PURPOSE: To study whether size or pattern of lymph node metastases have prognostic value for patients with resected non–small cell lung cancer.
METHODS: We evaluated the largest diameter and pattern of lymph node metastases in 201 patients who had undergone at least a lobectomy with dissection of mediastinal lymph nodes for primary lung cancer between January 1996 and December 1998. For patterns of lymph node metastases, we evaluated resected lymph nodes on H&E stains for the presence of sinus permeation (SP), stromal change (SC), and extracapsular invasion (ECI).
RESULTS: The pathological status of lymph node metastases was pN0 in 145 patients, pN1 in 20 patients, and pN2 in 36 patients. Micrometastases (mi) as defined between 0.2 mm and 2 mm in largest diameter were detected in 5 patients with pN1 disease and 4 patients with pN2 disease. Isolated tumor cells (ITC) as defined less than 0.2mm were detected in no patients. There was no significant difference in survivals between micrometastases and macrometastases (ma) (pN1mi vs pN1ma; p = 0.439, pN2mi vs pN2ma; p = 0.319). But we also find no significant defference in both pN0 vs pN1mi and pN1 vs pN2mi (pN0 vs pN1mi; p = 0.897, pN1 vs pN2mi; p = 0.684). Among 9 patients with micrometastases, SP was detected in 5 patients but SC and ECI were detected in no patients. Three of them died because of recurrence, in all of whom SP was detected.
CONCLUSION: Subdividing TNM stage by size and pattern of lymph node metastases would more accurately predict patient prognosis.
CLINICAL IMPLICATIONS: none.
DISCLOSURE: Koji Kawaguchi, None.