Lung Adenocarcinoma: Causes, Symptoms, Diagnosis, Treatment, and Prevention
One kind of lung cancer that begins in the cells lining the lungs' airways and producing mucus is called lung adenocarcinoma. About 40% of all occurrences of lung cancer are of this most prevalent kind of non-small cell lung cancer. Symptoms of lung adenocarcinoma might include weight loss, shortness of breath, coughing, and chest discomfort. A number of things, including smoking, exposure to chemicals, genetic alterations, and infections, can result in lung adenocarcinoma. A physical examination, imaging studies, and a biopsy can all be used to diagnose lung adenocarcinoma. Options for treatment include immunotherapy, targeted therapy, radiation therapy, chemotherapy, and surgery.
Causes
Lung adenocarcinoma stems from alterations in lung cell DNA, leading to abnormal growth and division. These DNA changes can either be hereditary or acquired over time. Common causes of lung adenocarcinoma include:
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Smoking: The primary risk factor for lung adenocarcinoma and other lung cancers. Smoking induces DNA damage in lung cells, elevating the likelihood of cancer-causing mutations. Risk escalates with the quantity of cigarettes smoked, duration of smoking, and age at which smoking commenced.
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Exposure to toxins: Substances like asbestos, radon, air pollution, and secondhand smoke can harm lung cell DNA, heightening adenocarcinoma risk. Certain occupations, such as mining, construction, or manufacturing, may involve exposure to these toxins.
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Genetic mutations: EGFR, KRAS, ALK, or ROS1 mutations can predispose lung cells to adenocarcinoma development. These mutations may be inherited or acquired through random errors or environmental factors. Specific drugs targeting these mutations can impede their effects and slow cancer cell growth.
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Infections: Human papillomavirus (HPV), tuberculosis, or HIV infections can compromise the immune system, hindering the body's ability to combat abnormal lung cells. Some infections directly impact lung cell DNA, fostering cancerous changes.
Symptoms
Lung adenocarcinoma may not cause any symptoms in its early stages, and may be detected by a routine chest X-ray or CT scan. However, as the cancer grows and spreads, it can cause various symptoms, such as:
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Coughing, which may be persistent, dry, or productive of blood or mucus
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Chest pain, which may be sharp, dull, or aching, and may worsen with breathing, coughing, or lying down
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Shortness of breath, which may be due to the cancer blocking the airways, compressing the lungs, or causing fluid to build up in the chest
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Weight loss, which may be due to the cancer consuming more calories, reducing the appetite, or causing nausea or vomiting
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Other symptoms, such as fatigue, weakness, fever, night sweats, hoarseness, or difficulty swallowing, which may be due to the cancer affecting other organs or systems of the body
Diagnosis
A physician will inquire about the patient's symptoms, medical history, and risk factors in order to make the diagnosis of lung adenocarcinoma. In addition, a physical examination will be conducted to look for physical indicators of lung adenocarcinoma, such as fluid in the chest, swollen lymph nodes, or unusual breath sounds. In order to confirm the diagnosis and identify the stage and kind of lung adenocarcinoma, the doctor may additionally prescribe certain tests, such as:
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Imaging tests, such as chest X-ray, CT scan, MRI, or PET scan, that can show the size, location, and spread of the tumor in the lungs and other parts of the body
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Biopsy, which is a procedure that involves taking a sample of the tumor tissue and examining it under a microscope to confirm the presence of cancer cells and identify their characteristics
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Molecular testing, which is a type of laboratory test that can analyze the DNA of the cancer cells and detect specific mutations that can guide the treatment and prognosis of lung adenocarcinoma
Treatment
Treatment for lung adenocarcinoma is tailored to the tumor's stage, type, and location, as well as the patient's overall health and preferences. The primary objectives include eliminating cancer cells, preventing recurrence or spread, and enhancing quality of life. Treatment modalities encompass:
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Surgery: Removal of the tumor and surrounding tissue via traditional open surgery or minimally invasive techniques like VATS or robotic surgery. Surgery may be supplemented with chemotherapy or radiation to improve outcomes.
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Chemotherapy: Employing drugs to kill or inhibit cancer cell growth. Administered pre or post-surgery, or as primary therapy for advanced cases, chemotherapy can be intravenous or oral, alone or combined with other medications.
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Radiation Therapy: High-energy rays or particles target and damage cancer cell DNA. Given before or after surgery, or as the main treatment for inoperable cases, radiation therapy may be external or internal.
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Targeted Therapy: Drugs pinpoint and attack specific molecules or pathways crucial for cancer cell survival, such as EGFR, ALK, or ROS1 mutations. Administered intravenously or orally, targeted therapy may be used alone or in combination.
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Immunotherapy: Utilizing drugs to activate the immune system against cancer cells, particularly effective for tumors with high PD-L1 levels. Given intravenously, immunotherapy can be standalone or combined with other treatments.
Prevention
While certain instances of lung adenocarcinoma may be unavoidable due to genetic or environmental factors, there are proactive steps individuals can take to mitigate their risk:
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Smoking Cessation: Quitting smoking stands as the foremost and most impactful measure to prevent not only lung adenocarcinoma but also other lung cancers. This decision also reduces the likelihood of developing heart disease, stroke, and COPD.
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Avoiding Toxin Exposure: Steering clear of toxins like asbestos, radon, air pollution, and secondhand smoke can significantly lower the risk of lung adenocarcinoma. Occupations involving exposure to these toxins, such as mining or construction, may necessitate protective gear or routine screening.
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Nutritious Diet: Consuming a balanced diet rich in vitamins, minerals, antioxidants, and fiber boosts the immune system, mitigating inflammation and oxidative stress that can harm lung cell DNA.
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Regular Exercise: Engaging in moderate and regular exercise enhances lung function and capacity, reducing the likelihood of obesity, diabetes, and cardiovascular disease—conditions that can compromise lung health and increase adenocarcinoma risk.
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Routine Check-ups and Screenings: Regular medical evaluations and screenings help identify and address lung health issues, including infections, diseases, or tumors. Lung cancer screenings, typically through low-dose CT scans, facilitate early detection and treatment of adenocarcinoma and other lung cancers when curability prospects are highest.
