Lung cancer is a public health problem because it is the leading cause of cancer-related deaths. Doctors explain that it is caused by smoking.
Lung cancer is the leading cause of cancer-related deaths worldwide. The disease is more prevalent in men, is primarily caused by smoking, and is diagnosed in advanced stages, according to the World Health Organization (WHO).
It is defined as a type of cancer that begins when the body’s cells grow uncontrollably in the lungs. It is much more likely in people who smoke, although it can also appear in those who are passive smokers (those who are exposed to the smoke of other smokers). It is estimated that smoking is the main cause of 85 percent of all cases.
According to Walter García Gonzalez, head of oncologic surgery at the National League Against Cancer (Incan), if tobacco were eliminated worldwide, approximately 30 percent of cancers could be avoided, since smoking also causes mouth, esophageal and pancreatic cancer, etc.
Like other types of cancer, lung cancer does not present symptoms in the early stages, so it is diagnosed when it is already very advanced and treatment options are limited.
WHO notes that lung cancer is the leading cause of cancer deaths, with an estimated 1.8 million deaths (18%) in 2020.
Symptoms of lung cancer
“One of the main characteristics of lung cancer is that it is asymptomatic when it starts. The person does not have any discomfort. When it is in advanced stages, the patient has a cough and phlegm with blood. They even have difficulty breathing when the cancer has already spread widely and has caused bleeding in the lung,” says García González.
The most common symptoms of lung cancer are:
- Persistent cough
- Coughing up blood, sometimes in small amounts
- Chest pain
- Fatigue
- Weight loss is a known cause
- Suffering from recurrent lung infections
- Difficulty breathing
- Loss of appetite
- Problems to work
- Snoring at night
- Constant headache
Types of lung cancer
Lung cancer is divided into two types, depending on how the cancer cells look under a microscope. This is important to determine, as this will help decide on the treatment to follow. The most common are:
Non-small cell lung cancer
This type accounts for about 85 percent of lung cancer cases. It is characterized by slow growth and is divided into squamous cell carcinoma (epidermoid carcinoma), adenocarcinoma, and macrocytic (or large cell) carcinoma, depending on the types of lung cells.
The American Cancer Society notes that this grouping is done because the treatment method and prognosis are often similar.
Small cell lung cancer
This type of lung cancer is the most common in heavy smokers. It tends to grow and spread faster than non-small cell lung cancer.
In most cases, this type of cancer has spread beyond the lungs by the time it is diagnosed. Because it grows quickly, it usually responds well to chemotherapy and radiation therapy. Unfortunately, though, the cancer may return at some point.
Causes of lung cancer
Experts agree that cigarette smoking is the main cause of lung cancer. The risk of developing this type of cancer varies depending on the number of cigarettes smoked and the number of years for which one has smoked.
In people who quit smoking, the risk of developing lung cancer decreases, but ex-smokers continue to have a higher risk of developing lung cancer than those who have never smoked.
“Smoking is thought to cause lung cancer by damaging the cells that line the lungs. When you inhale cigarette smoke, which is full of cancer-causing substances (carcinogens), changes occur in lung tissue almost immediately,” explains the Mayo Clinic.
Other risk factors include air pollution, exposure to second-hand tobacco smoke, use of open fires for cooking and heating, as well as exposure to carcinogenic substances such as asbestos, radiation, radon, arsenic, and nickel, among others.
Diagnosis and treatment
Diagnostic methods will consist, first, of a physical examination. If there are suspicions, the doctor will request an X-ray or a CT scan of the lungs.
A biopsy will also be requested, which consists of taking a sample of lung tissue to determine what type of cancer it is. “ The biopsy is very complicated because you have to insert a camera from the mouth and it remains in the lungs. If the tumor is in the bronchi, where the device goes down to take the biopsy, then it is easier, but if not, it is very difficult because you have to explore more,” says García Gonzalez.
Regarding treatment, it will depend on the type of cancer and its spread. These may be surgery, radiotherapy, chemotherapy, targeted treatment, and immunotherapy.