Worldwide, lung cancer is the leading cause of cancer-related death. However, according to the latest medical research reports [1–3], if the nature and symptoms of cancer are correctly identified at an early stage, it can be cured. The cancer spreads to other parts of the body through the blood and lymphatic system, which is a process called metastasis, and then quickly causes the development of secondary tumors [4]. Some high-risk factors like smoking, breathing polluted air, and living in a polluted area can negatively affect the prognosis and quality of life of lung cancer patients [1, 5]. Lung cancer can also be hereditary [2].
At the beginning of the twentieth century, the incidence of lung cancer was very low, but now its incidence is increasing rapidly [4, 6]. According to the GLOBOCAN 2012 report, there have been 1.8 million new cases (incidence) of lung cancer globally, constituting 12.9% of the total estimated cancer incidence in the year 2012 [2]. Of these cases, 58.0% are from the underdeveloped countries [2]. Hungary had the highest incidence of lung cancer (51.6%), followed by Serbia (45.6%) and Korea (44.2%) [2]. In 2012, lung cancer incidences for both men and women were highest in North America; the incidences were lowest in Africa, followed by Latin America and the Caribbean. In the same year, incidence of lung cancer in men was highest in Hungary (76.6%), followed by Armenia (72.9%) and Macedonia (44.2%) [2]. In India, the lung cancer mortality is high [7]. In 2012, the World Health Organization (WHO) reported that, worldwide, lung cancer causes 1.59 million deaths [8]. Tobacco-smokers aged above 50 years are at the highest risk for lung cancer. Presently, incidence of lung cancer is low in women, but changes in lifestyle might increase it in the future.
Based on the aforementioned data, it is clear that the worldwide incidence of lung cancer is alarming; indeed, it has become the most common and fatal type of cancer. The main objectives of this study were to assess the incidence of lung cancer and the associated mortality, and to analyze the on-going research in the field of computational methods for lung cancer detection. An in-depth analysis of the current research will be helpful in the development of new techniques to detect lung cancer at an early stage.
Data sources and methods
For this study, we collected data on lung cancer incidence and mortality in the United Kingdom (UK), the United States (US), India, and Egypt from the following sources [3]. We have also considered data sources from France and Switzerland, as these organizations collect and publish global data.
UK
General Register Office for Scotland: A repository that maintains medical statistics and records of births and deaths.
Information Services Division (ISD), Scotland: Part of National Services Scotland. Provides health data to all, free of charge.
National Cancer Intelligence Network (NCIN): Established to improve clinical outcomes, cancer care, and prevention. Since April 2013, part of Public Health England.
Northern Ireland Cancer Registry: Established in 1994 and located in the Centre for Public Health, Queen’s University Belfast. Maintains cancer incidence and mortality data. Funded by the Public Health Agency for Northern Ireland.
Northern Ireland Statistics and Research Agency: A repository that maintains medical data and social research as well as records of deaths and births.
Office for National Statistics (ONS): A statistical institute of the UK. Collects and publishes population, social, and economic statistics.
United Kingdom and Ireland Association of Cancer Registries (UKIACR): Focuses on developing cancer registration in the UK and Ireland for the purpose of studying and controlling cancer.
Welsh Cancer Intelligence and Surveillance Unit (WCISU), Wales: The national cancer registry of Wales. Stores and publishes data on cancer incidences in Wales.
US
Centers for Disease Control and Prevention (CDC): It helps in detecting and responding to new and emerging health threats. The aim of CDC is to tackle the biggest health problems that cause disability and death.
Surveillance, Epidemiology, and End Results (SEER) database: An authoritative source of information on cancer incidence and survival in the US.
India
Indian Cancer Society (ICS): A non-profit organization established by Dr. Darab Jehangir Jussawalla and Mr. Naval Tata for cancer awareness, detection, cure, and survival. Also gathers cancer-related incidence and mortality data from different cities in India.
Indian Council of Medical Research (ICMR): A council in New Delhi, India, for the preparation, collocation, and support of biomedical research. Main research focus is to control communicable diseases, cancer, cardiovascular diseases, blindness, and diabetes and to develop healthcare strategies. Launched the National Cancer Registry Program (NCRP) to collect reliable cancer data, conduct epidemiologic studies, design cancer control strategies, and organize cancer awareness programs.
Institute of Cytology and Preventive Oncology (ICPO): It is a leading institute under the ICMR. It provides awareness, prevention strategies, and treatments of leading cancers in India.
Egypt
Gharbiah Population-based Cancer Registry (GPCR): Sponsored by the Middle East Cancer Consortium and the Egyptian Ministry of Health. Publishes annual statistics of cancer incidence and mortality as well as possible control strategies.
International Association of Cancer Registries (IACR): A professional society that collects cancer-related incidence, mortality, and survivorship data for a specific population group.
National Cancer Registry Program of Egypt (NCRP): Supported by the Egyptian Ministry of Communications and Information Technology. Collects cancer data, conducts data analysis, operates training programs, and develops cancer control strategies.
Other countries
World Health Organization (WHO), Switzerland: Established in 1948 in Geneva, Switzerland. Part of the United Nations. Dedicated to all matters of global health.
International Agency for Research on Cancer (IARC), France: A specialized cancer research agency of the WHO. Develops and enhances cancer prevention measures, identifies malignancies at the earliest possible stage, and publishes periodic reports on cancer incidence.
GLOBOCAN 2014, France: A project of the IARC and the WHO. Estimates cancer incidence, mortality, and prevalence at the national level for 184 countries.
Systematic procedures and methods, surveys, and existing studies yield epidemiologic indicators that are capable of showing the process and the outcomes of a disease. Based purely on calculations and numerical information, quantitative indicators or methods can be useful. Useful quantitative indicators include incidence, prevalence, and mortality. Incidence measures new cases of lung cancer in the present population, whereas mortality is the estimate of deaths due to lung cancer in the total population [9, 10]. In this study, we used incidence and mortality to elucidate the effects of lung cancer on the population.
Incidence was calculated by using the formula as follows [2, 9, 10]:
Incidence = (LCCCP/TPRCP) × 10N
LCCCP = Number of new lung cancer cases in the current period
TPRCP = Number of total population at risk in the current period
N = 1, 2, 3…. [Sample population]
Mortality was calculated using the formula [2, 9, 10]:
Mortality = (DCCP/TPCP) × 10N
DCCP = Number of death cases in the current period
TPCP = Number of total population in the current period
N = 1, 2, 3…. [Sample population].
The current period means the years considered for the calculation of incidence and mortality.
Knowing the cancer survival rate in a given population enables researchers to estimate cancer trends and patterns as well as people’s fitness levels. Net survival shows the probability of surviving cancer without considering death from other causes. Since net survival is not influenced by other causes, it gives reliable results [11]. Two general approaches were used to estimate net survival: specific survival and relative survival. Specific survival is calculated from causes of cancer deaths [11] and is used mainly for clinical trials. According to Parkin et al. [12], sometimes the cause of death may be unavailable or unreliable; in such a case, it is not possible to correctly estimate survival. However, survival from other diseases can be helpful in finding the survival status of the patient with the disease under study by finding the differences between the other diseases and the total occurrences. It can be calculated by relative survival [12].
$${\text{Relative survival rate}}\; = \;\frac{\text{Observed survival proportion}}{\text{Expected survival proportion}}\; \times \; 100\%$$
Expected survival can be calculated by Ederer I, Edere II, and Hakulinen methods. In this study, we used net survival and relative survival rates.