Risk factors for local recurrence after lobectomy and lymph node dissection in patients with non-small cell lung cancer: Implications for adjuvant therapy

Objectives: The objective of this study was to investigate clinicopathological risk factors for local recurrence in patients who underwent either complete resection with lobectomy or more extensive resection with hilar and mediastinal lymph node dissection for non-small cell lung cancer (NSCLC). The role of adjuvant therapy was also explored. Materials and methods: We reviewed the records of 1012 consecutive stage NSCLC patients who underwent complete resection. The median follow-up time was 59 months. The risk factors for local recurrence were investigated by multivariate analysis using Cox's proportional hazards regression model. Results: Local recurrence was identified in 9.4% of the patients. The most significant risk factor for local recurrence was lymph node metastasis (NI: hazard ratio [HR] = 2.27, p = 0.009; N2: HR = 6.85, p < 0.0001). For the subgroup of patients with lymph node metastasis (n = 289), the independent risk factors for local recurrence were N2 disease with N1 metastasis (N2 with N1; HR = 3.46,p < 0.0001) and non-receipt of adjuvant platinum-based chemotherapy (HR = 1.91, p = 0.018). The 5-year freedom from local recurrence rates were 96.1%, 84.1%, 85.0%, and 53.5% for N0, N1, skip N2, and N2 with N1 stages (p < 0.0001). Conclusion: Local recurrence is significantly associated with poor overall survival. Therefore, local control is essential for radical cure of NSCLC. N2 with N1 status was the primary risk factor for local recurrence, while adjuvant chemotherapy improved local control. These data have important implications for postoperative radiotherapy and highlight the need to devise more effective eligibility criteria for this modality in patients with lymph node metastasis.