Xiao Ding1, Zhouguang Hui2, Honghai Dai1, Chengcheng Fan2, Yu Men2, Wei Ji2, Jun Liang2, Jima Lv2, Zongmei Zhou2, Qinfu Feng2, Zefen Xiao2, Dongfu Chen2, Hongxing Zhang2, Weibo Yin2, Ning Lu3, Jie He4, Luhua Wang5. 1. Cancer Center, Shandong Provincial Hospital Affiliated with Shandong University, Jinan, People's Republic of China; Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. 2. Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. 3. Department of Pathology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. 4. Department of Thoracic Surgery, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. 5. Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People's Republic of China. Electronic address: wlhwq@yahoo.com.
Abstract
INTRODUCTION: The current pathologic nodal classification (pN) based on anatomic location of involved lymph nodes (LNs) is unsatisfactory in distinguishing heterogeneous pN1 or pN2 non-small cell lung cancer (NSCLC). For the first time we comprehensively compared the prognostic significance of the number of positive LNs (nN), the ratio of the number of positive to removed LNs (LN ratio [LNR]), the combination of pN and nN (pN-nN), the combination of pN and LNR (pN-LNR), and pN to identify a superior classification. METHODS: We identified 700 patients with pN1 (n = 203) or pN2 (n = 497) NSCLC. We classified the patients into four nN categories (nN1, nN2, nN3-6, and nN≥7), four pN-nN categories (pN1-nN1-2, pN1-nN≥3, pN2-nN1-6, and pN2-nN≥7); four LNR categories (LNR≤0.05, 0.1≥LNR>0.05, 0.4≥LNR>0.1, and LNR>0.4), and four pN-LNR categories (pN1-LNR<0.1, pN1-LNR≥0.1, pN2-LNR<0.4, and pN2-LNR≥0.4). The log-rank test was used to analyze differences among groups, and Cox regression was used to evaluate relationships between each classification and survival. RESULTS: In adjusted analyses, pN-LNR was an independent prognostic factor for patients with pN1 or pN2 NSCLC, as were pN-nN, LNR, nN, and pN. pN-LNR was prognostically superior to the other four classifications. Postoperative radiotherapy (PORT) was an independent prognostic factor for pN2 NSCLC. Analyses stratified by LNR showed that PORT did not improve survival in patients with pN2-LNR<0.14 NSCLC, whereas significantly improved survival times in pN2-LNR≥0.14 NSCLC. CONCLUSIONS: We propose a potential revised nodal classification, pN-LNR, to further stratify patients with pN1 or pN2 NSCLC into subgroups so as to more precisely predict survival and help tailor individualized postoperative treatment.
INTRODUCTION: The current pathologic nodal classification (pN) based on anatomic location of involved lymph nodes (LNs) is unsatisfactory in distinguishing heterogeneous pN1 or pN2non-small cell lung cancer (NSCLC). For the first time we comprehensively compared the prognostic significance of the number of positive LNs (nN), the ratio of the number of positive to removed LNs (LN ratio [LNR]), the combination of pN and nN (pN-nN), the combination of pN and LNR (pN-LNR), and pN to identify a superior classification. METHODS: We identified 700 patients with pN1 (n = 203) or pN2 (n = 497) NSCLC. We classified the patients into four nN categories (nN1, nN2, nN3-6, and nN≥7), four pN-nN categories (pN1-nN1-2, pN1-nN≥3, pN2-nN1-6, and pN2-nN≥7); four LNR categories (LNR≤0.05, 0.1≥LNR>0.05, 0.4≥LNR>0.1, and LNR>0.4), and four pN-LNR categories (pN1-LNR<0.1, pN1-LNR≥0.1, pN2-LNR<0.4, and pN2-LNR≥0.4). The log-rank test was used to analyze differences among groups, and Cox regression was used to evaluate relationships between each classification and survival. RESULTS: In adjusted analyses, pN-LNR was an independent prognostic factor for patients with pN1 or pN2NSCLC, as were pN-nN, LNR, nN, and pN. pN-LNR was prognostically superior to the other four classifications. Postoperative radiotherapy (PORT) was an independent prognostic factor for pN2NSCLC. Analyses stratified by LNR showed that PORT did not improve survival in patients with pN2-LNR<0.14 NSCLC, whereas significantly improved survival times in pN2-LNR≥0.14 NSCLC. CONCLUSIONS: We propose a potential revised nodal classification, pN-LNR, to further stratify patients with pN1 or pN2NSCLC into subgroups so as to more precisely predict survival and help tailor individualized postoperative treatment.