OBJECTIVE: Aim: To investigate the role of thymidine phosphate and IL-6 in the pathogenesis and survival rate in women with breast cancer.. PATIENTS AND METHODS: Materials and Methods: Sixty women diagnosed with breast cancer (with age ranging between 25-65 years) were included in the current study. Of these, 40 women relapse after 6 months of follow up, while 40 patients were non-relapsed. RESULTS: Results: Statistical analysis pointed out that thymidine phosphorylase may be significantly increased in relapsed women comparing to non-relapsed women (4.48±0.24 ng/ml and 1.12±0.18 ng/ml respectively, p value <
0.0001). Regarding IL-6, the current study also found that IL-6 tends to be increased in relapse BC comparing to non-relapsed BC (8.6±0.92 pg/ml vs. 6.82±1.14 pg/ml respectively, p-value<
0.0001. There was a high significant positive correlation between thymidine phosphorylase and IL-6 (r=0.368
p-value <
0.01). The sensitivity and specificity in predicting relapse in breast cancer were 0.83 and 0.64 for TP and 0.78, and 0.65 respectively. CONCLUSION: Conclusions: It is suggested that thymidine phosphate activity and IL-6 serum levels after six months of follow up, have a dual synergistic impact on the pathogenesis of relapse for BC. These biomarkers can also be used in the prediction of relapse rate in women diagnosed with BC.