Symptoms of Small Cell Lung Cancer
Small cell lung cancer (SCLC) typically presents with symptoms related to a large hilar mass and bulky mediastinal lymphadenopathy, causing cough (77%) and dyspnea (34-45%), along with frequent symptoms of widespread metastatic disease such as weight loss, debility, bone pain, and neurologic compromise. 1
Respiratory Symptoms
- Cough: Present in approximately 77% of patients 1
- Dyspnea/shortness of breath: Occurs in 34-45% of patients 1
- Hemoptysis: Present in about 10% of patients 1
- Wheezing: Due to partially obstructing endobronchial lesions 1
- Chest pain: Experienced by 42% of patients 1
- Hoarseness: Due to left vocal cord paralysis from tumor invasion or lymphadenopathy 1
Symptoms Related to Local Spread
- Hemidiaphragm elevation: From phrenic nerve compression 1
- Dysphagia: Due to esophageal compression 1
- Superior vena cava syndrome: Present in 13% of patients 1
- Pericardial effusion and tamponade 1
- Cervical or supraclavicular lymph node enlargement 1
- Post-obstructive pneumonia with fever 1
Metastatic Disease Symptoms
- Brain metastases (present in 15% of patients at diagnosis): Headache, focal weakness or numbness, confusion, slurred speech, gait instability, incoordination 2, 1
- Leptomeningeal carcinomatosis: Headache, confusion, cranial nerve palsy, diplopia, slurred speech, radicular back pain, spinal cord compression 2, 1
- Adrenal metastases: Mid-back or flank pain, costovertebral angle tenderness 2, 1
- Liver metastases (most common site of distant metastasis, occurring in 60% of metastatic cases): Right upper quadrant pain or tenderness, jaundice, fatigue, fever, hepatomegaly 2, 1
- Bone metastases: Bone pain, spinal cord compression with back pain, muscle weakness, numbness, paresthesia, loss of bowel and bladder control 2, 1
Systemic Symptoms
- Weight loss: Experienced by 30% of patients 1, 3
- Weakness or fatigue: Present in 52% of patients 1
- Anorexia/cachexia 2, 1
Paraneoplastic Syndromes
SCLC is frequently associated with paraneoplastic syndromes that may precede the diagnosis of the tumor 2:
Endocrine Syndromes
- SIADH (Syndrome of Inappropriate ADH secretion): Occurs in 5-10% of SCLC patients, presenting with malaise, weakness, confusion, obtundation, and laboratory findings of hyponatremia, euvolemia, and low serum osmolality 2, 1
- Cushing's syndrome (ectopic ACTH secretion): Less common than SIADH, causing weight gain, moon facies, hypertension, hyperglycemia, and laboratory findings of high serum cortisol and ACTH 2, 1
Neurologic Syndromes
- Lambert-Eaton myasthenic syndrome: Proximal leg weakness caused by antibodies directed against voltage-gated calcium channels 2
- Paraneoplastic encephalomyelitis: Confusion, obtundation, dementia 2
- Sensory neuropathy: Pain and sensory loss 2
- Cerebellar degeneration: Ataxia and dysarthria 2
- Cancer-associated retinopathy: Visual loss and photosensitivity 2
Clinical Presentation Patterns
It's important to note that approximately 60% of patients with SCLC may be asymptomatic at diagnosis 3. However, most patients present with advanced disease, with 70% having extensive-stage disease at diagnosis 3, 4.
Diagnostic Considerations
Chest imaging typically demonstrates central hilar masses (85%) or mediastinal lymphadenopathy (75%) 3. Unlike non-small cell lung cancer, low-dose CT screening does not seem to be effective for detecting early-stage SCLC due to the aggressiveness of the disease 2.
The NCCN guidelines recommend that if neurologic paraneoplastic syndrome is suspected, a comprehensive paraneoplastic antibody panel should be considered 2.
Understanding these symptoms is crucial for early recognition and prompt management of SCLC, although the disease is often diagnosed at an advanced stage due to its aggressive nature and rapid progression.