Predictors and survival impact of station 4L metastasis in left non-small cell lung cancer.

BACKGROUND: It remains unclear about the predictors and survival impact of station 4L metastasis in left-sided non-small cell lung cancer (NSCLC). This study aims to investigate these issues to explore the significance of station 4L lymph-node dissection (LND).

METHODS: We retrospectively enrolled 405 patients with station 4L LND, and divided them into the positive station 4L metastasis group and the negative station 4L metastasis group. The logistic regression was performed to identify the predictors of station 4L metastasis. The survival outcomes including disease-free survival (DFS) and overall survival (OS) were analyzed in pN2 patients to explore the prognostic effect of station 4L metastasis.

RESULTS: There were 48 (11.9%) patients in the positive station 4L metastasis group and 357 (88.1%) patients in the negative station 4L metastasis group. Station 5 metastasis (P = 0.008, OR 7.578, 95% CI 1.710-33.589), station 10 metastasis (P = 0.004, OR 7.133, 95% CI 1.904-26.717), and cN2 (P = 0.010, OR 5.062, 95% CI 1.473-17.392) were independent risk factors of station 4L metastasis. In pN2 patients, the positive station 4L metastasis group had inferior DFS (P = 0.019) and OS (P = 0.006) compared with the negative station 4L metastasis group, and station 4L metastasis was the independent risk factor for poor prognosis.

CONCLUSION: It is of great necessity to perform station 4L LND in left NSCLC, because station 4L metastasis is not rare and has an unfavorable prognosis.