Lung cancer also known as lung carcinoma, is a lung tumor which is known when or characterized by uncontrolled cell growth in tissues of the lung. If this disease is not treated well or left untreated, this unwanted growth can spread in entire body with the process of metastasis. There are two main types of lung cancer, that are first, small cell lung carcinoma ( SCLC ) and non-small-cell lung carcinoma ( NSCLC ). The most common symptoms of lung cancer are coughing ( coughing with blood also ), weight loss, shortness of breath and chest pains.
It is shocking to know that 85 percent of lung cancer cases happen because of long-term tobacco smoking. It is a large percentage of cases. And about 10 to 15 percent of cases appear to happen to them who never smoke. These causes arise because of various factors such as a combination of genetic factors, exposure to radon gas, asbestos, second hand smoke, or other forms of air pollution. Lung cancer can be detected through chest radiographs and computed tomography scans. Further, the diagnoses is confirmed by biopsy which is performed by bronchoscopy or CT-guidance.
How can a person prevent lung cancer?
Yes, an individual can prevent him or her from lung cancer. Avoid smoking and various forms of air pollution these are the only two way a person can save him or her from lung cancer. Treatment and long-term outcomes depends on the type of case, the stage ( spread area ), and the person overall health. It is not unknown that most of cases are not curable. The treatment options include, and are the following:
- And, Radiotherapy.
In 2012, there were about 1.8 million cases of lung cancer which resulted in 1.6 million deaths. This data makes lung cancer the number one cause of cancer related death in men and second major reason of deaths in women after breast cancer. According to a survey, about 17. 4 percent of people in United States survive for five years after the diagnosis of lung cancer.
Signs and symptoms of lung cancer
Following are the signs and symptoms which may result in lung cancer when diagnosed:
- Respiratory symptoms: coughing, coughing up blood, wheezing, or shortness of breath.
- Systemic symptoms: weight loss, weakness, fever, or clubbing of fingernails.
- Symptoms due to the cancer mass growing on nearby body parts: chest pain, bone pain, superior vena cava obstruction, or difficulty in swallowing food.
- If the cancer is growing in the airways it may produce or cause difficulty in breathing as well.
Symptoms of lung cancer
- Poor appetite if only sudden.
- Weight loss.
In most of the cases the cancer spreads to other parts of the body way long before the person starts noticing the symptoms of it and seek medical attention. Common places where lung cancer spreads are the brain, bones, adrenal glands, opposite lung, liver, pericardium, and kidneys.
Causes of lung cancer
Cancer starts developing when or following damage to genetic DNA and epigenetic changes. These drastic changes affects the normal functions of the cell, which also includes cell proliferation, programmed cell death ( apoptosis ) and DNA repair. As more damage happens to the body, the risk of lung cancer increases.
Smoking, particularly of cigarettes, is the main cause behind the lung cancer. Cigarette smoke contain at least 73 known carcinogens, including benzo(a)pyrene, NNK, 1,3-butadeine, and a radio active isotope of polonium, polonium-210.
Passive smoking, is the cause of lung cancer in non-smokers, meaning when a person is smoking near by you, smoke is exhaled by you. A passive smoker can be defined as a person living or worker working or living with a person who smokes. Those who live with a person who smoke have a 20 to 30 percent risk factor of getting lung cancer. And who work in an environment of smoking have 16 to 19 percent risk of getting lung cancer. Passive smoking is 3,400 deaths from lung cancer each year in the USA. Marijuana smoke contains many of the same carcinogens as those in tobacco smoke. According to a study conducted in 2014, it was found that smoking cannabis doubles the risk of lung cancer.
Radon gas is a colorless and odorless gas generated by the breakdown of radioactive radium, which is the decay product of uranium which is found in earth’s crust. Radon is the second most cause of lung cancer in the USA, causing 21, 000 deaths each year.
Asbestos can cause various lung related disease including lung cancer. Both tobacco smoking and asbestos have a synergistic effect on the formation of lung cancer. Asbestos can also cause other forms of cancer such as pleura, called mesothelioma ( which is different from lung cancer ).
Air pollution is a vast term. Outdoor air pollutants, especially chemicals released from the burning of fossil fuels, increases the risk of lung cancer. Indoor pollutants such as the burning of charcoal, dung, wood, or crop residue which is used for cooking and heating are also a main reason behind lung cancer. This risk effects 2.4 billion people globally, as is accounted for 1.5 percent of lung cancer deaths.
About 8 percent of lung cancer is due to inherited factor. In relatives of people with lung cancer the risk is doubled.
- Some metals ( aluminium production, cadmium, and cadmium compounds, beryllium and beryllium compounds, iron and steel founding, nickel compounds, arsenic and inorganic arsenic compound.
- Some product of combustion, coal, coal gasification, iron and steel founding, coke production, soot, and diesel engine.
- Ionizing radiation.
- Some toxic gases.
- Rubber production and crystalline silica dust.
Stages of lung cancer
Small cell lung cancer staging
The most common cause behind small cell lung cancer is smoking of tobacco and accounts for 20 percent cases. This often starts in the bronchi, then within no time start growing in other parts of the body too, including the lymph nodes. There are two stages to small cell lung cancer as well and they are following:
- Limited stage – In this stage the cancer is only in one lung.
- Extensive stage – In this stage the cancer has been already spread to other lung and fluid of cancer starts spreading to other body parts.
Non- small lung cancer staging
This stage uses the TNM system:
Tumor: It describes the real size of the tumor.
Lymph node: It helps in indicating either the cancer is present in lymph node or not.
Metastasis: In this step it is aimed to find out that whether the cancer has spred to other body parts or not such as liver, kidney etc.
The first step in diagnosing lung cancer is chest radiographic. This may reveal an obvious mass, consolidation, or pleural effusion. CT imaging is typically used to provide more information about the type and extent of disease. Bronchoscopy and CT- guided biopsy both are often used to sample the tumor for histopathology process.
Radio therapy is often given with chemotherapy, and may be used in a curable form for people suffering from NSCLC who are not eligible for surgery. This is a high form of radio therapy and is known as radical radio therapy. Some people with N2 lymph node may benefit from this radio therapy. When a potential is seen in a case, they are recommended radio therapy with chemo therapy. And if cancer blocks the airway, an artificial passage is created for patient by doing a little surgery. Compared to radio therapy, brachytherapy provides a reduction in treatment and also reduce radiation exposure to health care staff.
Prophylactic cranial irradiation (PCI) is a type of radio therapy which contact the brain directly, and is used to reduce the risk of metastasis. PCI is most useful in SCLC cases.
The chemo therapy duration or procedure depends in the size of tumor. Small- cell lung carcinoma ( SCLC ), even early stage disease is treated with the help of chemo therapy and radiation. In SCLC, cisplatin and etoposide are most common used. The most common used drugs are gemcitabine, paclitaxel, docetaxel, pemetrexed, etoposide or vinorelbine.
Various treatment can take place through bronchoscopy for the management of airway obstruction and bleeding too. If because of lung cancer the airway gets blocked then the following steps can be taken:
- Rigid bronchoscopy
- Balloon bronchoscopy