Fibrinogen/Albumin Ratio Index Is an Independent Prognosis Predictor of Recurrence-Free Survival in Patients After Surgical Resection of Gastrointestinal Stromal Tumors

Abstract

Background: Nutritional status, systemic inflammation, and coagulation mechanism are closely related to tumor progression. Herein, we examined the role of fibrinogen-to-albumin ratio index (FARI) in the prognosis of gastrointestinal stromal tumors (GISTs) and developed a novel nomogram predicting recurrence-free survival (RFS). Methods: We retrospectively analyzed data from 357 GIST patients admitted at the gastrointestinal surgery of the Beijing Hospital from January 2008 to January 2018 and underwent curative resection. FARI was calculated as fibrinogen level (g/L) /albumin level (g/L). The cutoff point of FARI was set using the point with the largest Youden index on the receiver operating characteristic curve with the 5-years recurrence-free survival as an endpoint. We used the Kaplan-Meier approach and multivariable Cox regression model to study the impact of FARI on recurrence-free survival. Finally, we developed a nomogram based on tumor size, location, mitotic index, and FARI to predict RFS. The nomogram was assessed by calculating concordance probabilities and testing calibration of predicted RFS with observed RFS. Concordance probabilities were also compared with the National Institute of Health (NIH) risk classification system. Results: The ROC curve revealed that the best cutoff point of the FARI was set as 0.08. The patients were classified into the FARI-high (≥0.08) and FARI-low (<0.08) groups. FARI was significantly associated with age, size of the tumor, NIH risk category, and Mitotic Index (all P < 0.05). FARI was weakly associated with NLR and PLR. FARI and PNI had a weak negative association. Multivariate analysis showed that the NIH risk category and FARI were independent prognostic predictors for worse outcomes concerning RFS in GIST patients. In the high-risk subgroup, patients with low FARI also had a more prolonged RFS than patients with high FARI (P < 0.05). The nomogram had a concordance probability of 0.802 (SE 0.025). Nomogram predictions were well-calibrated. Concordance probabilities of the nomogram were better than NIH risk classification system [0.802 [0.025] vs. 0.737 [0.024], p < 0.01]. Conclusion: We established that preoperative FARI is a novel serum biomarker to predict the prognosis after surgical resection of GISTs. The nomogram incorporating FARI could be used to help the decision-making of clinical treatment.

Keywords: albumin; fibrinogen; fibrinogen-to-albumin ratio index; gastrointestinal stromal tumors; prognosis.

Figure 1

The receiver operating characteristic (ROC) analysis of NLR, PLR, PNI, and FARI. The areas under the curve (AUC) for RFS were 0.592 (p = 0.014), 0.572 (p = 0.053), 0.623 (p = 0.001), and 0.638 (p < 0.001) for NLR, PLR, PNI, and FARI, respectively. NLR, neutrophil-to-lymphocyte ratio; PLR, platelet-to-lymphocyte ratio; PNI, prognostic nutritional index; FARI, fibrinogen-to-albumin ratio index.

Figure 2

Kaplan–Meier survival curves for RFS according to FARI (A), NLR (B), PLR (C), and PNI (D) in GIST patients. (A) The 5-years RFS rate of patients in the FARI-low group was significantly better than those in the FARI-high group (85.6 vs. 66.3%, p < 0.001). (B) The 5-years RFS rate of patients in the low-NLR group was significantly better than those in the high-NLR group (86.5 vs. 76.0%, p = 0.008). (C) The 5-years RFS rate of patients in the low-PLR group was significantly better than those in the high-PLR group (84.6 vs. 75.5%, p = 0.002). (D) The 5-years RFS rate of patients in the low-PNI group was significantly worse than those in the high-PNI group (69.3 vs. 86.3%, p < 0.001). NLR, neutrophil-to-lymphocyte ratio; PLR, platelet-to-lymphocyte ratio; PNI, prognostic nutritional index; FARI, fibrinogen-to-albumin ratio index.

Figure 3

Kaplan–Meier survival curves for recurrence-free survival according to the FARI in very low & low (A), intermediate (B), and high risk (C) subgroup. A more prolonged recurrence-free survival was also observed in patients in the FARI-low group in the high-risk subgroups (P = 0.048), but not in the very low & low and intermediate subgroup, respectively (P = 0.989, 0.856). FARI, fibrinogen-to-albumin ratio index.

Figure 4

Nomogram to predict the probabilities of 2-years and 5-years recurrence-free survival of primary GIST. Points are assigned for size, mitotic index, site of origin, and FARI by drawing a line upward from the corresponding values to the “Points” line. The sum of these four points, plotted on the “Total points” line, corresponds to predictions of 2-years and 5-years recurrence-free survival (RFS).

Figure 5

Calibration of nomogram-predicted recurrence-free survival (RFS). Actual 5-years RFS is shown compared with nomogram-Predicted Probability of 5-years RFS.