Survival and treatment of non-small cell lung cancer stage I-II treated surgically or with stereotactic body radiotherapy: patient and tumor-specific factors affect the prognosis.

BACKGROUND: This study was designed to define clinical baseline parameters associated with impaired survival of patients with stage I or II non-small cell lung cancer (NSCLC) who underwent surgery or stereotactic body radiotherapy (SBRT). METHODS: From January 2001 to January 2011, 425 patients (216 surgery, 209 SBRT) were identified with clinical stage I or II NSCLC. Cox proportional-hazards regression analyses were used to investigate risk factors for mortality. RESULTS: Median age of patients in the surgery and SBRT groups was 65 and 74 years, respectively. A smaller proportion of the surgical group had Charlson Comorbidity Index (CCI) score ≥1 compared with the SBRT group: 52 and 72 % (p < 0.001), respectively. Overall survival in the surgical group at 2 and 4 years was 79 and 65 %, respectively. In the SBRT group, this was 65 % at 2 years and 44 % at 4 years. In the surgical group older age, CCI score = 4 and clinical stage = IIB were associated with long-term mortality. In the SBRT group, this was CCI score ≥5 and clinical stage >IA. The area under the curve was calculated for the model with clinical and tumor factors: 0.77 for the surgery and 0.85 for the SBRT group. CONCLUSIONS: Both patient characteristics and survival of NSCLC I-II patients undergoing surgical treatment or SBRT differ considerably. Long-term survival as a result of treatment strategy of NSCLC patients might be optimized by focusing on patient and tumor specific factors. In addition to TNM staging, the consideration of patient age and CCI can be useful for prognostication of NSCLC patients.