Adjuvant chemotherapy may improve outcome of patients with non-small-cell lung cancer with metastasis of intrapulmonary lymph nodes after systematic dissection of N1 nodes

OBJECTIVE: Survival benefit of adjuvant chemotherapy (AC) of patients with intrapulmonary lymph node (IPLN) metastasis (level 12−14) needs investigation. We evaluated the impact of AC on patients whose metastatic nodes were limited to intrapulmonary levels after systematic dissection of N1 nodes. METHODS: First, 155 consective cases of lung cancer confirmed as pathologic N1 were collected and evaluated. Patients received systematic dissection of N2 and N1 nodes. For patients with IPLN metastasis, survival outcomes were compared between those receiving AC and those not receiving AC. RESULTS: In this group, 112 cases (72.3%) had IPLN metastasis and 55 cases (35.5%) had N1 involvement limited to level 13−14 without further disease spread to higher levels. Patients with IPLN involvement had a better prognosis than that of patients with hilar-interlobar involvement. For the intrapulmonary N1 group (level 12−14-positive, level 10−11-negative or unknown, n=112), no survival benefit was found between the AC group and non-AC group [5-year overall survival (OS): 54.6±1.6vs. 50.4±2.4 months, P=0.177]. However, 76 of 112 cases for whom harvesting of level-10 and level-11 nodes was done did not show cancer involvement in pathology reports (level 12−14-positive, level 10−11 both negative), oncologic outcome was better for patients receiving AC than those not receiving AC in this subgroup (5-year OS: 57.3±1.5vs. 47.1±3.2 months, P=0.002). CONCLUSIONS: Oncologic outcome may be improved by AC for patients with involvement of N1 nodes limited to intrapulmonary levels after complete examination of N1 nodes.