Pancoast Tumor Workup

• The blood workup for patients with Pancoast tumors is not specific and results are not diagnostic.

  • Lung cancers produce various substances. Elevated levels of oncofetal carcinoembryonic antigen and beta-2 microglobulins are associated with many lung cancers. Unfortunately, these findings are not diagnostic because levels of these chemicals are also elevated by other nonspecific causes such as smoking and bronchitis.
  • Tumor markers, such as bombesin, neuron-specific enolase, and other peptides, are common with small cell cancers and are related to the stage of the disease. They may aid in distinguishing differentiated from undifferentiated forms of lung cancer.
  • Various tumor oncogenes, including K-ras, c-myc, TP53, and HER-2/neu, have also been identified in patients with lung cancers. Although the presence of these oncogenes has some prognostic value, they are not important for staging of the cancer.
• Routine blood work in all patients with a lung cancer includes a CBC count, BUN/creatinine level, WBC count, and urinalysis. Coagulation parameters, such as prothrombin time, activated partial thromboplastin time (aPTT), and platelet count, are appropriate. Unless metastatic disease is evident, liver function tests are not regularly performed. Any patient deemed a surgical candidate has blood drawn for a cross match.
• Urinalysis is performed in all patients prior to surgery, and a catheter specimen is obtained in women if the initial urinalysis result suggests contamination.

• Radiographic features

  • Chest radiographs may reveal a small homogenous apical cap or pleural thickening; they may show a thin plaque at the lung apex in the area of the superior sulcus or they may reveal a large mass, depending on the stage when first diagnosed. Suggestive films should prompt the astute diagnostician to order apical lordotic views to better visualize the area.
  • Bone destruction of the posterior 1-3 ribs may sometimes be apparent. Rib invasion or vertebral body infiltration may be evident on a plain chest radiograph.
  • Mediastinal enlargement may be apparent.
• CT scanning and MRI

  • CT scanning and MRI of the neck, chest, and upper abdomen have replaced older radiographic studies. MRI is useful for evaluating resectability.
  • CT scanning helps identify invasion of the brachial plexus, chest wall, and mediastinum. Images can also reveal involvement of the vena cava, trachea, and esophagus. Contrast CT scanning is useful to assess subclavian vessel involvement.
  • MRI findings are more accurate than CT findings for assessing invasion of cervical structures and vertebral bodies. MRI has no advantage over CT scanning in the evaluation of the mediastinum. In fact, CT scanning is much better than MRI for assessing the mediastinum for lymph nodes. Rib or transverse process involvement is not a sign of inoperability; however, involvement of the vertebral body makes achieving an adequate margin of resection very difficult and reduces the odds for survival.
• Arteriogram or venogram: Rarely, arterial or venous involvement of the subclavian artery or vein occurs; thus, an arteriogram or a venogram may be helpful. This is usually accomplished in a retrograde fashion, although it can be approached from the opposite extremity or from the leg.

• A baseline ECG is performed on all patients for comparison to postoperative ECG tracings (if one is performed).

• Bronchoscopy helps evaluate the tracheal and bronchial lumens; however, because most Pancoast tumors are peripheral, the diagnostic yield is low.
• Tissue diagnosis is obtained based on results from percutaneous needle biopsy, either under fluoroscopy or with CT-guided procedures.
• Staging is based on scalene node biopsy results from palpable nodes or mediastinoscopy findings.

The concept of classifying tumors according to tumor-node-metastasis (TNM) descriptions was elaborated in 1946. This system takes into account the characteristics of the local tumor (T), the presence or absence of regional lymph node involvement (N), and the presence or absence of distant metastases (M). Several staging systems have evolved since then. The most recent system is the 2002 revision of the International Staging System (ISS) for Non Small Cell Lung Cancer, which is unchanged from the 1997 revision. The overall stage of the tumor (stages I-IV) depends upon the particular combination of T, N, and M characteristics for the given patient. If the extent of disease cannot be assessed for any of these features, the suffix "X" is attached (ie, TX, NX, or MX).