作者：广东省肺癌研究所 杨学宁 & LAMP

单站N2非小细胞肺癌术前治疗是否有效？

315. How Effective Is Induction Therapy with Surgery for Single Station Histologic N2 NSCLC?

Hari B. Keshava, Kay S. Tan, Joseph Dycoco, *James Huang, *Valerie W. Rusch, *Daniela Molena, *Prasad S Adusumilli, Smita Sihag, *Bernard J. Park, *David R. Jones, *Gaetano Rocco
Memorial Sloan Kettering Cancer Center, New York, NY

Invited Discussant: *Enrino A. Rendina

Objective: The 8th edition TNM classification has introduced the prognostic stratification of N+ subsets.Pathologic single station N2 (pSSN2) can be found incidentally after surgery in cN0 patients (occult pSSN2) treated with surgery-first (SF), or after histological confirmation of cSSN2, with induction therapy followed by surgery (IS). The purpose of this study is to examine the effectiveness of IS compared to SF for pSSN2 by measuring differences in long-term (5 and 10 years) disease-free survival (DFS) and overall survival (OS).
Methods: A retrospective review of prospectively collected data was performed identifying patients with pSSN2 NSCLC who had undergone pulmonary resection for lung cancer between 2000 and 2017. The SF group included patients with occult pN2 disease who were treated with surgery prior to any adjuvant chemotherapy, while the IS group had known pre-operative N2 disease treated with induction therapy prior to surgery. Differences were assessed using Wilcoxon rank-sum or Fisher’s exact tests. A matching-weights procedure was used to create a pseudopopulation in which patients had similar characteristics without excluding patients. A logistic model was used to derive the odds of receiving surgery-first using demographic, clinicopathologic, and surgical variables. DFS and OS were calculated using Kaplan-Meier approach for the unmatched and matched-weighted populations.
  Results: We identified 325 patients with pSSN2; 151 patients were treated by SF whereas 174 were treated by IS. Average age was similar in both groups with 67 years (25th - 75th percentile: 58-72) in the SF group and 66 (58-73) years in the IS. Prior to matching-weights, the IS group had larger tumors on pre-treatment CT scans (3.3 cm [2.1.-5.1] versus 2.3 cm [1.4-3.2], p<0.0001) which were more metabolically active on pre-treatment PET scans (SUVmax 10.3 [5.8 - 14.5] versus 6.3 [3.2 - 11.1]). Surgical extent was similar in both Groups (sublobar at 27% vs 20%, lobar or bilobar at 70% vs 77%, and pneumonectomy at 3% for both groups; p=0.3). Both groups had a similar percentage of patients with adenocarcinoma (74% and 72%) and squamous cell carcinoma (13% and 17%). Unmatched DFS was significantly different between the SF and IS Cohorts, however after matching-weights, DFS at 5 and 10 years were 39% and 26% in the SF group versus 33% and 17% in the IS group (p=0.263). This relationship held true for OS, as unmatched OS was different, while after matching, OS at 5 and 10 years were 49% and 27% in the SF group versus 44% and 18% in the IS group (p=0.278). (Figure 1).
  Conclusions: Our data confirms the prognostic stratification of N2 disease recommended in 8th edition classification. Induction therapy and surgery for pSSN2 has been effective in producing DFS and OS similar to occult pSSN2, usually treated with primary surgery followed by adjuvant treatment. Given this, a clinical trial may be indicated to compare IS to SF for pSSN2.