During the 70th World Health Assembly in 2017, health leaders globally reaffirmed cancer control as a critical health priority, with plans to systematically strengthen cancer services over time. Lung cancer mortality is projected to be around 3 million cases per year by 2040, compared to 1.8 million in 2020. While mortality rates of lung cancer have been decreasing in some parts of the world, especially in Western countries like in the U.K. — the opposite is true in Asia. Additionally, the prognosis for lung cancer in Asia is poor compared with other cancers. Globally, about 70% of lung cancer cases are diagnosed at a late stage, the result of which is a dismal 10%-20% of patients surviving five years after diagnosis in most countries.
Beyond the significant burden of lung cancer in the region, Asian populations also face a vastly different demographic and epidemiology of lung cancer patients than Western populations. A higher and increasing number of nonsmokers are being diagnosed with lung cancer. Nonsmoking lung cancer patients are also more likely to be women. For example, one study showed as high as 52.5% of nonsmoking patients diagnosed in South Korea were women. Additionally, there is a higher prevalence of epidermal growth factor receptor mutations in Asians, 40-55% compared to 15-25% in Westerners. These unique factors mean that Asia requires a differentiated approach to lung cancer management.
Furthermore, because of the smoking-related stigma associated with lung cancer, combined with the fact that it remains an underserved area in national cancer screening programs in the region, has led to missed opportunities for early detection and better outcomes for patients.
So, how can we achieve the best-tailored solutions that drive improved lung cancer outcomes in Asia?
Early screening not only enables higher quality diagnosis, more rapid access to care, and the best opportunity to reduce the number of deaths, but also results in significant cost-savings to the individual and health care systems at large. Treatment for patients who are diagnosed earlier costs two to four times less compared to treating patients diagnosed in more advanced stages. While many economies around the world have implemented national screening programs for other cancers such as breast cancer, more can be done to ensure access to lung cancer screening in Asia.
This week’s 2023 World Conference on Lung Cancer in Singapore, provides an excellent platform to highlight the importance of early and effective lung cancer screening in Asia. As part of efforts to maximize this opportunity, a leading group of experts discussed the significance of ensuring early screening in the region.
As part of our efforts to improve lung cancer management, we also need to ensure that the “atypical” lung cancer population group of nonsmokers and women are not left behind by health care systems and screening programs in Asia. Therefore, other risk factors must be considered, especially in never-smokers. Identifying the right high-risk patients to screen for lung cancer is critical, with experts urging nonsmokers in Asia aged 50-75 years with a family history of lung cancer to be included in lung cancer screening programs, in addition to heavy smokers. In a first-of-its-kind policy, Taiwan has implemented a lung cancer screening program that includes high-risk nonsmokers with a family history of lung cancer.
Researchers have also found a link between air pollution and the increasing prevalence of lung adenocarcinoma, a type of nonsmall cell lung cancer. This underscores the importance of reducing air pollutant emissions, especially in Asia where emissions of black carbon and sulfate are increasing.
There is also an urgent need to utilize an effective and sensitive screening method in national screening programs. Using low-dose computed tomography, or LDCT — a screening tool that uses a computer with low-dose X-rays to generate a series of images — has demonstrated a 20% reduction in lung cancer mortality due to diagnosis at earlier stages of the disease.
While several medical societies and ministries of health have recommended utilizing LDCT to screen for high-risk populations, it is still not implemented in routine lung cancer screening programs in most parts of Asia. This is due to challenges such as perceived cost, lack of reimbursement, lack of infrastructure and trained staff, reluctance of eligible high-risk individuals, as well as national guidelines.
To help drive positive health lung cancer outcomes in Asia, we need to improve equitable access to lung screening, through a resource-stratified strategy. Many places in Asia lack the capacity and capability to introduce LDCT screening. Comprehensive cancer diagnosis and treatment services were reported to be available in more than 90% of high-income countries, 50% in middle-income countries, but less than 40% in low-income countries.
Introducing technological advancements, including artificial intelligence-assisted chest X-ray, or CXR, may also be a pragmatic approach to overcoming these challenges and driving earlier diagnoses. The use of AI algorithms has been shown to increase the identification of lung cancers on CXR by 17.4%, which would have otherwise been missed, and showed an overall increase in detecting smaller tumors.
For instance, in Thailand, Qure.ai, an AI solution for automated interpretation of CXRs was introduced in selected primary care facilities. According to internal data, over 36,500 AI-assisted CXR scans have been successfully completed so far. In settings where cost, practicality, and capability are considerations, AI-CXR is an affordable yet effective approach to screening high-risk populations for lung cancer at national level, before funneling them to more sensitive screening approaches, including LDCT.
At AstraZeneca, we are committed to transforming lung cancer. As part of our commitment, we aim to screen five million patients by 2025, which will include our partnership with Qure.ai. To date, almost 128,000 scans for lung cancer risk have been processed in over 25 countries through this partnership. The technology has identified high-risk cases in 1.6% of scans, which otherwise may have gone undetected.
Asia’s policymakers have a crucial opportunity to save the lives of these at-risk patients, thanks in part to the latest advances in lung cancer screening technologies. As governments anticipate the increase in cancer prevalence, we have a responsibility to build and establish sustainable and equitable health systems, so lung cancer patients have the same access to best-case outcomes across Asia. Furthermore, with climate change being one of the exacerbators of lung cancer, a comprehensive approach to lung cancer care also needs to consider climate action.
Together with reinforcing smoking cessation policies, we must ensure access to effective lung screening programs for high-risk populations, if Asia wishes to seize its opportunity to reduce the burden of this deadliest cancer.