Local failure patterns after radical resection and adjuvant chemotherapy in patients with pN2 nonsmall-cell lung cancer: A retrospective analysis

Background: The patterns of local failure in stage pN2 nonsmall-cell lung cancer (NSCLC) patients undergoing radical resection and adjuvant chemotherapy are controversial. Methods: The sites of local failure were compared in subgroups of patients with relevant clinicopathologic features (e.g., location and size of primary lesions). Results: Totally 75 patients with local failure after radical resection and adjuvant chemotherapy for pN2 NSCLC were included in the analysis. Thirty-seven (49.3%) patients had distant metastasis. The median duration from surgical resection to local failure was 11 months (range: 3-45 months). Sites with >= 10% failure rate in all subgroups based on the location of the primary lesions included 4R, 7, the ipsilateral hilum, and the stump. Additional sites with >= 10% failure rate included 2R, 2L, 4L, and 5 for lesions in the left upper lobe; 4L and 5 for lesions in the left lower lobe; and 2R and 3P for lesions in the right upper-middle lobe. Squamous cell carcinoma affected the stump failure rate compared to adenocarcinoma (56.3% vs. 18.0%, P = 0.003). Tumor diameter >= 5 cm affected the stump failure rate compared to tumor diameter < 5 cm (44.0% vs. 18.0%, P = 0.016). Skip N2 metastasis affected the ipsilateral hilum failure rate compared to nonskip N2 metastasis (7.5% vs. 31.4%, P = 0.008) Conclusions: For pN2 NSCLC patients undergoing radical resection and adjuvant chemotherapy, different lung lobes had different high-risk failure sites. Left lung cancer is prone to bilateral mediastinal lymph nodes recurrence, while right lung cancer mainly recurs with ipsilateral mediastinal lymph nodes. Moreover, the local failure patterns are influenced by pathological type, tumor size, and skip N2 metastasis.