DEFINITION
A superior sulcus (or Pancoast) tumor is a neoplasm of pulmonary origin that is located in the most apical recess of the pulmonary sulcus (i.e., the thoracic costovertebral gutter) and that arises from the lung apex. Pancoast’s syndrome is classically associated with pain in the arm and shoulder, weakness and atrophy of small muscles of the hand, and Horner’s syndrome (ipsilateral ptosis, miosis and anhidrosis).
PATHOLOGY
- ▪
The majority of superior sulcus tumors are NSCLC.
- ○
Most commonly squamous cell, followed by adenocarcinoma and large cell. Some series cite adenocarcinoma as the most common.
- ○
- ▪
Small cell lung cancer accounts for approximately 5% of cases.
- ▪
Rarely other masses or tumors may simulate Pancoast’s syndrome. These include
- ○
Neoplastic: adenoid cystic carcinoma, metastatic disease, lymphoma, plasmacytoma, other primary thoracic tumors
- ○
Aneurysms, cervical rib syndrome, amyloid nodules
- ○
Pulmonary infections (including fungal, bacterial, mycobacterial, and parasitic)
- ○
ANATOMIC CONSIDERATIONS
- ▪
Knowledge of the thoracic inlet anatomy is important because superior sulcus tumors can invade important anatomic structures contained therein ( Fig. 29-1 ).
Figure 29-1
Anatomy of the thoracic inlet.
(From Rusch VW. Management of pancoast tumours. Lancet Oncol 2006;7:997-1005, with permission.)
- ▪
The thoracic inlet can be divided into anterior, middle, and posterior compartments.
- ▪
Anterior compartment : ventral to the anterior scalene muscle (subclavian vein, internal jugular vein, sternomastoid, omohyoid muscle)
- ▪
Middle compartment : between middle and anterior scalene muscles (subclavian artery, trunks of brachial plexus, phrenic nerve)
- ▪
Posterior compartment : posterior to middle scalene muscle (brachial plexus nerve roots, stellate ganglion, vertebral bodies)
- ▪
Although posterior involvement is the classic more common presentation, anterior, middle, or combined involvement may occur, which complicates the optimal surgical approach (see later).
- ▪
Figure 29-2 depicts the anatomy of the brachial plexus.
Figure 29-2
Anatomy of the brachial plexus.
(From Arcasoy SM, Jett JR. Superior pulmonary sulcus tumors and Pancoast’s syndrome. N Engl J Med 1997;337:1370-1376, with permission.)
CLINICAL FEATURES
Clinical Presentation
- ▪
The most common initial presenting symptom in most superior sulcus tumors is arm and shoulder pain (90%, but wide range).
- ○
Mechanism of pain: tumor invasion of brachial plexus, parietal pleura, ribs (first and second) or vertebral bodies.
- ○
Pain may radiate to the ipsilateral head and neck, axilla, anterior chest, scapula, or arm. (The latter often in an ulnar distribution, that is, half of fourth and fifth digit ipsilateral to the tumor.)
- ○
Pain is often initially misdiagnosed as nonspecific musculoskeletal pain or bursitis.
- ○
- ▪
Pancoast’s syndrome is seen later in the course of disease.
- ○
Pancoast described superior vena cava (SVC) syndrome as part of this syndrome
- ○
Shoulder and arm pain in the C8, T1, and T2 dermatomes, as described earlier (axilla, medial aspect of the arm, forearm and medial portion of fourth finger and the fifth finger)
- ○
Hand small muscle weakness, atrophy, and paresthesias occur with involvement of the C8 and T1 nerve roots.
- ○
Horner’s syndrome (ipsilateral ptosis, miosis and anhidrosis) is seen in 25% to 50% of patients (83% in one study).
- ▪
Caused by involvement of the paravertebral sympathetic chain and the stellate ganglion (see Fig. 29-2 ).
- ▪
- ○
- ▪
Supraclavicular lymph nodes are noted in 25% to 35% of patients.
- ▪
Extension of the tumor through the intervertebral foramen may result in spinal cord compression, with variable neurologic sequelae, including paraplegia. Intervertebral foramen invasion is noted in about 5% earlier in the course of the disease and as high as 25% in patients presenting late.
- ▪
Occasionally a SVC syndrome may develop (see Chapter 28 on Superior Vena Cava Syndrome).
- ▪
Phrenic nerve involvement can occur.
- ▪
Typical “pulmonary” symptoms including cough, hemoptysis, and dyspnea are uncommon presenting symptoms, likely as a result of the peripheral location of the tumor.
Staging Classification
- ▪
Staging is done as per the International System for Staging Lung Cancer (TNM staging system) as adopted by American Joint Committee for Cancer (see Chapter 21 on Staging of Lung Cancer).
- ○
Owing to the location, most superior sulcus tumors are T3 (chest wall involvement) or T4 (invasion of vertebrae, great vessels, esophagus, or trachea).
- ○
Depending on the nodal status, nonmetastatic tumors are stage IIB (N0), IIIA (N1, N2) or IIIB (N3).
- ○
Metastatic tumors are by definition stage IV.
- ○
DIAGNOSITIC WORKUP
Laboratory Studies
- ▪
Serum chemistries and cell counts, including a complete blood count, liver function tests, and electrolytes, are indicated as part of the routine workup of lung cancer patients.
Imaging Studies
Chest X-ray Study
- ▪
Findings include an apical cap greater than 5 mm, a discrepancy between the apical caps greater than 5 mm, an apical mass, and first- or second-rib or thoracic vertebrae destruction ( Fig. 29-3 ).
Figure 29-3
Chest radiographs in a patient with right superior sulcus tumor. A, Note: in the upper film, an apical density larger than 5 mm is just discernable and the patient was asymptomatic. B, Seventeen months later, the patient presented with typical symptoms, and the superior sulcus tumor has grown in size and is now clearly present.
Computed Tomography
- ▪
Contrast-enhanced computed tomography (CT) is more useful than a chest x-ray study (CXR) in tumor staging and in further delineating the tumor.
- ▪
Sensitivity of mediastinal lymph node involvement is about 65%. If the CT scan shows normal nodes, there is an 18% chance of N2 disease ( Fig. 29-4 ).
Figure 29-4
A, Chest computed tomography scan showing large superior sulcus tumor on the right. B, Significant mediastinal adenopathy is evident in this patient.
- ▪
Limited ability to identify vessel, nerve, and chest wall invasion
- ▪
Can demonstrate obvious rib and vertebral destruction
- ▪
Inferences for chest wall involvement: no visible fat plane; significant apposition of tumor with pleural surface (>3 cm) but specificity low.
- ▪
Can demonstrate vessel compression or encasement
Magnetic Resonance Imaging
- ▪
Superior to CT for evaluation of brachial plexus, vertebral body destruction, extension into spinal canal through intervertebral foramina, vascular, and chest wall involvement ( Fig. 29-5 ).
Figure 29-5
Magnetic resonance imaging scan depicting superior sulcus tumor with vertebral involvement and cord compression by the tumor mass.
(Reprinted with permission from eMedicine.com, 2007. Available at: http://www.emedicine.com/radio/topic515.htm .)
Positron Emission Tomography
- ▪
Positron emission tomography ( PET), while not well studied in this subset of patients, is generally accepted as part of the workup of patients with NSCLC. This method may be helpful in the evaluation of mediastinal nodal involvement and distant metastases.
Tissue Diagnosis
- ▪
Because the differential is broad (benign apical cap, infection such as tuberculosis or aspergillus-associated pleural reaction, lymphoma, primary chest wall tumors, neural tumors, lipoma, metastatic pleural disease, radiation fibrosis, cervical rib), tissue is required for diagnosis.
- ○
Guided transthoracic needle biopsy is diagnostic in up to 95% of cases.
- ○
Sputum cytology has a yield between 11% and 20%.
- ○
Bronchoscopy is typically low yield due to the peripheral location of the tumor (diagnosis in 10% to 40% of cases).
- ○
Video-assisted thoracic surgery or thoracotomy will be diagnostic if other modalities fail.
- ○
Further Workup/Special Studies
Mediastinoscopy
- ▪
Pathologic staging of mediastinum is necessary before treatment.
- ▪
Thus, it is generally recommended as part of the surgical staging before final treatment decisions, especially as this study affects treatment approaches and prognosis.
Imaging for Metastatic Disease
- ▪
The CT scan of the chest generally includes cuts of the upper abdomen including the liver and adrenals, and thus, may be useful in the evaluation of metastasis to these sites.
- ▪
Superior sulcus tumors commonly metastasize to the brain; therefore, routine brain imaging (CT or MRI) is generally recommended.
- ▪
PET scans, as noted earlier, are generally useful in the evaluation of patients with NSCLC.
- ▪
A bone scan is indicated in patients with appropriate symptoms.
Pulmonary Functions Testing
- ▪
Indicated in all patients in whom surgical resection is considered
PROGNOSIS
- ▪
Poor prognostic factors include the presence of Horner’s syndrome, advanced stage, invasion of the great vessels or vertebral bodies, and longer duration of symptoms.
- ▪
Good prognostic factors include early stage, complete respectability, less than 5% total body weight loss, and good preoperative performance status.
TREATMENT
- ▪
The treatment of superior sulcus tumors continues to evolve but typically involves multimodality therapy
- ▪
An outstanding historical perspective has been provided by Valerie Rusch, in which four eras of management were described. These eras can be summarized as follows:
- ○
First Era: early treatment approaches by Chardack and MacCallum (1956; radical resection and postoperative radiation ), and Shaw, Paulson, and Kee (1961; preoperative radiation followed by radical resection ).
- ○
Second Era:
- ▪
30 Gy preoperative radiation over 2 weeks, followed by an en bloc resection of the lobe and chest wall nerve roots via an extended posterolateral thoracotomy. This became the standard approach for the next 3 decades.
- ▪
Studies over this time highlighted issues with limited ability to perform curative resection and poor outcome with mediastinal node involvement, vertebral, or vascular involvement. This was confirmed in a study of 225 patients treated between 1974 and 1988.
- ▪
Survival in that study highlighted the need for new treatment strategies. Five-year survival after treatment was 46% for T3N0, 13% for T4N0 and 0% for N2 disease.
- ▪
- ○
Third Era: This was characterized by several new surgical approaches to deal with tumors in which subclavian vessels or the spine was involved. This included
- ▪
Anterior transcervical-thoracic approach for tumor invasion of subclavian vessels
- ▪
Transmanubrial osteomuscular sparing approach (spares clavicle)
- ▪
Approaches to facilitate lung and spine exposure, including hemiclamshell anterior thoracotomy and partial median sternotomy
- ▪
Approaches to deal with spinal involvement to include vertebrectomy and spine stabilization
- ▪
- ○
Fourth Era: This relates to induction chemoradiation, followed by en bloc resection. Key trials and data summary:
- ▪
4th era treatment applies to patients in whom mediastinoscopy is negative.
- ▪
Southwest Oncology Group (SWOG 9416-1060) phase II trial. N = 110 (T3-4; N0-1)
- ▪
Two cycles of etoposide and cisplatin plus 45 Gy concurrent radiation, then resection (if stable or tumor regression), then 2 additional cycles of etoposide and cisplatin
- ▪
Main results :
- ○
Seventy-five percent of patients underwent resection (most lobectomy and chest wall resection)
- ○
Of these, a third had a complete pathologic response (CR) and a third showed minimal residual disease.
- ○
Complete resection in 91% of T3 lesions and 87% for T4 lesions.
- ○
Only 42% could complete post operative chemotherapy.
- ○
Survival data : The 5-year survival rate was 54% in patients with complete resection and 44% overall. In patients with CR at surgery, the estimated 5-year survival rate was about 70% versus about 40% in those with residual disease. Note: these are impressive data compared with studies over the last 30 years, in which the 5-year survival rate was 30% and complete resection possible in less than 50% of patients.
- ○
Disease progression was mainly due to metastatic disease (e.g., brain).
- ○
Similar survival data were reported in single institution study.
- ○
- ▪
- ○
- ▪
Summary details of posterior and anterior surgical approaches, including management of spine/neurologic involvement
- ○
Posterior
- ▪
The posterior approach for Pancoast’s tumors is the optimal approach for lesions attached to the ribs posteriorly or to the vertebral bodies. It begins with an extended posterolateral incision. This usually involves transection of the latissimus dorsi and serratus anterior muscles. Posteriorly, the incision is extended to the top of the scapula with transection of the teres and rhomboid muscles.
- ▪
Resection of ribs is part of the procedure, and it is the reason that this is not a minimally invasive procedure. An adequate margin around the tumor is imperative, so at least one rib above and one rib below the ribs to which the tumor is attached are resected.
- ▪
The rib resection is performed first, and then a standard lobectomy and node dissection are performed. Visualization of the tumors attachment to the ribs can be very helpful to determine which intercostal space is entered for the resection.
- ▪
The pulmonary resection should be a lobectomy, not a wedge resection because a wedge resection has a higher local recurrence rate. The margins of resection must be clean because local radiation does not then prevent local recurrence.
- ▪
- ○
Anterior
- ▪
The anterior approach is the procedure of choice for a Pancoast tumor attached anteriorly to the ribs of the anterior chest or subclavian vessels.
- ▪
The incision is made just superior to the clavicle, then in the midline of the chest over the sternum, and then laterally into (usually) the fourth intercostal space. This provides excellent exposure to the subclavian vessels and the brachial plexus. This is not seen well through a posterior incision.
- ▪
- ○
Spine/neurologic involvement:
- ▪
Spinal involvement is not a contraindication to resection if all disease can be resected. This requires a spine surgeon as part of the team. The operation should include an en bloc resection of the ribs, the lobe, and the spine.
- ▪
Neurologic involvement is also not an absolute contraindication to resection.
- ▪
The posterior cord of the brachial plexus can be resected. However, more extensive involvement of the brachial plexus is a contraindication to resection.
- ▪
The phrenic nerve is adjacent to the brachiocephalic vein and SVC. This means that clear margins will not be obtained with the resection, so phrenic nerve involvement precludes a resection with curative intent .
- ▪
- ○
- ▪
Treatment complications :
- ○
Surgical mortality rates range from 0 to 14%.
- ○
Post-thorocotomy complications include
- ▪
Pneumonia (chest wall instability and pain limit effective bronchial toilet)
- ▪
Wound infection
- ▪
Bronchopleural fistula
- ▪
Chylothorax and hemothorax
- ▪
Ulnar nerve paralysis (damage to C8 +/- T1)
- ▪
Horner’s syndrome (high dorsal root sympa-thectomy)
- ▪
Pulmonary embolism
- ▪
Subclavian vein injury or thrombosis
- ▪
- ○
Radiation may result in skin irritation, esophagitis, pneumonitis, and pulmonary fibrosis
- ○
Chemotherapy-related complications specific to the therapy or regimen chosen
- ○
- ▪
Primary stand-alone radiation therapy and other issues:
- ○
Indication: patients with unresectable or metastatic disease, serious comorbidities that render them inoperable, poor performance status
- ○
Provides good palliation for pain
- ○
60 to 65 Gy given with unresectable disease
- ○
In unresectable disease, concurrent chemotherapy and radiation can be considered depending on patient factors
- ○
Some studies have shown up to 40% 5-year survival rates using radical radiation alone in localized tumors.
- ○
Postoperative radiation therapy may be considered in unresectable or incompletely resected tumors.
- ○
Stay updated, free articles. Join our Telegram channel
Full access? Get Clinical Tree
