The burden of bladder cancer in the Middle East
The reality of bladder cancer is far from what we would need to do to control it. Bladder cancer has become an increasingly serious public health issue because it is a multifactorial disease that is associated with both genetic and environmental factors. In addition, according to the American Institute for Cancer Research, bladder cancer is the 10th most common cancer in the incidence ranking worldwide. It is the sixth most commonly occurring cancer in men. It is the 17th most commonly occurring cancer in women. Bladder cancer is frequent and has a high mortality rate in the Middle East and in the world.
Figure 1: Map showing bladder cancer incidences in both sexes worldwide [1]
According to the American Institute of Cancer Research, Lebanon had the highest incidence rate of bladder cancer in 2018. It is the third most common cancer in Lebanon. These incidence rate of bladder cancer in Lebanon is among the highest worldwide across all age groups in both sexes. However, according to the World Health Organization (WHO), Egypt has the highest mortality rate in the world 7.98%.
Table 1: The estimated incidence and mortality of bladder cancer according to world area, 2012, males. ASR = Age-standardized rate per 100,000. Numbers are rounded to the nearest 10 or 100, and may not add up to the total. The population size of the world regions were retrieved from the Population Reference Bureau, Washington, DC.[2]
According to a recent paper published on 2016 by Mahdavifar et al., in 2012, there were 429,793 bladder cancer cases and 165,084 bladder death cases occurred in the world. Lebanon and Turkey were among the top five countries that had the highest age-standardized incidence; Lebanon 16.6/100,000, Turkey 15.2/100,000. Five countries that had the highest age-standardized death rates were Turkey 6.6 per 100,000, Egypt 6.5/100,000, Iraq 6.3/100,000, Lebanon 6.3/100,000, and Mali 5.2/100,000.
There are no major advances in the control of bladder cancer in the last 25 years. The symptoms and signs of this disease are not exclusive to bladder cancer and may be an indication to other diseases such as urinary tract infection or stones in the kidneys or the bladder. Most of the symptoms such as blood in urine, pain during urination, being unable to urinate, frequent urination, lower back pain on one side, loss of appetite, and weight loss are most likely to be caused by other diseases.
We need to approach bladder cancer control through different approaches. Those approaches are primary, secondary, and tertiary prevention. Primary prevention includes avoiding the exposure to carcinogenic agents or behaviors and it is applied to broad populations. Secondary prevention targets existing, more specific risks in more closely defined higher-risk populations. Tertiary prevention aims to prevent or control the symptoms and morbidity of established cancer, or the morbidity caused by cancer therapy.
There are many risk factors associated with bladder cancer including old age, race, gender, cigarette smoking, water arsenic, (chemotherapy and radiation therapy), and genetic susceptibility. Genetic susceptibility is one of the most important risk factors which is associated with bladder cancer risk. A recent systematic review published on April 2017 has identified 28 genetic susceptibility loci for bladder cancer.[3]
Smoking remains the most important risk factor associated with bladder cancer. In Egypt, we do not have an operation policy, strategy or action plan for controlling and/or reducing the smoking prevalence in the society. We need to act and work with the policy makers to work on this issue to prevent bladder cancer.
Moreover, the researchers have been working on two different approaches to study genetic susceptibility as it has been well identified with its association with bladder cancer risk. The two approaches are the variant/gene candidate and the agnostic (Genome-Wide Association Study [GWAS]) approach. The GWAS studies provide a clear evidence and results about the genetic variants which associated with bladder cancer risk.
The knowledge we get form GWAS studies is an important part of the prevention of bladder cancer. And because of the advancement of the human genome project, we were able to conduct more GWAS studies of human diseases to identify genetic variants or susceptibility loci associated with an inherited increase or decrease risk of developing a specific disease. GWAS have contributed to our understanding of the genetic basis of bladder cancer and also to find out about biologic pathways in order to find out new strategies for personalized and targeted medicine.
Most of those studies have been done by researchers in Europe, USA, and Asia in which they sometimes do not focus on the genetic susceptibility in the Middle East and Africa. Therefore, we need to pay more attention and conduct more GWAS studies to identify all the epidemiological investigations on the genetic association with bladder cancer risk and to assess and/or estimate the likely magnitude of that association. We need to raise the awareness on conducting those genetic studies because six countries (Egypt, Iraq, Turkey, Syria, Lebanon, and Iran) in the Middle East are among the top 10 globally with the prevalence of bladder cancer.
Additionally, the importance to increase the awareness about bladder cancer is increasing because there are no advances in the control of the bladder cancer. The field of bladder cancer research needs an important support from the patients because they are not aware of the causes of bladder cancer. They are also not aware of the symptoms because it is also unspecific to bladder cancer. They do not know how they can prevent bladder cancer. Also, the field need support from the medical community and from the health policy makers to raise the fund for bladder cancer research. The treatment options are very expensive and have not improved over a long time. The main reason for this issue is the lack of funding for bladder cancer research from the funding organizations. Despite the fact of the high incidence and high prevalence rate of bladder cancer, the treatment has not changed that much because of the low funding. Therefore, there is an urgent need to increase the quality for research of bladder cancer, so we need fund to do be able to do this. There is another reason for low funding on bladder cancer research that might be caused by the difference in cancer registration in the western countries.
On the contrary, cancer registry in the Middle East is still in its beginning and we still do not have electronic medical record system in most of the hospitals in the Middle East. The Middle East Cancer Consortium (MECC) is a good example of regional collaboration in cancer registry but it is still not well established and inadequate. MECC was established through an official agreement of the Ministries of Health of Cyprus, Egypt, Israel, Jordan, and the Palestinian Authority. The agreement was signed in Geneva in May 1996. Turkey later joined the Consortium in June 2004.
The aim of this consortium is to reduce the incidence and the impact of cancer in those countries and to increase the knowledge and ultimately to decrease the burden of cancer in the Middle East countries. Cancer registry is an important tool to enhance cancer control and cancer research in the Middle East. “The cancer registry is essential to cancer control, and cancer control is essential to (the survival of) the cancer registry.” Armstrong, B.K. Cancer Causes & Control 3:569 (1992).
Figure 5: Cancer research funding for the USA in 2010 (A) and the UK in 2012 (B)[4]
Figure 6: Cancer research funding divided by cancer specific mortality in the USA (A) and the UK (B)[4]
Figures 5 and 6 show that most of the cancer research funding in different Western countries goes to those cancer types that has higher incidence rate.
The bladder cancer community should advocates research on bladder cancer and should collaborate and work together with the policy makers to raise the required fund for research.