Clinical Significance Of Lactate Dehydrogenase(LDH) In Advanced Lung Cancer

Objective Lung cancer has the highest incidence among malignant tumor in the world, which causes great harm to human health. Lactate dehydrogenase is one important enzyme in glycolytic pathway, as well as a regular project in the biochemical testing. This study is aimed to investigate the clinical significance of lactate dehydrogenase(LDH) in lung cancer.Part 1 To explore the differential diagnosis value of serum LDH in Lung space occupying lesionsMethods Clinical data from 72 lung cancer patients with lung space occupying lesions were retrospectively collected. All hospital diagnosis were confirmed. All patients were divided into lung cancer group and benign lung diseases group according to the hospital diagnosis and 50 healthy controls from medical center were involved. To compare the expression lever of serum LDH in different groups.Results 1.The levels of LDH in lung cancer group, benign lung diseases group,and the healthy control group were 275.26±85.85u/L;247.00+/-80.12u/L and 159.78+/-36.24u/L. The difference of LDH between lung cancer group, benign lung diseases group and control group was statistically significant(P ﹤ 0.05).While the difference of LDH between lung cancer and benign lung diseases group was not statistically significant(P>0.05). 2.In 42 lung cancer patients, the level of LDH had no statistically significant difference between different age, gender, smoking history and pathological types(P>0.05).While there was remarkable difference between different clinical stages in LDH( P﹤0.05).Part 2 To explore the value of serum LDH’s dynamic detection in evaluation the chemotherapy effect in patients with advanced lung cancerMethods Chose 91 patients with advanced lung cancer from respiratory medicine who accepting at least 2 cycles’ chemotherapy. Serum LDH and tumor markers before and after two cycles’ chemotherapy were collected. Assessed the chemotherapy effect with the response evaluation criteria in solid tumors(RECIST). To analyze the relationship between the variation of serum LDH, tumor markers and chemotherapeutic efficacy in patients with advanced lung cancer. Furthermore,the role of variation ratios of LDH and tumor markers was evaluated in predicting chemotherapy effect by application of receiver operating characteristic(ROC) curve.Results 1. The result of response evaluation in 91 patients with advanced lung cancer was:CR in 5 cases(5.49%), PR in 46 cases(50.55%), SD in 21 cases(23.08%), PD in19 cases(20.89%). 2. After two cycles’ chemotherapy,the difference of serum CEA in objective response group and no response group was statistically significant(P ﹤ 0.05).There were no statistical differences in the levels of serum LDH,SCC,NSE before and after chemotherapy between different chemotherapy efficacy group(P>0.05).According to different pathological features of lung cancer,further analysis found that the differences in the levels of serum NSE before and after chemotherapy were statistically significant between different chemotherapy efficacy in SCLC patients(P<0.05). Differences in the levels of serum LDH,SCC before and after chemotherapy had no statistical significance between different chemotherapy efficacy even in different pathological types(P>0.05).3. The variation ratio of LDH and CEA were positively correlated with chemotherapy effect(rLDH=0.213,P=0.042;rCEA=0.584,P=0.000).The variation ratio of SCC and NSE were unrelated to chemotherapy effect(P>0.05). 4. There was significant correlation between the variation ratio of LDH,CEA and chemotherapy effect,the areas under the ROC curve of LDH,CEA were 0.622(95%CI: 0.502-0.741),0.840(95%CI:0.753-0.927).There were no significant correlations between the variation ratio of SCC or NSE and chemotherapy effect(AUC < 0.500).Conclusion The serum LDH in patients with lung space occupying lesions may take no significance in the differential diagnosis between benign and malignant lung disease. The variation of serum LDH level before and after chemotherapy may be inappropriate to predict the chemotherapy effect, while the variation ratio of LDH was correlated with different chemotherapy effect,and it maybe a effective indicator to evaluate the chemotherapy effect in patients with advanced lung cancer.