Treatment of clinical T4 stage superior sulcus non-small cell lung cancer: a propensity-matched analysis of the surveillance, epidemiology, and end results database

Purpose/Objective(s): Treatments for superior sulcus non-small cell lung cancer (SS-NSCLC) have evolved, but adequate treatments of T4 disease have not been found. The aim of our study was to evaluate the prognostic factors and optimal treatment strategy for patients with T4 SS-NSCLC. Materials/Methods: We utilized the Surveillance, Epidemiology, and End Results (SEER) database (1973–2015) to identify patients diagnosed with T4 stage SS-NSCLC (according to the 7th edition American Joint Committee on Cancer (AJCC) staging system) from 2004 to 2015; those with M1 disease were excluded. Propensity score matching (PSM) with Kaplan–Meier and Cox proportional hazards’ models was performed to estimate prognosis. Results: A total of 384 patients were included. The majority was male (59.4%) at stage IIIB (56.6%), with N2 accounting for 45.3%. A total of 47 patients underwent cancer-directed surgery, while radiotherapy alone was received by 60.2% of patients. Median overall survival (OS) and lung cancer-specific survival (LCSS) were 12 and 17 months, respectively, and the 5-year OS and LCSS rates were 15.8 and 25.4%, respectively. In the matched population, the median survival outcomes were better following surgery (OS: 25 compared with 9.0 months, P<0.001; LCSS: not available (NA) compared with 11.0 months, P<0.001). Multivariate Cox analysis showed that ages ≥ 66 years (hazard ratio (HR) = 1.639, P=0.001), unmarried status (HR = 1.356, P=0.034), and tumor size ≥ 6.0 cm (HR = 1.694, P<0.001) were associated with inferior OS. Cancer-directed surgery (HR = 0.537, P=0.009) and radiotherapy (HR = 0.644, P=0.006) were independent prognostic factors for patients with T4 SS-NSCLC. Conversely, in the subgroup analysis, favorable impacts of radiotherapy were observed for nonsurgical patients (OS: HR = 0.58, P<0.001; LCSS: HR = 0.55, P<0.001). Conclusion: Our study showed that T4 stage SS-NSCLC patients had a poor prognosis. Surgical resection remains the best option for those with resectable disease. For nonsurgical T4 SS-NSCLC patients, radiotherapy should be actively considered.