Stage II embryonal predominant NSGCT: Minimizing treatment burden.

Abstract

634 Background: Embryonal carcinoma predominance (ECP) in the orchiectomy specimen is linked to a higher risk of retroperitoneal and systemic relapse. Both chemotherapy and primary retroperitoneal lymph node dissection (RPLND) are recommended options for stage II disease, but the approach that minimizes treatment burden remains unclear. Methods: We queried the Indiana University Testicular Cancer Database to identify patients with non-seminomatous germ cell tumors (NSGCT) and ECP >50% in the orchiectomy specimen, stage II with retroperitoneal adenopathy <5 cm, and normal serum tumor markers. Patients with malignant transformation (n=3) or bilateral cancer (n=3) or receiving 1-2 cycles of BEP after orchiectomy were excluded (n=14). Treatment courses and outcomes were compared. Results: Between 2005 and 2022, 142 patients met the criteria. Of 67 patients who underwent primary RPLND, 62 had active EC in final pathology. Adjuvant chemotherapy (2 cycles of EP or BEP) was given to 5 patients. After a median follow-up of 37.7 months, 10 recurred, with a recurrence-free survival (RFS) of 85.1%. Following induction chemotherapy for documented recurrence, 9 patients were disease-free, with 1 disease-related death. Disease-free survival (DFS) was 98.5%. There were no in-field recurrences in the primary RPLND group. Of the 75 patients who received chemotherapy, 25 required post-chemotherapy (PC) RPLND, which revealed either teratoma or necrosis, and no active cancer was found. One recurred and needed re-do RPLND. Five patients who achieved complete remission after chemotherapy recurred, requiring second-line and high-dose chemotherapy. The RFS was 92%, with a median follow-up of 34.1 months. DFS was 97.3%. Univariate analysis showed pre-orchiectomy AFP >100 ng/mL (OR 7.6, 95% CI 1.6–54.9) and teratoma >5% in the orchiectomy specimen (OR 4.1, 95% CI 1.3–13.2) were associated with the need for PC-RPLND, but no parameters were predictive in multivariate analysis. Conclusions: Primary RPLND achieved complete remission as a single treatment modality in 85% of patients, compared to 67% for chemotherapy. Primary RPLND may reduce treatment burden in early-stage II ECP NSGCT in well-selected patients.