Abstract: Objective To investigate the value of serum D-dimer in evaluating chemotherapy effect and prognosis in patients with non-small cell lung cancer(NSCLC). Methods A total of 60 patients with NSCLC were collected from June 2022 to December 2023. They were divided into effective group (n=45) and ineffective group (n=15) according to the difference of chemotherapy effect. Serum D-dimer levels was measured by immunoturbidimetry and was then compared between the two groups. The efficacy of the above indexes in predicting chemotherapy effect was analyzed by receiver operating characteristic (ROC) curve. In addition, patients were divided into good prognosis group (n=40) and bad prognosis group (n=20) according to their prognosis. Univariate and multivariate analysis was used to determine the factors affecting the prognosis of NSCLC patients. Results The serum D-dimer level in the ineffective group was (1.30±0.42) mg/L, which was higher than that in the effective group (0.97±0.32)mg/L(t=3.192, P＜0.01). ROC curve analysis confirmed that the area under the curve(AUC) of serum D-dimer level to predict chemotherapy failure in NSCLC patients was 0.760, the sensitivity was 0.667 and the specificity was 0.711. The Joden index was 0.356, the optimal threshold was 1.16 mg/L, and the 95% CI was 0.631-0.889. Univariate analysis showed that TNM stage, differentiation degree of the cancer cells, lymph node metastasis and serum D-dimer level were related to the prognosis of patients with NSCLC (all P＜0.05). Multivariate Logistic regression analysis showed that the risk factors for poor prognosis in NSCLC patients included the TNM stage Ⅳ; Low differentiation; Lymph node metastasis and serum D-dimer (all OR＞1, P＜0.05). Conclusions Serum D-dimer can provide reliable evidence to the evaluation of chemotherapy effect and prognosis of NSCLC patients.

Key words: non-small cell lung cancer, D-dimer, chemotherapy effect, prognosis