Impact of Nodule Density in Women With Sublobar Resection for Stage IA Adenocarcinoma

Background: This study sought to examine the impact of nodule density on recurrence and survival in female patients with lung adenocarcinoma treated by lobectomy or sublobar resection.

Methods: In this retrospective study of female patients who underwent surgical resection for pathologic stage IA adenocarcinoma, patients with preoperative imaging were included for analysis if the consolidation-to-tumor ratio was 0.5 (solid-predominant ground-glass opacity [GGO]) to 1.0 (solid). Kaplan-Meier curves were generated to estimate overall survival (OS) and disease-free survival (DFS). Risk estimates were calculated using multivariable Cox proportional hazards models.

Results: For all 357 patients sublobar resection demonstrated worse 5-year DFS compared with lobectomy (76.4% vs 67.9%, P = .05). Multivariable modeling showed worse DFS with sublobar resection (hazard ratio, 1.55; P = .06) and tumors ≥ 2 cm (hazard ratio, 2.32; P = .05). On radiologic evaluation the solid-predominant GGO group (n = 81) demonstrated a smaller solid component compared with the solid nodule group (n = 163; 1.49 cm vs. 1.84 cm, respectively; P < .001) yet comparable total size. The solid-predominant GGO group showed improved 5-year OS (90.8 vs 76.8, P = .01) and DFS (79.3 vs 67.2, P = .05) compared with the solid nodule group. Additionally the solid-predominant GGO group demonstrated equivalent OS (90.8% vs 90.8%, P = .93) and DFS (76.0% vs 81.7%, P = .60) with sublobar resection compared with lobectomy.

Conclusions: In this report of female patients with stage IA adenocarcinoma, sublobar resection was associated with worse DFS compared with lobectomy in whole-group analysis. However patients with solid-predominant GGOs demonstrated improved 5-year OS and DFS compared with patients with solid nodules with equivalent outcomes regardless of resection type.