Cancer Overview


According to World Health Organisation (WHO), Cancer is the 2nd leading cause of death in the world and is responsible for the death of about 10 million people yearly. Between 30-50% of cancer cases are preventable by making healthy lifestyle changes such as avoiding tobacco, getting immunized against cancer-causing infections, and going for regular check-ups to facilitate early cancer detection.

What is cancer?

Cancer is a group of cell-related diseases where cells in a specific part of the body over grow and reproduce uncontrollably.

Normally, body cells receive instructions to stop dividing and undergo cell death in a process called apoptosis. The body then produces new cells to replace the dead ones. This may sound odd, but it is absolutely a positive process that helps us maintain our body cells. The components that instruct cells to stop dividing and die are lacking in cancerous cells and as such the affected cells continue to grow and divide without control. The cells build up in the body and can form tumors. 

WHO estimated that 9.6 million people died from cancer in 2018 and nearly 10 million in 2020. About one-third of cancer deaths are caused by tobacco use, alcohol consumption, high body mass index, lack of physical activity, and low intake of fruits and vegetables. 

Breast, colon, lung, rectum, and prostate are the most common cancers.

There are cancer stages that help to describe the size of a tumor and how far it has grown. Cancer stages help to determine the severity of cancer and the best treatment options.

There are various types of cancer staging systems but the most common one is the TNM staging system.

TNM staging system;

T- describes the tumor size. (with numbers 1 to 4, 1 for small, and 4 for large)

N- stands for lymph nodes. (with numbers 0-3, 0 indicates that no lymph node has cancer and 3 indicates that many lymph nodes do

M- stands for metastases. (describes if cancer has spread to another part of the body, with numbers 0 or 1, 0 means it has not spread and 1 means it has spread)


Cancer can cause a wide range of symptoms depending on which part of the body is affected. Some general symptoms of cancer are;

  • Bleeding for no known reason
  • Cough that doesn't go away
  • Nausea and vomiting
  • Fatigue
  • Fever
  • Headache
  • Weight loss/gain for no known reason

However, sometimes, a cancer diagnosis can come out with no report of symptoms. If you notice any major change in how you feel or the way your body works, talk to your doctor, if it's not cancer, you can find out what's going on and treat it if needed, if it's cancer, you would have a chance to treat it early.


The major cause of cancer is changes to the DNA in cells also known as mutation. Genetic mutations can either be inherited or caused by external factors like radiation, UV light, alcohol, air pollution, cigarette smoking, parasites, viruses, bacteria, contaminated drinking water, and food.

Risk factors

The exact reason why a person develops cancer is usually not known but research studies have shown that certain risk factors may increase a person's chances of developing cancer. Below are five cancer risk factors. See National Cancer Institute for more risk factors.


The most significant risk factor for cancer generally and for many specific cancer types is age progression. The incidence rates of cancer continue to increase as age increases, though cancer can be diagnosed at any age. For instance, bone cancer is most often diagnosed in children and adolescents under the age of 20. 

Cancer-causing substances

Some substances can damage DNA when exposed to the environment. Examples of such substances that can cause cancer include:

  • Chemicals in tobacco smoke
  • Wood dust
  • Arsenic
  • Formaldehyde
  • Spot
  • Nickel compounds
  • Radon

This does not mean that they necessarily cause cancer, the duration of exposure, amount, and genetic factors influence whether a person would develop cancer or not from these substances.


The more alcohol you drink, the higher your risk of cancer. There is a much higher risk for people that smoke tobacco and also drink alcohol.

HIV/AIDS Infection

People with HIV/AIDS have increased risks of cancers caused by infectious agents such as liver, cervical and anal cancers amongst others, and those not caused by infectious agents such as lung cancer.


Obesity increases the risks of some cancer types such as breast, colon, and kidney cancers.

You can reduce your risk of cancer by making a few changes to your lifestyle

The following lifestyle factors have the greatest impact on your risk of cancer. We will also look at what you can do to reduce your risk from today.


Not only does a healthy diet help in reducing cancer risks, but it also helps you maintain a healthy weight. Though a healthy diet does not guarantee that a person would not get cancer.

Cut down on sugary drinks, processed meat, red meat, and alcohol. 

High-fiber foods like whole grains, fruits, vegetables, and dairy products like milk and cheese can reduce the risk of bowel cancer.

Physical activity

Physical activity can help to regulate certain hormones that contribute to cancer development and helps to keep the immune system healthy. Regular exercise also helps you to maintain a healthy weight. 

Getting more physical activity lowers the risk for cancers such as colon, breast, and prostate cancers.

Kids should get at least one hour of moderate-intensity activity such as walking, bicycling, and dancing,  or vigorous-intensity activities such as running, jogging, and swimming each day with vigorous-intensity activity for at least three days each week.

Adults should get at least 150 minutes of moderate-intensity or 75 minutes of vigorous-intensity activity each week, preferably spread throughout the week.


Obesity increases the risk of cancer types such as kidney, breast, colon, and ten other types of cancer. Losing excess weight, getting regular physical activity, and following a healthy diet plan can help reduce the risk of getting these obesity-related cancers.


The American Cancer Society Guideline for Diet and Physical Activity for Cancer Prevention recommends that it is best not to drink alcohol, if not, reduce your alcohol intake to one drink in a day or less for women and two drinks or less in a day for men.


Research studies have shown that adequate hydration is associated with a reduced risk of colorectal cancer.


A study concluded that getting less than 6 hours of sleep can be a risk factor for some types of cancer. Getting adequate sleep could help reduce the risk.

Mental health

Psychological stress such as mental or emotional pressure may cause people to fall quickly into certain habits like heavy alcohol drinking, overeating, and smoking which increase a person's cancer risk. 

Emotional and social support like counseling and a support group can help to positively improve your mental health.


Keeping your emotional health balanced is necessary for your physical health. Self-care is important for overall good health. 


Cancer is a group of cell-related diseases that can be deadly. While early cancer detection provides the best chance for early cancer treatment, prevention is key, and this can be achieved by maintaining a healthy lifestyle.

Diagnostic testing

At Klarity we use the latest technology when it comes to diagnostic testing. Our home blood tests give you health insights and personalised recommendations. Find out which test you should take. 


  1. Cancer [Internet]. 2017 [cited 2022 Sep 18]. Available from:
  2. Cancer [Internet]. [cited 2022 Sep 18]. Available from:
  3. What do cancer stages and grades mean? [Internet]. 2018 [cited 2022 Sep 18]. Available from:
  4. Risk factors for cancer - nci [Internet]. 2015 [cited 2022 Sep 18]. Available from:
  5. Does eating a healthy diet reduce my risk of cancer? [Internet]. Cancer Research UK. 2019 [cited 2022 Sep 18]. Available from:
  6. Obesity and cancer | cdc [Internet]. 2022 [cited 2022 Sep 18]. Available from:
  7. Keren Y, Magnezi R, Carmon M, Amitai Y. Investigation of the association between drinking water habits and the occurrence of women breast cancer. Int J Environ Res Public Health [Internet]. 2020 Oct [cited 2022 Sep 18];17(20):7692. Available from:

Faridah Ojulari

Bachelor of Pharmacy - BPharm, Pharmaceutical Sciences, University of Ilorin

Faridah Ojulari is a Medical Writer and a Bachelor of Pharmacy undergraduate from Nigeria.

She has a burning passion for writing and providing credible medical and health information.

Over the years as a Pharmacy student and medical writer, she has developed strong research, management, and communication skills.

Faridah is an avid learner and has taken various certification courses including research writing in the sciences, content creation, digital marketing, and data analysis.
She strongly believes that the most important skill a person can have is communication. presents all health information in line with our terms and conditions. It is essential to understand that the medical information available on our platform is not intended to substitute the relationship between a patient and their physician or doctor, as well as any medical guidance they offer. Always consult with a healthcare professional before making any decisions based on the information found on our website.
Klarity is a citizen-centric health data management platform that enables citizens to securely access, control and share their own health data. Klarity Health Library aims to provide clear and evidence-based health and wellness related informative articles. 
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