Anatomic Lung Resection is Associated with a Better Prognosis Compared with Wedge Resection for Small Stage IA Adenocarcinoma with Predominantly Non-lepidic Histology

PS051 

Abstract Submission 

Peter Kneuertz (1), Mahmoud Abdel-Rasoul (2), Jane Zhao (3), Desmond D'Souza (3), Robert Merritt (3)

(1) Thoracic Surgery Division, The Ohio State University Wexner Medical Center, Columbus, Ohio, (2) Center for Biostatistics, The Ohio State University Wexner Medical Center, Columbus, OH, (3) Thoracic Surgery Division, The Ohio State University Wexner Medical Center, Columbus, OH

*Peter Kneuertz    -  Contact Me
Thoracic Surgery Division, The Ohio State University Wexner Medical Center

Mahmoud Abdel-Rasoul    -  Contact Me
Center for Biostatistics, The Ohio State University Wexner Medical Center

Jane Zhao    -  Contact Me
Thoracic Surgery Division, The Ohio State University Wexner Medical Center

Desmond D'Souza    -  Contact Me
Thoracic Surgery Division, The Ohio State University Wexner Medical Center

*Robert Merritt    -  Contact Me
Thoracic Surgery Division, The Ohio State University Wexner Medical Center

*Peter Kneuertz    -  Contact Me
The Ohio State University Wexner Medical Center

Objective: Sublobar resection is oncologically effective for small peripheral Ia non-small cell lung cancer (NSCLC), but the role of non-anatomic wedge resection for tumors with high-risk histologic features remains controversial. This study compares the long-term prognosis of patients with non-lepidic variants of adenocarcinoma treated with anatomic vs. non-anatomic lung resection for small (<2cm) pathologically node negative tumors.
Methods: The National Cancer Database (2004-2017) was queried for patients with invasive mucinous (MA), predominantly papillary (PA) and solid type (SA) lung adenocarcinoma who were staged pT1N0 after surgery and with tumor size <2 cm on surgical pathology. Overall survival was compared between non-anatomic (wedge) versus anatomic resection (segmentectomy/lobectomy) using inverse probability of treatment weight (IPTW) adjusted Kaplan-Meier and Cox regression analyses.
Results: A total of 2,766 patients (64.2% MA, 29.0% PA, 6.7% SA) were analyzed, accounting for 5.7% of all patients with invasive stage IA1-2 adenocarcinoma who underwent surgery in the study period. The comparison groups comprised of 2,138 (77.3%) patients who underwent anatomic lobectomy or segmentectomy and 628 (22.7%) patients treated with wedge resection. Demographics and clinical characteristics were well balanced after IPTW. The complete R0 resection rate was similarly high (anatomic 99.3% vs. wedge 98.2%; p=0.12), but anatomic resection was associated with a higher number of lymph nodes removed (>10 nodes, 38.1% vs. 13.1%; p<0.001). Ninety-day mortality was 1.9% in both groups. IPTW adjusted survival was significantly longer after anatomic resection for MA (5-year OS, 85.4% vs. 75.2%; p=0.010) and PA adenocarcinoma patients (5-year OS, 81.3% vs. 72.3%, p=0.018), but not for the SA type (Figure). On multivariable analysis, adjusting for IPTW, demographics, comorbidities, margin status and number of lymph nodes removed, anatomic resection remained independently associated with improved survival for patients with MA (HR 0.76 (95% CI:0.59-0.98; p=0.034) or PA (HR 0.62 (95% CI: 0.42-0.89; p=0.009).

Conclusions: Invasive mucinous and predominantly papillary adenocarcinoma represent a small portion of small stage I lung adenocarcinoma patients. Anatomic resection is associated with better lymph node harvest and improved long-term survival compared with wedge resection for these adenocarcinoma histologic types.

Lung Cancer