Sawyer T E, Bonner J A, Gould P M, Foote R L, Deschamps C, Trastek V F, Pairolero P C, Allen M S, Shaw E G, Marks R S, Frytak S, Lange C M, Li H
Division of Radiation Oncology, Mayo Clinic and Mayo Foundation, Rochester, Minnesota 55905, USA.
Cancer. 1997 Oct 15;80(8):1399-408. doi: 10.1002/(sici)1097-0142(19971015)80:8<1399::aid-cncr6>3.0.co;2-a.
Previous nonsmall cell lung carcinoma studies have shown that patients with ipsilateral mediastinal (N2) lymph node involvement who underwent surgical resection have a greater local recurrence rate than those with less lymph node involvement (N0, N1). Therefore, it was hypothesized that complete surgical clearance of subclinical lymph node disease is difficult in N2 patients and that adjuvant postoperative thoracic radiotherapy (TRT) may be beneficial.
A retrospective review was performed to determine the local recurrence and survival rates for patients with N2 disease undergoing complete surgical resection with or without adjuvant TRT. Between 1987 and 1993 at the Mayo Clinic, 224 patients underwent complete resection of N2 nonsmall cell lung carcinoma. More than one mediastinal lymph node station was sampled in 98% of patients; 39% then received adjuvant TRT (median dose, 50.4 grays).
The median follow-up time was 3.5 years for the patients who were alive at the time of the analysis. The surgery alone versus surgery plus TRT groups were well balanced with respect to gender, age, histology, tumor grade, number of mediastinal lymph node stations dissected or involved, and involved N1 lymph node number. There were slightly more patients with right lower lobe lesions (compared with other lobes), patients with multiple lobe involvement, and patients with only one N2 lymph node involved in the surgery alone group. After treatment with surgery alone, the actuarial 4-year local recurrence rate was 60%, compared with 17% for treatment with adjuvant TRT (P < 0.0001). The actuarial 4-year survival rate was 22% for treatment with surgery alone, compared with 43% for treatment with adjuvant TRT (P = 0.005). On multivariate analysis, the addition of TRT (P = 0.0001), absence of superior mediastinal lymph node involvement (P = 0.005), and fewer N1 lymph nodes involved (P = 0.02) were independently associated with improved survival rate.
This study, which to the authors' knowledge is the largest evaluating adjuvant TRT in N2 nonsmall cell lung carcinoma, suggests that adjuvant TRT may improve local control and survival.
既往非小细胞肺癌研究表明，接受手术切除的同侧纵隔（N2）淋巴结受累患者的局部复发率高于淋巴结受累较少（N0、N1）的患者。因此，有人推测N2期患者难以完全手术清除亚临床淋巴结疾病，术后辅助胸部放疗（TRT）可能有益。
进行一项回顾性研究，以确定接受或未接受辅助TRT的完全手术切除的N2期疾病患者的局部复发率和生存率。1987年至1993年期间，梅奥诊所224例患者接受了N2期非小细胞肺癌的完全切除术。98%的患者对不止一个纵隔淋巴结站进行了采样；其中39%随后接受了辅助TRT（中位剂量，50.4格雷）。
分析时存活患者的中位随访时间为3.5年。单纯手术组与手术加TRT组在性别、年龄、组织学、肿瘤分级、切除或受累的纵隔淋巴结站数量以及受累的N1淋巴结数量方面均衡良好。单纯手术组中右下叶病变患者（与其他叶相比）、多叶受累患者以及仅一个N2淋巴结受累的患者略多。单纯手术治疗后，4年精算局部复发率为60%，辅助TRT治疗为17%（P<0.0001）。单纯手术治疗的4年精算生存率为22%，辅助TRT治疗为43%（P=0.005）。多因素分析显示，加用TRT（P=0.0001）、无纵隔上淋巴结受累（P=0.005）以及受累N1淋巴结较少（P=0.02）与生存率提高独立相关。
据作者所知，本研究是评估N2期非小细胞肺癌辅助TRT的最大规模研究，表明辅助TRT可能改善局部控制和生存率。
