Perioperative CRP: A novel inflammation‐based classification in gastric cancer for recurrence and chemotherapy benefit

BACKGROUND: Perioperative C‐reactive protein (CRP) levels have effects on the prognosis of cancer patients. We intended to determine the prognostic value of combining the two for gastric cancer (GC). METHODS: Data were extracted from a clinical trial. By calculating the area under the curve (AUC) and the C‐index, the predictive value of CRPs among different time points, including preoperative (pre‐CRP), postoperative days 1, 3, and 5 (post‐CRPs), and postoperative maximum CRP (post‐CRP(max)), was derived. Multivariate analysis was performed to further explore the independent variates for recurrence‐free survival (RFS). RESULTS: Finally, 401 patients were available in the present study. For RFS, higher AUC (0.692) and concordance index (0.678) of pre‐CRP were observed when compared with those of post‐CRPs. Further, among post‐CRPs, post‐CRP(max) had the highest predictive values (AUC: 0.591; concordance index: 0.585) among the other post‐CRPs. The threshold values in predicting RFS for pre‐CRP and post‐CRP(max) were 3.1 mg/L and 77.1 mg/L. Multivariate analysis showed both pre‐CRP≥3.1 mg/L (high‐pre‐CRP) and post‐CRP(max)≥77.1 mg/L (high‐post‐CRP(max)) were risk factors for RFS. Postoperative chemotherapy benefit was further analyzed for patients with stage II/III GC and indicated that patients with pre‐CRP<3.1 mg/L had better prognosis without benefit from postoperative adjuvant chemotherapy (ACT), p = 0.557. In high‐pre‐CRP patients, only patients with post‐CRP(max)≥77.1 mg/L but not post‐CRP(max)<77.1 mg/L benefited from postoperative ACT (RFS: 33.2% vs 49.9% for non‐chemotherapy group and chemotherapy group, respectively, p = 0.037). Analyses for overall survival obtained the similar outcomes. CONCLUSIONS: Both high‐pre‐CRP and high‐post‐CRP(max) are associated with worse prognosis in GC. ACT seems to only improve the prognosis for stage II/III GC with pre‐CRP≥3.1 mg/L and post‐CRP(max)≥77.1 mg/L after radical gastrectomy. Further studies are needed to confirm these findings and explore the potential mechanism.