Prevention Is Key in the 'War on Cancer'

Becky McCall

October 22, 2015

LONDON, UK — Understanding the causes of cancer as a foundation for prevention is central to success in the war on cancer in coming years, says Dr Christopher Wild, PhD, director of the International Agency for Research on Cancer (IARC), speaking at a one-day healthcare forum in London discussing how to measure success in combating the disease.

Dr Wild has been a cancer researcher for 30 years, and he says he is always being asked about finding a cure for cancer. But nobody has ever asked him, "Can we prevent cancer yet?" "Before I retire, I want someone to ask me this."

Acknowledging significant improvements in the survival rates for many cancers, he asserted that there were others for which little progress had been made. The predicted 60% increase in cancer burden over the next 2 decades, mostly as a result of the ageing population, is a significant threat. "No country, however rich, can treat its way out of the cancer problem. I think the key objective should be to reduce the number of people getting cancer by prevention, and then the budget can be used effectively to purchase the drugs needed."

He added that the costs of cancer in Europe, representing around 1% of the gross domestic product (GDP) in some central and Eastern European countries (approximately 120 billion euros, 2009) as well as the number of patients in these countries were both set to double. "The economics dictate that cancer services for this burden are not sustainable, which is why it is important to look at the bigger picture and attack environmental determinants such as tobacco use."

Translating Existing Cancer Knowledge Into Prevention

Dr Wild explained that one measure of success would be to implement the knowledge gained over the last 60 years about cancer and translate this into preventive interventions that work on the ground. Understanding the environmental causes, associations, and risk factors for cancer is central to the work of IARC.

"There are some striking disparities in patterns of cancer worldwide," remarked Dr Wild. "For example, cancer of the esophagus can be the most common cancer in men in East Africa but it is hardly seen in West Africa," he said, pointing out that, "such a striking difference is not due to genetics, so we're looking at behavioral and environmental factors to find clues to the causes."

Similarly, significant differences exist at the mutational and molecular level of cancers. These can be driven by different regional exposures and risk factors. "Colorectal cancer in India versus colorectal cancer in the US can look very different in this respect," he said, adding that, "our approach needs to take this knowledge and go back to look at the population to understand the causes and then the avenues of prevention."

Illustrating how identifying a pattern of tumor mutation can aid discovery of the cause of a cancer, Dr Wild discussed how, in 2014, the IARC published results that found a correlation between clear-cell renal cell carcinoma and exposure to aristolochic acid in Romania.

Pathology showed that kidney cancers from patients in the United Kingdom, Russia, the Czech Republic, and Romania looked the same but that mutations in the cancers sourced from Romania had a very different pattern of base pair changes. This pattern had previously been associated with aristolochic acid, an environmental carcinogen naturally found in plants including the European birthwort that is widespread in the Balkans as well as in wheat.

Aristolochic acid was found in the tissue of kidney cancer patients in Romania, relating to environmental exposure, but not in kidney cancer patients from elsewhere. "This carcinogen had never before been associated with kidney cancer, and was the first time cancer research had been approached this way," said Dr Wild.

He also pointed out that he believed early detection played a significant role in addition to primary prevention. He explained that around 50 years ago, cervical cancer rates in Nordic countries were the same as they are today in sub-Saharan Africa. "In these Nordic countries, cancer rates were reduced by screening and women's access to screening. But also today, the rates of cervical cancer in Romania are like sub-Saharan Africa. We are not implementing what we know," he emphasized.

Equal Access to Benefits in High- and Low-to-Middle Income Countries

Turning to the balance of benefits between high- and low-to-middle-income countries, Dr Wild highlighted how the benefits from cancer research needed to be made equally accessible across populations. "The measure of mortality against incidence of cancer gives an indication of survival. This ratio is 0.4 in the US and in parts of sub-Saharan Africa it is 0.8, so in the latter case, around 80% of people with cancer die from it," he said. Access to treatment “needs to improve in the populations that need it most," he added.

Dr Wild explained that when IARC started 50 years ago, the developing world offered opportunity to learn something about unusual cancer patterns that would benefit the world more generally. "These findings and any associated solutions weren't necessarily adopted by developing countries at the time because they had more pressing problems...but now we see these countries want research conducted to address problems which they are facing, because their cancer rates are climbing."

Improved Survival, Greater Than 3% Spend on Prevention, and Continued Attack on Tobacco

Also speaking in the session was Kevin Harrington, MD, Joint Head of the Division of Radiotherapy and Imaging, The Institute of Cancer Research, London, UK. He said that he regards ; success as the situation whereby clinicians found that new patients now had a 65% chance of 5-year survival from their disease. "Our goal is to maximize that. However, I know radiation therapy is very effective in cancer but I am disappointed that there are huge disparities in the national and international availability of good quality technology for radiation delivery." He also highlighted the importance of educating medical staff to deliver the best quality treatment possible.

Dr Harrington also said that he focuses on aiming to cure a patient the first time he met them. "The best chance to cure is when first diagnosed, because advanced metastatic disease has a vanishingly small chance of cure. I want to see the most advanced drugs used upfront."

Taking a pan-European stance, Alojz Peterle, Member of the European Parliament (MEP) and president of the MEPs Against Cancer group, Brussels, Belgium, remarked that he considered success to be when European Union (EU) member states invest more than 3% of their health budgets on prevention, and diminish the inflow of new patients. "I would like to see joint EU action. Citizens don't like discrimination."

He also noted that all member states needed to have regulated registries so countries can compare results, and for all member states to have a national plan.

Echoing Peterle, Cary Adams, MD, chief executive officer for the Union for International Cancer Control in Geneva, Switzerland, also highlighted the importance of registries. "With poor data, a national cancer control plan is essentially a piece of paper. Without this, we can't measure success or judge where priority investment should be."

The MEP also emphasized that he would like to see a continuation of the war on tobacco. "Sixteen percent of all Europeans under 30 years die from a tobacco related illness, 70% of all lung cancers are caused by tobacco. I believe that the response of the European community so far has been OK, not good, but OK."

The World Health Organization Framework Convention on Tobacco Control has been signed up to by 50 of 53 countries. "Less than 10% of these countries have images on cigarette packets and less 10% of countries have stopped the promotion of cigarettes and about half have increased taxes on tobacco," he noted.

War on Cancer: A Unified Battle in the 21st Century was held October 20, 2015, in London, UK. It was sponsored by The Economist.

Dr Wild has disclosed no relevant financial relationships.

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