Comparison of sublobar resection and lobectomy for patients with small (≤2cm) second primary non-small-cell lung cancer.

Background This study aimed to investigate whether sublobar resection (SR) is equivalent to lobectomy for small (<= 2 cm) second primary lung cancer (SPLC). Methods We identified 834 patients with T1aN0M0 SPLC from the Surveillance, Epidemiology, and End Results (SEER) database during 2000-2016. Overall survival (OS) was compared between lobectomy and SR after propensity-score matching. A total of 228 patients with SPLC were identified from three institutions in China as the validation set. Results SR was an independent risk factor for patients with 1 to 2 cm SPLC (SR vs Lob: hazard ratio [HR], 1.593; 95% confidence interval [CI], 1.186-2.141; P = .002) but not for patients with SPLC <= 1 cm (SR vs Lob: HR, 1.206; 95% CI, 0.790-1.841; P = .385). Subgroup analysis on the SEER data indicated that OS favored lobectomy compared with SR for contralateral SPLC <= 2 cm but not for ipsilateral ones (ipsilateral: P = .692; contralateral: P = .030). Our multi-institutional data also revealed that SR was equivalent to lobectomy for patients with <= 2 cm ipsilateral SPLC. Conclusions SR is equivalent to lobectomy for SPLC <= 1 cm but not for SPLC > 1 to 2 cm. SR might be recommended for patients with ipsilateral small SPLC considering the difficulty in reoperations.