Paclitaxel, ifosfamide, cisplatin (TIP) for the treatment of intermediateand poor-risk nonseminomatous germ cell tumors with an inadequate decrease in tumor markers: a phase II study

Abstract

Purpose: To evaluate efficacy of TIP (paclitaxel, ifosfamid, cisplatin) in the 1st line treatment of germ cell tumors patients with unfavorable decline of serum tumor markers after 1 cycle of the standard regimen of chemotherapy. Patients and methods: In this phase II multicenter, nonrandomized trial, patients were enrolled from 4 centers of the Russian Federation. Patients were included if they were older than 18 years, had evidence of testicular, retroperitoneal, or mediastinal nonseminoma based on histologic findings or clinical evidence (high serum human chorionic gonadotropin or alpha-fetoprotein levels) that matched International Germ Cell Cancer Consensus Group (IGCCCG) intermediate and poor prognosis criteria. All patients got one cycle of BEP regimen (bleomycin 30 mg on days 1, 3, 5, etoposide 100 mg / m 2 on days 1–5, cisplatin 20 mg / m 2 on days 1–5). Patients with unfavorable serum tumor markers decline after the first cycle of chemotherapy at day 18–21 received four cycles of TIP regimen (paclitaxel 120 mg / m 2 on days 1–2, ifosfamide 1500 mg / m 2 on days 2–5, and cisplatin 25 mg / m 2 om days 2–5, granulocyte-colony stimulating factor 5 mg / kg on days 6–15). In the presence of a residual tumor larger than 1 cm and the technical possibility of its removal, surgical treatment was performed. The primary endpoint was 1-year progression-free survival. Results: Between 2017 and 2021, 28 patients were included in our study: seven patients with an intermediate prognosis according to IGCCCG classification and twenty-one with poor risk. Median follow-up was 15,5 months (range, 4,4–38,3 months). The 1-year progression-free survival and overall survival in intention-to-treat population were 76,6 % and 81,0 %, respectively. One-year progression-free survival and overall survival according IGCCCG classification were 100 % and 100 % for an intermediate risk patients and 68 % and 73,8 % for a poor risk, respectively. The favorable response rate (complete response + partial response with normalization STM) was observed in 19 (68 %) patients. During the follow-up period, disease progression was noted in 9 (32 %) patients, 7 (25 %) patients died, including one from an aggressive growing mature teratoma syndrome. Eleven (39 %) patients underwent surgical treatment: retroperitoneal lymph node dissection (55 %), mediastinal lymph node dissection (36 %), pulmonary resection (9 %). Pathological complete response was achieved in 6 (55 %) patients, mature teratoma — 2 (18 %), viable tumour — 3 (27 %). TIP showed acceptable safety profile and only in one case tumor lysis syndrome was observed. Conclusions: The TIP regimen may improve the results of treatment in the first line with unfavorable decrease of serum tumor markers after the first cycle of chemotherapy, which requires further study in a randomized trial.