1. Pathophysiologic Etiology
1.1. According to American Cancer Society (2021), Mayo Clinic (2021), and McCance, K. L., (2019), exposure to chronic irritants, ionizing radiation, or carcinogens causes damage that typically starts in the epithelial cells of the respiratory tract. Cells that are affected because of exposure become mutated or have changes in their gene expressions and cellular processes. When this process continues, it affects the DNA causing genomic instability. Through instability, lung cancer develops through deletion of the short arm of chromosome 3. This eventually leads to the activation of oncogenes while simultaneously deactivating the Tumor-suppressor genes which causes continued uncontrolled cell growth that turns into tumor mass with a source of energy through angiogenesis. From here, the tumor can become malignant if the growth expands to the basement membrane and can even metastasize by breaking off from the original growth place and taking root somewhere else (American Cancer Society, 2021; Mayo Clinic, 2021; McCance, K. L., 2019).
1.1.1. - 10% - 15% are Small cell lung cancer (SCLC). SCLC occurs almost exclusively in heavy smokers and is less common than non-small cell lung cancer. Cancer can develop near the Main Bronchus. - 80% - 85% are Non-small cell lung cancer (NSCLC). NSCLC is an umbrella term for several types of lung cancers. Non-small cell lung cancers include squamous cell carcinoma, adenocarcinoma and large cell carcinoma. - Other types of lung tumors: less than 5% are Lung carcinoid tumors; Meanwhile, adenoid cystic carcinomas, lymphomas, and sarcomas, and hamartomas are rare.
1.2. Cells in early differentiation that mutate are more aggressive than more mature cells
1.3. Cancer cells divide more rapidly and are more metabolic than normal body cells. secreting cancers cause damage to the body by hypersecretion
1.4. Cancer in the lung may be the primary site or a metastatic secondary site from a distant body area
2. Causative Factors
2.1. Exposure to chemicals, radiation, and hazardous materials
2.1.1. Aluminum production Arsenic and inorganic arsenic compounds Beryllium and beryllium products Bis(chloromethyl) ether; chloromethyl methyl ether (technical grade) Cadmium and cadmium compounds Chromium (VI) compounds Coal, indoor emissions from household combustion Coal gasification Coal-tar pitch Coke production Hematite mining (underground) Iron and steel founding MOPP (vincristine-prednisone-nitrogen mustard-procarbazine mixture) Nickel compounds Painting Plutonium Radon-222 and its decay products Rubber production industry Silica dust, crystalline Soot Sulfur mustard Tobacco smoke, secondhand Tobacco smoking X-radiation, γ-radiation
3. Risk Factors
3.1. History & Lifestyle
3.1.1. History of or current cigarette smoking (including electronic and hookah) is the leading cause of lung cancer
3.1.1.1. Personal or family history of lung or any other type of cancer
3.1.1.1.1. Previous radiation therapy exposure
3.1.2. Environmental/Air Indoors
3.1.2.1. Secondhand smoke aka Environmental Tobacco Smoke (ETS)
3.1.2.2. Exposure to strong organic and inorganic irritants such as Asbestos and Radon
3.1.2.3. High level of Arsenic in water found in Southeast Asia and South America
3.1.2.4. Air Pollution
3.1.2.4.1. World's most polluted countries includes: Bangladesh, Pakistan, India, Mongolia, Afghanistan
3.2. Occupational Hazards
3.2.1. Art glass, manufacturing of glass container, uranium, arsenic8, beryllium, cadmium, silica, vinyl chloride, nickel compounds, chromium compounds, coal products, mustard gas, chloromethyl ethers, Diesel exhaust, and talc mills
4. Diagnostic Tests
4.1. CXR, MRI, CT scan, PET scan, US
4.1.1. CXR can show "Coin Lesion"
4.2. Bronchoscopy
4.3. Lung tissue biopsy
4.3.1. Cancers are evaluated using the TNM method
4.3.1.1. TNF = Tumor size, spread to lymph Nodes, and Metastasis status
4.4. Sputum for cytology
5. Common Findings
5.1. Persistent cough, wheezing, dyspnea, fever, weight loss, night sweat, anorexia, pleural friction rub, hoarseness, and coughing up blood
5.1.1. Symptoms of lung cancer do not appear until the disease is already at an advanced stage. Also has a high rate for metastasis
5.1.2. Possible to have pain if lung cancer metastasized in bone