Dr. Foo Chuan Kit, Bayer Schering Pharma’s medical director for South Asia and Hong Kong, addresses the importance of tackling cancer in Asia.
Asia is facing a population explosion which will change the global disease landscape. Sixty percent of the world’s inhabitants – some 4 billion people – currently live in Asia, with 40 percent in China and India alone. By 2050, the continent’s population is predicted to rise to a staggering 6.5 billion people.
As the population continues to grow it is also continuing to age. In 2005 just 10 percent of Asians were aged 60 and above; by 2050 this figure will be closer to 28 percent, with Japan and Singapore expected to have the world’s highest proportions of over-80s.
With these trends emerging it is no surprise that cancer rates are climbing fast. Asia is facing a new epidemic, and it will not be long before the majority of the world’s cancer patients will be living in the continent.
In the face of this threat there is an urgent need to redress the global balance of cancer research. Most clinical trials continue to take place in the US and Europe, yet there are many important differences in the evolution of the disease between continents which demand further investigation.
The distribution of cancer is different in Asia, where certain types predominate in comparison to the West. Stomach cancer was the most common newly-diagnosed cancer in East Asia in 2007, yet did not feature in the top four most common types for North America or Northern and Western Europe. Liver cancer is particularly common in both East and South-East Asia, with lung, breast, colorectal and nasopharyngeal cancers also highly prevalent in these areas.
For men, according to 2002 data, prostate is the most common cancer type in the US, Australia and most of Europe, yet lung, liver and oral cancer dominate in Asia. Breast cancer is the most common type for women in most countries worldwide whereas in China stomach cancer is the most prevalent. In India and several other South and South East Asian countries cervical cancer is the most common type among women.
Understanding the reasons for these discrepancies is an important emerging area of investigation. Liver cancer in Asians, for example, is largely caused by hepatitis B, whereas hepatitis C and cirrhosis from alcohol abuse are more common causes among Caucasians. For nasopharyngeal cancer, a higher prevalence has been observed in Southern Chinese than in Northern Chinese, so there appear to be intra-ethnic differences as well. For other cancers, however, these regional variations and their explanations remain unclear.
These geographical differences also raise interesting questions as to the efficacy of cancer drugs in Asian patients. Gefitinib, for example, yielded disappointing results in clinical trials of western adenocarcinoma patients but was recently shown to be effective in non-smoking Asians with this cancer.
The optimal dosing for Asian patients is another important area of research. Docetaxel and carboplatin for example, appear to induce more side effects among Asian lung cancer patients than among Caucasians, and the dosages need to be adjusted accordingly. The response to these drugs also seems to be higher among Asian patients, but more research is still needed to better understand these observed differences.
With so many unanswered questions the need to invest in Asia is greater than ever. At Bayer Schering Pharma we have committed S$20 million over the next 6 years into research in Singapore alone. In Asia Pacific as a whole we enrolled less than 100 patients in clinical trials in 2005; by the end of 2007 we had 3,700 patients participating in 64 different trials.
The growing investment from pharmaceutical companies is great news for Asia. The increasing number of research collaborations, such as our recently-signed agreement with the National University of Singapore, will give patients unprecedented access to exciting new drugs. The increasing focus on translational research, meanwhile, will help to minimize the time from bench to bedside, enabling new compounds to enter clinical trials as early as possible. The recruitment of patients also seems to be quicker in Asia Pacific, with our data suggesting that the enrollment process here is twice as fast as the global average.
As our understanding of cancer in Asia improves so too will our treatments. This investment in Asia-specific research must be sustained in order to strengthen our defences in the face of the future epidemic.
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