Preoperative malnutrition with mild hypoalbuminemia associated with postoperative mortality and morbidity of colorectal cancer: a propensity score matching study

BACKGROUND: Malnutrition with hypoalbuminemia (albumin < 35 g/L) is an important factor in predicting risks associated with colorectal cancer surgery. However, there is limited data about the effects of mild hypoalbuminemia with small decreases in albumin on postoperative complications. METHODS: This is a retrospective study using the multi-institutional, nationally validated database of the American College of Surgeons-National Surgical Quality Improvement Program (ACS-NSQIP) to investigate mild hypoalbuminemia and its association with postoperative mortality and morbidity by using a propensity score matching method. RESULTS: In a group of 30,676 colorectal cancer patients who received surgery, 5230 had mild hypoalbuminemia (< 35 and > =30 g/L) and 21,310 had normal albumin levels (> = 35 g/L). Significant differences were noted in 21 clinical characteristics between the two groups. After 1:2 propensity score matching postoperative mortality was significantly associated with mild hypoalbuminemia (OR = 1.74; p < 0.001). There were significant associations between mild hypoalbuminemia and 11 postoperative morbidities including deep vein thrombosis, pulmonary embolism, superficial and deep surgical site infection, pneumonia, septic shock, ventilator> 48 h, blood transfusion, return to operating room, stroke and re-intubation. Mild hypoalbuminemia was also associated with overall complication (B = 0.064, p < 0.001) and length of total hospital stay (B = 2.236, p < 0.001). CONCLUSIONS: In colorectal cancer, this is the first propensity score matching study of malnutrition with mild hypoalbuminemia which demonstrates that a mild decrease in serum albumin contributes significantly to poor postoperative outcome. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12937-019-0458-y) contains supplementary material, which is available to authorized users.