Clinical profiles and intraoperative identification of complex glands in stage I lung adenocarcinoma

This study aimed to investigate the potential of complex glandular patterns (CGP) in lymph node micrometastasis (LNMM) and to determine the clinical beneficiaries in stage I lung adenocarcinoma (LUAD) with CGP. Meanwhile, the feasibility of detecting CGP on frozen section was also evaluated.

We retrospectively analysed the clinicopathological characteristics of 848 pathologic-stage I LUADs. A logistic regression model and a Cox proportional-hazards model were conducted to define the risk factors for LNMM and survival respectively. Furthermore, 5 pathologists reviewed frozen sections of 100 LUADs independently.

The logistic regression model indicated that CGP [odds ratio 3.89, 95% confidence interval (CI) 2.46-6.15; P < 0.001] was an independent predictor of the presence of LNMM. Subgroup analysis revealed that CGP-present/LNMM-positive LUAD had the highest risk of both loco-regional and distant recurrence. Moreover, adequate lymphadenectomy [recurrence-free survival: hazard ratio (HR) 0.61, 95% CI 0.40-0.95; P = 0.028; overall survival: HR 0.64, 95% CI 0.41-0.99; P = 0.043] and adjuvant chemotherapy (recurrence-free survival: HR 0.30, 95% CI 0.18-0.52; P < 0.001; overall survival: HR 0.33, 95% CI 0.19-0.57; P < 0.001) brought survival benefits to CGP-present patients, especially to CGP-present/LNMM-positive subgroup. Across the 5 pathologists, sensitivity ranged from 59 to 68% and specificity ranged from 79 to 83%, with moderate diagnostic agreement and high interobserver agreement for detecting CGP on frozen section.

LNMM was more frequently observed in stage I LUAD with CGP. Adequate lymphadenectomy and adjuvant chemotherapy were associated with improved survival in CGP-present patients, especially in CGP-present/LNMM-positive subgroup. Additionally, it is feasible to identify CGP on frozen section intraoperatively.