| Objective: Colon cancer(CC)is a common gastrointestinal malignancy,and accurate prediction of preoperative lymph node status is essential for selecting the best treatment option and judging the prognosis of patients.The aim of this study is to investigate the predictive significance of a novel inflammation-nutrition biomarker(platelet × albumin)/ lymphocyte ratio(PALR)for lymph node metastasis(LNM)in patients with clinically node-negative(c N0)CC.Methods: This study continuously collected the data,including the clinicopathological data,imaging data and the results of the first peripheral blood test after admission from800 patients with primary CC who received radical CC surgery in our hospital from March 2016 to June 2021.After screening by inclusion and exclusion criteria,data from269 patients with c N0 CC were finally analyzed retrospectively.Youden index was used to determine the optimum cut-off value of PALR based on receiver operating characteristic(ROC)curve,and patients were categorized into high-and low-PALR cohorts according to the optimum cut-off value.Gender,age,tumor location,depth of invasion,degree of tumor differentiation,tumor size,carcinoembryonic antigen(CEA)and PALR were included in logistic regression analyses to determine the independent indicators of LNM.Based on the results,the LNM prediction model of patients with c N0 CC was constructed.The internal validation of the model was performed via a bootstrap resample approach(1000 samples),together with the calculation of a corrected concordance index(C-index).The area under the ROC curve(AUC),decision curve analysis(DCA),and calibration plots were used to evaluate the nomogram.The nonlinear relationship between PALR and the risk of LNM was explored using a restricted cubic spline(RCS)function,and the sensitivity analysis was performed to repeat the main analyses with the quartile of PALR.Results: According to postoperative pathological results,192 patients were LNM negative while 77 patients were LNM positive,with a LNM rate of 28.6%.Significant difference was observed between LNM-positive group and LNM-negative group while considering patients with higher PALR(P = 0.002).Based on the Youden’s index,the optimum cut-off value of PALR for predicting LNM of patients with c N0 CC was 5.62,the diagnostic sensitivity and specificity were 41.2% and 77.1%,respectively.The AUC value of PALR for predicting LNM was 0.607(95% confidence interval [CI],0.546-0.666).Multivariate analysis showed that sex,depth of tumor invasion and PALR(odds ratio = 2.118,95%CI,1.182-3.786,P = 0.011)were independent predictors of LNM in c N0 CC patients.RCS visualized the uptrend linear relationship between PALR and the risk of LNM(p-value for non-linearity > 0.05).A nomogram incorporating PALR was constructed and the AUC value of the nomogram for predicting LNM was 0.654,which was significantly higher than that of PALR alone.The adjusted C-index of the nomogram after 1000 times of bootstrap resampling was 0.637.The calibration plots showed that the calibration prediction curve fitted well with the ideal curve(Hosmer-Lemeshow test: P =0.993),the DCA curves showed that the nomogram had good clinical benefit and the sensitivity analysis further confirmed the robustness of our findings.269 patients were categorized into high-and low-PALR cohorts according to the optimum cut-off value,the results showed a significant association between higher PALR and the parameters including right-sided CC(P = 0.028),larger tumor size(P = 0.019),higher platelet/lymphocyte ratio(P < 0.001),and higher LNM rate(P = 0.002).Conclusion: PALR is an independent predictor of LNM in patients with c N0 CC.The nomogram constructed based on PALR has the certain predictive ability and can provide a reference for the individualized preoperative LNM risk assessment and the formulation of treatment strategies for patients with c N0 CC. |
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