Effect of neoadjuvant chemoradiation on preoperative pulmonary physiology, postoperative respiratory complications and quality of life in patients with oesophageal cancer

BACKGROUND: It remains controversial whether neoadjuvant chemoradiation (nCRT) for oesophageal cancer influences operative morbidity, in particular pulmonary, and quality of life. This study combined clinical outcome data with systematic evaluation of pulmonary physiology to determine the impact of nCRT on pulmonary physiology and clinical outcomes in locally advanced oesophageal cancer. METHODS: Consecutive patients treated between 2010 and 2016 were included. Three-dimensional conformal radiation was standard, with a lung dose-volume histogram of V20 less than 25 per cent, and total radiation between 40 and 41·4 Gy. Forced expiratory volume in 1 s (FEV1), forced vital capacity (FVC) and diffusion capacity for carbon monoxide (DLCO) were assessed at baseline and 1 month after nCRT. Radiation-induced lung injury (grade 2 or greater), comprehensive complications index (CCI) and pulmonary complications were monitored prospectively. Health-related quality of life was assessed among disease-free patients in survivorship. RESULTS: Some 228 patients were studied. Comparing pulmonary physiology values before with those after nCRT, FEV1 decreased from mean(s.d.) 96·8(17·7) to 91·5(20·4) per cent (-3·6(10·6) per cent; P < 0·001), FVC from 104·9(15·6) to 98·1(19·8) per cent (-3·2(11·9) per cent; P = 0·005) and DLCO from 97·6(20·7) to 82·2(20·4) per cent (-14·8(14·0) per cent; P < 0·001). Five patients (2·2 per cent) developed radiation-induced lung injury precluding surgical resection. Smoking (P = 0·005) and increased age (P < 0·001) independently predicted percentage change in DLCO. Carboplatin and paclitaxel with 41·4 Gy resulted in a greater DLCO decline than cisplatin and 5-fluorouracil with 40 Gy (P = 0·001). On multivariable analysis, post-treatment DLCO predicted CCI (P = 0·006), respiratory failure (P = 0·020) and reduced physical function in survivorship (P = 0·047). CONCLUSION: These data indicate that modern nCRT alters pulmonary physiology, in particular diffusion capacity, which is linked to short- and longer-term clinical consequences, highlighting a potentially modifiable index of risk.