Advances in Human Biology

ORIGINAL ARTICLE
Year
: 2019  |  Volume : 9  |  Issue : 3  |  Page : 222--227

Incidence and mortality of cervix cancer and their relationship with the human development index in 185 countries in the world: An ecology study in 2018


Zaher Khazaei1, Malihe Sohrabivafa2, Kamyar Mansori3, Hasan Naemi4, Elham Goodarzi5,  
1 Department of Epidemiology, School of Public Health, Ilam University of Medical Sciences, Ilam, Iran
2 Student Research Committee, Dezful University of Medical Sciences, Dezful, Iran
3 School of Public Health and Safety, Shahid Beheshti University of Medical Sciences, Tehran; Department of Biostatistics and Epidemiology, School of Medicine, Zanjan University of Medical Sciences, Zanjan, Iran
4 Iranian Research Center on Healthy Aging, Sabzevar University of Medical Sciences, Sabzevar, Iran
5 Department of Public Health, School of Public Health, Social Determinants of Health Research Center, Lorestan University of Medical Sciences, Khorramabad, Iran

Correspondence Address:
Elham Goodarzi
Social Determinants of Health Research Center, Lorestan University of Medical Sciences, Khorramabad
Iran

Abstract

Introduction: Invasive cervix cancer is one of the most common causes of female genital cancer and accounts for 30% of cancers in developing countries and 5% in developed countries. Economic, social and sexual differences are associated with an increased risk of the cancer in women. Methods: This is a descriptive–analytic study based on incidence and mortality data extracted from the World Cancer Bank. The incidence and mortality rates and cervix uteri cancer distribution maps were drawn for world countries. To analyse data, correlation test and regression tests were used to evaluate the correlation between the incidence and mortality with Human Development Index (HDI). The statistical analysis was carried out by Stata-14, and the significance level was estimated at the level of 0.05. Results: The results showed a significant negative correlation between cervix cancer incidence rate (r = −0.570,P < 0.001) and mortality (r = −0.699,P < 0.001) with the HDI index. Negative and significant correlation was found between the incidence rate with the gross national income (GNI) (r = −0.37,P < 0.0001), Mean years of schooling (MYS) (r = −42,P < 0.0001), Life expectancy at birth (LEB) (r = −0.64,P < 0.0001) and Expected years of schooling (EYS) (r = −0.41,P < 0.0001). There was a significant negative correlation between the mortality rate and GNI (r = −0.42,P < 0.0001), MYS (r = −0.57,P < 0.0001), LEB (r = −0.73,P < 0.0001) and EYS (r = −0.56,P < 0.0001). The linear regression model showed that the increase of HDI (B = 91.8, confidence interval [CI] 95%: [−146.6, −37]) and LEB (B = −0.86, CI 95% [−1.3, −0.3]) decreased and increased MYS (B = 1.31, CI 95% [0.05, 2.5]) and EYS (B = 2.9, CI 95% [1.5.4.4]) significantly increased the incidence of cervix uteri (P < 0.05). Linear regression model showed that the increase of HDI [B = 91.8, CI95%: (-146.6, -37)] and LEB [B = -0.86, CI95% (-1.3, -0.3)] decreased the incidence and increase of MYS [B = 1.31, CI95% (0.05, 2.5)] and EYS [B = 2.9, CI95% (1.5.4.4)] significantly increased the incidence of cervical uteri (P <0.05). And increased HDI [B = 89.3, CI95% (-124.9, -53.8)] and [B = -0.3, CI95% (-0.6, -0.04)] reduced mortality and increased GNI [B = 0.009, CI95% ( 0.001, 0.1)], MYS [B = 0.8, CI95% (1.1.2.9)] and EYS [B = 2.04, CI95% (1.1.4.9)] significantly increased mortality of cervical cancer (P <0.05). Conclusion: Women in moderate to low HDI societies face poor socioeconomic conditions and should be considered as target groups for the prevention of cervix cancer. Moreover, prevention interventions should be focused on this group to ultimately bring about a positive change in the level of morbidity and mortality caused by cervix cancer.



How to cite this article:
Khazaei Z, Sohrabivafa M, Mansori K, Naemi H, Goodarzi E. Incidence and mortality of cervix cancer and their relationship with the human development index in 185 countries in the world: An ecology study in 2018.Adv Hum Biol 2019;9:222-227


How to cite this URL:
Khazaei Z, Sohrabivafa M, Mansori K, Naemi H, Goodarzi E. Incidence and mortality of cervix cancer and their relationship with the human development index in 185 countries in the world: An ecology study in 2018. Adv Hum Biol [serial online] 2019 [cited 2020 Feb 23 ];9:222-227
Available from: http://www.aihbonline.com/text.asp?2019/9/3/222/266219


Full Text



 Introduction



Cervix cancer or invasive cervix cancer with 53,000 new cases is the second most important cancer in women worldwide,[1] and about 2% of women develop it before they reach the age of 80.[2] The mortality rate of cervix cancer varies from country to country. According to the World Health Organization, 85% of cases of cervix cancer are in developing countries.[3] The highest rates are reported for Mexico with 15,000 women and the lowest for Germany, 2/1000 women.[2] The average age of cervix cancer is 52 years of age.[4] The use of contraceptives, nourishment, pregnancy, sexual immorality and sexually transmitted diseases have been introduced as potentiating or endangering the risk of cervix cancer. In the meantime, human papillomavirus (HPV) infection and smoking are two important factors effective in spreading this cancer.[5],[6],[7] Factors such as age, race, low level of education or income, heredity, high parity and age of the first sexual intercourse are also known to be associated with cervix cancer.[8],[9],[10],[11]

The most important symptoms of cervix cancer include any abnormal discharge from the vagina (increased bleeding in the menstrual cycle, bleeding between the two menstrual periods and post-menopausal bleeding), severe pelvic pain, severe weight loss and anorexia.[12]

Cervix cancer is an invasive and prevalent cancer type with varying morbidity and mortality rates in different parts of the world, especially in developing countries.[13],[14] Despite many efforts to reduce mortality caused by this cancer in recent years, more than 288,000 women worldwide die each year due to this cancer.[4] In various studies, the role of lifestyle, Human Development Index (HDI) and socioeconomic factors on morbidity and mortality of cancers, including cervix cancer, has been confirmed. Therefore, prevention of cervix cancer plus its early diagnosis are critical factors in controlling the disease and increasing the survival of patients. In this study, we tried to examine the factors involved in cervix cancer and its association with the HDI.

 Methods



Given the limited quality and coverage of existing cancer data in the world, especially in low-income or middle-income countries, it is necessary to be cautious in interpreting these data. The International Agency for Research on Cancer (IARC) approach is not just to evaluate, compile and use data from other institutions, but the intention of the centre is to work with country centres to improve the quality of native data, data coverage and analytical capacities. The urgent need for investing in the coverage of cancer-based population data in low- and middle-income countries was to launch the Global Initiative for the Cancer Registry Development (GICR) in cooperation with the IARC. The GICR aims to provide information on cancer control, which can be regularly promoted through coverage, quality and use of population-based cancer data. A summary of the steps used to calculate the incidence of cancer, its mortality and its prevalence are presented below. The calculation methods vary from country to country, and the quality of the national computing data depends on the coverage, accuracy, time of the outbreak and the deaths at each country.

Incidence

The methods used to calculate the incidence associated with gender and age in each country, in order of priority, fall into the following broad categories: (1) The reported national incidence rate announced by 2018 (45 countries). (2) The most recently observed (national or regional) rates were applied to the population in 2018 (50 countries). (3) The rates were calculated using national mortality data with modelling, as well as the mortality rate for the incidence of cancer recording in that country (14 countries). (4) The rates were calculated using national mortality using modelling, mortality rate, and incidence of cancer recording in neighbouring countries (37 countries). (5) The national incidence rate for age and sex for all cancers was obtained by calculating means for the overall rates in neighbouring countries. Finally, these levels were partitioned to obtain a national incidence for each specific site using the relative frequency of cancer data (7 countries). (6) Rates were calculated as a mean of the neighbour countries.

Mortality

The methods used to calculate mortality rates associated with genital and age-related cancer in each country, in priority order, are categorised as follows: (1) the observed national mortality rates were announced by 2018 (81 countries). (2) The latest observed national mortality rates for the population in 2018 were applied (20 countries). (3) The rates were calculated using data obtained through modelling, as well as the ratio of deaths to the prevalence of cancer reported by cancer rate reports of neighbouring countries (81 countries). (4) Rates were calculated as a mean of the neighbour countries (3 countries).[15],[16]

Human Development Index

HDI is a composite index of three dimensions – life expectancy, study rates and access to the resources needed to have a decent life. All the groups and regions with significant progress on all components of HDI have grown faster than those with low or intermediate HDIs. As the indicator shows, the worlds are unequal, because national means do not represent different experiences of people's lives. There are numerous inequalities in the northern and southern countries, and income inequalities have increased in each country and between countries.[17],[18],[19]

 Results



According to the results of the Cancer Registry in 2018, 8,622,539 new cases of cancer and 4,169,387 cancer deaths were registered in women, of which 569,748 new cases (6.6%) and 311,365 (7.5%) died due to cervix cancer. Therefore, cervix cancer is the fourth most common cancer and the fourth cause of death due to cancer in women [Figure 1].{Figure 1}

The results showed that the highest incidence 27.6 in 100000 and mortality (20 in 100,000) were in the African continent, with the lowest incidence (6.4 in 100,000) and mortality (1.9 in 100,000) in cervix cancer in North America [Figure 2].{Figure 2}

[Table 1] shows the incidence and mortality rate of cervix cancer among the countries of the world. The results of the study showed that the highest incidence of cervix cancer in the world was in Swaziland countries (75.3/100,000), Malawi (72.9/100,000) and Zambia (66.4/100,000), respectively. The highest mortality rate of cervix cancer was related to Malawi (54.5/100,000), Swaziland (52.5/100,000) and Burundi (50.3/100,000) [Figure 3].{Table 1}{Figure 3}

The results of analysis of variance showed that the highest mean incidence (32.48/100,000) was related to low human development, and the lowest incidence (9.58/100,000) was related to very high human development, which was statistically significant (P < 0.0001). The highest mortality rate (25.3/100,000) was related to low human development, and the lowest mortality rate (3.1/100,000) was related to very high human development, which was statistically significant (P < 0.0001) [Table 1].

The results showed a significant negative correlation between cervix cancer incidence rate (r = −0.570, P < 0.001) and mortality (r = −0.699, P < 0.001) with the HDI index [Figure 4].{Figure 4}

The results showed that there was a negative and significant correlation between the incidence rate with the gross national income (GNI) (r = −0.37, P < 0.0001), MYS (r = −42, P < 0.0001), LEB (r = −0.64, P < 0.0001) and EYS (r = −0.41, P < 0.0001). There was a significant negative correlation between mortality rate and GNI (r = −0.42, P < 0.0001), MYS (r = −0.57, P < 0.0001), LEB (r = −0.73, P < 0.0001) and EYS (r = −0.56, P < 0.0001) [Table 2].{Table 2}

Linear regression model showed that the increase in HDI [B = 91.8, CI95%: (-146.6, -37)] and LBE [B = -0.86, CI95% (-1.3, -0.3)] decreased the incidence of cervical cancer and On the other hand, the increase in MYS [B = 1.31, CI95% (0.05, 2.5)] and EYS [B = 2.9, CI95% (1.5.4.4)] significantly increased the incidence of cervix uteri (P <0.05).

The results of regression analysis showed that the increase in HDI [B = 89.3, CI95% (-124.9, -53.8)] and LBE [B = -0.3, CI95% (-0.6, -0.04)] decreased mortality and increased GNI [B = 0.009, CI95% (0.001, 0.1)], MYS [B = 0.8, CI95% (1.1.2.9)] and EYS [B = 2.04, CI95% (1.1.4.9)] significantly increased the mortality rate of cervical cancer uteri (P <0.05) [Table 3].{Table 3}

 Discussion



Women make up about half of the world's population, and their health during fertility years is very important because of the impact on the next generation. Cancer and the problems caused associated with it change the way people live and cause many problems in all aspects of a person's life, including physical, psychological, social, economic and family dimensions.[20]

In 2012, the incidence of cervix cancer and its mortality have varied widely. Many African countries such as Guinea, Zambia, Comoros, Tanzania and Malawi have cervix cancer incidence rates of at least 10–20 times higher than those in Western Asia, European countries, Iran, Saudi Arabia, Syria, Egypt and Switzerland. HDI, poverty, per capita expenditure on health, urbanisation and literacy rate are significantly associated with morbidity and mortality of cervix cancer. The incidence and mortality of cervix cancer had an inverse relationship with low human development and gender inequality. The increase of 0.2 units in HDI is accompanied by a 20% reduction in the risk of cervix cancer and a 33% reduction in the risk of mortality associated with this cancer. Higher per capita levels are independently associated with a reduction in the risk of death.[21]

In 2012, the highest age-standardised rates associated with cervix cancer occurs in countries with moderate to communities with high prevalence of cervix cancer often have younger, less educated and illiterate populations. On the other hand, the most important factor in cervix cancer is the infection with the HPV which has a higher prevalence in countries with low HDI due to lack of sexual health.

Also, these communities are facing increased cervix cancer incidence and mortality due to low financial support, a lack of the Pap smear screening test or poor-quality screening tests. All dimensions of HDI also had a significant relationship with morbidity and mortality of cervix cancer.[21]

In the current study, cervix cancer was identified as the fourth most common cancer and the fourth leading cause of cancer death in women. There was a negative and significant correlation between cervix cancer mortality and mortality and HDI index. There was also a negative and significant correlation between the three dimensions of HDI with morbidity and mortality of cervix cancer. The linear regression model showed that with increasing HDI and life expectancy, morbidity and mortality rates decreased. Meanwhile, with an increase in the average years of education, the morbidity and mortality of cervix cancer increased. The increase in GNI has also been accompanied by increased mortality.

Researchers believe that several factors contribute to the development of cancers, stemming, in 90%–95% of cases, from environmental and lifestyle factors. For example, in developing countries, infections account for 26% of the causes of cancers.[22],[23] Therefore, infection with the HPV is the most important factor in developing cervix cancer in developing countries with low financial resources.[24] Illiteracy is another major cause of cancer in developing countries, which leads to inadequate understanding of illness and inappropriate self-care.[25] According to studies conducted on morbidity and mortality, cervix cancer is higher at lower levels of the community, i.e., levels with lower education and income levels. Meanwhile, women in more advanced societies generally pay more attention to their health and to screening tests as a result of higher levels of income, education and awareness. Naturally, these also have more social access to health information, health care, healthy foods and live in more healthy environments.[26]

In societies with medium to low HDI, women are forced to work outside home due to work, family and industrial problems which leaves them with less time for paying attention to their health. In these countries, women are also affected by inadequate social economic conditions, with increasing numbers of births and poor menstrual health. It is clear that with increasing the number of pregnancies, women are more likely to suffer from more maternal harm, various contraceptives and gynaecological surgeries. All of the above are associated with an increase in the incidence of genital infections.[26] Mechanisms such as trauma during labour, hormonal changes during pregnancy, immune suppression and anatomical changes in the cervix oedema region in people with high parity increase the risk of cervix cancer.[27]

In most Third World and developing countries, women face a number of cultural, social, religious, economic and economic difficulties in conducting a Pap Smear screening test, among which are the lack of awareness of the need for a test, lack of advice from a physician, stress, embarrassment at the time of the test, high cost, low age, high age, not respecting their privacy and fear of positive test results.[28]

In the present study, with the increase of HDI, the GNI and average years of education, the rate of morbidity and mortality of cervix cancer decreased. It can be stated that accurate recording systems for cancer, more and more accurate screening tests, the familiarity of women in the community with signs of a cervix cancer and the diagnosis of cancer cases in the early stages of the disease are likely the causes. Finally, considering the impact of a number of socioeconomic and cultural factors on the development of cervix cancer in different societies, it is necessary to plan to raise the attention of women to their health, to raise their awareness about the fatal nature of the disease and encourage them to participate in cervix cancer screening programs.

 Conclusion



Women in moderate to low HDI societies face poor socioeconomic conditions and should be considered as target groups for the prevention of cervix cancer. Moreover, prevention interventions should be focused on this group to ultimately bring about a positive change in the level of morbidity and mortality caused by cervix cancer.

Acknowledgments

The authors gratefully acknowledge the many cancer registries worldwide and their staff for their willingness to contribute their data to this exercise.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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