|Year : 2017 | Volume
| Issue : 3 | Page : 806-812
Risk factors of lung cancer among women in Menoufia governorate, Egypt
Naser M Abd ElBary1, Nagwa N Hegazy2, Marwa K Abo Aianh MBBCh 3
1 Department of Oncology, Faculty of Medicine, Menoufia University, Menoufia, Egypt
2 Department of Family Medicine, Faculty of Medicine, Menoufia University, Menoufia, Egypt
3 Department of Family Medicine in Health Sector, Tanta, Gharbia, Egypt
|Date of Submission||18-Oct-2016|
|Date of Acceptance||11-Dec-2016|
|Date of Web Publication||15-Nov-2017|
Marwa K Abo Aianh
Department of Family Medicine in Health Sector, Tanta, Gharbia, 31511
Source of Support: None, Conflict of Interest: None
The objectives of this study were to assess the risk factors and distribution of lung cancer among women in Menoufia governorate.
Lung cancer used to be thought of as a man's disease, but women now account for almost half of new cases and deaths from lung cancer.
Patients and methods
The study was a case–control study. Women were selected according to the following inclusion criteria: adult females above 18 years, histopathological proof lung cancer, controlled comorbidity. The recruited participants were 60 women from the clinical oncology hospital records from January 2011 to December 2015 in Menoufia University, Shebin Elkom, Menoufia Governorate. Sixty women were found meeting our inclusion criteria. A similar number of controls was recruited from the patients' female relatives. Both groups were subjected to a questionnaire and clinical examination for clinicoepidemiological study and determination of risk factors of cancer lung.
The most common type of lung cancer among women was adenocarcinoma (56.7%). The risk factors for developing lung cancer in women were passive smoking smoking, performing oophorectomy before menopause and using coal for cooking or warming (P < 0.001).
The risk factors for developing lung cancer among women were passive smoking, smoking, oophorectomy before menopause, use of hormonal replacement therapy among smoking, and use of organic fuel (coal) for cooking or warming. Having breast cancer or having radiation therapy may influence the progress of lung cancer.
Keywords: lung cancer, risk factors, women
|How to cite this article:|
Abd ElBary NM, Hegazy NN, Abo Aianh MK. Risk factors of lung cancer among women in Menoufia governorate, Egypt. Menoufia Med J 2017;30:806-12
|How to cite this URL:|
Abd ElBary NM, Hegazy NN, Abo Aianh MK. Risk factors of lung cancer among women in Menoufia governorate, Egypt. Menoufia Med J [serial online] 2017 [cited 2019 Nov 15];30:806-12. Available from: http://www.mmj.eg.net/text.asp?2017/30/3/806/218298
| Introduction|| |
Lung cancer is one of the most common cancers in the world. It is a leading cause of cancer death in men and women in the USA. Cigarette smoking causes most lung cancers. The more cigarettes smoked per day and the earlier the age at which one started smoking, the greater the risk of lung cancer. High levels of pollution, radiation and asbestos exposure may also increase the risk .
Lung cancer appears to behave differently in women. Several studies have reported sex differences in the clinical presentation, histology, and outcome of lung cancer. Women are more likely to present with lung adenocarcinoma, tend to receive diagnosis at an earlier age, and are more likely to be diagnosed with localized disease. Women may also be more predisposed to molecular aberrations resulting from the carcinogenic effects of tobacco. However, they do not appear to be more susceptible to develop lung cancer .
| Patients|| |
The study was a case–control study conducted at the clinical oncology hospital in Menoufia University, Shebin Elkom, Menoufia Governorate, Egypt. Women were selected according to the following inclusion criteria:
Inclusion criteria for cases
The inclusion criteria included adult females above 18 years, histopathological proof of lung cancer, controlled comorbidity, and living in Menoufia Governorate. The recruited participants were women from the clinical oncology hospital records from January 2011 to December 2015 in Menoufia University, Shebin Elkom, Menoufia Governorate, Egypt. Sixty women were found meeting these inclusion criteria. A similar number of controls (60) were recruited from the patients' female relatives with the following inclusion criteria: adult females above 18 years, living in Menoufia Governorate, and having no known morbidity.
Exclusion criteria included women with psychological disorders.
| Methods|| |
Both case and control groups who participated in the study were interviewed using a predesigned interview questionnaire which has two parts: The first part includes questions, which assesses the socioeconomic status, the second part assesses the risk factors of lung cancer by asking about smoking, type of smoking, housing beside fumes, homes beside highway, working in cotton ginning, working in glass production factories, working in paint industry, working in pesticide industry, working as a professional driver, using coal for cooking or warmth, exposure to radiation, past medical history of pneumonia, tuberculosis (TB), breast cancer, radiation therapy, gynecological and obstetric history by asking about menstrual cycle, early menopause, oophorectomy before menopause, and receiving hormone replacement therapy among smokers.
The study was approved by the Ethical Committee of the Faculty of Medicine, Menoufia University; an official permission letter was obtained and directed to the administrators in the faculty. Informed consent was obtained from all participants after simple and clear explanation of the research objectives. The consent form was developed according to the standard of Quality and Improvement System in Ministry of Health in Egypt.
This included the statistical analysis of the collected data; the data were tabulated and analyzed by SPSS (Statistical package of Social Science), version 20 using an IBM personal computer (SPSS Inc., Chicago, Illinois, USA).
Quantitative data were expressed as mean and standard deviations (mean ± SD) and were analyzed applying Student's t-test.
Qualitative data were expressed in number and percentage and analyzed applying χ2-test.
- P value of more than 0.05 was considered statistically nonsignificant
- P value less than 0.05 was considered statistically significant
- P value less than 0.001 was considered statistically highly significant.
Regression analysis is a statistical process for estimating the relationships among variables. It includes many techniques for modeling and analyzing several variables, when the focus is on the relationship between a dependent variable and one or more independent variables.
| Results|| |
The prevalence of nonsmall-cell lung cancer (adenocarcinoma 56.7%, squamous cell lung cancer 20%, large cell lung cancer 5%) was 81.7% and that of small-cell lung cancer was 18.3% [Figure 1].
Grade 2 had the highest percentage than other grades which represented 43.3% [Figure 2].
There was a highly statistically significant higher level of exposure to fumes, using organic fuel (coal) for cooking or warming, presence of smokers in the family, and undergoing oophorectomy before menopause (P > 0.001) among the studied groups and a statistically significant difference between the studied groups regarding smoking, taking hormonal replacement therapy among smokers, and early menopause before the age of 45 years (P > 0.05) [Table 1].
[Table 2] shows that the presence of smokers in the family, using organic fuel (coal) for cooking or warming, being smokers, undergoing oophorectomy before menopause, and receiving hormonal replacement therapy among smokers were independent risk factors for the occurrence of lung cancer among women with odds ratios of 19.2, 6.7, 13.1, 7.3, and 2.6, respectively.
|Table 2: Logistic regression analysis of independent risk factors for developing cancer among women|
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There was a highly statistically significant difference between the studied groups regarding working in cotton ginning factories, exposure to asbestos (P < 0.001), and a statistically significant difference between the studied groups regarding the use of organic fuel (coal) for cooking or warming, having uterine tumors, having TB, and receiving hormonal replacement therapy among smokers (P < 0.05) [Table 3].
|Table 3: Factors having significant relation to different pathological types of lung cancer|
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[Table 4] shows that there was a statistically significant higher rate of lung cancer occurrence among those with previous history of breast cancer. Moreover, the higher rate of lung cancer was recorded among women with previous exposure to radiation therapy and women with diabetes mellitus (P < 0.05).
|Table 4: Factors having significant relation to different grades of lung cancer|
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[Table 5] shows that history of breast cancer and those with previous exposure to radiation therapy were independent risk factors for developing different stages of lung cancer among women with odds ratios of 11.7 and 9.2, respectively.
|Table 5: Logistic regression analysis of independent risk factors for developing different stages of lung cancer among women|
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| Discussion|| |
Although cigarette smoking was an important cause of lung cancer, showing a clear dose–response trend, the majority of lung tumors, particularly adenocarcinomas, occurred among nonsmokers .
Environmental tobacco smoke may account for some, but probably few, of the cancers among nonsmokers, as there was little or no association with those who never lived with a smoker. Among nonsmoking women married to smokers, however, there was an upward trend in risk associated with increasing years of exposure. This latter finding is consistent with reports in other parts of the world. This study agrees with the data from nearly a dozen studies evaluating passive smoking reporting  an overall 30% excess of lung cancer [relative risk (RR) = 1.3, 95% confidence interval = 1.1–1.5] among nonsmoking women married to smokers, with the RR reaching1.7 among those most heavily exposed. Environmental tobacco smoke (also called second-hand smoke) is classified by the International Agency for Research on Cancer as a cause of lung cancer. An estimated 15% of lung cancer cases in never-smokers in the UK is linked to environmental tobacco smoke .
An increased risk of lung cancer in women who received hormonal replacement therapy (HRT) was noted in a large-scale epidemiologic cohort study; however, no adjustment was made for the amount of smoking . In a case–control study, 180 women who had lung cancer were evaluated for their history of smoking and hormonal replacement therapy . There was, however, a statistically significant synergy between smoking and HRT. In addition, the investigators reported an increased risk of adenocarcinoma associated with HRT odds ratio (1.7). Adami et al.  also showed an increased risk (RR = 1.26) of lung cancer in women receiving HRT in their study. It appears that the higher circulating levels of estrogen in women compared with men, coupled with their lower rate of DNA repair, make women particularly susceptible to the carcinogenic influence of tobacco smoke. There are also data suggesting that HRT may exert a protective effect. The result has shown that smoker women who received HRT had a higher risk factor for developing lung cancer.
In an interesting case–control analysis, Schabath et al.  compared the effects of menopause on lung cancer risk in 422 women with lung cancer and 577 controls . They found that although most characteristics of menstruation and pregnancy were not associated with lung cancer risk, an increased risk was observed in women who had a non-natural menopause, which predominantly included women who had bilateral ovariectomy . They also observed an inverse association of lung cancer risk with the age of menopause, that is, women who were less than 45 years of age at the onset of menopause had a higher risk of developing lung cancer.
Although another study suggested that there is a potential protective effect of increased or prolonged estrogen exposure, others have found an increase in lung cancer related to estrogen exposure Nawa et al. . However Swensen et al.  found no difference between length and degree of estrogen exposure and the development of lung cancer but suggested that female smokers with lung cancer who were receiving hormone replacement therapy had increased mortality compared with nonsmokers with lung cancer who were receiving hormone replacement therapy.
The estrogen receptors (ERs) ERα and ERβ have also been implicated as a possible link to lung cancer in women. ERβ, which is found in both healthy lung and lung tumors, is expressed to a similar extent in both men and women. In contrast, ERα, which is not normally present in the lung tissue, can be overexpressed in adenocarcinoma of the lung in women. However, the rates of expression vary widely, ranging from 7 to 97%, and some studies have found similar overexpression in both men and women Swensen et al. . An in-vitro study revealed that ER expression was similar between the sexes. However, although estradiol had no effect on the adenocarcinoma cells in the men, estradiol stimulated the growth of adenocarcinoma cells in women Balkman et al. . Such a result points toward varying biology.
Similar results were found in the current research, which also showed that the lung cancer was higher among women whose houses were beside the industrial fumes due to environmental pollution. This result is in agreement with Tang et al.  who found that environmental pollution is one of the most important risk factors of cancer either in men or women. A study in Japan Toyooka et al.  found that exposure to fumes for a long period is one of the most important risk factors for lung cancer. However, highway housing had no relation to lung cancer. These results agree with Gazdar and Thun  who found also that it may worsen other pulmonary health problems such as chronic obstructive pulmonary disease and asthma.
These results were parallel to those of many different studies which confirmed a great association between lung cancer and utilization of coal in cooking or warming. Seow et al.  found a positive correlation between lung cancer and using coal for cooking and warming. However, Hecht et al.  denied the association between lung cancer and using coal in different aspects of life. Moreover, that study had denied any significant association between work in cotton ginning factories, glass production factories and pesticide industry, and lung cancer which coincide with Schabath et al.  who reported similar results. However, Samet et al.  stated that more long prospective studies are needed to confirm this positive or negative associations.
These results are in agreement with Klein et al.  who found no relation between lung cancer and pulmonary TB. However, there are many epidemiological studies on concurrent pulmonary tuberculosis and lung cancer as that reviewed by Cheng et al. , who stated that patients with active pulmonary tuberculosis had a higher risk of dying from lung cancer or other malignancies, despite the high mortality from tuberculosis. Furthermore, the mortality trends of TB in Taiwan had been well described by age–period–cohort analysis; early birth cohorts were seen to have a relatively higher risk of mortality. Thus, the antagonistic hypothesis between the two diseases may have been based on the fact that tuberculosis patients had mostly died young, or they did not survive long enough to contract cancer before the advent of modern tuberculosis treatments.
| Conclusion|| |
Lung cancer among women has several risk factors. The main are passive smoking, being smoker, using organic fuel (coal) for cooking or warming, homes beside fumes, undergoing oophorectomy before menopause, receiving hormonal replacement therapy among smokers, early menopause before the age of 45 years, women with history of breast cancer. Those with previous exposure to radiation therapy may influence the progress of lung cancer, which should be prevented or at least minimized in order to prevent or reduce the incidence of the disease to the lowest level.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
| References|| |
De Perrot M, Licker M, Bouchardy C. Sex differences in presentation, management, and prognosis of patients with non-small cell lung carcinoma. J Thorac Cardio Vasc Surg 2000; 119
Kan G. Tuberculosis and its control in Beijing. Chin med J 1981; 94
Howe G, Lindsay J, Coppock E, Miller AB. Isoniazid exposure in relation to cancer incidence and mortality in a cohort of tuberculosis patients. Int. J Epidemiol 1979; 8
Olsson H, Landin-Olson M, Gullberg B. Retrospective assessment of menstrual cycle length in patients with breast cancer, in patients with benign breast disease, and in women without breast disease. J nut Cancerlnsr 1983; 70
Lubin J, Blot WJ. Assessment of lung cancer risk factors by histologic category. J Natl Cancer Inst 1984; 73
Chaudhuri IK, Thomas P, Walker MJ, Briele HA, Das Gupta TK, Beattie CW. Steroid receptors in human lung cancer cytosols. Cancer Lett 1982; 16
Taioli E, Wynder EL. Endocrine factors and adenocarcinoma of the lung in women. J Natl Cancer Inst 1994; 86
Adami HO, Persson I, Hoover R, Schairer C, Bergkvist L. Risk of cancer in women receiving hormone replacement therapy. Int J Cancer 1989; 44
Schabath MB, Wu X, Vassilopoulou-Sellin R, Vaporciyan AA, Spitz MR, et al.
Hormone replacement therapy and lung cancer risk: a case–control analysis. Clin Cancer Res 2004; 10(Pt 1)
Ramnath N, Menezes RJ, Loewen G. Hormone replacement therapy as a risk factor for non-small cell lung cancer: results of a case–control study. Oncology 2007; 73
Schwartz AG, Wenzlaff A, Prysak GM. Reproductive factors, hormone use, estrogen receptor expression and risk of non small-cell lung cancer in women. J Clin Oncol 2007; 25
Nawa T, Nakagawa T, Kusano S, Kawasaki Y, Sugawara Y, Nakata H. Lung cancer screening using low-dose spiral CT: results of baseline and 1-year follow-up studies. Chest 2012; 122
Swensen SJ, Jett JR, Hartman TE, Midthun DE, Mandrekar SJ, Hillman SL, et al.
CT screening for lung cancer: five-year prospective experience. Radiology 2015; 235
Balkman JD, Mehandru S, DuPont E, Novak RD, Gilkeson RC. Dual energy subtraction digital radiography improves performance of a next generation computer-aided detection program. J Thorac Imaging 2011; 25
Tang DL, Rundle A, Warburton D. Associations between both genetic and environmental biomarkers and lung cancer: evidence of a greater risk of lung cancer in women smokers. Carcinogenesis 2008; 19
Toyooka S, Tsuda T, Gazdar AF. The TP53 gene, tobacco exposure, and lung cancer. Hum Mutat 2003; 21
Gazdar AF, Thun MJ. Lung cancer, smoke exposure, and sex. J Clin Oncol 2007; 25
Seow A, Duffy SW, Ng TP. Lung cancer among Chinese females in Singapore 1968–1992: time trends, dialect group differences and implications for etiology. Int J Epidemiol 2008; 27
Hecht S, Seow A, Wang M. Elevated levels of volatile organic carcinogen and toxicant biomarkers in Chinese women who regularly cook at home. Cancer Epidemiol Biomarkers Prev 2010; 19
Schabathet MB, Vassilopoulou-Sellin R, Vaporciyan AA. Hormone replacement therapy and lung cancer risk: a case–control analysis. Clin Cancer Res 2004; 10
Samet JM, Avila-Tang E, Boffetta P. Lung cancer in never smokers: clinical epidemiology and environmental risk factors. Clin Cancer Res 2009; 15
Klein F, Amin Kotb WF, Petersen I. Incidence of human papilloma virus in lung cancer. Lung Cancer 2009; 65
Cheng YW, Chiou HL, Sheu GT, Hsieh LL, Chen JT, Chen CY et al.
The association of human papillomavirus 16/18 infection with lung cancer among nonsmoking Taiwanese women. Cancer Res 2011; 61
[Figure 1], [Figure 2]
[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]