Clinical and pathological outcomes of patients with germ-cell tumor undergoing surgical resection of residual disease after high-dose chemotherapy.

e17012 Background: In patients (pts) with germ-cell tumor (GCT) treated with high-dose chemotherapy (HDCT) and peripheral-blood stem-cell transplantation (PBSCT), residual disease after HDCT both within and outside the retroperitoneum poses a major challenge. We report the pathologic and clinical outcomes of pts with GCT who underwent surgical resection of post-HDCT residual disease. Methods: The prospectively maintained Indiana University testicular cancer database was queried for pts who underwent surgery after HDCT with PBSCT from 1990-2025. The Kaplan-Meier method was used to analyze overall survival (OS) using the log rank test to compare groups. Start date for OS was time of first cycle of HDCT. Results: 97 pts underwent surgical resection after HDCT. The median age at diagnosis was 27.9 years (range, 16.1-54.5). Primary site was testis in 92% of pts. 95 pts (98%) had NSGCT. IGCCCG risk at diagnosis was good in 25 pts (26%), intermediate in 14 (14%) and poor in 58 (60%). 53 pts underwent a post HDCT RPLND, 14 underwent thoracic surgery, 4 underwent brain met resection and 8 underwent surgical resection at other sites. 18 additional pts underwent multiple surgeries; 5 underwent both thoracic surgery + RPLND, 6 underwent hepatectomy + RPLND and 3 underwent brain met resection with either an RPLND or lung surgery. Pathologic outcomes are described in Table 1. 75 out of the 97 pts (78.4%) who underwent post HDCT surgical resection had either residual non-teratomatous GCT or teratoma. In the 18 pts who underwent surgical resection at multiple sites, 10 (56%) had discordant pathologic findings between the sites. Post-HDCT surgery was done in the setting of elevated tumor markers in 40 (41.2%) pts vs. normal tumor markers in 57 (58.8%) patients. 5yr OS of the entire cohort was 64.2% (53.1-73.3). 5 yr OS of pts with normal tumor markers at resection was 74.3% (60.4-83.9). 5 yr OS of patients with residual non-teratomatous GCT at time of surgical resection was 34.4% (19.4-49.9). Conclusions: In pts who underwent post HDCT-surgery, irrespective of surgical location, 78% had either residual non-teratomatous GCT or teratoma. OS was worse for pts with residual non-teratomatous GCT at time of resection of post-HDCT residual disease. Pathologic outcomes**. Surgery TotalN= 97 RPLND-Teratoma -GCT-MT* -Necrosis only 5331 (58%)17 (32%)4 (7%)13 (25%) Thoracic-Teratoma-GCT-Necrosis only 144 (29%)8 (57%)5 (36%) Brain-Teratoma-GCT-Necrosis only 41 (25%)3 (75%)1 (25%) Other-Teratoma-GCT-MT-Necrosis only 81 (13%)5 (63%)1 (13%)1 (13%) *Malignant Transformation. **Several patients had multiple pathologic components at resection.