Prognostic significance of persistent mediastinal metastasis following induction therapy in large (> or = 2cm) N2 or N3 non-small cell lung cancer

Objective: It is controversial whether or not surgery is beneficial for patients with non-small cell lung cancer accompanied by persistent lymph node metastasis in the mediastinum following induction therapy. We have therefore conducted a retrospective study to assess this issue Methods: Eligibility criteria were defined as follows: 1) the period of treatment was between January 1991 and April 1998, 2) the clinical stages were IIIA (N2) or IIIB (N3) with large lymph nodes (> or = 2 cm), 3) induction therapy had been administered, 4) tumor was resected completely, 5) at least one mediastinal lymph node had necrosis or scar if the pathological N status was p-N0 or p-N1 and 6) the p-stage was not IV. Dichotomous variables included the radiographic response of the tumor, the T status, and the N status. Results: Thirty-nine patients were eligible. There were 29 males and 10 females aged from 27 to 74 years, and involved 20 cases of adenocarcinoma. The pathological N status was as follows: p-N0 in 18 patients, p-N1 in 3, p-N2 in 16, and p-N3 in the other 2. In overall survival, the median survival time (MST) was 34 months and the actuarial 5-year-survival rate (5-YSR) was 28%. The group of patients with either N0 or N1 (n-21) had a 71-month MST and a 54% 5-YSR, and the group of patients with either N2 or N3 (n=18) had a 13-month MST and a 5-YSR of 0% (p<0.0001). On multivariate analysis, the pathological N factor was confirmed as an independently significant. Conclusions: Our retrospective study found that the survival rate of patients with persistent mediastinal nodal metastasis was very poor. A prospective study is needed to investigate whether or not surgery is beneficial for these patients.