702P - Survival and related factors in testicular non-seminomatous patients undergoing high-dose chemotherapy and autologous stem cell transplantation: Experience of Turkey's highest volume transplantation center

Background

The prognosis of relapsed/refractory testicular non-seminomatous germ cell tumors is poor. If there is still residual disease after the first line treatment or in case of recurrence, second line and beyond lines systemic therapies are used. We conducted this study to present our survival data and side effect profile after a single application of high dose chemotherapy and autologous stem cell transplantation (HDCT and ASCT), as well as the evaluation of clinical factors affecting survival.

Methods

The data of 103 patients who received HDCT and ASCT between 01 January 2017 - 2023 were retrospectively evaluated. The patient group consisted of those who progressed radiologically or biochemically after the first-line standard cisplatin treatment or those who underwent surgery for residual disease and then relapsed. The high dose chemotherapy regimen consisted of carboplatin 700 mg/m2/day on D1-3, etoposide 750 mg/m2/day on D1-3. Demographic and clinicopathological characteristics of the patients, treatment related complications, time to progression and time to death were recorded. Radiological response was assessed by positron emission tomography/computed tomography (PET/CT) three months after treatment.

Results

Median age is 27. The most common subtype was mixed germ cell. There were 64.1% patients in the IGGGCG poor risk group. Before HDCT, serum tumor markers were within the normal range in 63.1% of the patients. A history of platinum refractory disease was present in 15.3%.

HDCT was performed in 93.2% of patients after the second line. Median PFS was found to be 10 months and OS was 17.4 months in the entire group. Myelotoxicity was observed in all patients. After HDCT, death occurred in 5.8% of patients in the first 100 days. In multivariate analysis, platinum refractory disease, AFP and/or beta HCG elevation, and NLR elevation were found to be significant in terms of prognosis.

Conclusions

It is possible to achieve significant survival thanks to HDCT and ASCT in a group of patients with a poor prognosis, where precision oncology treatments cannot be used frequently. Treatment-related mortality is low. Toxicity is manageable.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Musa Baris Aykan.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.