Detection of Occult Micrometastases in Patients With Clinical Stage I NSCLC: A Prospective Analysis

OBJECTIVES:

• Determine whether the presence of occult micrometastases (OM) detected by immunohistochemistry or reverse transcriptase-polymerase chain reaction (RT-PCR) in histologically negative lymph nodes or bone marrow is associated with poorer survival among patients with stage I non-small cell lung cancer.
• Determine the incidence of OM in histologically negative lymph nodes and bone marrow by immunohistochemistry (staining for cytokeratins and the CEA glycoprotein) or RT-PCR (to detect CEA mRNA) in these patients.
• Assess the sensitivity of immunohistochemistry relative to RT-PCR for detecting OM in these patients.
• Determine the relationship between tumor size (or T-stage) and the presence of OM detected by immunohistochemistry or RT-PCR in these patients.
• Determine the relationship between the presence of OM and disease-free survival in these patients.
• Determine the relationship between the site of OM and incidence of recurrence, site of recurrence, and survival of these patients.

OUTLINE: At the time of thoracotomy and pulmonary resection, patients have samples of bone marrow, primary tumor, and intrathoracic lymph nodes harvested. The presence of occult metastases in bone marrow and lymph nodes is assessed using immunohistochemistry or reverse transcriptase-polymerase chain reaction.

Patients are followed every 6 months for 5 years.