LUNG CANCER (Bronchogenic Carcinoma) BIO 218 Human Anatomy
Summary: What is Lung Cancer? Lung Cancer is the growth of abnormal tissue characterized by the progressive, uncontrolled multiplication of cells. This abnormal growth of new cells does not develop into healthy lung tissue but rather manifest into a tumor or also called a neoplasm. As tumors become larger and more numerous, they inhibit the lung’s ability to provide the blood stream with oxygen. Lung Cancer arises from the epithelium of the tracheobronchial tree. As a tumor enlarges, the surrounding bronchial airways and alveoli become irritated, inflamed, and swollen. The adjacent alveoli may fill with fluid or become consolidated and collapse. As the tumor protrudes into the tracheobronchial tree, excessive mucous production and airway obstruction develop.
Summary: (cont.) Major Pathological changes in lung cancer: Inflammation, swelling, and destruction of the bronchial airways and alveoli Excessive mucous production Tracheobronchial mucous accumulation and plugging Airway obstruction (either from blood, from mucous accumulation, or from a tumor projecting into a bronchus) Atelectasis (collapse of part or all of the lung) Alveolar consolidation (liquid-filled alveolar space) Cavity formation Pleural effusion (buildup of fluid between the layers of tissue that line the lungs and chest cavity)
Summary: (cont.) 2 Different types of tumors Benign Tumors Remain in one place and do not appear to spread. Do not endanger life unless they interfere with the normal functions of other organs or affect a vital organ. They grow slowly and push aside normal tissue but do not invade it. Not invasive or metastatic. Malignant Tumors Composed of embryonic, primitive, or poorly differentiated cells. They grow in a disorganized manner and so rapidly that the nutrition of the cells becomes a problem. Invade surrounding tissues and may be metastatic (cancer spreading beyond its site of origin to other parts of the body). Malignant changes may develop in any portion of the lung, they most commonly originate in the mucosa of the tracheobronchial tree. Metastasis refers to cancer spreading beyond its site of origin to other parts of the body.
Types of Lung Cancer: How is Lung Cancer Classified? Lung Cancer can be classified into 2 main types, based on the histological appearance of the cancer under a microscope. Non-small cell lung carcinoma (NSCLC) 80% of all lung cancer in the U.S. Squamous cell carcinoma 30% Adenocarcinoma 35%-40% Large cell carcinoma (Undifferentiated) 10%-15% Small cell lung carcinoma (SCLC) 20% of all lung cancer in the U.S. Small cell (or oat cell carcinoma) 14% Adenocarcinoma (high magnification) Oat cell carcinoma
Etiology & Epidemiology: What are the causes and risks of Lung Cancer? Lung cancer is the leading cause of cancer deaths in the U.S. According to the American cancer Society 2008 surveillance report, it is estimated that more than 214,000 new cases of lung cancer are reported in the U.S. annually. 114,000 in males 100,000 in females Cigarette smoking is the most common cause of lung cancer. It is estimated that cigarette smoke contains more than 4,000 different chemicals, many of which have proved to be carcinogens (class of substances that are directly responsible for damaging DNA, promoting or aiding cancer). A genetic predisposition toward developing lung cancer also plays a role in the incidence of lung cancer. Environmental or occupational risk factors for lung cancer include the following: Benzopyrene and radon particles associated w/ uranium mining Radiation and nuclear fallout Polycyclic aromatic hydrocarbons and arsenicals Asbestos fibers Diesel exhaust Nitrogen mustard gases Nickel Silica Benzopyrene: wood burning, Polycyclic aromatic hydrocarbons: potent atmospheric pollutants, Asbestos: found in the demolition or renovation of a home, Chloromethyl methyl ether: found in industrial solvent Vinyl chloride Chloromethyl methyl ether Air pollution Coal and iron mining
Symptoms of Lung Cancer Persistent or intense coughing Pain in the chest, shoulder, or back from coughing Hoarseness of the voice Harsh sounds while breathing (stridor) Difficulty breathing and swallowing Chronic bronchitis or pneumonia Sputum production (mucus coughed up from the lower airways) Changes in color of the sputum Coughing up blood or blood in the sputum (hemoptysis) Increased respiratory rate (tachypnea) Increased heart rate and blood pressure (tachycardia) Cyanosis (blue or purple coloration of the skin) Stridor: high-pitched breathing sound caused by a blockage in the airway
Screening and Diagnosis Chest X-ray (most common screening test) Computed tomography (CT) scan Positron emission tomography (PET) scan A definitive diagnosis, however, can be made only by viewing a tissue sample (biopsy) under a microscope. Procedures to obtain a tissue biopsy include: Bronchoscopy Thoracoscopy Mediastinoscopy Transbronchial needle (open lung) biopsy Sputum cytology Thoracentesis Videothoracoscopy
Staging of Lung Cancer Non-Small Cell Lung Carcinoma Stage 0: The cancer is limited to the lining of the bronchial airways. There is no involvement of the lung tissue or distant metastasis. Cancer is usually found during bronchoscopy. When found and treated early, cancers at this stage can often be cured. Stage I: The tumor is less than 3 cm and is located in lobar or distal airways. There is no lung tissue involvement or distant metastasis. Stage II: Cancer has invaded neighboring lymph nodes or spread to the chest wall. There is no distant metastasis. Stage IIIA: The tumor is any size. The tumor is in the main bronchus, or the tumor is accompanied by atelectasis or obstructive pneumonitis (inflammation of lung tissue) of the entire lung. Local invasion involves chest wall, diaphragm, mediastinum, pleural, or parietal pericardium. Stage IIIB: The cancer has spread locally to areas such as the mediastinum, heart, great vessels, trachea, esophagus, vertebral body. Stage IV: The cancer is of any size, involves any of the lymph node groups, and has spread to other parts of the body, such as the liver, bones, or brain. Small Cell Lung Carcinoma (harder to detect early) Limited: The cancer is confined to only one lung and to its neighboring lymph nodes. Extensive: The cancer has spread beyond one lung and nearby lymph nodes. It may have invaded both lungs, more remote lymph nodes, or other organs.
Diagnostic Imaging Normal Chest X-ray Non-Small Cell Lung Carcinoma Radiologic Findings Small oval or coin lesion Large irregular mass Alveolar consolidation Atelectasis Pleural effusion Involvement of the mediastinum or diaphragm Diagnostic Imaging Normal Chest X-ray Chest x-ray of normal appearance taken from the back of an adult male Non-Small Cell Lung Carcinoma Large central lesion diagnosed as non-small cell carcinoma Non-Small Cell Lung Carcinoma A right lower lobe squamous cell carcinoma Non-Small Cell Lung Carcinoma Right upper lobe lesion diagnosed as adenocarcinoma
Diagnostic Imaging (cont.) Small Cell Lung Carcinoma 2 months later Small Cell Lung Carcinoma At the time of diagnosis Small Cell Lung Carcinoma 5 weeks later
General Management of Lung Cancer Surgery Wedge resection: partial removal of a lung lobe Segmentectomy: removal of a lung segment or segments of the lung Lobectomy: removal of 1 lung lobe Bilobectomy: removal of 2 lung lobes Pneumonectomy: removal of whole right or left lung Respiratory Care Treatment Protocols Oxygen therapy protocol Bronchopulmonary hygiene therapy protocol Lung expansion therapy protocol Aerosolized medication protocol Chemotherapy Radiation Therapy Comfort (Supportive) Care
Prognosis 5 Year Survival Rate The 5-year survival rate refers to the percentage of patients who live at least 5 years after their cancer is diagnosed. The numbers to the left are survival rates calculated from the National Cancer Institute’s Surveillance, Epidemiology, and End Results database, based on people who were diagnosed with non-small cell lung carcinoma between 1998 and 2000. The overall 5-year survival rate for stage 4 non-small cell lung cancer is sadly less than 5%. The overall 5-year survival rate for extensive stage small cell lung cancer is 6%. Average survival is 6 to 12 months with treatment, but only 2 to 4 months without treatment. Stage 5-year Survival Rate 49% I 45% II 30%-31% IIIA 14% IIIB 5% IV 1%
Conclusion Lung cancer is by far the leading cancer killer in both men and women in the United States. In 1987, it surpassed breast cancer to become the leading cause of cancer deaths in women. This cancer causes more deaths than the next three most common cancers combined (colon, breast, and prostate). One important key to beating this disease is prevention in ways of avoiding or discontinuing cigarette smoking and passive or second-hand smoking. Smoking, a main cause of small cell and non-small cell lung cancer, contributes to 80% and 90% of lung cancer deaths in women and men, respectively. Men who smoke are 23 times more likely to develop lung cancer. Women are 13 times more likely, compared to non- smokers. That said, there are reports of people who have survived and done well for many years who had an early diagnosis and detection of lung cancer and received the necessary treatment that best suits their particular circumstance.
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