Compared with the early days of chemotherapy in the 1950s, when Sidney Farber and his colleagues worked with a mere handful of molecules, doctors now have a huge arsenal of drugs to utilise. But many of them, particularly the newer, biological treatments, are prohibitively expensive – even for the richest countries – while offering only modest survival benefits. It’s clear we need to be smarter with our drugs, developing molecular tests to tell which patients will benefit from modern targeted therapies, as well as finding ways to widen access for older drugs whose effectiveness has been proven.
We need larger, more effective international clinical trials for new treatments, as well as publication of all trial results, whether positive or negative. And pharmaceutical companies must learn to work together to test combinations of new drugs together, which are more likely to work than single agents given one at a time.
Into the future
Cancer has always been with us, and it continues to be a major and growing challenge. We know that research is our greatest weapon in this fight, and that although we’ve made great progress over the past century, we still have a long way to go. Advances are being made all the time in our understanding of the complex array of diseases that we call cancer, particularly as a result of the genetic revolution. But there’s still little that doctors can do when faced with cancer spreading aggressively round the body, even in hospitals in the wealthiest cities in the world.
Across the globe, many people are living longer. But, because cancer is mainly a disease of old age, this is a prime driver of rising cancer rates. Scientists must keep working to understand the biology that underpins cancer, finding smarter, more effective ways to diagnose, treat and prevent it. And policymakers and healthcare providers must ensure that they are prepared to fight cancer in the 21st century, taking advantage of the benefits that this research continues to bring.