Improvement of pulmonary function after lobectomy for non-small cell lung cancer in emphysematous patients

Pulmonary emphysema is frequently associated with lung cancer and, because of the impaired pulmonary function involved, it may contraindicate surgical treatment. However, improvement of pulmonary function has been observed after surgical resection in patients with advanced emphysema. The aim of this study was to evaluate whether pulmonary emphysema, as assessed by pulmonary function tests and radiological evaluation, can influence postoperative respiratory function after lobectomy for non-small cell lung cancer (NSCLC).

Respiratory function was evaluated before and after lobectomy for NSCLC. Radiological evaluation of emphysema was performed on chest X-ray and CT scan. Patients that had undergone chemo- or radiotherapy or had segmental or lobar atelectasis were excluded from the study.

Thirty-five patients entered the study. A decrease in static lung volumes was observed after surgery. Total lung capacity (TLC) decreased from 6.58+/-0.92 to 5.46+/-0.77 l; functional residual capacity (FRC) from 3.70+/-0.88 to 2.96+/-0.73 1 and residual volume (RV) from 2.93+/-0.78 to 2.2+/-0.53 l. However, in a subgroup of 10 patients (Group 1), dynamic volumes after surgery were unchanged or slightly increased (forced vital capacity (FVC) from 3.23+/-0.65 to 3.3+/-0.68 l; forced expiratory volume in 1 s (FEV1) from 2.14+/-0.51 to 2.25+/-0.54 l), and airway resistances (sRaw) decreased from 15.58+/-5.18 to 11.42+/-5.25 cm H2O/s. Preoperative data showed that these patients had a greater obstruction, with FEV1 changing from 69+/-12.42 to 72.70+/-13.72% of predicted, as compared with a change from 87+/-12.7 to 72.08+/-13.10% in the other group of 25 patients (Group 2). Correlation analysis reached statistical significance between FEV1% variation (deltaFEV1%) and preoperative FEV1 and FVC% (r = -0.49, P = 0.002 and r = -0.5, P = 0.001, respectively) and between delta (FEV1)% and radiological scores for 3-level CT (r = 0.39, P = 0.04) and the sum of chest X-ray, single and 3-level CT scores (r = 0.49, P = 0.01).

Pulmonary function may remain unchanged or even increase after lobectomy in patients with a pronounced emphysematous component of airway obstruction. The identification of preoperative parameters that identify this group of patients could extend the indications for the treatment of lung cancer in patients with pulmonary emphysema.