What is the most prevalent cancer in Nigeria?
This question has remained largely unanswered in our country and continent as a whole. It is pertinent we answer this question if we are serious about reducing the cancer burden in our country.
What is cancer? To the uninformed and uninitiated - it is the same disease arising from different parts of the body, to the informed and uninitiated - it is a disease characterized by the aberrant growth of cells resident in different organs that outlives the initiating stimuli, while to the informed and initiated - cancers are a diverse group of diseases sharing a common phenotype of uncontrolled growth. Research has shown that there exists marked heterogeneity amongst: the same type cancer arising from different populations of people, and in the same cancer arising in a single individual. Simply put, breast cancers seen in Indian women may differ from those seen in Nigerian ladies. Furthermore there may exist different cancers types in a single cancer in a single individual. This complex observation means that In the future cancers will be classified and defined based on its molecular profiles rather than anatomy. Treatment will thus be offered based on these molecular changes (the so-called “individualization of cancer therapy” or “personalized therapy” which has been recently publicized). The recent sequencing of the entire human genome means that this is achievable. The cost and or skills required for this process remains unknown but it will definitely be expensive and out of reach of developing countries like Nigeria.
What causes cancer? According to the international agency for the research on cancer (IARC) environmental agents and genetics are responsible for most cancers. It is postulated that if we can remove all the environmental factors alone we will reduce cancer by a whooping 80%. These environmental agents include: Physical agents (radiation), chemical agents (tobacco, dyes, diets), and biological agents (viruses and bacteria). Persistent exposure to these agents either as a result of chronic use and or increasing age predisposes and individual to develop cancer.
Nigeria and Africa as a whole has been spared largely from the “cancer epidemic” that has been seen in western parts of the world. This is largely due to absence of these agents, but mostly it is due to the low life expectancy, which precludes the development of most cancers. However, as we adopt a more western life style, and begin to live longer as a result of our successes over infections and life style diseases, we will inadvertently be heading towards the realm of a “cancer epidemic”.
So how prepared are we for this? In 2012 the Nigerian government spent 5.95% of its total budget on health ($1.8billion) this is surpassed only by the budgets of the security agencies (police and military formations), and education ministry. This amount will be distributed to the 18 teaching hospitals, the 45 federal medical centers, 12 training institutes, 16 port health services, the 10 health boards, the National health insurance scheme, the health ministry and other ancillary parastatals. 75% of this sum will be spent on personnel cost and recurrent expenditure and 25% on capital projects. Let us compare this to health spending in other climes.
The US National cancer institute in Bethesda Maryland has an annual budget of $5billion (this is irrespective of the US government spending on health). In the UK, Cancer research UK (CRUK), medical research council (MRC), and Wellcome trust spends about $600million, $216 million, and $100 million on cancer research respectively (this is irrespective of the NHS spending). To examine the impact of this differential spending lets take a look at new cases (incidence) and deaths (mortality) ascribed to cancer in 2008.
The IARC estimates that there were 12.7 million new cancer cases and 7.6 million cancer deaths worldwide in 2008. In men and women, the incidence of cancer is highest in Northern America, Australia/New Zealand and in Northern and Western Europe. The lowest cancer incidence rates are in Middle and Western Africa and in South-Central Asia for men and in Middle and Northern Africa for women. The ratios of incidence between developed and developing regions are 1.8 in men and 1.6 in women, while the same ratios for mortality are much lower, 1.2 in men and almost 1.0 in women. In summary although men and women in Africa have a lower chance of developing cancer they have almost the same risk of dying from cancer as those living in “high risk regions”. This is largely due to the above difference in health care spending and or the type of cancer prevalent in the different climes.
What do we have to do? It is apparent that Nigeria and other African countries cannot afford to spend similarly on health care as the western countries. Also, the little available spending on health care is often prioritized to the reduction of the high rates of maternal and infant mortality and the HIV pandemic, which continues to be a problem in Africa. This paucity of funds makes it difficult to develop an armamentarium of an efficient cancer service. Despite these challenges we must still provide our people with access to cancer care. To do this effectively we must spend our “scarce resources” in the best possible way to maximize efficiency. This can only be done if we accurately characterize the cancers in our country. To do this we must identify at risk populations and areas of high incidence so that we can treat and prevent these cancers respectively. This can be done when we set-up a fully functional cancer registry.
What is a cancer registry?
The idea of using a written, catalogued registry of man's afflictions in order to understand them better dates to at least the late 16th century. In this period, the English Crown appointed elderly, epidemic-scarred women to prowl the countryside in search of the dead and dying. These 'Ancient Matrons' published weekly 'Bills of Mortality' for each parish, tabulating deaths by causes such as 'the purples' (probably leukemia), 'riting of the lights', 'consumption' (often an effect of cancer), and of course, the plague.
The first modern use of case registries for the study of cancer was in 1956 when the American College of Surgeons (ACoS) formally adopted a policy to encourage, through their Approvals Program, the development of hospital-based cancer registries. It was believed that by periodically reviewing the results of cancer treatment regimens, the hospitals and physicians might reveal weaknesses in local patterns of care and ultimately develop a better understanding of the disease and its treatment. With the advent of the computer this process became less tedious.
There are two major types of cancer registries: hospital-based registries and population-based registries. There are two sub-categories under hospital-based registries: single hospital registry and collective registry.
The goals of hospital-based registries include:
• Improvement of patient care
• Professional education
• Administrative information
• Clinical research
The goals of population-based registries are:
• Cancer prevention
• Early detection
• Determination of cancer rates and trends
• Patterns of care and outcomes
• Evaluation of control efforts
The information collected by cancer registries can be placed into four categories: patient demographics, tumor (cancer) identification, treatment, and outcome.
Cancer registries continue to gather data after the cancer patient has received treatment. This data consists of information concerning the outcome of the treatment. Patient status is updated regularly to maintain accurate surveillance information. In brief, the importance of cancer registries lies in the fact that they collect accurate and complete cancer data that can be used for cancer control and epidemiological research, public health program planning, and patient care improvement. Ultimately, all of these activities reduce the burden of cancer.
Any cancer registration in Nigeria?
Presently there’s no national cancer register in Nigeria. However, there are three population based registers in; Ibadan, Calabar and Maidugri and several hospital based registries in; lagos, enugu, zaria, kano, illorin. Although these registers’ are somewhat functional there is the need to improve their activities and at the same time develop a national frame work on cancer registration. Luckily the federal ministry of health has begun this process as part of the national cancer action plan. There is however the need for our collective contributions and criticism to this process so we can all contribute to the reduction of the cancer burden in our country
Translational radiobiology Group, Paterson Institute for Cancer Research, University of Manchester, Manchester M20 4BX, United Kingdom