What is Lung Cancer?
The abnormal growth of cells that begins in one or both lungs, generally in the cells lining the air passages is known as lung cancer. These abnormal cells do not grow into a healthy lung tissue and as a result of this, they divide for forming tumors. These innumerable and large tumors weaken the lungs and due to this they cannot provide the bloodstream with oxygen.
Types of Lung Cancer
Non-Small Cell Lung Cancer: This cancer can be categorized into three main types-
- Large Cell Carcinoma : This type got its name from the big rounded cells that can be examined under a microscope. Undifferentiated carcinoma is the other name for this type.
- Squamous Cell Carcinoma : It is considered as the most common type of lung cancer that grows in the cell lining the airways. Smoking is the leading cause of this type of lung cancer.
- Adenocarcinoma : This type grows from the cells which produces mucus in the airway lining.
Mesothelioma : This is considered as not so common type that may affect the covering of the lung. Mesothelioma lines inside the chest and covers the surface of the lungs. People who are suffering from asbestos develop this type of lung cancer.
Small Cell Lung Cancer : In this type of lung cancer, the cancer cells appear to be very small when examined under the microscope. It is also referred to as oat cell cancer. Smoking is considered as the leading cause of this type of lung cancer. It is a fast-developing lung cancer that may spread very quickly.
Rarer Types of Lung Cancer: Carcinoid tumor is considered as a rare type of lung cancer. This is also considered as a type of neuroendocrine cancer. Soft tissue sarcomas are also a rare type of lung cancer.
Stages of Small Cell Lung Cancer
Extensive Stage: The cancer in this stage has spread to different areas of the chest or different parts of the body.
Limited Stage: The cancer in this stage is on one side of the chest that involves only one part of the lung and also surrounding lymph nodes.
Stages of Non-Small Cell Lung Cancer
Stage 1 : In this stage, cancer has not spread to lymph nodes and is located in the lungs.
Stage 2 : In this stage, cancer is there in surrounding lymph nodes and in the lung.
Stage 3 : Also known as locally advanced disease, this type of cancer is there in the lymph nodes in the middle of the chest and lungs. This stage can be further categorized into 2 subtypes –
- When the cancer spreads to the lymph nodes at the same side of the chest from where cancer has begun. This stage is known as IIIA stage.
- When the cancer spread to the lymph nodes above the collar bone and on the opposite side of the chest then this stage is referred to as IIIB stage.
Stage 4 : In this advanced stage, the cancer has spread to both the lungs to different parts of the body that may include liver or some other organ.
Symptoms of Lung Cancer
- Difficulty in swallowing
- Raspy, chronic or hacking coughing sometimes with blood-streaked mucus
- Weakness and pain in the hand, shoulder or arm
- Frequent respiratory infections such as pneumonia or bronchitis
- Weakness, severe headaches, body pain, fatigue, intermittent fever, loss of appetite and weight
- Continuous increase in shortness of breath, wheezing and also constant chest pain
- Face and neck swelling
Diagnosis of Lung Cancer
A number of test are performed for diagnosing lung cancer that include –
Tissue Sample (biopsy): In biopsy procedure, an abnormal cell sample is removed. A biopsy can be performed in a number of ways that include bronchoscopy. In bronchoscopy, abnormal areas of the lungs are examined by light tube that is passed down through the throat and is then advanced into the lungs. Mediastinoscopy is yet another biopsy procedure in which tissue samples are taken from lymph nodes by making an incision at the base of the neck and then inserting surgical tools from behind the breastbone. Needle biopsy is used for collecting suspicious cells by using CT images or X-ray that guide a needle from the chest into the lung tissue.
Imaging Tests: In this, an abnormal nodule or mass can be easily detected through an x-ray image of the lungs. Small lesions can also be detected while performing an x-ray.
Spuctum Cytology: The presence of lung cancer cells can be easily detected by examining the spectrum under the microscope.
Lung Cancer Treatment
The treatments for lung cancer depend on the stage of the cancer, personal characteristics, health status, type of the cancer and age. A number of therapies are provided to a patient as there is no single treatment available for lung cancer. Radiation, surgery and chemotherapy are considered as the major lung cancer treatment.
Radiation Therapy: Here high energy rays are targeted on the lung cancer tumors for destroying them. A damaged is caused to the molecules which are responsible for making cancer cells. High-energy gamma rays are utilized in radiation therapy (also known as radiotherapy) and are emitted from the metals like high-energy x-rays or radium that are produced in a special machine. The major treatment for lung cancer is radiation therapy used for destroying cancer cells that have metastasized or also for destroying the remaining cells left after the surgery.
Surgery: One of the oldest methods for treating lung cancer is surgery. The surgical removal of the tumor and surrounding lymph nodes is done if there is I or II stage cancer that has not metastasized. Palliative or curative are the two types of lung cancer surgeries. Palliative surgery may not remove cancer but can remove an open airway or obstruction that was making the patient uncomfortable. Curative surgery removes all types of cancerous tissue in those patients who are in early stage lung cancer.
Chemotherapy: Strong chemicals are used in chemotherapy that interferes with cell division process and damages DNA or proteins. The aim of these treatments is to rapidly divide the cells. The normal cells can be recovered from any chemical-induced damage whereas cancer cells cannot be recovered. The medicines in chemotherapy travel in a systematic way by passing from the complete body and destroying the original tumor cells that have spread in the whole body. Usually many therapies are combined that also includes many types of chemotherapy. Sometimes, chemotherapy is also provided as adjuvant therapy which is designed for reducing cancer recurrence risk and also destroys the existing cells after the surgery. In order to make surgery more successful, chemotherapy can also be given before surgery (known as neo-adjuvant theory) for shrinking the tumors.