398 Kinetics of tumor marker decline as an independent prognostic factor in patients with relapsed metastatic germ-cell tumors. M. MEGO 1,2* , K. REJLEKOVA 1,2 , M. RECKOVA 1 , Z. SYCOVA-MILA 2 , J. OBERTOVA 1,2 , J. RAJEC 1,2 , J. MARDIAK 1,2 . 1 Department of Medical Oncology, School of Medicine, Comenius University, Bratislava, Slovakia, e-mail: misomego@gmail.com 2 Department of Medical Oncology, National Cancer Institute, Bratislava, Slovakia Received September 18, 2008. Early serum tumor marker decline (STMD) during chemotherapy was shown to predict survival in patients with poor prognosis non-seminomatous germ cell tumors (GCT) in the first line. Te aim of the study was to assess the prognostic value of STMD in relapsed GCT`s patients. From January 1995 to December 2007, all patients treated for GCT´s with salvage therapy at the National Cancer Institute of Slovakia were identified from the tumor registry database and screened retrospectively for serum AFP and βHCG level at the time of relapse. STMD rate was calculated for each patient and each tumor marker with an abnormal marker value at baseline and each tumor marker M (HCG or AFP) using only two values: the baseline value (M 0 ) and the value obtained afer one cycle of chemotherapy (day 21 value; M 1 ). Te decline rate was calculated using a logarithmic transformation, and it was expressed as a theoretical number of weeks necessary to normalization that was called predicted time to normalization. Decline rates were classified into „favorable“ or „unfavorable“. Totally, 75 patients were identified, 39 had favourable (group A) and 36 unfavorable (group B) STMD. Te 2-year and 5-year PFS rates were 61% and 58% for group A and 17% and 7% group B (p < 0.00001). Simillary, the 2-year and 5-year OS rates were 79% and 68% for group A and 24% and 16% for group B (p < 0.00001). Of all the baseline characteristics that were included in the Cox model, STMD was the most important predictor of PFS and OS. We suggest that STMD is strong independent prognostic factor in GCT patients treated with salvage chemotherapy. Prospective studies of different approaches in this patient`s population based on STMD are warranted. Keywords: germ cell cancer; salvage chemotherapy; serum tumor marker decline β-human chorionic gonadotropin (βHCG) and α-fetoprotein (AFP) at relapse. Patients with a progression-free interval of less than 2 years, less than CR to induction chemotherapy and high markers at relapse (AFP > 100 kU/l, βHCG > 100 IU/l) formed a poor-prognosis group [10]. Motzer in an earlier report identified CR to induction therapy, testis primary site and normal serum βHCG and LDH as favourable prognostic factors [2]. Early serum tumor marker decline during chemotherapy was previously shown to predict survival in patients with poor prognosis of disseminated non-seminomatous GCT in first line [11]. AFP decline during the first 6 weeks of salvage chemotherapy predicts PFS in patients with disseminated GCT. Massard et al showed that high-dose chemotherapy in relapsed germ cell tumors may be beneficial only to selected patients with a favorable AFP decline [12]. Te aim of this retrospective study was to assess the prognostic value of the kinetics of tumor marker decline in patients with relapsed disseminated germ-cell tumors treated in a single institution. * Corresponding author Germ cell tumors (GCT) belong to the most chemosensi- tive solid tumors and represent a model for a curable cancer [1]. Cisplatin represents the mainstay in the treatment of GCTs. Cisplatin-based 1 st line chemotherapy can cure about 70%-80% of patients with disseminated testicular cancer [2, 3, 4]. Salvage chemotherapy with standard dose cisplatin plus previously not utilized drugs will cure 20-25% of patients who were not initially cured with their induction chemotherapy [5, 6, 7, 8]. Treatment efficacy strongly correlates with prognostic fac- tors [9]. Te first and the most important prognostic factor is complete remission (CR) that is achieved either with primary cisplatin-based chemotherapy only or with cisplatin-based chemotherapy (partial remission) followed with surgical complete removal of all residual tumor masses. Fossa et al. identified three prognostic factors in relapsed germ cell tumors which remain significant in multivariate analysis: progression free interval, CR to induction treatment and the level of serum doi:10.4149/neo_2009_05_398 NEOPLASMA 56, 5, 2009