Prognostic utility of lactate dehydrogenase in patients with metastatic seminoma.

Abstract

604 Background: Serum tumor markers play an important role in risk classification, prognostication, staging, and monitoring of treatment in germ-cell tumors (GCTs). While alpha-fetoprotein (AFP) and human chorionic gonadotropin (hCG) are validated prognostic markers, recent investigations have suggested a correlation with lactate dehydrogenase (LDH) and treatment response and survival. Here, we evaluated LDH levels and survival in patients with advanced seminoma. Methods: The prospectively maintained Indiana University (IU) testicular cancer database was queried for patients with metastatic seminoma treated with first-line therapy. Pts were assigned to having a LDH <2.5 upper limit of normal (ULN) or ≥2.5 ULN based on pre-treatment LDH levels. Baseline characteristics were summarized. The Kaplan-Meier method was used to analyze progression free survival (PFS) and overall survival (OS). Results: 113 pts were included in the study. Median age at diagnosis was 39.21 (22.80-68.72). Primary site was testis in 104 (92%), retroperitoneum in 6 (5.3%), and mediastinum in 3 (2.7%). Metastasis sites were retroperitoneal lymph nodes in 85%, pelvic lymph nodes in 12.4%, lung in 7.1%. IGCCCG risk was good in 92% and intermediate in 8%. 68.6% of pts were treated with BEPX3, 19.8% with EPX4, 1.2% with VIPX4, and 9.3% with other regimen. Median hCG was 3.50 (0.5-11,600). Median LDH was 349 (34-6550). Median follow-up was 2.30 years (0.02-19.11). 61 pts had LDH <2.5 ULN, 52 pts had LDH ≥2.5 ULN. For those with LDH <2.5 ULN, 3yr PFS was 91.5% (78.7-96.8) vs. 62.8% (45.2-76.1) for those with LDH ≥2.5 ULN, p= 0.0050. However, 3yr OS for those with LDH <2.5 ULN was 100% (100-100) vs. 95.2% (82.0-98.8), p= 0.6218. Conclusions: Patients with metastatic seminoma and LDH ≥2.5 ULN had inferior 3-yr PFS compared with normal LDH, but there was no difference in OS.