Every patient with a pancoast tumor of the lung should be evaluated by a Pancoast-experienced thoracic surgeon (and neurosurgeon) before ruling out surgery, and before starting induction therapy.
Lary A. Robinson, MD
Senior Member, Thoracic
Moffitt Cancer Center, Tampa, FL
ï»¿One of the most distressing and vexing presentations of lung cancer is that of the superior sulcus tumor. In 1932 when Henry Pancoast, the first chairman of radiology at the University of Pennsylvania, initially described this tumor that bears his name, he wrongly thought that it started from embryonic rests that invaded the lung. Later, it was determined that this cancer started primarily in the upper lobe of either lung and involved the apex of the pleural cavity (the superior sulcus). The tumor causes severe, painful symptoms by invading the brachial plexus, ribs, vertebrae, subclavian vessels, and occasionally the stellate ganglion.Unfortunately the presenting arm and shoulder pain and neurologic symptoms may be misleading, often delaying the diagnosis for months while mistaken benign orthopedic causes such as cervical spine disease are investigated. The characteristic Pancoast symptoms include some or all of the following: (1) dysesthesias, paresthesias, and weakness in the arm and hand in the C-8, T-1, and T-2 distribution; (2) subclavian (vein or artery) impairment to the involved upper extremity; (3) pain in the shoulder, upper arm, scapula and/or shoulder; (4) Horner’s syndrome (ptosis, miosis, anhidrosis, and apparent enophthalmos due to the ptosis). The diagnosis requires symptoms plus a lung cancer located in the apex of chest (superior sulcus).
An estimated 3% to 5% of non-small cell carcinomas present with a symptomatic Pancoast tumor. With 17,860 new lung cancers in Florida yearly (2012 data), approximately 550 of these are Pancoast tumors and deserve evaluation for potential curative, multimodality therapy. Squamous cell carcinoma represents 52% of Pancoast cases, with the rest comprised of 23% adenocarcinomas, 20% large-cell carcinomas, and only 5% small-cell carcinomas.Lung masses with a Pancoast tumor presentation require the same initial evaluation as other lung masses (chest CT with contrast and PET scan). To assess the extent of chest wall involvement and to further stage the tumor, an MRI with contrast of the brachial plexus and thoracic inlet (which includes the upper thoracic vertebrae) is mandatory. Once a Pancoast tumor is suspected, a needle biopsy is needed for a histologic diagnosis since induction therapy is recommended. If the tumor is deemed potentially resectable, then pulmonary function tests and possibly a cardiac evaluation are recommended.Prior to 1950, this was a uniformly fatal tumor. In 1961, Shaw, Paulson, and Kee described neoadjuvant radiotherapy followed by surgery for Pancoast tumors, and they had some long-term survivors. Forty years later in 2001, the phase II Intergroup Pancoast tumor trial added chemotherapy to the induction regimen (two cycles of induction cisplatin/etoposide chemotherapy with concurrent 4500 cGy radiotherapy followed by resection), reporting an excellent 41% 5-year survival in the 83 of 111 patients who subsequently underwent surgery. This regimen has been adopted as the current standard of care.
However, there are a number of significant limitations of the concurrent preoperative chemoradiotherapy regimen. In these debilitated, highly symptomatic patients, induction chemoradiotherapy causes significant morbidity, as indicated by the fact that only 75% of the patients in the Intergroup trial could tolerate treatment long enough to undergo surgery. The 4500-cGy preoperative radiation dose is not tumoricidal. Since the surgical incision directly crosses the radiation portal (radiated skin), there are potential wound problems. Finally, and most importantly, if there are close or microscopically positive surgical margins, further radiotherapy after surgery is generally ineffective since this split course radiation has generally proven unsuccessful. Additionally, postoperative chemotherapy in Pancoast patients is poorly tolerated.In order to avoid the drawbacks of induction chemoradiotherapy, the thoracic oncology program has adopted a slightly different approach, which is also favored by several other major cancer centers. We use induction chemotherapy with a platinum doublet for three cycles. The tumor pain usually lessens or resolves within 7 to 10 days after beginning chemotherapy. A chest CT with contrast is repeated after chemotherapy to verify there has been no progression. Surgical resection is then performed 3 to 5 weeks after completing chemotherapy. Six weeks after surgery, patients start full dose radiotherapy (6600 cGy) to the tumor bed, which is tumoricidal for close margins and any residual microscopic disease. This entire treatment regimen is well tolerated, as evidenced by virtually 100% of our current series of 105 Pancoast patients completing all therapy including surgery, with only a 1.9% operative mortality. This series will be published soon.
Even the most skilled thoracic surgeons have neither the training nor experience to comfortably approach the vertebrae and transverse processes to aggressively obtain a complete resection of these invasive cancers. For this reason, our highly experienced, oncologic neurosurgeons perform the surgery jointly with our thoracic surgeons, thereby allowing uniformly complete resections. Advanced T4 tumors requiring vertebral body resection may be readily handled by our neurosurgeons with the implantation of the appropriate instrumentation to stabilize the spine. Vascular surgeons are occasionally involved for vascular reconstruction of a major vessel (subclavian artery) when it is involved by tumor.Most ECOG performance status 1 or 2 Pancoast tumor patients with adequate cardiopulmonary reserve will tolerate induction chemotherapy, surgery and postoperative radiotherapy with a very low expected morbidity and mortality. Patients with T3N0 or T3N1, as well as selected T4N0 or T4N1 tumors with no mediastinal lymph node involvement, should be considered for treatment including surgery. If mediastinal N2 node involvement is suspected, we generally obtain histologic confirmation of tumor in the nodes by EBUS, EUS, or mediastinoscopy before ruling out surgery.
Contraindications to surgery for Pancoast tumors are definite N2 or N3 mediastinal lymph node metastases or extensive involvement of the brachial plexus, and these patients need chemoradiotherapy alone. Interestingly, we rarely encounter Pancoast tumors with nodal metastases or unresectable chest wall involvement, probably because the pain from the tumor brings the patient to medical attention before there is unresectable spread.
The key point is to have every patient evaluated by a Pancoast-experienced thoracic surgeon (and neurosurgeon) before ruling out surgery, and before starting induction therapy.