P3-220: Pulmonary function tests as a predictor of quantitative and qualitative outcomes after thoracic surgery for lung cancer

Abstract

Pulmonary function tests (PFT) are used to select non-small cell lung cancer (NSCLC) patients suitable for thoracic surgery. The present study aimed to explore the impact of PFT on both quantitative (morbidity, mortality, overall survival) and qualitative (quality of life-QOL) out-comes of patients undergoing thoracic surgery for NSCLC. Patients with proven or highly probable NSCLC referred for thoracic surgery were eligible. Postoperative outcomes as morbidity, 90-day mortality, QOL based on the Psychological Global Well Being Index (PGWBI) and on the European Organization for Research and Treatment of Cancer quality of life Questionnaire (EORTC QLQ-C30), and overall survival were studied according to the results of the preoperative PFT (forced expiratory volume in one second, FEV1; vital capacity, VC; residual volume, RV; total lung capacity, TLC; airways resistance, RAW; diffusing capacity corrected for alveolar volume, DLCO/VA). A total of 110 patients were studied with 94 patients eligible for analysis. Postoperative mortality and morbidity affected 9.5 and 40% of patients, respectively. These patients presented with significantly lower preoperative values of VC, TLC and DLCO/VA and higher preoperative values of RAW when compared with patients with an uncomplicated postoperative course (Table I). A better survival was correlated with higher preoperative values of FEV1, VC and TLC and a lower pulmonary distension, especially when ex-pressed as a percentage of predicted value (Table II). None of the postoperative QOL scores was influ-enced by preoperative PFT results.Table IComparison of pulmonary functional parameters according to postoperative course (n=94)Uncomplicated postoperative courseComplicated postoperative courseDifference (95% CI)p-valueFEV1 (L)2.6 ± 0.82.4 ± 0.80.2 (−0.7 – 0.6)0.12FEV1 (% pred)91 ± 2183 ± 238 (−1.7 – 17.3)0.11VC (L)3.9 ± 0.93.4 ± 1.10.5 (0.1 – 0.9)0.02VC (% pred)101.3 ± 17.989.6 ± 19.311.7 (3.7 – 19.8)<0.01TLC (L)6.8 ± 1.16.2 +/- 1.50.6 (−0.1 – 1.3)0.09TLC (% pred)106.5 ± 14.796.5 ± 1810 (1.3 – 18.6)0.02RV/TLC (%)39.1 ± 9.643.3 +/- 9.7−4.2 (−9 – 0.5)0.08RV/TLC (% pred)108.7 ± 25.5113.8 ± 26.6−5.1 (−18.8 – 8.6)0.46RAW (cmH20/L/s)1.8 ± 0.62.5 ± 1.3−0.7 (−1.3 −0.1)0.02RAW (% pred)69.2 ± 35.691 ± 47.1−21.8 (−45.9 – 2.3)0.05DLCO/VA (mL/min/mmHg/L)3.6 ± 0.73 ± 0.90.6 (−0.1 – 1.1)0.02DLCO/VA (%pred)75.2 ± 15.865.2 ± 17.610 (1.5 – 18.5)0.05Abbreviations:CI, confidence interval; FEV1, forced expiratory volume in one second;% pred, percentage of the predictive value; VC, vital capacity;TLC, total lung capacity;RV, residual volume; RAW, airways resistance;DLCO/VA, diffusing capacity corrected for alveolar volume.*Results presented as mean ± SD (range) Open table in a new tab Table IIComparison of pulmonary functional parameters according to overall survival (n=94)Live patientsDead patientsDifference (95% CI)p-valueFEV1 (L)2.6 ± 0.82.2 ± 0.70.4 (−0.5 – 0.9)0.08FEV1 (% pred)89.4 ± 2276.2 ± 16.713.2 (−0.7 – 26.6)0.05VC (L)3.7 ± 13.1 ± 0.80.6 (0.1 – 1.2)0.06VC (% pred)97.7 ± 19.984.1 ± 9.413.6 (2 – 25.3)0.02TLC (L)6.6 ± 1.35.4 ± 1.41.2 (−0.4 – 2.1)<0.01TLC (% pred)104 ± 15.586 ± 1918 (5.8 – 30.1)<0.01RV/TLC (%)40.2 ± 9.348.5 ± 10.7−8.3 (−15 – −1.5)0.02RV/TLC (% pred)107.7 ± 24.6132.8 ± 24.8−25.1 (−43.8 – 6.2)0.01RAW (cmH20/L/s)2.1 ± 1.12.7 ± 0.9−0.6 (−1.4 – −0.3)0.20RAW (% pred)76.4 ± 41.7100.4 ± 45.9−24 (−56.9 – 9)0.12DLCO/VA (mL/min/mmHg/L)3.4 ± 1.13.3 ± 0.90.1 (−0.6 – 0.8)0.69DLCO/VA (%pred)73.2 ± 17.669.4 ± 183.8 (−22.8 – 31.2)0.62Abbreviations:CI, confidence interval;FEV1, forced expiratory volume in one second;% pred, percentage of the predictive value;VC, vital capacity; TLC, total lung capacity;RV, residual volume; RAW, airways resistance;DLCO/VA, diffusing capacity corrected for alveolar volume.*Results presented as mean ± SD (range) Open table in a new tab Abbreviations: CI, confidence interval; FEV1, forced expiratory volume in one second; % pred, percentage of the predictive value; VC, vital capacity; TLC, total lung capacity; RV, residual volume; RAW, airways resistance; DLCO/VA, diffusing capacity corrected for alveolar volume. *Results presented as mean ± SD (range) Abbreviations: CI, confidence interval; FEV1, forced expiratory volume in one second; % pred, percentage of the predictive value; VC, vital capacity; TLC, total lung capacity; RV, residual volume; RAW, airways resistance; DLCO/VA, diffusing capacity corrected for alveolar volume. *Results presented as mean ± SD (range) In conclusion, PFT allow a relatively good prediction of postoperative quantitative outcomes such as postoperative morbidity, mortality as well as overall survival after thoracic surgery for NSCLC, especially when functional parameters are expressed as a percentage of predicted value. However, PFT remain poorly related to postoperative qualitative outcomes, making QOL a separate and essential assessment of postop-erative NSCLC patients health status.