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Cancer in Africa: Everything You Need to Know

Cancer is a complex disease that encompasses over 100 different types, each with its unique characteristics. In all forms of cancer, the normal control mechanisms of cell division go awry, resulting in uncontrolled growth and the ability of cancer cells to invade surrounding tissues. This disruptive process can initiate in various locations within the human body, making cancer a versatile and widespread health concern.

What is Cancer?

Cancer is a widespread disease that affects the human body, and its impact is significant, especially in Africa. The body consists of a diverse community of cells, each playing a crucial role in maintaining the body’s normal functioning. For instance, nerve cells facilitate neural signals, lung cells enable gaseous exchange, and intestinal cells aid in nutrient absorption from the digestive tract. Every cell has its designated function, occupying specific spaces within the body.

Ideally, cells remain within their boundaries and do not encroach upon the territory of neighboring cells. However, cancer disrupts this harmony. It is a group of diseases characterized by abnormal cell growth that possesses the potential to invade or spread to other parts of the body. In Africa, cancer poses a significant health challenge, with numerous types affecting the population. In fact, over 100 different types of cancers have been identified in humans.

What makes cancer particularly dangerous is its ability to cause uncontrolled cell division, leading to the spread of cancerous cells into surrounding tissues. It is noteworthy that cancer can originate in various regions of the human body, making it a versatile and formidable adversary.

Statistics reveal that Africa faces its share of cancer-related challenges. According to recent data, cancer incidence rates have been steadily rising in various African countries. In some regions, limited access to healthcare and late-stage diagnoses contribute to higher cancer mortality rates. Efforts to raise awareness, improve cancer screening programs, and provide better treatment options are essential in combating this disease throughout the continent. Cancer’s impact on Africa underscores the importance of continued research, prevention strategies, and accessible healthcare services.

How does cancer form?

The process of cell division through mitosis is responsible for the formation of new cells in the body, occurring when the body requires them. This division is tightly regulated by the cell cycle, ensuring that cells grow, replicate, and eventually replace old or damaged cells. Normally, aged or damaged cells undergo programmed cell death, allowing new cells to take their place. However, in certain cases, cells can become abnormal and defy this natural process. Instead of dying as they should, these aberrant cells persist and continue to live, leading to the formation of unnecessary new cells.

The uncontrolled growth of these needless cells poses significant problems for the body. They multiply uncontrollably, forming abnormal outgrowths known as tumours. Tumours have the tendency to disrupt the normal functioning of surrounding cells and tissues. They exert pressure on healthy cells, displacing them and consuming vital nutrients required for their own unrestricted growth. Tumours can be classified into two main types: benign and malignant.

Benign tumors, although not generally life-threatening, can still pose risks, particularly when they develop in critical areas like the brain. Since the brain is enclosed within the fixed-sized cranium, the continuous expansion of benign tumors can damage healthy brain tissue, potentially leading to severe complications or even death. On the other hand, malignant tumors are always considered serious and demand immediate attention. If left undetected and untreated, they can invade nearby tissues and spread to distant parts of the body through a process known as metastasis.

The occurrence of tumours, especially malignant ones, highlights the importance of timely detection and treatment. In Africa, like in other parts of the world, it is crucial to promote awareness about cancer and ensure access to proper healthcare facilities for early diagnosis and effective intervention. By detecting malignant tumours at an early stage and implementing appropriate treatment measures, it becomes possible to increase the chances of successful outcomes and potentially save lives.

A picture showing the proliferation of a cancerous cell.
This diagram illustrates how cancer is formed. Normal cells have similar shapes and size as shown in the first drawing labelled normal. As a person ages, their cells keep developing mutations. At a point, a normal cell develops enough mutations that it begins to grow slightly faster than the surrounding cells (the reddish cell in the centre of the second drawing, labelled “single hyperproliferative cell”). Hyperproliferative means the cell grows faster than normal cells. When enough hyperproliferative cells accumulate, a small benign tumour called an adenoma develops (third drawing). The adenoma does not have the normal organization, but it has not broken through the basement membrane. With time, the adenoma progresses into a carcinoma. The cells in the carcinoma break through the basement membrane and spreads to the spaces of other cells. Look at the fourth drawing, a tumour cell can be seen in the lower right-hand corner breaking into a small blood vessel (pink segmented circle). It will spread to other tissues through the bloodstream. This process is known as metastasis.

Differences between Cancer Cells and Normal Cells

  • Normal cells grow into specialised cells with specific functions, whereas cancer cells do not undergo specialization. They are less specialised compared to normal cells.
  • Cancer cells disregard the commands from proteins and genes that regulate cell multiplication and cell death. They ignore signals that normally instruct cells to stop dividing. They also fail to respond to signals that activate programmed cell death, known as apoptosis, which is the body’s natural way of eliminating damaged, worn out, or unnecessary cells.
  • Cancer cells have the ability to induce the formation of blood vessels that supply tumors with oxygen and nutrients necessary for their growth. These blood vessels also help remove waste products from tumors.
  • Cancer cells possess the capability to evade the immune response. While the immune system is responsible for protecting the body against pathogens and disease-causing agents and eliminating harmful cells, cancer cells can avoid destruction by the immune system.

What Causes Cancer?

G pictorial representation of normal and cancerous cells

Cancer is classified as a genetic disease because it arises from alterations in an organism’s genes. However, it is important to distinguish this from being a hereditary disease, which refers to conditions passed down from parents to their offspring through genes. While certain individuals may possess genes that increase their susceptibility to cancer, it does not mean that cancer itself is inherently hereditary.

The main underlying cause of cancer is the gradual accumulation of mutations over an extended period of time. These mutations can occur spontaneously or be triggered by external factors such as exposure to carcinogens or certain lifestyle choices. It is worth noting that not all genetic changes lead to the development of cancer; rather, it is specific changes in certain genes that play a crucial role.

These genes are categorized into three primary groups: proto-oncogenes, tumor suppressor genes, and DNA repair genes. Proto-oncogenes are originally normal genes that, when mutated or activated, can promote uncontrolled cell growth and contribute to the development of cancer. Tumor suppressor genes, on the other hand, normally function to regulate cell division and prevent the formation of tumors. When these genes undergo mutations or are inactivated, they lose their ability to restrain excessive cell growth. Lastly, DNA repair genes are responsible for fixing errors and mutations in the DNA. If these genes are defective, the accumulation of further mutations becomes more likely, increasing the risk of cancer.

What are protooncogenes?

Proto-oncogenes play a vital role in regulating cell growth and division. However, if these genes undergo specific alterations or become overactive, they can transform into oncogenes, which have the potential to initiate cancerous cell growth.

What are Tumour Suppressor Genes?

Tumor suppressor genes play a crucial role in restraining cell growth and division. When these genes lose their ability to inhibit excessive cell growth and multiplication, cells can proliferate uncontrollably, significantly increasing the likelihood of cancer development.

What are DNA repair genes?

DNA repair genes are responsible for the crucial task of repairing damaged DNA within cells. As cells naturally undergo mutations, these genes play a vital role in maintaining genomic stability by rectifying these mutations. However, when DNA repair genes themselves acquire mutations, they may introduce errors or defects during the DNA repair process. This can result in the propagation of genetic abnormalities or mutations in the genes they are meant to repair, thereby amplifying the risk of developing cancer.

Do Viruses cause cancer

Oncoviruses are a group of viruses known for their ability to cause cancer. Several oncoviruses have been identified, including:

  • Hepatitis B and Hepatitis C viruses: These viruses are linked to the development of hepatocellular carcinoma, a type of liver cancer.
  • Kaposi’s sarcoma herpesvirus: This virus is associated with the occurrence of Kaposi’s sarcoma, a cancer that affects the skin and other organs, as well as primary effusion lymphomas.
  • Human papillomavirus (HPV): HPV is a well-known oncovirus responsible for cervical cancer and other types of cancer, such as anal, vaginal, vulvar, penile, and oropharyngeal cancers.
  • Epstein-Barr virus (EBV): EBV is associated with B-cell lymphoproliferative diseases and can contribute to the development of nasopharyngeal carcinoma, a type of head and neck cancer.
  • Human T-cell leukemia virus-1 (HTLV-1): HTLV-1 is linked to the development of T-cell leukemias and lymphomas.

In addition to viruses, certain bacteria can also pose a risk for cancer development. For example, Helicobacter pylori infection is strongly associated with gastric carcinoma, a form of stomach cancer.

Parasitic infections have also been implicated in cancer. Schistosoma haematobium, a parasitic worm, is linked to squamous cell carcinoma of the bladder. Liver flukes, specifically Opisthorchis viverrini and Clonorchis sinensis, are associated with cholangiocarcinoma, a type of bile duct cancer.

Environmental Causes of Cancer

Causes of cancer are not solely attributed to mutations but can also result from environmental factors such as heat, radiation, chemicals, and more. These factors, known as carcinogens, have the potential to induce cancer. For instance, ultraviolet radiation from sunlight is a significant contributor to many non-melanoma skin cancers. Ionizing radiation, which can originate from medical imaging or radon gas, is another source of potential carcinogenic exposure. Additionally, certain substances like chemicals and pollutants have been identified as carcinogens.

CarcinogenOccupational ExposureCancer Risk
4-aminobiphenylChemical and dye workersBladder
ArsenicMining, pesticide workersLung, skin, and liver
AsbestosConstruction workersLung
AuramineDye workersBladder
BenzeneLeather, petroleum, rubber, and chemical workersLeukemia
BenzideneChemical, dye, and rubber workersBladder
Bis (chloromethyl) etherChemical workersLung
ChromiumMetal workers, electroplatersLung
Isopropyl alcoholManufacturing by strong acid processLung
Leather dustBoot and shoe manufacturing and repairNasal and bladder
Mustard gasMustard gas workersLung, larynx, and nasal
NaphthylamineChemical, dye, and rubber workersBladder
Nickel dustNickel refiningNasal and lung
RadonUnderground miningLung
Soots, tars, and oilsCoal, gas, and petroleum workersLung, skin, and bladder
Vinyl chlorideRubber workers, polyvinyl chloride manufacturingLiver
Wood dustsFurniture manufacturingNasal
Adapted from LSU Health Sciences Center

Cancer in Africa

Incidence of Cancer in Africa


Cancer incidence in Africa is on the rise. According to the World Health Organization (WHO), an estimated 847,000 new cancer cases were diagnosed in Africa in 2020 alone. This number is projected to increase significantly in the coming years due to factors such as population growth, aging, and changing lifestyles.

Leading Types of Cancer in Africa


Breast, cervical, prostate, liver, and colorectal cancers are among the leading types of cancer in Africa. Breast and cervical cancers affect women disproportionately, while prostate cancer is the most commonly diagnosed cancer among men. Liver cancer is prevalent due to a high prevalence of viral hepatitis infections, and colorectal cancer is also on the rise, linked to changing dietary habits.

Mortality Rates of Cancer in Africa


Cancer-related mortality rates in Africa are alarming. According to the Global Cancer Observatory, approximately 591,000 cancer-related deaths occurred in Africa in 2020. Limited access to early detection and treatment facilities, as well as late-stage diagnosis, contribute to higher mortality rates.

Impact of Infections on Cancer in Africa


Infectious agents play a significant role in cancer development in Africa. Human papillomavirus (HPV) is a leading cause of cervical cancer, while hepatitis B and C viruses contribute to liver cancer. Efforts to improve vaccination programs and promote awareness about these infections are crucial in reducing cancer incidence.

How Challenges in Healthcare Infrastructure Affects Cancer Fight in Africa


Africa faces numerous challenges in tackling the cancer burden. Limited access to healthcare facilities, shortage of healthcare professionals, inadequate infrastructure, and limited funding for cancer prevention and treatment programs are significant obstacles. These challenges hinder early detection, timely treatment, and effective management of cancer cases.

Importance of Awareness and Prevention:
Raising awareness about cancer prevention and early detection is vital. Promoting healthy lifestyle choices, such as tobacco cessation, healthy diet, regular physical activity, and sun protection, can significantly reduce the risk of developing cancer. Additionally, increasing access to screening programs and vaccines can lead to earlier detection and improved outcomes.

Types of Cancer

Carcinoma

Adenocarcinoma affects glandular tissues like the breast, colon, and prostate gland.
Basal cell carcinoma begins in the lower part of the skin’s epidermal layer.
Squamous cell carcinoma, also known as epidermoid carcinoma, affects the skin and linings of organs like the stomach, intestines, lungs, bladder, and kidneys.
Transitional cell carcinoma occurs in the transitional epithelium found in organs such as the bladder, ureters, and renal pelvis.


Sarcoma

Sarcoma refers to cancer of the soft tissues, including tendons, muscles, fat, blood vessels, lymph vessels, and nerves. Examples include osteosarcoma, liposarcoma, and leiomyosarcoma.

Leukemia

Leukemia is a cancer of the bone marrow, where abnormal white blood cells enter the bloodstream and disrupt the functions of normal blood cells. It can lead to decreased oxygen levels, impaired blood clotting, and weakened immune response.


Lymphoma

Lymphoma occurs when abnormal lymphocytes accumulate in the lymph nodes and vessels. It is categorized into non-Hodgkin lymphoma and Hodgkin lymphoma.


Multiple Myeloma

Multiple myeloma affects plasma cells in the bone marrow, leading to the formation of tumor patches across the bones.


Melanoma

Melanoma is a type of skin cancer that develops from melanocytes, the cells responsible for producing melanin. It can also affect other pigment-containing tissues, including the eyes.


Brain and Spinal Cord Tumors

These tumours are associated with the central nervous system, such as astrocytic tumours originating from star-shaped cells in the brain.

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Other Types of Tumours

Germ Cell Tumors

Germ cell tumors develop from reproductive cells, such as sperm and egg cells.


Neuroendocrine Tumors

Neuroendocrine tumours affect tissues that produce and release hormones in response to nervous signals. These tumours can cause various symptoms and may be either benign or malignant.


Carcinoid Tumours

Carcinoid tumors are slow-growing tumors commonly found in the gut, particularly in the small intestine and rectum. They have the potential to metastasize to other parts of the body, such as the liver. Carcinoid tumors often secrete hormones like serotonin or prostaglandins, which can lead to carcinoid syndrome.
It’s important to note that early detection plays a significant role in the successful treatment of many cancers. Maintaining a healthy lifestyle and a balanced diet can also contribute to preventing and managing health issues. While there are still many unanswered questions about cancer, ongoing research aims to provide valuable insights that will aid in improved diagnosis and treatment in the future.

Disclaimer: The information provided in this article is for educational purposes only. It is crucial to seek advice and care from accredited healthcare professionals and institutions for personalized guidance and treatment.

References

What is cancer by the National Cancer Institute

Genetics of Cancer by LSU Health Science Center

Cancer

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