Correlation Analysis Between TK1(Thymidine Kinase 1) And Chemotherapeutic Effect And Prognosis In Patients With Breast Cancer

Objective:To investigate the influence of thymidine kinase 1(TK1) on prognosis of breast cancer patients; and to compare TK1 with several of serological biomarkers(e.g. Carcinoembryonic Antigen(CEA), Carbohydrate Antigen 15-3(CA15-3))and to explore the correlation between them.Materials and Methods:Patients were enrolled into this study with histologically or cytologically confirmed breast cancer. All patients enrolled were inpatients from June 2015 to April 2016 in Jiangsu Cancer Hospital, and blood sample collected before and after chemotherapy. We collected demographic characteristics, clinicopathologic characteristics and laboratory indexes from medical records. By comparing the change of TK1 before and after adjuvant chemotherapy, we explored the correlation between the expression of TK1 and clinicopathologic characteristics in group A. In group B, CT(computed tomography) and MRI(magnetic resonance imaging) were used to evaluate response of treatment, the correlation between expression of TK1 in people of group B and chemotherapeutic response was investigated to explore the value of TKl in predicting curative effect of neoadjuvant chemotherapy and palliative therapySPSS 19.0 software was used in statistical analysis. Continuous variables were summarized by descriptive statistics, categorical variables by frequency, count data by Chi-square test. Measurement data was expressed as mean ± standard deviation. Chi-square test was used to compare TK1 and several serological biomarkers and investigate the association between TK1 and curative efficacy. P<0.05 was considered statistically significant.Results:(1) According to the treatments, all patients(N=87) in our study were divided into two groups, group A and group B.46 patients in group A were postoperative breast cancer patients accepted adjuvant chemotherapy which was predominantly TAC; the rest of 41 patients in group B accepted neoadjuvant chemotherapy or palliative therapy. The positive rate of serum TKl in both group A and B before chemotherapy was greater than 85%. No significant differences between TKl and several serological biomarkers(e.g. CEA, CA15-3) were detected in patients in two groups before chemotherapy.(2) In group A, before chemotherapy, serum TKl has no significant difference with clinicopathological characteristics(e.g. age, Her-2 expression and TNM classification); In group B, TKl expression before therapy had no significant correlation with clinicopathological characteristics(e.g. age, Her-2 expression and presence of distant metastasis). The expression of serological biomarkers (e.g.CEA,CA15-3) in group A and group B had no significant difference with clinicopathological characteristics(e.g. age, Her-2 expression, TNM classification and presence of distant metastasis).(3) The expression of TKl significantly decreased in group B for patients with curative effect, significantly increased in patients who accepted neoadjuvant chemotherapy or palliative therapy but with poor response(p<0.005). The variation of other serological biomarkers were also positively associated with treatment response, while only CA15-3 had significant influence(p=0.01).(4) There was a significant correlation between TKl and therapeutic efficacy in patients of group B(r=0.77). TKl tended to be more sensitive in detecting palliative or neoadjuvant therapeutic efficacy than other selected serum biomarkers.Conclusions:The expression of TKl after neoadjuvant chemotherapy or palliative treatment was associated with effectiveness for patients. The expression of TKl significantly decreased in patients who responded to treatments and TKl significantly increased in group B patients who did not responded. Thus, the increase of TK1 after treatments may predict poor outcome in patients with breast cancer.