Increased minute ventilation-to-carbon dioxide slope during cardiopulmonary exercise test is associated with poor postoperative outcome following lung cancer resection.

OBJECTIVES: Ventilatory efficiency [minute ventilation-to-carbon dioxide output slope (VE/VCO2 slope)] can be measured at sub-maximal workload during cardiopulmonary exercise test. The aim of this study is to assess the association between VE/VCO2 slope and outcome after lung cancer resections. METHODS: Retrospective, single-centre analysis on all patients undergoing lung resection for cancer (April 2014-August 2022) and with a preoperative cardiopulmonary exercise test. VE/VCO2 slope >40 was chosen as high-risk threshold. Logistic regression analysis was used to test the association of VE/VCO2 slope and several patient- and surgery-related factors with 90-day mortality. RESULTS: A total of 552 patients were included (374 lobectomies, 81 segmentectomies, 55 pneumonectomies and 42 wedge resections). Seventy-four percent were minimally invasive procedures. Cardiopulmonary morbidity was 32%, in-hospital/30-day mortality 6.9% and 90-day mortality 8.9%. A total of 137 patients (25%) had a slope of >40. These patients were older (72 vs 70 years, P = 0.012), had more frequently coronary artery disease (17% vs 10%, P = 0.028), lower carbon monoxide lung diffusion capacity (57% vs 68%, P < 0.001), lower body mass index (25.4 vs 27.0 kg/m2, P = 0.001) and lower peak VO2 (14.9 vs 17.0 ml/kg/min, P < 0.001) than those with a lower slope. The cardiopulmonary morbidity among patients with a slope of >40 was 40% vs 29% in those with lower slope (P = 0.019). Ninety-day mortality was 15% vs 6.7% (P = 0.002). The 90-day mortality of elderly patients with slope >40 was 21% vs 7.8% (P = 0.001). After adjusting for peak VO2 value, extent of operation and other patient-related variables in a logistic regression analysis, VE/VCO2 slope retained a significant association with 90-day mortality. CONCLUSIONS: VE/VCO2 slope was strongly associated with morbidity and mortality following lung resection and should be included in the functional algorithm to assess fitness for surgery.

Minimally invasive segmentectomy and lobectomy for peripheral stage IA1-2 non-small-cell lung cancer: a case-matched cohort study from a UK Centre.

OBJECTIVES: The objective of this study is to compare in a real-world series the short- and long-term results of segmentectomy and lobectomy for peripheral clinical stage IA non-small-cell lung cancer (NSCLC). METHODS: Single-centre cohort study including a series of consecutive patients undergoing minimally invasive segmentectomy or lobectomy for peripheral (outer third of the lung) clinical stage IA NSCLC (January 2017-August 2022). Propensity score case matching analysis generated 2 matched groups of patients undergoing segmentectomy or lobectomy. Short-term (morbidity and mortality) and long-term [overall survival and event-free survival (EFS)] outcomes were compared between the 2 matched groups. EFS was calculated by including death resulting from any cause and any recurrence as events. RESULTS: Propensity score generated 118 pairs of patients undergoing minimally invasive segmentectomy or lobectomy. The median follow-up was 30 months (95% confidence limits (CL) 4-64). The median postoperative length of stay was 4 days in both groups. Ninety-day mortality was similar (segmentectomy 2.5% versus lobectomy 1.7%, P = 1). Three-year overall survival [segmentectomy 87% (76-93) versus lobectomy 81% (72-88), P = 0.73] and EFS [segmentectomy 82% (72-90) versus lobectomy 78% (68-84), P = 0.52] did not differ between the groups. Loco-regional recurrence rate [segmentectomy 4.2% (5/118) versus lobectomy 9.3% (11/118), P = 0.19] was similar despite a lower nodal upstaging [segmentectomy 3.4% (4/118) versus lobectomy 14% (17/118), P = 0.005]. The occurrence of compromised resection margins (pR1 or pR uncertain) was similar between the groups [segmentectomy 7.6% (9/118) versus lobectomy 9.3% (11/118), P = 0.81]. CONCLUSIONS: This observational series confirms the non-inferiority of segmentectomy compared to lobectomy in treating peripherally located stage IA NSCLC.