Smoking cigarettes can unfavorably affect the body in many ways, particularly raising the risks of serious heart and respiratory diseases. The effects of smoking are caused when substances are burned and absorbed into the bloodstream. These highly toxic and carcinogenic compounds contained in cigarettes significantly increase the risks of developing lung cancer, tracheal cancer, bladder cancer and pancreatic cancer. Moreover, toxic chemicals such as carbon monoxide and tar cause serious damages to the vessels which eventually lead to ischemic heart disease and stroke. Although smoking is a hard habit to break since nicotine is highly addictive, smoke cessation is highly recommended to lower chances of heart and lung conditions.
Facts and statistics of smoking
Statistical data revealed by World Health Organization (WHO) in 2018 indicates that the tobacco epidemic is one of the biggest public health threats, killing several million people a year. Cigarettes are smoked by over 1.1 billion people globally. More than 7 million of those deaths are the result of direct tobacco use while around 890,000 deaths are the result of non-smokers being exposed to second-hand smoke.
Apart from lung cancer and other respiratory diseases, cigarette smoking claims 3 million deaths from cardiovascular diseases (CVDs) such as heart failure and cerebrovascular diseases such as stroke. Cigarette smoking is a toxic and carcinogenic mixture of more than 7,000 chemicals which badly affect the body. Therefore, smoke prevention and cessation is the best possible way to remain healthy.
Cigarette smoking and lung cancer
Smoking can primarily cause lung diseases by damaging airways and the small air sacs (alveoli) found in the lungs. Lung diseases caused by smoking include COPD (chronic obstructive pulmonary disease) which includes emphysema and chronic bronchitis. It can eventually result in lung cancer. Over the past decade, lung cancer has exhibited a disproportionately high mortality and increasing mortality trend. In Thailand, lung cancer recently ranks the second most common male cancer and the fourth most common cancer found in female. More importantly, lung cancer remains the first leading cause of cancer related deaths in Thailand. Most of lung cancer deaths are mainly caused by smoking and many others are caused by exposure to secondhand smoke.
Lung cancer does not cause any specific signs and symptoms until it has spread, presented with advanced manifestations related to affected organs. However, the most common symptoms of lung cancer may include a chronic cough, coughing up blood or rust-colored sputum (spit or phlegm), chest pain, shortness of breath or wheezing, hoarseness, unintentional weight loss, loss of appetite, fatigue and weakness. Bone pain is possible symptom, representing advanced or metastatic stage. To early screen lung cancer without any signs and symptoms, people with “high risk” of lung cancer should consider annual lung cancer screening by using low-dose CT (computerized tomography) scan. High risk groups are defined as people who have at least a 30 pack-year history of smoking and currently smoke or having smoke quitting within the past 15 years. A pack year is calculated by multiplying the number of packs of cigarettes smoked per day by the number of years the person has smoked. For example, 30 pack-year is equal to smoking 2 packs (40 cigarettes) per day for 15 years. An early screening by using low-dose CT largely helps to find lung cancer at an earlier stage even before symptoms arise. Early detection significantly increases the chances of being cured and results in a better quality of life”.
In case that lung cancer is suspected, additional test is tissue sample. A sample of abnormal cells in the lungs will be further removed in a procedure called a biopsy. A biopsy sample may also be taken from lymph nodes or other areas where cancer might spread. The pathogenic results obtained from biopsy reveal the specific characteristics of abnormal cells and type of lung cancer which determine disease prognosis. After lung cancer has been diagnosed, imaging tests might be required to determine the extent (stage) of lung cancer. Staging tests may include CT, MRI and PET/CT. The results from imaging procedures will be used to further guide appropriate treatment plans.
The two general types of lung cancer include small cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Lung cancer can be treated in several ways, depending on the type and stage whether it has spread to other organs while taking into consideration of individual patient’s conditions and underlying diseases. Non-small cell lung cancer can be treated with surgery (as a first line therapy for early stages), chemotherapy, radiation therapy, targeted therapy, or a combination of these treatments. Small cell lung cancers are usually treated with radiation therapy and chemotherapy. In stage 4 lung cancer, chemotherapy, targeted and immunotherapy are major treatments. “Immunotherapy” is a novel therapy that uses medicines to stimulate a patient’s immune system (cytotoxic T-cells) to recognize and destroy cancer cells more effectively. Nevertheless, immunotherapy is generally reserved for patients with advanced or relapsed lung cancer. Even though, the advancements in cancer treatment has rapidly progressed resulting in prolonged life expectancy and improved survival rates, lung cancer has ranked number 1 as the leading cause of cancer related deaths. Smoking cessation can considerably decrease risks of develop lung cancer while early detection with low-dose CT significantly helps to identify lung cancer at its earlier stages, leading to more chances of being cured.
Cigarette smoking and heart diseases
Smoking damages the lining of the arteries, leading to a build up of accumulated fatty deposits (known as atherosclerotic plaque) which narrows the artery, leading to the restriction of blood circulation and several cardiovascular conditions. Cigarette smokers are prone to develop vessel damages and restrictions by 10-15 years quicker than non-smokers. More interestingly, a number of studies show that women with smoking while using birth control dramatically increases risk of experiencing coronary artery disease (CAD), with relative risk up to 40, compared to women without these aggravating factors. In addition, the risks to develop myocardial infarction (also known as a heart attack) increase up to 10 times compared to non-smoking women. The severity is relatively associated with exact amount and total duration of smoking.
Nicotine, an addictive chemical component found in cigarette, stimulates the body to produce adrenaline which makes the heart beat faster and raises blood pressure, thus the heart works even harder. Nicotine also increases the risk of myocardial infarction. Blood is more likely to clot, which increases the risk of having heart diseases such as a heart attack and stroke.
Carbon monoxide, another toxic substance may contribute to smoking-induced cardiovascular disease. Exposure to carbon monoxide has been strongly associated with increased cardiovascular morbidity and mortality. When cigarette smoke is inhaled into the lungs, carbon monoxide passes through the lining of the lung into the blood where it attaches to red blood cells. As a result, myocardial muscles have less oxygen supply. This causes circulation problems and high blood pressure. As a result, it increases the risks of heart attack and stroke. The risks of developing cardiovascular diseases of former smokers who have quitted longer than 10 years are significantly lowered as almost similar as non-smokers.
Smoke cessation can be hard because smoking is more than just a “bad habit” – it’s an addiction. Not only because quitting is a difficult task mentally and emotionally, but it can also be an intense physical ordeal for the body to overcome an addiction to nicotine. Nevertheless, every minute of being smoke-free is a success for a better health. Becoming smoke-free is a journey that might take day by day, one step at time. Smoke cessation even for few hours can regulate abnormal heartbeat and blood pressure with reduced levels of toxic chemicals in the body. Maternal smoking during pregnancy, compared to non-smokers, raises risks for heart defects in babies such as fetal cardiac calcification and atherosclerosis (restricted blood flow of the arteries), with relative risk of 4 and 2, respectively.
To quit smoking successfully, smoking-related products must be entirely removed. Other triggers must be also avoided such as alcohol, stress and other smokers. At the beginning of smoke cessation program, nicotine withdrawal symptoms may include cigarette cravings, irritability, frustration, anger, anxiety and nervousness. Life style changes to cope with these symptoms are taking a deep breath, drinking more water, taking a cold shower/bath, eating a variety of foods as well as having regular exercise or staying active. Quitting smoking is not easy, but it is worth for a better health.
Dr. Eakachai Sathianpitayakul
Pulmonologist (Subspecialy: Critical Care Medicine, Pulmonary Medicine and Pulmonary Critical Care), Chest and Respiratory Center, Bangkok Hospital.
Dr. Chattanong Yodwut
Cardiologist, Bangkok Heart Hospital.
Dr. Potjana Jitawatanarat
Medical Oncologist, Bangkok Cancer Hospital