Introduction to Lung Cancer
Old airport road, Bengaluru Feb 9, 2017
Lung cancer tops the list of cancer deaths across the globe, India is not an exception. In India, cancer ranks second biggest killer (accounts for 15% of all death reported in 2013).
Lung cancer in India is the leading cause of cancer death among men and ranked 8th among Indian women, who have lower smoking rate.
The Cancer causing agent, carcinogen present in the cigarette smoke damages the lung tissues and prompt the growth of abnormal cancer cells in the lungs which eventually develops into a tumor. The tumor cells metastasize affecting the lymph nodes nearby and the other parts of the body such as the liver, bones, adrenal glands and even the brain.
During the early stages, lung cancer is difficult to diagnose as it does not show any signs and symptoms. Usually, signs and symptoms are seen only during the advanced stages of lung cancer. These symptoms are can be easily distinguished as there are many complications tagged along. It include changes in a chronic cough or “smoker’s cough”, coughing up blood or mucus, discomfort when swallowing, shortness of breath, chest pain, wheezing, hoarseness, weight loss, poor appetite, headache and fever.
Prevention is ‘always’ better than cure. Quit smoking, avoid being exposed to secondhand smoke and other carcinogens, include fruits and vegetables in your diet, reduce exposure to radon gas as well as asbestors and do regular exercise for easing out the risk of getting affected with lung cancer.
Diagnosing Lung Cancer
Through a close physical examination of lungs and chest the doctors will collect evidences of lung cancer. In most of the cases, firstly, the doctors will advise for imaging tests such as chest x-ray first for checking to see if there are any tumors. If any unnatural developments are observed on chest x-ray, then the doctor will recommend a CT scan to diagnose the exact size and location of the tumor. Apart from that an MRI scan can be administered to get more details of the organs and a PET scan to check the functions of the tissues.
Further, other test to diagnose lung cancer includes Sputum Cytology (detects the existence of lung cancer cells), biopsy, bronchoscopy (helps to collect small sample of tissue for biopsy as well as checks for cancerous cells), Mediastinoscopy (helps in biopsy of lymph nodes to determine whether the Cancer has spread to the lymph nodes), Fine-needle aspiration biopsy ( examines a part of the lung or pleura to diagnose the type of cancer), Thoracentesis ( detects cancer cells as well as remove fluid build-up in the chest), Video-Assisted Thoracoscopic Surgery (VATS) checks for cancer cells in the space between the lungs and chest wall and the edge of the lungs. Bone scans and CT scans determine whether cancer has spread to the bones, brain, or other parts of the body.
Different types of treatments
Surgery- If the cancerous cells have not spread beyond the chest, then the tumors can be removed through surgical methods.
The surgical procedure includes, Wedge resection (removes only the tumor and a edge of the healthy tissue), followed by segmental resection (removes a larger portion of the lung but not an entire lobe of the lung), Lobectomy (removes one lobe of the lung) and finally Pneumonectomy (removes an entire lung). In case, if the cancer has spread to the lymph nodes, then it may also be removed.
The high risks associated with these kinds of surgery are that it can cause infection and bleeding. Another is shortness of breath as the remaining portion of the lungs tissue needs expand over time for easy breathing. Respiratory therapy and breathing exercises can help in recovery during shortness of breath.
Chemotherapy- Usually, the doctors recommend chemotherapy before and after the surgery depend on how much the cancer has metastasized. In case of advanced lung cancer, chemotherapy slows down the growth of cancer cells, ease the symptoms and prolong survival. The treatment consists of a combination of medications intravenously as well as orally. Mostly, it is done as a series of treatments over a period of weeks or months, with time intervals between each treatment in order to recover.
Radiation therapy– This treatment can be administered before or after surgery. It is often recommended by the doctors to treat lung cancer that has metastasized to brain or bones.
It can also be used alone or with chemotherapy to treat lung cancer limited only to the chest. Radiation therapy is done by using high-powered beams like x-rays to destroy cancer cells. This can be done either external beam radiation or internally through putting needles inside the body, seeds or catheters. The doctors administer radiation therapy after surgery in case if there are still cancer cells remaining or even for the type of tumors that cannot be removed during surgery. The treatment can ease symptoms of lung cancer and prolonged survival in some people, with similar results to surgery.
Stereotactic radiotherapy- The patients suffering from lung cancers that are very small in size can undergo stereotactic radiation. This treatment uses many beams of radiation from different angles at the lung cancer in order to destroy it. Stereotactic therapy can be completed in one or a few sessions and can be used in place of surgery for small tumors.
Targeted therapies- These are new cancer treatments that aims at specific abnormalities in cancer cells. At present, there are three Targeted therapies that include Avastin (Bevacizumab), Tarceva (Erlotinib) and Xalkori (Crizotinib).
Avastin stops the oxygen and nutrient supply to the tumor cell thus restricting its further growth. Usually, Avastin is administered to treat advanced and recurrent lung cancer along with chemotherapy. Tarceva blocks the chemicals that help the cancer cells to grow and further divide. Before administering Tarceva, a biopsy of the lung cancer cells needs to be done to verify if the treatment is effective for people who have specific genetic mutations. Also, this treatment is less effective in smokers than nonsmokers. Xalkoril helps to blocks the chemical which permits the tumor to grow out of control. Xalkori can be recommended for advanced lung cancer specifically for those who have a particular genetic mutation (this can be clarified through genetic testing).
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