Postoperative prognostic nutritional index as a prognostic factor after non-small cell lung cancer surgery

The prognostic nutritional index (PNI) is an immunonutrition index. Although preoperative PNI (pre-PNI) has been reported as a prognostic factor for patients with surgically resected non-small cell lung cancer (NSCLC), it is unclear whether postoperative PNI (post-PNI) and perioperative PNI change is a prognostic factor.

Clinicopathological data from 262 consecutive patients who underwent lobectomy for NSCLC were collected. Pre-PNI and post-PNI were calculated within 1 month before surgery and at 1 month after surgery, respectively. We investigated which clinicopathological factors contributed to the post-PNI, the differences in prognosis according to the post-PNI status, and the impact of perioperative PNI change on prognosis.

We set 50 and 45 as an optimal cutoff value of pre-PNI and post-PNI for OS using a receiver operating characteristic curve. Patients who were older and male and who had lower pre-PNI, larger thoracotomy size, longer operative duration, larger blood loss during surgery, and postoperative pulmonary complications showed significantly lower post-PNI. The 5-year overall survival (OS), lung cancer-specific survival, and recurrence-free survival rates for the high/low post-PNI groups were 87.4%/58.4% (P < 0.001), 92.0%/74.8% (P = 0.001), and 80.5%/55.3% (P < 0.001). respectively. Multivariate analysis showed that the post-PNI was a significant prognostic factor (P < 0.001). We further revealed the equivalent OS with "low pre-PNI and high post-PNI" patients or "high pre-PNI and high post-PNI" patients.

Post-PNI status was a significant prognostic factor and perioperative PNI changes could play a significant role in the survival of patients with NSCLC after surgery.