Title: Sa1908 Onodera Index Independently Predicts Survival in Surgically Treated Colorectal Carcinoma
Abstract: INTRODUCTION: Onodera index (OI) combines circulating lymphocytes and albumin levels. It has been used as a nutritional and immunological marker and it has been recently proposed in Eastern literature its possible value as a predictive variable of prognosis in colorectal cancer (CRC). AIMS: To analyse the prognostic value of OI, assessed at initial diagnosis, on survival of patients with resected CRC. PATIENTS AND METHODS: We present a retrospective observational study including 207 consecutive patients with CRC and surgically treated on elective basis. Clinical follow-up was performed, documenting all cases of tumor-related deaths. OI was calculated according to the equation: [10 x serum albumin (g/dl) + 0.005 x circulating lymphocytes/mm2]. OI values 6 mcg/l, OI < 40 and OI ≥ 40. Univariant and multivariant analysis were performed [Cox model, stepwise, determining hazard ratio (HR) and 95% confidence interval (CI 95%)]. Finally, Fisher and square chi tests were used to compare 5-year mortality rates between groups with OI < 40 and OI ≥ 40, calculating odds ratio (OR) and CI. RESULTS: 26 patients (12.6%) presented a low OI. Median follow up was 81 months, with an interquartile range of 60-96. Overall tumor-related mortality was 23.7% and 19.8% 5 years after surgery. Variables with independent prognostic value in multivariant analysis are summarised in the following table below. 5-year mortality rate was significantly higher in patients with low OI: 42.3% vs 16.7% [OR = 3.69; CI = (1.42-9.58); p=0.002]. CONCLUSIONS: 1. A low Onodera index, assessed at initial CRC diagnosis, is associated with a worse survival curve after tumor resection. 2. This negative prognostic significance of an Onodera index < 40 has proved to have an independent predictive value. 3. Post-surgery 5-year mortality is higher in patients with a low Onodera index. Variables with independent prognostic value in multivariant analysis