Research Of Relevance Between Hyponatremia And Prognosis Of Small Cell Lung Cancer

Background and objective: Hyponatremia is common in small cell lung cancer,caused by inappropriate antidiuretic hormone syndrome(SIADH).When the concentration of serum sodium < 135mmol/L called hyponatremia,patients can appear all sorts of signs and symptoms,such as: nausea,headache,drowsiness,coma caused by epilepsy and cerebral edema.Due to different clinical manifestations,hyponatremia is often ignored by clinicians.The present research retrospectively analyzes the incidence and the prognosis of hyponatremia in small cell lung cancer before and after treatment.Materials and methods: All cases were between January 2010 and December 2013,confirmed by cytology/histology,treated first in Second Affiliated Hospital of Dalian Medical University of small cell lung cancer.We collected the selected patients' clinical data(serum sodium levels before and after treatment,age,sex,VA stage,smoking status,merger-related diseases,lactate dehydrogenase level,neuron-specific enolase level,carcinoembryonic antigen level,liver metastasis,brain metastasis,bone metastasis and pleural effusion and so on).According to the serum sodium levels before and after treatment,who were divided into normal group,hyponatremia before treatment group and hyponatremia after treatment group.We took the medical records and telephone follow-up of their survival.We used SPSS 13.0 statistical software for statistical data analysis.The method of X2 test was used to serum sodium level and clinical factors analysis.The method of Kaplan Meier was used to univariate analysis.The method of COX proportional hazards regression was used to multivariate survival analysis.When the value of P <0.05 was considered statistically significant.Results:(1)In 180 cases of SCLC patients,49 cases with hyponatremia and 131 patients without hyponatremia,namely the incidence rate of hyponatremia was 27.2%.There were 36 cases of hyponatremia before treatment,15 cases of mild hyponatremia,12 cases of moderate hyponatremia,9 cases of severe hyponatremia.There were 13 cases of hyponatremia after treatment,8 cases of mild hyponatremia,4 cases of mild hyponatremia,1 case of severe hyponatremia.(2)Serum sodium level and small cell lung cancer patients' age,gender,VA stage,smoking status,lactate dehydrogenase levels,the level of carcinoembryonic antigen,before treatment of liver metastases,brain metastases,bone metastases of no relevance(P > 0.05).Serum sodium level with small cell lung cancer patients' before treatment of pleural effusion,neuron-specific enolase levels have correlation.P values were 0.002 and 0.015,the differences were statistically significant.(3)The median survival time in 180 cases of small cell lung cancer patients was 13.1 months.The median survival time was 14.9 months in patients of normal group,the median survival time was 10.1 months in patients of hyponatremia before treatment group and the median survival time was 8.6 months in patients of hyponatremia after treatment group.P values were 0.005 and 0.000,with statistical significance.(4)Normal group one year survival rate was 63.4%,hyponatremia before treatment group one year survival rate was 44.4%,hyponatremia after treatment group one year survival rate was 23.1%.P values were 0.017 and 0.002,with statistical significance.Normal group two years survival rate was 29.8%,hyponatremia before treatment group two years survival rate was 11.1%,hyponatremia after treatment group two years survival rate was 0%.P values were 0.002 and 0.000,with statistical significance.(5)The response rate in normal serum sodium patients was 71.5%,and the response rate in hyponatremia before treatment group was 52.8%.P value was 0.031,with statistical significance.(6)Univariate analysis showed that VA stage,smoking status,LDH level,NSE level,CEA levels,sodium levels before and after treatment,liver metastasis,bone metastasis affect survival.Conclusions:(1)In small cell lung cancer patients,the serum sodium level is the independent factor affecting the prognosis,serum sodium level associated with poor outcome.(2)In small cell lung cancer patients,extensive period,smoking,LDH level higher than normal,NSE level higher than normal,CEA level higher than normal,liver metastasis,bone metastases are poor prognosis.(3)In small cell lung cancer patients,the serum sodium level and their sex,age,stage,smoking history,LDH level,CEA level,metastasis and other factors are no correlation,and pleural effusion and NSE level are positively correlated.