Can we predict chemotherapy response in patients with metastatic testicular cancer? Role of thrombocytosis as a novel marker

BACKGROUND: Primary treatment of choice for advanced germ cell tumors is 3 to 4 cycles of combination bleomycin-etoposide-cisplatin (BEP) chemotherapy. Although most patients treated for advanced germ cell tumors (GCT) will be cured, approximately 30% will fail to achieve a durable complete response (CR). Thrombocytosis has been found to be related with significantly shorter survival in many cancers. However, its role in testicular cancer patients has not been studied previously. The objective of this study was to investigate the relationship between thrombocytosis and chemotherapy response in patients with metastatic testicular cancer. METHODS: Records of 113 patients with advanced stage testicular cancer were reviewed. Treatment outcomes were classified as complete clinical response (cCR), partial clinical response (pCR), complete pathological response (cPR) and treatment failure and the relationship with thrombocytosis was investigated. Logistic regression analysis was performed to identify factors associated with treatment failure. RESULTS: Totally 103 patients met the eligibility criteria. Thrombocytosis was detected in 26 (25.2%) patients. Treatment failure was observed in 14 (53.8%) and 28 (36.4%) of the patients in the thrombocytosis and non-thrombocytosis groups respectively (P=0.037). Thrombocytosis and IGCCCG high-risk group are found as independent prognostic factors for treatment failure in multivariate analysis. CONCLUSIONS: Thrombocytosis is seen in 25% of patients with testicular GCT and it is found to be associated with poorer chemotherapy response in metastatic patients. It can be used to predict the response to chemotherapy.