Prognostic factors of oligometastatic non-small-cell lung cancer following radical therapy: A multicentre analysis

Abstract

Objectives: Patients with oligometastatic non-small-cell lung cancer (NSCLC) may benefit from therapy with curative intent. Our goal was to identify prognostic factors related to better prognosis in a multicentre analysis of patients who underwent surgery of primary tumours in combination with radical treatment of all metastatic sites. Methods: We retrospectively reviewed the records of oligometastatic patients who underwent resection of primary tumours at 4 centres (August 2001-February 2018). Oligometastasis was defined as ≤5 synchronous metastases in ≤2 organs. Radical metastatic treatment was surgery, radiotherapy or a combination. The Cox proportional hazards model was used for identification of prognostic factors on overall survival. Results: We treated 124 patients; 72 (58%) were men, mean age 60 ± 9.8 years, with 87 (70%) adenocarcinoma. Sixty-seven (54%) patients had positive pathologic-N stage (pN). Brain metastases were most common (n = 76; 61%) followed by adrenal (n = 13; 10%) and bone (n = 12; 10%). Systemic therapy was administered in 101 (82%) patients. Median follow-up was 60 months [95% confidence interval (CI) 41-86]. Thirty- and 90-day mortality rates were 0 and 2.4%, respectively. One-, 2-, and 5-year overall survival were 80%, 58% and 36%, respectively. Cox regression analysis showed that patients ≤60 years [hazard ratio (HR) 0.41, 95% CI 0.24, 0.69; P = 0.001] and patients with pN0 (HR 0.38, 95% CI 0.21-0.69; P = 0.002) had a significant survival benefit. The presence of bone metastases negatively affected survival (HR 2.53, 95% CI 1.05-6.09; P = 0.04). Conclusions: Treatment with curative intent of selected oligometastatic NSCLC, including resection of the primary tumour, can be performed safely and with excellent 5-year survival rates, especially in younger patients with pN0 disease.