Maintenance of the nutritional prognostic index predicts survival in patients with unresectable metastatic colorectal cancer.

Purpose: Nutrition and immunity significantly affect the progression of cancer in cancer patients. Therefore, the evaluation of the nutritional and immune status would be useful as a prognostic factor and to determine the optimal treatment strategy for patients with unresectable metastatic colorectal cancer who are receiving chemotherapy. The aim of this retrospective study was to evaluate the prognostic significance of the nutritional and immune status in patients with unresectable metastatic colorectal cancer treated with chemotherapy.

Methods: We retrospectively reviewed 80 patients with colorectal cancer. A total of 22 patients had metachronous unresectable cancer, and 58 patients had synchronous unresectable cancer. All patients underwent combination chemotherapy with oxaliplatin or irinotecan plus 5-fluorouracil/leucovorin as first-line chemotherapy. We then examined the correlations between the Onodera's prognostic nutritional index (OPNI) and the patients' clinicopathological features. The OPNI was calculated as follows: 10 × serum albumin (g/dl) + 0.005 × total lymphocyte count (per mm(3)). According to the receiver operating characteristic (ROC) curve analysis, the cutoff value for OPNI was 44.5.

Results: Patients with a pretreatment OPNI of ≧44.5 demonstrated a longer OS than those with a pretreatment OPNI of <44.5. Moreover, we categorized these patients into four groups according to the combination of the pre- and post-treatment OPNI. The patients in the group with both OPNIs ≥44.5 exhibited a better prognosis compared to the other group (p = 0.001).

Conclusion: The OPNI is considered to be a useful marker for predicting the long-term outcome in patients who receive chemotherapy for unresectable metastatic colorectal cancer.