Lung cancer is a pathological condition of abnormal and uncontrolled proliferation of cells in tissues of the lung to form diseased growths or tumors. Lung cancer can metastasize and spill over to over organs or it can remain localized within the lung. Lung cancer is easily spotted on chest x-rays and computed tomography (CT scans) and where confirmations are required, bronchoscopy or CT-guided biopsies are performed. The type of treatment selected (surgery, chemotherapy and radiation) vastly depend on the diagnosed cancer and its stage or degree of development and spread as well as on the patient’s overall health. Tragically though, even with treatment, the five year survival rate is only fourteen percent. Statistically speaking, lung cancer is responsible for nearly 1.5 million global deaths each year as it kills more men than any other cancer, while among women who die from cancer, lung cancer is second only to breast cancer.
Types of Lung Cancers
The classifications of lung cancers have significant bearings on their prognosis as well as on their treatment:
An overwhelming majority of lung cancers are carcinomas which are malignancies that originate in the epithelial cells and they are categorized by the size and the appearance of the cancerous cells –
- – Non-small cell lung carcinoma (NSCLC) accounts for 80.4 percent of all lung cancer occurrences and they include the following …
- Squamous cell lung carcinoma accounts for 31.2 percent of all lung cancers and it is a slow growing cancer which originates near the bronchials and typically forms vapor bubbles (cavitation) while leading to the untimely death of cells (nectosis).
- Adenocarcinoma accounts for 29.4 percent of lung cancers and it is the most common lung cancer among non-smokers. It most often begins in peripheral lung tissue.
- Large cell lung carcinoma or bronchioloalveolar carcinoma has the similar characteristics to adenocarcinoma but it is most common among women non-smokers.
- – Small cell lung carcinoma (SCLC) is also known as the oat cell carcinoma and it accounts for 16.8 percent of all lung cancers. It usually begins with the larger airways, the primary and the secondary bronchi, and grows very rapidly to significant sizes. The small cell lung carcinoma has a propensity for metastasizing and drifting into other organs, and it is strongly associated with smokers.
Cancers which metastasize from other organs such as the breast, ovaries, stomach, prostate etc., are still referred to by their origins and are treated accordingly. Therefore, pancreatic cancer that metastasized into the lungs continues to be pancreatic cancer and will be treated as a pancreatic cancer, not as a lung cancer.
Lung cancers can metastasize to any other organs but they most frequently metastasize to the bone, brain, liver and adrenal glands.
Most often recorded symptoms of lung cancer are:
- Shortness of breath (dyspnea), wheezing, hoarseness (dysphonia) and pneumonia
- Coughing up of blood (hemoptysis) and continuous and prolonged coughing bouts
- Pain in the chest and/or the abdomen
- Fatigue, loss of appetite and spontaneous loss of weight (cachexia)
- Difficulty swallowing (dysphagia)
- Deformity of the finger nails (clubbing)
Whether it is inhaled directly by a smoker or indirectly through second-hand smoke, the single most significant cause for lung cancer as well as all other cancers is tobacco smoke from cigarettes, pipes and cigars.