Long-term outcomes of surgical resection for stage IV non-small-cell lung cancer: A national analysis.

OBJECTIVE: Treatment guidelines recommend surgical resection in select cases of stage IV non-small-cell lung cancer (NSCLC) but are based on limited evidence. This study evaluated outcomes associated with surgery in stage IV disease.

METHODS: Factors associated with survival of stage IV NSCLC patients treated with surgery in the National Cancer Date Base (2004-2013) were evaluated using multivariable Cox proportional hazards analyses. Outcomes of the subset of patients with cT1-2, N0-1, M1 and cT3, N0, M1 disease treated with surgery or chemoradiation were evaluated using Kaplan-Meier analyses.

RESULTS: The five-year survival of all stage IV NSCLC patients who underwent surgical resection (n=3098) was 21.1%. Outcomes were related to the locoregional extent of the primary tumor, as both increasing T status (T2 HR 1.30 [p<0.001], T3 HR 1.28 [p<0.001], and T4 HR 1.28 [p<0.001], respectively, compared to T1) and nodal involvement (N1 HR 1.34 [p<0.001], N2 HR 1.50 [p<0.001], and N3 HR 1.49 [p<0.001], respectively, compared to N0) were associated with worse survival. Outcomes were also related to the extent of surgical resection, as pneumonectomy (HR 1.58, p<0.001), segmentectomy (HR 1.36, p=0.009), and wedge resection (HR 1.70, p<0.001) were all associated with decreased survival when compared to lobectomy. The five-year survival of cT1-2, N0-1, M1 and cT3, N0, M1 patients was 25.1% (95% CI: 22.8-27.5) after surgical resection (n=1761) and 5.8% (95% CI: 5.2-6.5) after chemoradiation (n=8180).

CONCLUSIONS: Surgery for cT1-2, N0-1, M1 or cT3, N0, M1 disease is associated with a 5-year survival of 25% and does not appear to compromise outcomes when compared to non-operative therapy, supporting guidelines that recommend surgery for very select patients with stage IV disease. However, surgery provides less benefit and should be considered much less often for stage IV patients with mediastinal nodal disease or more locally advanced tumors.