Lung Cancer

Lung cancer is cancer that begins in the lungs and causes cells to divide in the lungs uncontrollably. When such abnormal multiplication of cells occurs in the lungs, it causes the growth of tumors that minimize the ability of a person to breathe.

It is a common form of cancer among both men and women in the world. Lung cancer is mainly caused by smoking and inhaling fumes, and according to the World Health Organization, smoking accounts to up to 80% of the total cancer cases in the world.

The current lung cancer burden in the world is immense and should not be underestimated. It is important to note that lung cancer is the leading cause of cancer deaths in the world. As many people die of lung cancer annually than they die of breast cancer, prostate, ovarian, and colon cancers combined.

Lung cancer has been the most common type of cancer globally since 1985 in terms of both incidence and mortality. It is estimated that about 1,350,000 new lung cancer cases are diagnosed annually, which signifies 12.4% of total new cancer cases worldwide.

Similarly, lung cancer deaths are estimated to be around 1,180,000 signifying 17.6% of total cancer deaths globally. Therefore, lung cancer is the largest contributor to both new cancer cases and deaths annually. 

In Kenya, lung cancer is among the main types of cancers with high mortality rates and about 10 million Kenyans are at risk of the condition due to smoking and exposure to lit end cigarette, cigar, pipe, shisha, and smoke in hotels and restaurants, universities, places of work, and homes.


Sometimes individuals with lung cancer do not have symptoms until the disease is in the late stages. Since there are few nerve endings in the lungs, a tumor may grow without causing discomfort or pain.

However, when symptoms exist, they differ from one person to another and may include:

  • Hoarseness
  • A cough that does not go away and worsens over time
  • Continuous chest pain
  • Coughing up blood
  • Shortness of breath or wheezing
  • Frequent lung infections such as pneumonia or bronchitis

Other symptoms that may seem not related to the lungs or breathing include:

  • Headaches
  • Weight loss
  • Blood clots
  • Bone fractures or pain


Smoking is the main cause of the majority of lung cancers. It causes lung cancers in both smokers and non-smokers exposed to second hand smoke.

However, sometimes, lung cancer occurs in people who have never smoked and have no prolonged exposure to smoke. In such cases, the cause of lung cancer is not clear.

Doctors believe smoke causes lung cancer through destroying cells that line the lungs.

When a person inhales cigarette/shisha smoke, which is full of cancer-causing substances (carcinogens), changes in the lung tissue commence almost immediately.

Initially, the body may manage to repair the damage, but repeated exposure makes the normal cells aligned to the lungs to experience continuous damage that is difficult to repair.

After some time, these cells begin to act abnormally and develop cancer.

Types of Lung Cancer

The two main types of lung cancer include:

  • Small cell lung cancer: Occurs nearly exclusively in heavy smokers and is less common compared to non-small cell lung cancer.
  • Non-small cell lung cancer: It is an umbrella term for numerous types of lung cancers that behave in the same manner. These types include adenocarcinoma, squamous cell carcinoma, and large cell carcinoma.

Risk Factors

Risk factors associated with lung cancer include:

  • Smoking: The risk of lung cancer increases with the number of cigarettes you smoke every day or with the frequency of your shisha use. Quitting at any age can immensely lower your risk of developing lung cancer.
  • Exposure to secondhand smoke: The more you are exposed to secondhand smoke in bars, restaurants, universities, workplaces, and at home, the higher the risk of lung cancer.
  • Exposure to asbestos and other carcinogens: Workplace exposure to asbestos and other substances such as chromium, arsenic, and nickel increase the risk of developing lung cancer and worsen if you are a smoker.
  • Family history of lung cancer: People with a sibling, parent, or child with lung cancer have an increased risk of lung cancer. 


The doctor will ask you some questions concerning symptoms and family history before performing a lung cancer screening.

If the doctor identifies a suspicious lesion through screening, he or she may carry out several diagnostic tests to confirm whether lung cancer exists or not. They include:

  • Imaging Studies: It is the review of lung tissue using computed tomography (CT) and positron emission tomography (PET). Bone scans may equally indicate cancerous growths.
  • Tissue Sampling: If a doctor identifies a suspicious lesion on an imaging study, they may advise taking a sample of lung tissue to test for potentially cancerous cells. The sample may be taken through a bronchoscopy or through a more invasive surgical procedure to remove lung tissue.
  • Lab Testing: Sputum testing or blood-testing in the lab helps to check the presence of lung cancer. It helps determine the type of lung cancer and how to advance it has become.


Staging of cancer shows the extent of the spread of cancer through the body and its severity. This classification is significant for clinical support and direct treatment for positive results.

Staging definitions may vary, but doctors often stage non-small cell lung cancer using the size of the tumor and the spread to guide them. The stages include:

  • Hidden or occult: Cancer does not show on imaging scans, but cancerous cells may appear in the mucus or phlegm and may have reached other body parts.
  • Stage 0: The doctor identifies abnormal cells only in the top layers of cells lining the airways.
  • Stage I: A tumor has occurred in the lung but is less than 5cm and has not spread to other body parts.
  • Stage II: The tumor is smaller than 5cm and might have spread to the lymph nodes or smaller than 7cm and spread to nearby tissues but not lymph nodes
  • Stage III: Cancer has spread to the lymph nodes and reached others parts of the lung and nearby area.
  • Stage IV: Cancer has spread to distant parts of the body, such as the brain or bones.

Note that although small cell lung cancer is not common, it has its categories, limited and extensive, that refer to whether cancer has spread within or outside the lungs.


The treatment option for lung cancer largely depends on its location, stage, and severity. The doctor will also determine the general health of the patient before deciding on the treatment option. The options include:

  • Surgery: The doctor operates to remove cancerous lung tissue and tissues in the nearby areas where cancer may have spread.
  • Chemotherapy: The treatment employs drugs to shrink or get rid of cancer cells. The option typically targets rapidly multiplying cells, which makes it ideal for treating cancer. However, it is also associated with a few side effects, such as nausea and weight loss.
  • Radiation therapy: It uses high-energy rays to kill cancerous cells. A doctor may equally use radiation to shrink a tumor before removing it surgically. It is a very useful approach for cancers that occur in one location and have not spread.
  • Targeted Therapy: It is the use of specific medications that target a particular behavior in cancer cells. They include medicines that stop cancer cells from multiplying.

The most common treatment options for lung cancer are surgery and radiation therapy.

Lung cancer treatment mostly involves the collaboration of medical experts who include radiation oncologists, surgeons, pulmonary therapists, and pulmonologists.


  • Do not smoke if you have not started
  • Stop smoking if you are a smoker
  • Avoid secondhand smoke especially if you live or work with a smoker or when you visit bars and restaurants
  • Test your home for radon especially if you live in an area where radon is problematic
  • Avoid carcinogens at work
  • Eat a diet full of vegetables and fruits
  • Exercise most days of the week

For more information on diagnosis and/or treatment, speak to a doctor, or get access to a hospital near you through the Uzima Health App.