Tumor size linked to efficacy of lobectomy, segmentectomy for NSCLC

Lobectomy prolonged survival compared with sublobar resection for patients with T1a NSCLC tumors that were 2 cm or smaller, according to the results of a SEER analysis.

Patients who cannot undergo lobectomy — those with tumors between 1 cm and 2 cm — should undergo segmentectomy. Patients with tumors 1 cm or smaller have the option of segmentectomy or wedge resection, depending on patient profile and the physician’s surgical skills.

Lobectomy is the recommended standard surgical procedure for stage I NSCLC ( 3 cm). “However, controversy still remains about the recommended procedure for NSCLC 2 cm [or smaller]; similar long-term survivals after lobectomy and sublobar resection have been reported in several retrospective studies for this subgroup,” Chenyang Dai, MD, surgeon at Shanghai Pulmonary Hospital and Tongji University School of Medicine in Shanghai, China, and colleagues wrote. “By far, patients with NSCLC 2 cm [or smaller] were usually considered one group in the published studies with regard to the surgical procedure.”

Research has shown significantly different 5-year survival rates among patients with tumors 1 cm or smaller compared with patients with tumors larger than 1 cm to 2 cm. Because of this difference, the International Association for the Study of Lung Cancer staging project has recommended T1a tumors be additionally classified based on these tumor size groupings.

Dai and colleagues evaluated outcomes for patients with T1a NSCLC after lobectomy, segmentectomy or wedge resection, with a particular focus on patients with NSCLC 1 cm or smaller and larger than 1 cm to 2 cm.

Researchers used the SEER database to identify 11,520 patients (mean age, 65.5 years; 40% men) who underwent lobectomy and 4,240 patients (mean age, 68.3 years; 39% men) who underwent sublobectomy. Of the patients who underwent sublobectomy, 3,316 underwent wedge resection and 769 underwent segmentectomy; the other 155 patients in this group did not have data on the specific surgical procedure.

OS and lung cancer-specific survival (LCSS) served as the study’s primary endpoints.

Median follow-up was 52 months for the lobectomy group and 43 months for the sublobectomy group.

Among all patients, lobectomy prolonged OS (HR = 1.71; 95% CI, 1.59-1.83) and LCSS (HR = 1.66; 95% CI, 1.51-1.83) compared with sublobectomy.

Researchers then evaluated outcomes based on tumor size.

Eighty-six percent (n = 9,891) of the lobectomy group and 76% (n = 3,218) of the sublobectomy group had tumors larger than 1 cm to 2 cm. Of those who underwent sublobectomy, most underwent wedge resection (n = 2,495).

Lobectomy improved survival for patients with tumors larger than 1 cm to 2 cm compared with segmentectomy (OS, HR = 1.39; 95% CI, 1.17-1.65; LCSS, HR = 1.31; 95% CI, 1.04-1.65) and wedge resection (OS, HR = 2; 95% CI, 1.84-2.19; LCSS, HR = 1.98; 95% CI, 1.74-2.2). Segmentectomy demonstrated a benefit over wedge resection (OS, HR = 1.31; 95% CI, 1.13-1.51; LCSS, HR = 1.35; 95% CI, 1.11-1.64).

For patients with tumors 1 cm or smaller, the survival benefit of lobectomy persisted compared with segmentectomy (OS, HR = 1.48; 95% CI, 1.03-2.13; LCSS, HR = 1.81; 95% CI, 1.1-2.98) and wedge resection (OS, HR = 1.56; 955 CDI, 1.3-1.87; LCSS, HR = 1.48; 95% CI, 1.15-1.91). However, there was no difference in outcome between segmentectomy and wedge resection.

Results of multivariate analyses showed segmentectomy was independently associated with poorer survival compared with lobectomy for tumors larger than 1 cm to 2 cm (OS, P = .008; LCSS, P = .032) and 1 cm or smaller (OS, P = .041; LCSS, P = .02).

Wedge resection also was independently associated with poorer survival compared with lobectomy for all patients (> 1 cm to 2 cm: OS, P < .001; LCSS, P < .001; 1 cm: OS, P < .001; LCSS, P = .003) and compared with segmentectomy for patients with tumors larger than 1 cm to 2 cm (OS, P < .001; LCSS, P = .002), but not those with smaller tumors.

Researchers acknowledged that the retrospective nature of the study and the lack of data on ground-glass opacity–dominant adenocarcinoma may have limited these findings.

“In clinical practice, a considerable number of patients with NSCLC cannot tolerate a lobectomy because of compromised pulmonary reserve or advanced age; thus, sublobar resection with better preservation of pulmonary function, reduced morbidity and shorter operation time is a reasonable alternative for them,” Dai and colleagues wrote. “We hold the opinion that segmentectomy should be the procedure recommended for patients with NSCLC larger than 1 cm to 2 cm who are considered for sublobar resection. For those with NSCLC 1 cm [or smaller], the surgeon could rely on personal experience of surgical technique and assessment of the patient profile to determine the choice of segmentectomy or wedge resection.” – by Nick Andrews

Disclosure: Dai reports no relevant financial disclosures. Other researchers report honoraria, travel accommodations and research funding from, as well as speakers bureau and consultant/advisory roles with, BARD, Baxter, Covidien, Ethicon, Johnson and Johnson, Medela and Medtronic.