What are the signs and symptoms of lung cancer?

Semiology of Lung Cancer

The most common presenting symptom of lung cancer is chronic cough (occurring in approximately 65% of patients), followed by hemoptysis, dyspnea, chest pain, and weight loss, with the specific symptom pattern varying by histologic subtype and disease stage. 1, 2

Primary Pulmonary Symptoms

Local tumor effects produce the most frequent initial manifestations:

• Cough is the cardinal symptom, present in 65% of patients at diagnosis, resulting from endobronchial irritation, parenchymal infiltration, or postobstructive pneumonia 1, 2
• Hemoptysis occurs in 25-33% of patients and warrants immediate concern for endobronchial tumor, particularly in smokers with COPD—even scant blood-streaking should raise suspicion, as it may occur with normal chest radiography 1, 3
• Dyspnea affects approximately 17% at presentation and may accompany postobstructive pneumonia or pleural involvement 1, 2
• Chest pain (17.9% of patients) is often nonspecific initially, but pleuritic pain suggests pleural invasion 1, 2
• Localized or unilateral wheezing reflects endobronchial obstruction and should prompt evaluation for neoplasm 1

Critical diagnostic pitfall: Recurrent pneumonia in the same anatomic distribution or relapsing acute COPD exacerbations should immediately raise concern for underlying malignancy. 1

Symptoms of Intrathoracic Spread

Locoregional extension produces characteristic syndromes:

• Hoarseness from recurrent laryngeal nerve palsy (more common with left-sided tumors due to the nerve's circuitous route under the aortic arch), causing vocal cord paresis and predisposing to aspiration 1
• Pancoast syndrome from superior sulcus tumors includes shoulder/arm pain (brachial plexus invasion), Horner syndrome (ptosis, miosis, anhidrosis from sympathetic chain infiltration), and C8-T1-T2 distribution weakness and paresthesias 1
• Superior vena cava syndrome (lung cancer is the most common cause) presents with facial and neck swelling, dilated neck veins, prominent chest wall venous pattern, and occasionally dysphagia, cough, headache, or blurred vision 1
• Dysphagia from subcarinal adenopathy compressing the mid-esophagus 1
• Phrenic nerve dysfunction manifesting as elevated hemidiaphragm 1
• Pleural effusion causing dyspnea or chest pain, from direct tumor extension, metastatic implantation, or mediastinal lymphatic obstruction 1

Systemic and Metastatic Manifestations

Advanced disease symptoms include:

• Weight loss (8.3-33% of patients) with OR 2.1 for lung cancer diagnosis 6 months prior 1, 2, 4
• Fatigue (4.8% at presentation) with OR 1.6 for diagnosis 6 months prior 1, 2, 4
• Bone pain (5.9% initially, OR 2.7 at 6 months pre-diagnosis) suggesting skeletal metastases 1, 2, 4
• Headaches potentially indicating brain metastases 1
• Anemia from chronic disease or bone marrow involvement 1
• Paraneoplastic syndromes (various manifestations) 1

Physical Examination Findings

Key physical signs that significantly elevate diagnostic probability:

• Digital clubbing in a smoker with pleural effusion or lobar collapse is nearly pathognomonic for bronchogenic carcinoma 3
• Neck and supraclavicular lymphadenopathy (9.8% of patients, more common in nonsquamous histology) 2
• Chest crackles or wheeze (OR 3.1 at 6 months pre-diagnosis) 4
• Back pain (OR 2.5 at 6 months pre-diagnosis) 4

Histologic and Staging Correlations

Symptom patterns vary by tumor characteristics:

• Squamous cell carcinoma patients are significantly more likely to present with chronic cough and hemoptysis (OR 2.885 for symptoms overall) compared to adenocarcinoma 2
• Nonsquamous carcinoma more frequently causes metastatic pain and lymphadenopathy 2
• Stage III disease shows higher rates of cough and hemoptysis 2
• Stage IV disease demonstrates increased chest pain, dyspnea, weight loss, and fatigue 2
• Advanced stages correlate with higher odds of both symptoms and physical signs 2

Clinical Presentation Patterns

Approximately 25% of patients are asymptomatic at diagnosis (typically with earlier-stage disease), while the majority present symptomatically with more advanced disease (stage IIIB or IV). 1, 5 Symptomatic patients are more likely to have concurrent COPD. 1

Temporal pattern: Seven key symptoms (hemoptysis, cough, chest crackles/wheeze, bone pain, back pain, weight loss, fatigue) are significantly associated with lung cancer diagnosis 6 months or more before actual diagnosis, suggesting opportunities for earlier detection. 4