Clinical Factors Affecting Discrepancy Between Predicted and Long-term Actual Lung Function Following Surgery

Purpose Lung cancer surgery outcomes depend heavily on preoperative pulmonary reserve, with forced expiratory volume in 1 second (FEV1) being a critical preoperative evaluation factor. Our study investigates the discrepancies between predicted and long-term actual postoperative lung function, focusing on clinical factors affecting these outcomes. Methods This retrospective observational study encompassed lung cancer patients who underwent preoperative lung perfusion SPECT/CT between 2015 and 2021. We evaluated preoperative and postoperative pulmonary function tests, considering factors such as surgery type, resected volume, and patient history including tuberculosis. Predicted postoperative lung function was calculated using SPECT/CT imaging. Results From 216 patients (men:women, 150:66; age, 67.9 ± 8.7 years), predicted postoperative FEV1% (ppoFEV1%) showed significant correlation with actual postoperative FEV1% ( r = 0.667; P < 0.001). Paired t test revealed that ppoFEV1% was significantly lower compared with actual postoperative FEV1% ( P < 0.001). The study identified video-assisted thoracic surgery (VATS) (odds ratio OR, 3.90; 95% confidence interval CI, 1.98–7.69; P < 0.001) and higher percentage of resected volume (OR per 1% increase, 1.05; 95% CI, 1.01–1.09; P = 0.014) as significant predictors of postsurgical lung function improvement. Conversely, for the decline in lung function postsurgery, significant predictors included lower percentage of resected lung volume (OR per 1% increase, 0.92; 95% CI, 0.86–0.98; P = 0.011), higher preoperative FEV1% (OR, 1.03; 95% CI, 1.01–1.07; P = 0.009), and the presence of tuberculosis (OR, 5.19; 95% CI, 1.48–18.15; P = 0.010). Additionally, in a subgroup of patients with borderline lung function, VATS was related with improvement. Conclusions Our findings demonstrate that in more than half of the patients, actual postsurgical lung function exceeded predicted values, particularly following VATS and with higher volume of lung resection. It also identifies lower resected lung volume, higher preoperative FEV1%, and tuberculosis as factors associated with a postsurgical decline in lung function. The study underscores the need for precise preoperative lung function assessment and tailored postoperative management, with particular attention to patients with relevant clinical factors. Future research should focus on validation of clinical factors and exploring tailored approaches to lung cancer surgery and recovery.