Pancoast Tumor Definition and Clinical Characteristics
A Pancoast tumor is a lung cancer that arises in the apical lung and invades structures of the thoracic wall at the level of the first rib or above, frequently involving the brachial plexus, subclavian vessels, or spine. 1
Definition and Classification
- Pancoast tumors account for less than 5% of all bronchogenic carcinomas 2
- They are located at the apex of the lung and invade through tissue contiguity the apical chest wall and/or structures of the thoracic inlet 2
- The majority of these tumors are non-small cell lung cancers (NSCLC), with adenocarcinomas accounting for approximately two-thirds of cases, while the remainder are squamous cell and large cell carcinomas 2
- Classified as T3 when invading T1 or T2 nerve roots or the first rib, and as T4 when involving C8 or higher nerve roots, brachial plexus cords, subclavian vessels, vertebral bodies, or laminae 3, 1
Clinical Presentation
- Most patients present with the characteristic "Pancoast-Tobias syndrome" 2
- Symptoms include shoulder or chest wall pain radiating toward the axilla, scapula, and/or along the ulnar distribution of the upper arm 4, 1
- Neurological findings may include radicular pain or sensory changes in the ulnar hand due to invasion of the lower brachial plexus (C8-T1) 4
- Horner syndrome (ptosis, miosis, anhidrosis) may be present due to invasion of the stellate ganglion 4, 1
- Hand swelling may indicate subclavian or brachiocephalic vein compression 4
- Atrophy of hand and arm muscles may occur 2
Diagnostic Evaluation
- Chest radiographs may only show subtle apical pleural thickening as tumors can hide behind the first rib 4
- CT scan of the chest is essential to detect small lesions and provide anatomic detail 4
- MRI of the thoracic inlet and brachial plexus is recommended to better characterize possible tumor invasion of vascular structures or extradural space 3, 4
- A tissue diagnosis must be obtained prior to initiating any therapy 3, 4
- CT-guided transcutaneous needle biopsy is the preferred method for diagnosis 4
- Bronchoscopy, thoracoscopy, and biopsy of palpable supraclavicular nodes are alternative ways to obtain a tissue diagnosis 2
Staging and Treatment Approach
- Invasive mediastinal staging is recommended for all patients being considered for curative resection 3
- Extrathoracic imaging should include head CT/MRI and either whole-body PET or abdominal CT plus bone scan 3, 4
- Involvement of mediastinal nodes (N2, N3) and/or metastatic disease represents a contraindication to resection 3
- For potentially resectable tumors with good performance status, preoperative concurrent chemoradiotherapy followed by surgical resection is recommended 3, 1
- For unresectable, non-metastatic tumors with good performance status, definitive concurrent chemotherapy and radiotherapy are suggested 3
- For patients who are not candidates for curative-intent treatment, palliative radiotherapy is suggested for pain control 3
Surgical Considerations
- Complete resection (R0) is crucial for improved survival 3
- Surgical resection should consist of at least a lobectomy along with the involved chest wall structures 3
- Various surgical approaches exist, including anterior and posterior approaches to the thoracic inlet 2, 5
- The choice of approach depends on the location of the tumor (posterior, middle, or anterior compartment) and the extent of invasion 2
- Surgery should be performed at specialized centers with experience in these complex resections 3
Prognosis
- Treatment with preoperative radiation and resection has resulted in a median survival time of 22 months and a 5-year survival of 27% 3, 1
- The 5-year survival rate for R0 resections ranges from 54-77% 1, 2
- Negative prognostic factors include N2 or N3 lymph node involvement and incomplete resection 3, 1
- The main pattern of recurrence is distant metastases, especially in the brain 2