Cancer Control In An Economically Disadvantaged Setting: Nigeria

Introduction

The World Health Organization (WHO) has identified aging, infections, cancer and mental health as the four major health problems confronting mankind this century. The improvement in child health care and general health in the last quarter of the last century, especially in affluent societies, has resulted in a significantly increased proportion of older individuals in populations across the world. Care of the aged has therefore become a major health challenge in the world. The incidence of infectious diseases is also on the increase in all nations and HIV/AIDS and pulmonary tuberculosis have reached epidemic proportions in sub-Saharan African countries. Growing unemployment, poverty and stress have jointly contributed to an increase in mental health problems in the world, and cancer, which is the focus of this article, is a major health challenge in all populations, albeit underplayed in the past in developing countries. Neoplastic diseases are now known to also be a major cause of morbidity and mortality in these countries; more patients die from cancer than from HIV/AIDS, tuberculosis and malaria combined.

The WHO Technical Report No. 804 of 1990 reported that over 50% of cancer victims live in the poorer nations, which have less than 10% of the resources for cancer care and control. The dilemma of cancer patients in third world countries was further brought into focus with the realisation that they consume only 5% of cytotoxic drugs, the remainder being sold in the richer nations which account for only 39% of cancer cases.

In Nigeria, with a population of 120 million people in 2002, there are fewer than 100 practicing oncologists and no center exclusively focused on cancer research. There are only four active radiotherapy centers giving a ratio of one machine to about 30 million people, as against the recommended one per quarter million. The available spectrum of anti-cancer drugs is very limited and such drugs are not readily available. Imaging facilities for staging patients with cancer, such as computerized tomography (CT) and magnetic resonance imaging (MRI), are difficult to come by, and when available the cost of such studies puts them out of reach of the average citizen. The inability to properly classify the various types of hematological cancers owing to lack of Immunophenotypic, immunocytochemical and cytogenetic diagnostic facilities is of great concern to hemato-oncologists practicing in this part of the world.

This article will discuss the efforts made so far to control cancer in Nigeria and the factors militating against effective cancer care. Possible solutions to the problems identified will be highlighted.

The Development of Cancer Registration in Nigeria

Cancer is a major health problem in Nigeria, as it is in other African countries. Unfortunately, the importance of cancer as a health problem has been underplayed or totally neglected by all agencies that have been advising on and/or financing health projects in Africa over the years. These agencies, including the World Bank, USAID, the European Union's Directorate of Development, and many others, give priority to infant and maternal health, family planning and sexuality, malaria, control of HIV/AIDS and some other infectious diseases. The apparent neglect of cancer by these agencies, and the consequent lack of emphasis on this problem on the part of successive Nigerian governments, have resulted in a lack of development of cancer treatment facilities and cancer therapists. The result is the current situation in which cancer is, for the most part, an incurable disease in Nigeria, but less because of the nature of cancer, and more because of the limited resources and lack of education of the population. Unfortunately, prospects for improvement in the short term are bleak.

In Nigeria, neoplastic diseases were well known to traditional medical practitioners long before the advent of modern medicine. Cancer was then, and is still believed to be incurable. It is described by the Yoruba speaking people of South-west Nigeria as “Jejejere ara” i.e, a disease that eats the body.

Early efforts at cancer control in Nigeria started with the establishment of the first cancer registry in the Department of Pathology, UCH Ibadan, in 1960 by Prof GM Edington. The main objective of the registry was to record cancer incidence for use by health planners and research workers. In October 12, 1968, also at UCH Ibadan, the Nigerian Cancer Society (NCS) was founded. Its aims were, (1) assisting in the development of facilities for diagnosis and treatment of cancer, (2) educating the public on the problems of cancer and (3) conducting research in all aspects of cancer. The society has grown beyond Ibadan. Branches have spread to other parts of the country, although their impact is felt more in the urban centers than in the larger rural populations of the country. The first major success of the NCS was the publication in 1982 of the book Cancer in Nigeria-the proceedings of the NCS conference held in December 1979. The society remains in the forefront of cancer control in Nigeria, through its educational activities, publication of cancer education modules and cancer newsletters.

The Ibadan cancer registry is a population-based registry, serving a population of 1.22 million (1991 census) within its defined area of 70 square km in Ibadan, in the Oyo state of South West Nigeria. Data are collected from permanent residents suffering from cancer (i.e, persons who have been living in the area continuously for at least 12 months). Registry staff collect data on cancer by visiting all hospitals and health facilities (public, mission and private) in all the local government areas in the registry area at regular intervals. The chief sources of data are the histologically and/or cytologically confirmed cases of cancers from the pathology and hematology departments of the hospitals. Data are also abstracted from autopsy reports, hospital wards and clinics. Data are normally manually treated at all phases; the registry acquired its first CANREG computer program for data recording and management in 1997.

The success of the Ibadan cancer registry soon led to the establishment of other centers in university teaching hospitals across the country, including Zaria, Jos and Ilorin in northern Nigeria and Calabar and Enugu in South East Nigeria. The new centers in South West Nigeria are located in Ile-Ife, Eruwa and Lagos. Eruwa is the only registry established in a general hospital. With the exception of Ibadan cancer registry, all the other registries are hospital-based. In recognition of the role of cancer registries in cancer control in Nigeria, the Federal Ministry of Health established the “National Headquarters for Cancer Registries in Nigeria (NHCRN)” at UCH Ibadan in 1990, with the main objectives of coordinating the establishment and development of cancer registries in the country and organizing training programs in cancer registration.

Nigerian cancer registries contribute data to important publications such as Cancer Incidence in Five Continents in 1970 and 1976 (Ibadan Cancer Registry), the 1986 IARC Scientific Publication No. 75 on Cancer Occurrence in Developing Countries (Zaria cancer registry 1976-1978) and the 1988 IARC Scientific Publication No. 87 on International Incidence of Childhood Cancer (Ibadan Cancer Registry 1960-1984). The latest IARC Scientific Publication No. 153 of 2003 included a large quantity of data from six cancer registries in Nigeria (Ibadan, Zaria, Eruwa, Ile-Ife, Calabar and Enugu).

Site Frequency (%)      Site Frequency (%) 1960-80   1981-95 NHL (including Burkitt's) 14.9   NHL (including Burkitt's) 19.9 Liver 10.4   Liver 11.2 Prostate 6.3   Prostate 10.8 Connective tissue 5.4   Colorectal 4.9 Stomach 5.2   Connective tissue 3.7 HL 4.5   Skin (non melanoma) 3.6 Table 1. Relative frequency of the six commonest tumors in Nigerian males between 1960-1980 and 1981-1995. (Source: JO Thomas.Archives of Ibadan Med 2000, I : 5) * NHL = Non-Hodgkin's lymphoma. HL = Hodgkin's lymphoma. Site Frequency (%)   Site Frequency (%) 1960-80   1981-95 Cervix 19.9   Breast 25.7 Breast 11.2   Cervix 22.6 Choriocarcinoma 8.5   NHL (including Burkitt's) 4.4 NHL (including Burkitt's) 7.4   Ovary 4.0 Ovary 6.1   Liver 3.4 Connective tissue 3.7      Colorectal 2.8 Table 2. Relative frequency of the six commonest tumors in Nigerian females between 1960-1980 and 1981-1995. (Source: JO Thomas. Archives of Ibadan Med 2000, I:5) * NHL = Non-Hodgkin's lymphoma.

The estimated number of cases per year in Nigeria is predicted to be 100,000 at the present time, and by 2010, it is estimated that about 500,000 new cases will be diagnosed annually. A critical review of published data from Nigerian cancer registries (IARC publication 153 of 2003; 8797) and several other publications have confirmed some changing trends in the relative incidence of major cancers in both adults and children (Tables 1-3). In males, colorectal and non-melanoma skin cancers have displaced stomach and Hodgkin's lymphomas in the 1981-95 report (Table 1). In females, cancer of the breast has outstripped cancer of the cervix, with liver and colorectal cancers displacing choriocarcinoma and connective tissue cancers (Table 2). Burkitt's lymphoma remains the commonest cancer in Nigerian children, although the incidence is falling, most probably as a result of the better diet in children. Urbanization and increased awareness, diet, changing lifestyles, and many as yet unknown factors contribute to the increasing incidence of cancers of the breast, prostate, colon and rectum in Nigerians.

There is no doubt that cancer is a serious public health problem in Nigeria, but regrettably, its management has not been satisfactory due largely to the adverse effects of unfavourable economic factors. This experience is similar to that in other African countries which have similar economic problems.

The main objectives of cancer management are to enhance the quality of life of the sufferers, cure the disease with available resources and minimize the side effects of cancer therapy. Pre-therapy counseling of patients/relations is always emphasized with the aim of allaying their fear and providing emotional stability, even when the prognosis seems bleak; in particular, following repeated tumor recurrences and the development of refractoriness to cytotoxic drugs. The major limiting factors to successful treatment of cancer in Nigeria are the high cost of hospital care and the inability of a majority of the patients to obtain chemotherapy, poor supportive facilities and a high default rate.

The unhealthy state of cancer therapy in this country is best illustrated with reference to our experience with the management of 213 patients with Burkitt's lymphoma over a period of 13 years. Over 75% of patients presented in advanced stages C or D; 132 (62%) of the patients received less than the recommended number of cycles of chemotherapy before voluntary discharge from the hospital and, 41 (31%) of these did not complete a single chemotherapy cycle. The default rate was unacceptably high, with 166 patients (77.9%) failing to return for outpatient visits after a median follow-up period of 2.3 months (range = 0,67 months). A 5-year survival rate of only 1.9% was obtained, compared to almost 50% reported in E. Africa, using a similar combination therapy - cyclophosphamide, oncovin and methotrexate (COM). Our experience with Burkitt's lymphoma is similar to that of most other cancers, in that a large majority of patients present very late and are unable to purchase anti-cancer drugs.

Lack of human and material resources account, in large part, for the dismal results of cancer therapy in Nigeria, but poor planning and lack of positive political will are also major factors militating against effective cancer care in Nigeria. Here, and in many other sub-Saharan African countries, these difficulties have been compounded in the last 1 to 2 decades by the introduction of the disabling IMF/World Bank structural adjustment program (SAP) and by the emerging HIV/AIDS pandemic, which is now incapacitating millions of the economically productive members of society.

Cancer Prevention

The ever-dwindling government funding of health care is inconsistent with the increasing needs brought about by the increasing incidence of cancer in Nigeria. What then can we do in the face of this dilemma? Bearing in mind the WHO statement of 3rd of July 2002, that “of the 10 million cancer cases occurring annually, 1/3 can be prevented, another 1/3 can be effectively treated with early diagnosis, and palliative care can improve the quality of life of the last third”, it is reasonable to conclude that effective and sustainable cancer control measures are feasible, but will require a concerted effort on the part of all stake-holders in the country. In particular, it will be important to adopt preventive measures for many cancers, including education against behavior associated with an increased, risk and immunization and screening where feasible and cost-effective. For example, cancer of the liver can be effectively prevented through immunization against hepatitis B virus (HBV), as well as through compulsory screening of blood and blood products for HVB and HCV markers and by using disposable needles and syringes. Cervical cancer can be controlled through early detection by a “Pap smear” or by the more sensitive 'visual inspection technique' with acetic acid or Lugol's iodine. Vaccines against human papilloma virus (HPV) have already been shown to be effective, and could eventually effectively prevent cervical cancer. Regular self-examination of the breast during monthly periods and regular mammography examination of the breast will facilitate early detection of breast cancer, although mammography is unlikely to be cost-effective as a screening procedure in resource-poor countries such as Nigeria. Prevention could have a major impact on tobacco-related cancers as well as other tobacco related diseases. Lung cancer, a difficult disease to treat, is easily (in theory!) prevented by not smoking, but it is disappointing to note that, following recent aggressive campaigns against the tobacco industry in most western populations, tobacco companies have now shifted their advertisement to poorer parts of the world. Tobacco abuse has reached epidemic proportions in many such countries, including Nigeria, and we can anticipate a major increase in tobacco-related diseases in the coming years.

Site 1960-1984 Frequency   1985-1992 Frequency No %   No % Leukaemia 86 9.0   46 12.0    ALL 33 3.4   15 3.9 Lymphoma 539 56.3   152 39.7    Burkitt's 446 46.6   102 26.6    Hodgkin's 35 3.7   18 4.7 Brain & spinal tumours 47 4.9   61 15.9 Neuroblastoma 41 4.3   1 0.3 Retinoblastoma 67 7.0   37 9.7 Wilms tumour 67 7.0   24 6.3 Bone tumours 7 0.7   11 2.9 Soft tissue sarcomas 46 4.9   29 7.6    Kaposi sarcoma 1 0.1   0 0.0 Others 57 6.0   22 5.7 Total 957 100.0   383 100.0 Table 3. Patterns of childhood cancers in Nigeria: 1960-1992. (Adapted from Parkin et al. Cancer in Africa IARC Pub No 153, 2003, 96)

Lastly, cancer control would greatly benefit if the government were to establish a National Cancer Institute, with the objectives of providing clinical and investigative facilities for cancer care and research, the provision of postgraduate training in cancer, the coordination of cancer control activities in Nigeria and the encouragement of collaboration with cancer centers in other parts of the world. In order to identify areas deserving of major efforts, and to monitor the outcome of interventions, a Nigerian Cancer Institute should also monitor cancer trends in the country.