How do you know if you have lung cancer
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How Do You Know If You Have Lung Cancer?
Symptoms of Lung Cancer
Lung cancer is often suspected in individuals who exhibit symptoms such as hemoptysis (coughing up blood), persistent coughing, shortness of breath, chest pain, and recurrent infections . These symptoms are typically caused by the local or systemic effects of the tumor . However, it is important to note that less than 10% of patients are asymptomatic when the tumor is detected incidentally.
Initial Diagnostic Tests: Chest X-Ray and CT Scan
The first step in diagnosing lung cancer usually involves a chest X-ray (CXR). While CXR is a common initial investigation, it cannot reliably distinguish between benign and malignant masses without further imaging . Therefore, a computed tomography (CT) scan with contrast enhancement is often performed to obtain a more accurate staging and diagnosis . Low-dose CT (LDCT) screening has been shown to reduce mortality by 20% in high-risk populations, such as smokers.
Advanced Diagnostic Techniques
Sputum Cytology and Bronchoscopy
Sputum cytology is an acceptable method for diagnosing lung cancer, with a sensitivity rate of 66% and a specificity rate of 99%. For central, endobronchial lesions, flexible bronchoscopy (FB) has a high diagnostic yield of 88%. However, the sensitivity of bronchoscopy decreases for peripheral lesions, especially those smaller than 2 cm in diameter.
Transthoracic Needle Aspiration (TTNA) and Biopsy
TTNA is another effective diagnostic tool, with a pooled sensitivity of 90% for detecting lung cancer. However, it is associated with a higher risk of pneumothorax compared to bronchoscopic procedures.
Emerging Technologies: R-EBUS and EMN
Radial endobronchial ultrasound (R-EBUS) and electromagnetic navigation (EMN) bronchoscopy are emerging technologies that show promise in diagnosing peripheral lung cancers, with diagnostic yields of 73% and 71%, respectively.
Role of Pleural Fluid Cytology and Biopsy
In cases where a malignant pleural effusion is present, pleural fluid cytology has a mean sensitivity of about 72%. Thoracoscopic biopsy of the pleura offers the highest diagnostic yield, ranging from 95% to 97%.
Importance of Early Detection
Early detection of lung cancer is crucial for improving survival rates. General practitioners (GPs) play a vital role in identifying high-risk patients and those with non-resolving symptoms. Screening high-risk individuals with LDCT is recommended, although uptake remains low .
Conclusion
Diagnosing lung cancer involves a combination of symptom assessment, imaging techniques, and advanced diagnostic procedures. Early detection through screening and maintaining a high level of suspicion in symptomatic patients are key to improving outcomes. Various diagnostic modalities, including sputum cytology, bronchoscopy, TTNA, and emerging technologies like R-EBUS and EMN, play crucial roles in accurately diagnosing lung cancer.
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