Overview
The lungs are the organs that are present on either side of the chest, and they appear to be spongy. Three lobes appear to occur in the right lungs while there are two lobes of the left lung. Small structures look like a sack and are medically known as alveoli, which are present in the bronchioles. Bronchioles are the branches present in the lungs. During the inhaling process during respiration, the air reaches the lower bronchioles via the trachea, and at this point, oxygen combines with the blood for circulation. While during exhalation, carbon dioxide produces the byproduct of respiration, and the body removes it.
Lung cancer is a medical condition in which there is an abnormal division of cells in the lungs. Due to the uncontrollable division of the cells, there is the development of tumors that adversely affect the respiration’s essential process. Lung cancer and its various types are most prevailing in the whole US, and there is almost 25 percent of deaths happening due to this type of cancer. According to the American cancer society, there is a prediction of 228,820 patients with lung cancer that might appear in 2020. Thus, the people who smoke tobacco and other tobacco products are at greater risk of developing lung cancer.
There are two types of lung cancer, i.e., small-cell lung cancer (SCLC) and non-small cell lung cancer (NSCLC). Many treatment options are available for treating lung cancer, including targeted therapy, surgery, immunotherapy, radiation therapy, and chemotherapy. The type of treatment plan you opt for depends upon the stage and the type of cancer you have.
Lung Cancer Symptoms
Generally, there are no visible symptoms in the starting stages of lung cancer, but as the condition worsens, there is an occurrence of symptoms and signs. The occurrence of symptoms might also depend on the type of tumor and the tumor growth location on the lung. Some of the initial symptoms of lung cancer might include:
Pneumonia
Pneumonia is a lung infection in which there is an accumulation of fluid in the lungs, and the patient suffers from breathing difficulties. The tumor growth in the lung tissues increases the chances of developing pneumonia and weakens the patient’s immune system suffering from lung cancer. There is an accumulation of fluid in the cavity between the walls of the lungs and the chest, which leads to the breathing difficulties in the patients. The doctors suggest that there is frequent pneumonia in the patients with lung cancer as the state of the lungs is at stake due to the overgrowth of the cells in the tissues of the lungs.
Cough
Coughing appears as a persistent symptom in the early stages of lung cancer and sometimes causes chronic pain when a person coughs. The tumor present in the bronchi and airways causes inflammation and stimulates coughing, producing blood with regular coughing. Persistent and frequent coughing episodes are common in the earlier stages of lung cancer in the majority of the patients. The cough gets worse by time and leads to chronic coughing as the tumor grows. Sometimes in the advanced stages of lung cancer, blood production with a cough is a significant health risk. The persistent coughing episodes increases the pain in the chest, shoulders, and chest.
Bronchitis
Bronchitis is an infection of the airways in the lungs. In lung cancer patients, there is irritation and inflammation of the bronchi, which worsens with the tumor growth. In combination with the two other lung infections, bronchitis, pneumonia, and emphysema are in later stages of lung cancer. While some patients only develop chronic bronchitis, the doctors suggest that these patients do not progress towards the later stages of lung cancer. Some patients also develop asthma and tuberculosis, and bronchitis, thus indicating tumor growth in the lungs. There is an increase in mucus production in the airways, leading to the blockage of airflow through these air passageways in the patients with bronchitis. The persistent symptom of bronchitis leads to the lung damage, which is mostly permanent and greatly reduces the lung function.
Chest pain
Chest pain occurs with breathing or even while making conversations, laughing, or even sitting down. The chest pain a person is experiencing is a clear indication of air passageways blocking due to the tumor growth in the lungs. The cancerous cells growing abnormally in the lungs lead to enlargement of the lymph nodes, and the fluid build-up around the lungs or chest cavity, which causes excruciating pain in the chest. The pain arising in the chest is either sharp or constant and occurs at intermittent intervals. The chest pain in the lung cancer patients might be due to chest infections, resulting in cancerous growth.
Loss of appetite
Lung cancer patients usually suffer from loss of appetite due to the changes in taste, nausea, or chronic pain. The patients with lung cancer start eating less than the average amounts of food and lead to the eating disorder of anorexia, which ultimately causes weight loss. The blocking of the airways and the fluid accumulation in the chest cavity makes the lung cancer patients to eat less or not eat at all. The loss of appetite in lung cancer patients is medically known as cancer cachexia, which leads to muscle wasting and unintentional muscle wasting.
Shortness of breath
Due to the accumulation of fluid in the chest cavity, there is shortness of breath in lung cancer patients, and it is a common symptom among most of the patients. The medical professionals refer shortness of breath as Dyspnea, and as cancer spreads to the lungs, there is trouble with the flow of air through the air passageways. The shortness of breath also depends on the lung’s part affecting by cancer, and in the advancement of cancer, the patient experiences persistent coughing and severe shortness of breath.
Reduction in body weight
There is an unintentional loss of body weight due to fewer intakes of nutrients. The cancerous growth in the various parts of the lungs disrupts the respiration process and the persistent coughing or pain in the chest cavity, making the person eat less or not eat at all. Cancer growing in the lung also makes the body unable to utilize all the nutrients from food. Moreover, the abnormal growth of cancerous cells in the lungs stimulates the body burn more calories than usual, and even in the resting state of the body, there is the breakdown of healthy tissues.
Breathlessness
Breathlessness is a common symptom among lung cancer patients, which shows the lungs’ inability to carry on the process of respiration. Breathlessness is one of the distressing symptoms of patients having lung cancer. The lung cancer patients face difficulty catching their breath and feel tightness around their chest due to the compromise of the healthy respiration system. The symptoms of breathlessness make the patient less active physically because it becomes challenging to breathe if the patient does some physical activity.
Fatigue and weakness
There is a sensation of weakness and lack of energy because cancer lowers the number of red blood cells in your blood and, consequently, lesser oxygen to provide power. The patients with lung cancer experience persistent weakness and fatigue, and no matter how much the person rests or sleeps, there is no relieving from fatigue. The destruction of red blood cells and the lack of energy available for the body to make enough red blood cells make the person feel tired and weak all the time. The systemic weakness symptom is prevalent and becomes intense with the progression of cancer.
Respiratory infections
The tumors in the lungs block the airways and cause several breathing infections. There is a repetition of respiratory infections in patients with lung cancer, and these infections are recurring. The infections in the respiratory system might arise due to the blocking of airways. The tumor grows persistently, making it difficult for the lung to expand during the inhalation process fully. The primary respiratory infections resulting from lung cancer include lower respiratory tract infection (LRT) and bronchitis.
As we know, lung cancer symptoms also appear depending upon the tumor growth location on the lung. The metastasis of tumor occurring in the lung can reach to other body organs and might result in symptoms such as:
Bones Pain
Lung cancer leads to the developing pain in the ribs, back, or hips as cancer in the lungs spread extensively to the bones. According to the studies, almost 30 to 40 percent of patients with lung cancer develop bone metastasis during the disease’s progression. The lung cancer spreads into the bones and causes bone Mets, and these tumor growths are relocating from the primary tumor in the lungs.
Spinal cord and brain
The metastasis of tumors in the spine results in dizziness, headache, balance problems, or numbness. The tumors in the spine driving from the primary tumor in the lung progresses rapidly, and unfortunately, there is a poor prognosis for the treatment of this type of cancer. The spine tumors rapidly result in the patient’s paralysis in most cases, and the treatment is challenging for metastatic spine tumors.
Lymph nodes
The primary tumor of the lungs causes the development of lumps in the neck or the collar bone as cancer spreads to the lymph nodes in the nearby area in the extensive stage of lung cancer, when both of the lungs are suffering from tumor growth then the lymph nodes on both sides of the lungs suffer from cancer. There is swallowing of lymph nodes and glands in the chest area and leads to the stomach’s swallowing if cancer reaches the liver.
LiverÂ
In non-small cell lung cancer (NSCLC), there is a spread of lung cancer to the body’s distant organs, including the liver. There is yellowness of skin and eyes or jaundice, which indicates the liver metastasis, and the cancer cells develop aggressive tendencies. The cancer cells float in the blood circulation and start replicating themselves in new areas. The prognosis of liver metastasis due to lung cancer is almost five years, giving a survival rate of 5 percent.
The tumors forming at the upper portion of the lungs might result in the development of Horner syndrome, which causes symptoms such as:
Shoulder pain
There is severe pain in the shoulder, hand, arm, and scapula due to lung tumors, which affects the bones of the body, as mentioned earlier. There is a release of calcium ions in the bloodstream from the bones, leading to higher calcium levels in the blood, which further causes pain in the body.
Lack of sweat on the face
The tumor growing in the lungs causes the disruption of nerve stimulations of the central nervous system towards the face. There is a lack of sweating on the face’s area affecting the disruption of the nerve pathway.
Reduction in pupil size
There is constriction of the pupil, which is medically known as meiosis due to the nerve pathway’s disruption. The cancerous cells from the tumor in the lungs resulting in the disruption of nerve signals towards the face, and the reduction in pupil size happens on one side of the eye in most cases. The two muscles that control the pupil size are the circumferential sphincter muscle cells, and they are present in the iris, and the cancer cells disrupt the activity of these sphincter muscles.
Drooping of eyelids
The disruption in the nerve signal pathway, resulting from cancer cells of lungs, causes ptosis, i.e., the drooping of the eyelids. The superior tarsal muscles responsible for keeping eyelids in raised position effects from the partial opening and the eyelids start drooping down. The eyelid drooping doesn’t affect the vision or the health of the eye but is not life-threatening.
The tumors might secrete a hormone which leads to the development of the paraneoplastic syndrome, and the symptoms include:
Nausea
The patient suffering from a paraneoplastic syndrome manifests nausea as there is obstruction of gastrointestinal tracts due to the increased tumor growth. The chest cavity suffers from the abnormal growth of cancerous cells, leading to the pseudo-obstruction of the gastrointestinal tract, making the food go back towards the mouth.
High blood pressure
There is a production of systemic high blood pressure or hypertension, mainly due to the cancerous cells spreading in the lungs. There are renal malignancies in the patients with lung cancer, which significantly reduces kidneys’ function, thus leading to high blood pressure.
Vomiting
There is a manifestation of vomiting in the patients of lung cancer chronic obstruction of the gastrointestinal tract. The persistent vomiting leads to water retention and regurgitation of food from the stomach.
Seizures
There is a loss of nerve cells, which leads to cerebral degeneration in the brain’s site where the cancer is growing after relocating from the lungs.
High blood sugars
There is acute hyperglycemia or high blood sugar, as the function of the pancreas suffers from the cancerous growth relocating from the lung tumors.
Confusion
As there are degeneration nerve cells in the brain areas suffering from the attack of tumors originating from lung cancer, the patient suffers from confusion. The degeneration of nerve cells leads to confusion and loss of focus among the patients.
Muscle weakness
The paraneoplastic syndrome significantly causes weakness of proximal muscles leading to severe disability. There is an increase in serum muscle enzyme levels, which indicates the growth of cancer cells.
Coma
The PNS syndrome significantly affects the spinal cord, brain, and nerves leading to a coma condition, and it might be fatal for the patient. The comma becomes rapid and fluctuates as there is constant degeneration of nerves in the central nervous system.
Lung Cancer Types
Lung cancer, which develops in the bronchi, is known as “bronchogenic carcinoma.” According to health care professionals, there are two main types of lung cancer depending upon the appearance and the magnitude of the cancerous cells. The types include:
- Small-cell lung cancer (SCLC)
- Non-small cell lung cancer (NSCLC)
- Small- cell lung cancer (SCLC):
Almost 20 percent of cases of lung cancer patients are suffering from small-cell lung cancer. SCLC is the most fastly prevailing and most destructive type of lung cancer. Smokers are usually the easiest targets of developing small-cell lung cancer, while there is only a 1 percent chance of non-smokers developing SCLC. This type of lung cancer spreads quickly to other body parts, and usually, the diagnosis happens after cancer spreads to the many parts of the body. Due to the specific shape of the cells under the microscope in the SCLC cancer, they are also known as oat cell carcinoma
- Non-small cell lung cancer (NSCLC)
Non-small cell lung cancer appears to affect almost 80 percent of lung cancer patients and is known as the most general lung cancer type. NSCLC includes many types of tumor cells, and for this reason, it is divided into subtypes. Some patients have combinations of subtypes of NSCLC, and these subtypes comprise:
- Adenocarcinoma:
Adenocarcinomas are the most commonly occurring type of non-small cell lung cancer, and this cancer mostly develops in the outer areas or the peripheral areas of the lungs. Almost 50 percent of the NSCLC patients are adenocarcinoma, and most of the patients have a history of cigarette smoking.
- Squamous cell carcinoma:
Squamous cell carcinoma usually develops in the chest area where there is a presence of bronchi. This subtype of NSCLC is also known as epidermoid carcinoma. Almost 30 percent of the NSCLC patients suffer from squamous cell carcinoma.
- Large cell carcinoma:
Large cell carcinoma is usually the less frequently occurring type of NSCLC and sometimes also known as undifferentiated carcinoma.
Other types of lung cancer:
The less common types of lung cancer include:
- Cancers of supporting tissues:
The cancerous cells might also spread in the nearby tissues like cells of the immune system, the blood vessels, and the smooth muscle cells.
- Bronchial carcinoids:
Bronchial carcinoid is also known as neuroendocrine tumors, and it occurs in almost 5% of lung cancer patients. The occurrence of bronchial carcinoids is higher in the persons who are older than 40 years of age. Moreover, the size of the tumors developing in this type of cancer is smaller and falls in the range of 3-4 cm or sometimes less.
Lung Cancer Diagnosis
Healthcare professionals use several tests and procedures to confirm the presence of lung cancer in a patient accurately. Some of the tests and methods of lung cancer diagnosis include:
Physical examination:
The medical professional asks for the suspicious signs and symptoms of lung cancer that might explain lung cancer in a specific individual. Some of these physical symptoms might include the windpipe’s obstruction, difficulty in breathing, and smoking cigarettes. Similarly, the occurrence of cyanosis, i.e., the yellowing of the skin and eyes, also indicates the lack of oxygen supply to the blood and shows the occurrence of chronic lung cancer in the patient. Another physical symptom is the clubbing, i.e., the change in the nails bed tissues, indicating lung cancer in the patient.
Positron emission tomography (PET)
PET is a technique that utilizes the radioactive drugs to have a three-dimensional image of the drugs which live for a short time in the body tissues. The positron emission tomography is very much different from the CT scan. The PET scan helps check the functions of the body tissues and the metabolic activity of these tissues. In contrast, the CT scan helps in getting the image of the anatomy of the structures. The PET scans help in indicating the tumor in the cells, the type of cells in the tumor, and the magnitude of these cancerous cells’ growth. The patient receives a dose of the radioactive drug, which absorbs the tissues of the body and usually helps us get the scan of the chest. After absorbing in the body tissues, the drug emits positrons, which further emit the gamma rays in the body. A scanner then helps in developing the image of the cancerous cells and their growth rate.
Chest X-ray
Chest X-ray is one of the most common methods to diagnose lung cancer after the appearance of some suspicious physical symptoms in the patient. The chest X-ray includes the X-ray of the back, front, and sides of the chest. X-ray reveals the hamartomas, which are the areas of cancerous cells, and indicate cancer’s actual location in the lungs.
Bronchoscopy
The bronchoscopy procedure involves the insertion of a thin fiberoptic probe in the airways by either nose or mouth. The procedure reveals the areas of tumors, especially in the central areas of the lungs. There might be some complications after the process of bronchoscopies like lack of oxygen in the blood, irregular heartbeat, and blood in the cough.
Bone scans
The doctors also use bone scans to diagnose the spread of lung cancer to the bones. The bone scan technique is similar to PET scanning, as it also includes the use of radioactive material in the blood. The radioactive material accumulates in the bones, and the scanner reveals the radioactive material, and there is an image on the screen.
Magnetic resonance imaging (MRI)
MRI indicates the actual location of the tumor in the body. The MRI technique gives detailed and high-quality scans of the body organs and the smaller changes in the body. This technique uses radio waves, a computer, and magnetism to generate body image. There are no side effects of MRI scanning.
Blood tests
The blood testing helps detect the abnormalities or changes occurring due to lung cancer but is insufficient to diagnose lung cancer accurately. The higher levels of calcium and alkaline phosphatase in the blood indicate lung cancer’s spread to the bones. Moreover, the presence of abnormal amounts of liver enzymes, such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT), also reveals the damage occurring to the liver due to the spread of cancer in the body.
Sputum cytology
Sputum is the fluid in which the tracheal cells or bronchi of the lower respiratory tract secrete. In this technique, the doctor collects the sputum from the patient and looks for cancerous cells under the microscope’s light. This method is very economical for getting a proper diagnosis of lung cancer, and the chances of risks are significantly less. However, this method is not so accurate as the sputum might not always contain the cancerous cells.
Needle biopsy
Needle biopsy is a technique in which the tumor present in the lungs’ peripheral or outer areas goes without the diagnosis even after performing the bronchoscopy. The doctor inserts a smaller needle in the lung’s affected area and collects the sample of cells in the specific area. The doctor gives the local patient anesthesia before the procedure’s performance and then examines the cell sample to check the cancerous cells’ presence.
Thoracentesis
Thin needles are known as thoracentesis, help in diagnosing the cancerous cells that line the lungs’ walls, which lead to the pleural effusion. The accumulation of the fluid between the lungs and the chest wall is known as pleural effusion, and it goes undiagnosed usually. Still, the thoracentesis helps in revealing the cancerous cell in the walls of the lungs.
Lung Cancer Causes
The primary causes which play a role in the development of lung cancer are as follows:
Cigarette smoking
Smoking is one of the major causes of the development of lung cancer. Almost 90 percent of lung cancer patients are smokers of cigarettes—the development of lung cancer increases by the increasing number of cigarettes you smoke over time. The doctors consider the pack-years of a person and examine the smoking history by multiplying the pack of cigarettes per day by the number of years. The people who have authority pack-years of smoking are at the highest risk of developing lung cancer.
Tobacco smoking
Tobacco comprises about four thousand chemical components, most of which are carcinogenic. The chemical compounds such as nitrosamines and polycyclic aromatic hydrocarbons are the cancer-causing agents present in the tobacco smoke. Smoking can significantly increase the chances of lung cancer after each consequent year of smoking.
Exposure of asbestos fibers
The people who work in the silicate industry are at higher risk of getting exposure to asbestos fibers. The asbestos fiber tends to survive in the lungs for a lifetime. There is a prohibition law in many countries against the use of asbestos fiber around the housing areas. The inhalation of asbestos fibers results in the inflammation of the lining of the lungs and the abdominal cavity. The person having asbestos exposure is at a higher risk of developing lung cancer, and the chances are five times higher among the non-smoker individuals.
Second hand smoking
The passive or second hand smoking, which is the inhalation of smoke from the surrounding, might also increase the chances of developing lung cancer among the individuals who do not actively smoke. The people who live near the smokers and inhale the smoke from the environment are at 24 percent more risk of developing lung cancer than those who do not live around smokers.
Lung diseases
Some lung diseases happen to increase the chances of lung cancer development in the patient. Pulmonary fibrosis causes the scarring of the lung tissues and increases the chances of getting lung diseases up to 7 times even in the patients who are non-smokers. At the same time, the patients of chronic obstructive pulmonary disease (COPD) have 4 to 6 times more chances of developing lung cancer.
Lung Cancer Treatment
There are many treatment approaches in practice to treat lung cancer patients. The accurate method of treatment depends upon several factors like the stage and type of lung cancer. Following are the various treatment plans for treating lung cancer:
Radiation therapy
Radiation therapy utilizes high energies, x-rays, and some other radiations for treating lung cancer patients. The radiation therapy kills the cancerous cells, and there are no risks with this treatment option, like surgery. The use of radiation therapy can bring some adverse effects, such as reducing platelet count, fatigue, and reduction in WBC’s.
Surgery
A surgical operation involves removing the tumor and cancerous cells, and this technique is helpful in the early stages of cancer. The doctors use surgery in the patients depending upon the location and size of the tumors.
Chemotherapy
Chemotherapy involves using certain chemicals in the form of the drug, which kills the cancerous cells. Chemotherapy is a treatment option for the SCLC and NSCLC patients, and it stops the division and growth of cancerous cells in the body.
