Assessment of lung cancer risk factors and mortality in Qatar: A case series study

Abstract Background The global burden of cancer has exponentially increased over the last few years. In 2018 alone, approximately more than half of the 18.1 million individuals who had cancer succumbed to it. Lung cancer cases and fatalities are particularly on the rise. Therefore, exploring the factors surrounding lung cancer mortality is of utmost importance. Aims We investigate the clinicopathological and epidemiological characteristics of patients with lung cancer undergoing treatments, and their 5‐year survival rates from a case series study in Qatar. Methods and Results All patients' data (between January 2010 and December 2014) in this case series study were retrieved from Al‐Amal Hospital database. Kaplan‐Meier survival plots, life tables and Cox regression were utilized for the statistical analysis. A total of 229 lung cancer patients were included in this study; of which 23.6% are Qatari (40 males and 14 females) and 76.4% non‐Qatari (133 males and 42 females). Approximately 57.6% of our patients received at least one type of treatment. We observe a 5‐year survival rate of 9.4% in our patient cohort. We also observe other predictive factors, such as distant metastasis (adjusted hazards ratio, HR = 2.414, 95% CI: 1.035‐5.632), smoking status (adjusted HR = 3.909, 95% CI: 1.664‐9.180) and the treatment history (adjusted HR = 0.432, 95% CI: 0.270‐0.691), to be significant. Conclusion Lung cancer is a prevalent health condition in Qatar, particularly owing to the rising use of tobacco in the country. The survival rate for lung cancer patients in this country is lower, compared to the global average. Moreover, several factors such as distant metastasis, smoking status, and treatment history are associated with lung cancer survival in Qatar.

primarily if the tumor is still localized and not metastasized. A surgical operation can include the removal of the primary cancerous tissue from the lung and some from the neighboring healthy tissue. This is known as a wedge resection. Whereas surgical intervention that includes the removal of a large part of the lung is called segmental resection. 11 Factors affecting life expectancy with lung cancer include age, sex, race, lifestyle, and preexisting conditions. Life expectancy has been increasing alongside innovations in cancer treatment. In the 1970s, it was estimated that about 12.5% of the patients would live beyond 5 years of age with lung cancer. This increased to 17.3% in 2010 and varied depending on the type of cancer. 12 Patients diagnosed with cancer at the early stages, like stage one and two, have a longer life expectancy than those diagnosed at stage three or four.
Qatar's healthcare system exhibits average performance regarding the preparedness and response to cancer care. 13 Qatar's mixed healthcare delivery system includes both the public and the private sector, which provide primary and secondary cancer care, for instance, surgery radiotherapy and chemotherapy services. In the Middle East region, Qatar has amongst the highest healthcare budget to cater to both the natives and non-Qataris. Cancer care is available at a standardized annual fee where the nationals pay US$3 under the established government leading healthcare provider Hamad Medical Corporation. The non-nationals pay US$28 fee yearly, with the government requiring each employer to provide health coverage for the non-residents. 13  The epidemiological characteristics of lung cancer and their asso-  For analysis, the statistical package for social science (SPSS) 18 and R-Studio 19 were used. Pearson Chi-square test was used to assess the association between treatment history and various patient characteristics. This test provides information on the significance of any observed differences, as well as on the specific groups or categories which are responsible for the differences observed. 20

| Patients' characteristics
The demographic and clinical characteristics of the 229 lung cancer patients are presented in Table 1. Out of these, 75.5% were men and 24.5% were women. With respect to age groups, 25.8% of patients were aged below 50, 33.6% of patients were aged between 50 and 59 years, 21.8% of patients were between 60 and 99 years whereas   For example, the median survival time for female and male are 18.2 and 13.4 months, respectively. However, the log-rank test revealed that this difference is not statistically significant. Figure 1

| Life table
For evaluating yearly survival rates of lung cancer patients, a life table ( improve the situation. We must also highlight the industrialization of Qatar, and the associated environmental risks will also affect future studies on lung cancer cases. This will also be an essential area for future research, based on potential occupational exposure as a variable.

ETHICAL STATEMENT
Ethical Approval for this secondary retrospective analysis was obtained by the Institutional Review of Board of QU.

CONFLICT OF INTEREST
The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

AUTHOR CONTRIBUTIONS
All authors had full access to the data in the study and take responsi-

DATA AVAILABILITY STATEMENT
The data is available upon request.