There are many diseases and disorders of the lung. One of them is the lung cancer. This type of cancer is the cancer that starts in the lungs. Lungs are the pair of organs that play an important role in the breathing. When we inhale air it enters in to our lungs where gaseous exchange takes palace and oxygen is absorbed in capillaries and carbon dioxide is given out. Lung cancer is uncontrolled growth of abnormal and cancerous cells which starts either in one lung or in both lungs. Commonly it occurs in the cells that line the air passages. Abnormal cell does not develop in healthy lung tissue; they divide quickly and form tumors.
What is Lung cancer?
Lung cancer is the uncontrolled and abnormal growth of cells that start in one or both lungs. It commonly occurs in the cells that line the air passages. Abnormal cells do not develop into healthy lung tissues. They divide quickly and form tumors. When these tumors become large enough and they are more numerous. Moreover they undermine the lung’s ability to provide the blood with oxygen.
Those tumors that remain in one place and they do not seem to spread are called as benign tumors.
These malignant tumors are more dangerous tumors. They spread to other parts of the body either by the blood or by the lymphatic system. The Metastasis:
This term refers to cancer that spread beyond its site or area of the origin to some other parts of the body. When this type of cancer spreads to other parts of body it is much harder to treat it in successful way.
Primary lung cancer:
This type of lung cancer originates in the lungs.
Secondary lung cancer:
This type of cancer starts somewhere else in the body; it then metastasizes and reaches to the lungs. They are considered somewhat different types of cancers as compare to other types of cancers and are not treated in the same way as other cancers.
More about lung cancer:
Lung cancers can also start in the cells lining in the bronchi or in any other parts of the lung such as the bronchioles and alveoli.
Lung cancer is thought to start as an area of pre cancerous changes in the lungs. The first change that occurs in the genes inside the lung cells can cause the cells to grow at faster rate. Such cells may look a bit abnormal if they are seen under the microscope, however at this point they do not form a mass or a tumor. Also they cannot be seen on an x ray and they do not cause symptoms as such.
As the time passes on, these abnormal cells might acquire other gene change that can cause them to progress to the true cancer. When the cancer develops, these cancerous cells may make chemicals that cause the new blood vessels to form in nearby area. Such blood vessels nourish the cancerous cells, that can continue to grow and then form a tumor which is large enough to be easily seen on imaging tests like as x rays.
At some of the points during their life, these cells from the cancer may break off from the original tumor and spread which is known as metastasize in this way it spreads to other parts of the body. Such lung cancer is often a life threatening and dangerous disease as it tends to spread in such a way that even before it can be detected on an imaging test such as a chest x ray.
Types of lung cancer
There are 2 main and basic types of lung cancer which are listed below:
- Small cell lung cancer.
- Non-small cell lung cancer.
Small cell lung cancer:
This type of lung cancer is known as small cell lung cancer because of very small size of cancerous cells which is observed when seen under microscope. Small lung cancer account s for almost 10 percent to 15 percent of all types of lung cancer. This type of lung cancer is also known by some other names such as are oat cell cancer, oat cell carcinoma, small cell undifferentiated carcinoma. Its main cause is smoking that’s why it is very rarely seen in people who are involved in smoking. It usually begins in the bronchi which is located near the center of the chest. Moreover it tends to spread widely through the body early in the course of this disease.
Non-small cell lung cancer:
This type of lung cancer is known as non small lung cancer because of cancerous cells not being small when they are observed and seen under the microscope. Non small cell lung cancer accounts for almost 85 percent to 90 percent of lung cancers. It has three subtypes:
- Squamous cell (epidermoid) carcinoma.
- Large cell (undifferentiated) carcinoma.
These subtypes of non small lung cancer differ in their size, shape, and chemical composition. They are grouped together because their method of treatment and prognosis are often very similar.
Squamous cell (epidermoid) carcinoma:
Such type of lung cancer starts in its early versions of squamous cells that are flat cells which line the inside of the airways in the lungs. These are often linked to a history of smoking and they tend to be found in the middle part of the lungs, which is near the bronchus. Squamous cell carcinomas accounts for almost 25 percent to 30 percent of all types of lung cancer.
Adenocarcinomas accounts for almost 40 percent of all types of lung cancer. Such cancers begin in early versions of the cells that will normally secrete substances like mucus. Such type of lung cancer occurs commonly in any type of smokers, However, it is also the most common type of lung cancer in non smokers as well. It is most common in women as compared to men. It is more likely to occur in younger people and adults as compare to other types of lung cancer. It is commonly found in the outer parts of the lungs. It grows slower as compare to other types of lung cancer, and it is more likely to be found in lungs before it gets spread outside of the lungs.
People with adenocarcinoma which is called as adenocarcinoma in situ tend to have a better outlook as compare to those who are suffering from other types of lung cancer.
Large cell (undifferentiated) carcinoma: This type of cancer represents for almost 10 percent to 15 percent of lung cancers. This may appear in any part of the lungs. It can grow and spread quickly, that can make it very difficult to treat. It has a subtype which is known as large cell neuroendocrine carcinoma which is a fast growing cancer and it is very similar to that of small cell lung cancer.
It is very less common subtype of non small cell lung cancer
This is also very less common subtype of non small cell cancer.
Beside two main type of lung cancer, there are some other types of lung cancer.
Lung carcinoid tumors:
This type of the lung cancer accounts for almost less than 5 percent of all types and kinds of lung tumors. Most of them are very slow growing tumors and are called typical carcinoid tumors. Such tumors are generally cured by the surgery. Some carcinoid tumors can even spread, however they usually have a better prognosis or outlook as compare to small cell or non small cell lung cancer. Least common type are a typical carcinoid tumors. The prognosis for such tumors lies somewhere in between typical carcinoids and small cell lung cancer.
Adenoid cystic carcinomas:
This type of lung cancer is very rarely occurring. Moreover its risk factors are also somewhat different as compare to other types of lung cancer
This type of lung cancer is very rarely occurring. Moreover its risk factors are also somewhat different as compare to other types of lung cancer.
This type of lung cancer is very rarely occurring. Moreover its risk factors are also somewhat different as compare to other types of lung cancer.
Benign lung tumors:
It has one form which is known as hamartomas and they are very rarely occurring.
Cancers which spread to the lungs:
Cancers which start in other organs like in the breast, pancreas, kidney, or skin can sometime spread to the lungs. However, they are not lung cancers. For instance cancer that starts in the breast and then it spreads to the lungs is still breast cancer, but not lung cancer. Treatment for such as cancer that has spread to the lungs is based on which type of cancer it is.
Causes of Lung cancer:
Cancer is the result of cells which un-controllably grow and they do not die. However, normal cells in the body follow an ordered path of growth, division, and death. Programmed cell death which is also called as apoptosis, and when such process breaks down, the cancer starts to form. However, unlike regular or normal cells, cancerous cells do not experience programmed death and instead of continuing to grow and divide. It leads to a mass of abnormal and defective cells that grows out of control.
Another cause of lung cancer is that it occurs when lung cell gene mutation ( changes in base sequence) makes cell to become unable to correct DNA damage and defects and become unable to commit suicide. Mutations or changes can occur for variety of reasons or causes. Mostly lung cancers are the result of inhaling carcinogenic substances or smoking cigarette.
There are further causes of lung cancer that are listed below:
Carcinogen is a class of substances or compounds that are directly responsible for damaging and defecting DNA, promoting cancer. Tobacco, asbestos, arsenic, radiation like gamma and x-rays, the sun, and some compounds in car exhaust fumes which are all examples of carcinogens. When your body is exposed to carcinogens, or free radicals are formed which try to steal electrons from other molecules present in the body and become charged. Such free radicals damage cells and affect the ability to function and divide in normal way.
Almost 87 percent of lung cancers are related to smoking and to inhaling the carcinogens which are present in tobacco smoke. Moreover exposure to second hand smoke can damage cells so that cancer can occur.
Cancer can be the consequence of a genetic predisposition which is inherited from family members more specially from parents. It is also possible to be born with certain genetic mutations changes or a fault in a gene that makes it statistically more likely to develop cancer in later life stage. Genetic predispositions are considered to either directly cause lung cancer or they greatly increase one chance of developing lung cancer due to exposure to certain environment factors
Risk factors for Lung cancer:
Risk factors for the lung cancer are as below:
- Smoking might be the risk of lung cancer and its risk increases with the number of cigarettes which you smoke every day and the number of years you smoked.
- Exposure to second hand smoke.
- Exposure to gases to radon gas.
- Exposure to chemicals like asbestos and other chemicals. …
- Family history of lung disorders like lung cancer.
Who treats Lung cancer?
A doctor who specializes in lung and lungs disorders is known as pulmonologist and he treats lung cancer.
Symptoms of Lung cancer:
Listed below are the symptoms of lung cancer and signs of lung cancer.
- cough which does not go away and gets worst.
- Pain in chest that often gets worse while deep breathing, coughing, or while laughing.
- Loss in weight loss.
- loss of appetite.
- Blood in coughing or rust-colored sputum.
- Shortness of breath.
- Feeling of tiredness.
- Feeling of weakness.
- Treatment of Lung cancer:
- Choice of treatment in case of lung cancer depends upon the type and stage of cancer. Treatment of small cell lung cancer is somewhat different from treatment of non-small cell lung cancer.
Small cell lung cancer is treated with chemotherapy. However, non small cell cancer can also be treated with chemotherapy. Surgery is only suitable if there are no signs that the cancer has spread to the lymph glands in the centre of the chest. It is rare with small cell lung cancer. This type of cancer has usually spread at the time of diagnosis. Chemotherapy is usually the very main treatment. Patients might also have radiotherapy to treat this type of lung cancer.
Lung cancer can also be treated with radiation therapy. In this type of treatment radiations or waves are used to cure cancer.
Non small cell lung cancer is treated with surgery, chemotherapy, radiotherapy or even with a combination of all these treatment options. It greatly depends up on the stage that where the cancer has been diagnosed. Most of the people with advanced lung cancer may have biological therapy.
Planning of treatment:
Following are the factors that will be looked upon in order to plan your treatment:
- Type of lung cancer that you are suffering from.
- At what area of the lung cancer has occurred.
- General health of the patients.
- Whether it is spread or not.
- Test reports like blood tests and other tests.
- Patient own choice of treatment options.
Stages of cancer:
Stage 1 lung cancer:
Stage 1 non small cell lung cancer is very uncommon. Patients normally have surgery to remove part of the lung or all of the lung. If patient can not have an operation for other health reasons, the doctor may suggest radiation therapy instead to try to cure the cancer. There is another option for small tumors. if patient can not have surgery is RFA.
Stage 2 lung cancer:
For stage 2 non small cell lung cancer, patient may be offered surgery. It depends upon the position of the tumor, your surgeon may remove part of the lung or the entire lung. If the cancer is completely removed, your specialist may suggest the chemotherapy. Chemotherapy has the aim to lower down the risk of the cancer so that it may not come back or reapear. Doctors call this adjuvant chemotherapy. It is most important that your doctor talks to you beforehand about the benefits and side effects of chemotherapy. On case if the surgeon could not remove all of the tumor you may have radiation therapy after that.
If you can’t have surgery due to other health concerns, your doctor may offer radiation therapy or combined radiotherapy and chemotherapy. This treatment aims to try to get rid of the cancer completely.
Stage 3 lung cancer:
For stage3 non-small cell lung cancer patient may be able to have surgery, depending on where the cancer is in the lung. Patient may need to have the his entire lung removed. If the surgeon completely removes the cancer, you may then have chemotherapy in order to try to lower the risk of the cancer coming back. In case the surgeon finds cancer cells in the lymph nodes during the surgery they are likely to advise you to have chemotherapy and possibly radiation therapy after the operation.
If patient can not have surgery due to some other health concerns, the doctor may offer radiation therapy or combined radiotherapy and chemotherapy. Such treatment aims to try to get rid of the cancer disease completely.
If scans show signs of cancer in the lymph nodes on the opposite side of your chest, surgery is not possible. Patient may have a course of chemotherapy. After getting chemotherapy done patient might need further treatment with radiation therapy. If you are fairly fit you may have radiotherapy at the same time as the chemotherapy.
Stage 4 lung cancer:
Treatment for stage 4 non small cell lung cancer aim to control the cancer as long as it is possible and to shrink the tumor down to reduce and minimize symptoms. Most of the trials have used chemotherapy in the situation and that it can help the people to live longer time span as well as relieving symptoms.
Care team members:
Your care team consists of following doctors and members:
- Specialist surgeons.
- A doctor who has specialized in using drugs so as to treat cancer which is called medical oncologists.
- A doctor who has specialized in chest conditions
- Doctors who has specialized in symptom control
- Doctors who has specialized in radiotherapy and chemotherapy treatment which is called clinical oncologists.
- Specialist lung cancer nurses
- Doctors specializing in diagnosis from tissue specimens which is called histopathologists.
- Occupational therapist.
- Social workers.
- Health professionals or specialists.
Statistics of Lung cancer:
According to the National Cancer Institute, at the end of 2012 there will be 226,160 new lung cancer cases diagnosed and 160,340 lung cancer related deaths in the U.S.A. However on an average 1,370,000 deaths occur each year due to lung cancer. According to World Health Organization almost 7.6 million deaths globally are caused by cancer every year. Cancer accounts for 13 percent of all global deaths.
Survival rate of Lung cancer:
The American Cancer Society reports that lung cancer makes up to 14 percent of all diagnosed cancers in the U.S.A today. More people are added to it each year, more patients die of lung cancer alone than prostate cancer, breast cancer and colon cancers combined. An American man lifetime risk of developing lung cancer is 1 in 13 people; In case of women the risk is 1 in 16 women. These risk figures are for all US people, including people who are smokers, left smoking that is ex-smokers and non-smokers. The risk for a smoker is dramatically higher as compare to non smoker or ex smoker.
Most of the lung cancer patients are above the age of 60 years age when they are diagnosed. Lung cancer may take several years to reach a level where symptoms are observed and the sufferer decides to aquire medical help.