Low pre‐treatment nutritional index is significantly related to poor outcomes in small cell lung cancer

BACKGROUND: The importance of nutritional status and chronic inflammation has been emphasized in cancer. We investigated the impact of Onodera's prognostic nutritional index (OPNI) on clinical outcomes in small cell lung cancer (SCLC) patients. METHODS: Data from 220 SCLC patients treated with first‐line platinum‐based chemotherapy from 2006 to 2017 were retrospectively reviewed. The OPNI was calculated as 10 × serum albumin level (g/dL) + 0.005 × absolute lymphocyte count (/mm(3)). Patients with an OPNI of > 45, 40–45, or < 40 were categorized in high, intermediate, or low OPNI groups, respectively. RESULTS: The proportion of non‐responders to first‐line therapy increased as the OPNI decreased (high, intermediate, low OPNI groups: 6.7%, 18.0%, and 30.8%, respectively; P < 0.001). Early discontinuation of first‐line therapy because of treatment toxicity occurred more frequently in the lower OPNI groups (high, intermediate, low OPNI groups: 5.8%, 21.3%, and 25.6%, respectively; P < 0.001). The one‐year progression‐free and overall survival rates in the high, intermediate, and low OPNI groups were 29%, 19%, and 3%, and 61%, 46%, and 23%, respectively. In multivariate analyses, the low OPNI group was independently associated with poor progression‐free (hazard ratio 1.592; 95% confidence interval 1.009–2.511; P = 0.046) and overall (hazard ratio 1.911; 95% confidence interval 1.208–3.024; P = 0.006) survival compared to the high OPNI group. CONCLUSION: SCLC patients with an OPNI < 40 showed a low tolerance to chemotherapy and a poor prognosis. Further evaluation is needed to validate these findings.