Prognostic implication of metastasis limited to segmental (level 13) and/or subsegmental (level 14) lymph nodes in patients with surgically resected nonsmall cell lung carcinoma and pathologic N1 lymph node status

Abstract

BACKGROUND:In patients with nonsmall cell lung carcinoma (NSCLC) who have with pathologic N1 (pN1) lymph node status, the prognostic significance of segmental lymph node (level 13) metastasis and/or subsegmental lymph node (level 14) metastasis is unknown. METHODS: Lymph node metastasis patterns were analyzed in 230 patients with NSCLC who had pN1 status. Clinical outcomes were examined for 230 patients with pN1 status and 700 patients with pN0 status. The pN1 group was stratified into 4 subgroups according to the highest level of lymph node involvement. RESULTS: The 5-year disease-free survival (5DFS) rates for pN1 and pN0 patients were 50.1% and 90.5%, respectively. The highest level of lymph node involvement was a significant prognostic indicator; the 5DFS rates for patients with pN1 status who had level 13/14, lobar (level 12), interlobar (level 11), and hilar (level 10) lymph node metastasis were 69.4%, 46.4%, 46.7%, and 37%, respectively. Patient outcomes were significantly worse for those with pN1 status who had only level 13/14 lymph node metastasis than for patients with pN0 status (P ¼ .0034), and outcomes were significantly worse for patients with pN1 status who had level 11/12 lymph node metastasis than for patients who had only level 13/14 lymph node metastasis (P ¼ .021). The median number of level 13/14 lymph nodes examined was 3 (range, 0-22 level 13/14 lymph nodes), and metastases to these lymph nodes were detected in 61% of patients who had pN1 status. A single lymph node pN1 disease, single-level pN1 status, and squamous cell carcinoma histopathology also were indicators of a better patient outcome. CONCLUSIONS: The current results indicated that the highest level of lymph node involvement may be used to stratify the outcome of patients who have NSCLC with pN1 status. Patients with pN1 status who had only level 13/14 lymph node metastasis had an intermediate 5DFS rate between that of patients with pN0 status and other patients with pN1 status. Routine examination of level 13/14 lymph nodes is important for accurate pathologic staging and for the predicting clinical outcome of patients with NSCLC. Cancer 2012;118:4512-8.

Pathologic N1 disease in lung cancer: the segmental and subsegmental lymph nodes

“…There were stations where no LN could be found (13). Stations without LN were also observed in the reports concerning peripheral LNs (3)(4)(5)8,11).…”

“…In the paper of Rena and coworkers (11) the median number of examined level 13+14 LNs was 2 (range, 0-6) and 57% of pN1 patients had metastasis at that level. Maeshima and coworkers (8) found a median number of examined 13/14 LNs of 3 (range, 0-22; 13/14 LNs), and metastases to these LNs were detected in 61% of patients who had pN1 status. In the series reviewing pN0, pN2 and pN1 patients, the frequency of segmental LN involvement is not so high.…”

“…The same kinds of results have subsequently been commonly reported. Maeshima and coworkers (8) reported that the 5-year DFS rates for pN0, level 13/14 pN1, lobar (level 12), interlobar (level 11), and hilar (level 10) pN1 were 90.5%, 69.4%, 46.4%, 46.7% and 37%, respectively. Reviewing stage II (T1a-T2bN1M0) NSCLC, Li and coworkers (9) observed that peripheral zone LN involvement was a statistically significant indicators of higher OS and DFS by univariate analyses, and Liu and coworkers (10), that hilar/interlobar nodal zone involvement was significant predictors for worse OS by multivariate analysis (P=0.001).…”

“…On the other hand, the role of the surgeon and of him alone is of paramount importance in a particular situation which is not part of what is mentioned by Wang and coworkers (3) and the others. In effect, in all series (3)(4)(5)8,11), the resection considered as "lesser resection" is a lobectomy that allows surgeons or pathologists to dissect intralobar LNs in the resected part of the lung. In the case of still lesser resections the quality of surgery actually depends upon the surgeon's skill and this point must be emphasized here.…”

The “N”—factor in non-small cell lung cancer: staging system and institutional reports

“…The "N"-factor in non-small cell lung cancer: staging system and institutional reports the value of missed LNs metastasis at re-dissection of pulmonary specimens with curative intent (8,9), and others studied the prognostic impact of the number of metastatic LNs and their relative location after hilar-mediastinal nodal dissection (10,11). Maeshima et al described the prognostic implications for N1 status; they stratified N1 nodal status based on hilar/ interlobar zone (level 10-11 nodes) versus the peripheral zone (level 12, 13 and 14 nodes) in 230 patients affected by pN1 disease from a Japanese population.…”