How Cigarette Smoking Cause Lung Cancer?
It has been estimated that tobacco use or smoking is responsible for the deaths of millions of people across the world with many of these deaths occurring prematurely. Depending on today’s data, it is estimated that deaths attributable to tobacco use will rise to around 10 million in the coming years, and almost one-third of all adult deaths are expected to be related to cigarette smoking.
We have all heard that smoking is one of the largest causes of lung cancer across the world. Smoking is known to be a cause of various chronic diseases, primarily it is responsible for cardiovascular and cerebrovascular disorders, chronic obstructive pulmonary disease (COPD) and cancers.
What is Lung Cancer?
Lung cancer is one of the most common types of cancer which occur in both men and women and is associated with morbidity and mortality. Each year, a large number of men die from lung cancer. Evidence suggests that most of the patients who are diagnosed from lung cancer are found to be smokers. The rate of smokers suffering from lung cancer is much higher than non-smokers having lung cancer.
Lungs are the vital organs in the human body and are responsible for multiple functions that are important for survival. Lungs help to bring oxygen to other organs and tissues in the body and also helps to take out carbon dioxide out of the body. Whenever an individual breathes, lungs absorb the oxygen from the air and deliver to the rest of the body. Lung cancer is accompanied by a wide range of symptoms such as a cough that comes with blood, unexplained weight loss, loss of appetite, shortness of breath, and fatigue.
Lung cancer occurs when the cells in the lungs begin to grow uncontrollably. Lung cancer is primarily of two types - Small cell lung cancer and non-small cell lung cancer. Small cell lung cancer begins in the middle of the lungs, whereas non-small cell lung cancer begins in the cells of the lungs that begin to grow uncontrollably and leads to the formation of a tumor. Non-small cell lung cancer can begin anywhere in the lungs. Non small cell lung cancer is further divided into three - adenocarcinoma, squamous cell carcinoma, large cell carcinoma.
Non small cell lung cancer is divided into four stages that explain the severity of cancer. Stage one indicates that the cancer is found in the lungs but has not spread outside the lung. Stage two indicates that cancer is present in the lungs along with the nearby lymph nodes. Stage three indicate that cancer is found in the lymph nodes on the side of the chest where cancer began or on the other side of the chest. Lastly, stage four indicates that cancer has spread to both sides of the lungs and to its nearby parts.
Role of smoking in causing lung cancer
Exposure to tobacco is a major risk factor for lung cancer. Smoking is a preventable cause of lung cancer. Multiple studies have been conducted to investigate the association between the consumption of tobacco and the risk of developing cancer.
Cigarette smoking consists of thousands of chemicals and there is no denying to say that these chemicals act as a poison to a body. When these chemicals get into the body, it damages the functioning of various organs in the body. Nicotine and tar are the most harmful chemicals present in cigarette smoking. There is evidence that proves that intake of tar from cigarette smoke can cause damage to damage to the epithelium of the airways.
Chemicals like nicotine enter the lungs whenever an individual inhale smoke and this affects the functioning of the lungs. It interferes with filtering and cleaning it. Chemicals that are present in cigarette smoke can damage the DNA which plays a vital role in transferring genetic messages to every cell of the body. Any damage to DNA can lead to uncontrollable growth of cells and results in the development of cancer.
In clinical research, muller ascertained the amount of tobacco consumed in men who are diagnosed with lung cancer during a certain period of time consumed by the healthy men of the same age. He observed that a greater proportion of patients with lung cancer were heavy smokers, on the contrary, non smokers were in control. Therefore, he concluded that an increase in the carcinoma of the lungs is primarily due to an increase in the consumption of tobacco.
Second hand smoke can also responsible for the development of lung cancer. Second hand tobacco smoke also contain chemicals that are present in cigarette smoking but in low concentration. Although the concentration of chemicals is low, the risk of developing cancer is high.
Also, the risk of developing lung cancer in people who smoke also depends on the duration of the smoke. For how long an individual is smoking and how many cigarettes he smokes per day. The more an individual is in exposure to tobacco smoke, the higher the risk of developing lung cancer.