Predicting the response to a bronchodilator in patients with airflow obstruction and lung cancer

Efficacy of preoperative inhaled LAMA/LABA combinations in patients with lung cancer and untreated COPD

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is associated with a high incidence of postoperative pulmonary complications (PPCs). When untreated COPD is found before lung cancer surgery, we have been actively intervening therapeutically with inhaled long-acting muscarinic antagonist (LAMA)/long-acting β2-agonist (LABA) combinations. We investigated the efficacy of preoperative LAMA/LABA treatment.

METHODS

We reviewed data from 261 patients who underwent pulmonary resection for primary lung cancer. Of these, 59 patients showed unrecognized obstructive ventilatory impairment on respiratory function testing. We administered inhaled drugs for 38 patients, of whom 22 patients treated with LAMA/LABA combinations and diagnosed with COPD were retrospectively analyzed regarding improvement of respiratory function and postoperative course.

RESULTS

Median duration of LAMA/LABA treatment was 19.5 days (interquartile range (IQR), 10.5-28.3 days). Percentage predicted vital capacity (%VC) (pretreatment: 95.6%, IQR 91.9-111.7 vs posttreatment 102.8%, IQR 92.3-113.0), forced expiratory volume in 1 s (FEV1) (1.76 L, 1.43-2.12 vs 2.00 L, 1.78-2.40), forced VC (FVC) (2.96 L, 2.64-3.47 vs 3.22 L, 2.95-3.74) and percentage predicted FEV1 (80.1%, 68.4-97.0 vs 91.6%, 80.3-101.9) were all significantly improved (p < 0.05 each). FEV1/FVC tended to be improved, but not significantly. No significant difference in improvement of respiratory function was seen between short-term (≤2 weeks) and normal-term (>2 weeks) treatment. PPCs occurred in 4 of 22 patients (18.2%), showing no significant difference compared to patients with COPD previously treated with inhaled drugs (2/20; 10.0%).

CONCLUSIONS

Respiratory function is improved by preoperative LAMA/LABA treatment even in the short term. Starting treatment allows even COPD patients diagnosed on preoperative screening to experience the same frequency of PPCs as previously treated patients.

Preoperative risk assessment with computed tomography in patients undergoing lung cancer surgery

Background

Although whole lung computed tomography (CT) is included in the routine workup before lung cancer surgery, it is not utilized to assess the preoperative pulmonary function.

Methods

Two hundred ninety patients (development cohort) who underwent lung lobectomy for cancer in our institute and another 100 patients (validation cohort) who subsequently underwent the same operation in a referral hospital were included. The total lung volume (TLV) and emphysematous lung volume (ELV) were obtained by quantitative CT.

Results

The TLV was higher in patients with a smoking history than in those without. The ELV to the TLV was higher in elderly patients than in younger patients. The regression equation for forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV₁) were developed using CT-derived variables, together with sex, age, height, and smoking habit, by a multiple regression analysis in the development cohort. The regression equation-based FVC and FEV₁ were significantly correlated with the actual FVC and FEV₁ in the development cohort, as well as in the validation cohort. The predicted postoperative FEV₁ (ppo%FEV₁) calculated based on the regression equation was also correlated with the postoperative FEV₁ value obtained by the conventional method (R=0.53), and the regression equation-based ppo%FEV₁ was a significant predictor of postoperative cardiopulmonary complications (P=0.02).

Conclusions

Whole lung CT can be used to assess the preoperative pulmonary function in patients undergoing lobectomy for cancer. This method may be helpful in preoperative risk assessment, particularly in patients who have difficulty in implementation of spirometry.