Prognostic implication of pulmonary function at the beginning of postoperative radiotherapy in non-small cell lung cancer

Abstract

PURPOSE: The purpose of this study was to investigate the prognostic effect of

pulmonary function at the beginning of postoperative radiotherapy (PORT) in

non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: From January 2002 to

December 2012, 115 patients with NSCLC who underwent PORT and took the forced

expiratory volume in 1 second (FEV1) at the beginning of PORT were analysed. PORT

began within 4-6weeks following surgery, and the 3-dimensional conformal

technique was used with conventional fractionation. The high and low FEV1 groups

were divided by the median absolute value of FEV1 at the beginning of PORT, and

we compared the clinical factors and survival between two groups. RESULTS: The

median absolute value of FEV1 at the beginning of PORT was 1.68L (range,

0.83-3.89), and patients were divided into low and high FEV1 groups (<1.68L

versus 1.68L). Patients in the low FEV1 group showed a lower preoperative FEV1

(mean, 1.94L versus 2.73L, p<0.001) and received more pneumonectomy (36.8% versus

8.6%, p<0.001) compared to the high FEV1 group. The overall median follow-up time

was 31months (range, 3-110), and 5-year locoregional recurrence-free survival

(LRRFS), distant metastasis-free survival (DMFS) and overall survival (OS) were

52.4%, 48.9%, and 45.9%, respectively. Five-year OS of the low FEV1 group was

significantly lower than that of the high FEV1 group (35.4% versus 56.9%,

p=0.002), and no significant differences were found in LRRFS and DMFS. In a

multivariate analysis, the difference of OS between the low and high FEV1 groups

remained significant (Hazard Ratio=2.04, CI, 1.18-3.55, p=0.011). CONCLUSIONS:

The FEV1 at the beginning of PORT was an independent significant prognostic

factor in patients with NSCLC who received PORT. Considering this analysis was

limited to only patients receiving PORT, further studies are warranted to compare

the survival effect of postoperative pulmonary function between groups

with/without PORT.