Survival of patients with non-small cell lung cancer according to lymph node disease: single pN1 vs multiple pN1 vs single unsuspected pN2.

PURPOSE

This study was designed to describe the characteristics and survival of NSCLC patients treated with surgery and single pN1 disease, multiple pN1, and single unsuspected pN2.

METHODS

In 2005-2009, we treated 378 lung cancer patients with surgery with radical intent; 152 cases were pN1 or pN2. We excluded patients with neoadjuvant treatment, incomplete resection, incomplete lymph node dissection, metastasis, cN2 disease, multiple pN2, SCLC, and lack of PET-CT. All patients were staged with TNM 2010. We included 72 patients: 21 single pN1, 26 multiple pN1, and 25 single unsuspected pN2. Statistical analysis included descriptive statistics, chi-square test, Kaplan-Meier, log-rank test, and Cox proportional hazard model.

RESULTS

The sample included 62 men (86 %) and 10 women (14 %), mean age 64 ± 9 years. The three subgroups did not show statistically significant differences in the main characteristics. Adjuvant treatment was performed in 56 patients (78 %). The 5 year overall survival (OS) for single pN1 was 73 %; for multiple pN1, 34 %; and for single unsuspected pN2, 25 % (P = 0.15). The mean OS for single pN1 was 63 ± 6 months; median OS for multiple pN1 was 45 (range, 42-48) months and for single pN2 was 54 (range, 32-77) months. Multivariate analysis found the following negative prognostic factors of OS: for single pN1, age, female sex, and microscopic intratumoral lymphatic and vascular invasion; for multiple pN1, ≤10 lymph nodes resected.

CONCLUSIONS

Patients with single pN1 had better OS than patients with multiple pN1. Patients with single unsuspected pN2 had OS similar to that of multiple pN1.