Clinical outcomes and histological findings of patients with advanced metastatic germ cell tumors undergoing post-chemotherapy resection of retroperitoneal lymph nodes and residual extraretroperitoneal masses.

Objectives: To assess clinical outcomes of patients with advanced germ cell tumor undergoing post-chemotherapy retroperitoneal lymph node dissection with or without extraretroperitoneal mass resection.

Methods: Between 1998 and 2013, 175 retroperitoneal lymph node dissections for advanced metastatic germ cell tumors were carried out at Kyoto Prefectural University of Medicine, Kyoto, Japan. Of patients receiving retroperitoneal lymph node dissections, 156 underwent post-chemotherapy retroperitoneal lymph node dissection with or without extraretroperitoneal mass resection as first surgery after completion of chemotherapy. Of these 156 patients, 47 underwent both post-chemotherapy retroperitoneal lymph node dissection and extraretroperitoneal mass resection.

Results: The histological findings were necrosis in 59.6%, teratoma in 31.4% and viable cancer in 9.0% at retroperitoneal lymph node. At extraretroperitoneal mass resection, necrosis was present in 59.6%, teratoma in 31.9% and viable cancer in 8.5%. Overall histological discordance between retroperitoneal lymph node and extraretroperitoneal mass was found in 31.9%. Five-year disease-free survival stratified by retroperitoneal lymph node histology in 156 patients was 91.3% for necrosis, 78.7% for teratoma and 63.5% for viable cancer (log-rank, P = 0.009). Antegrade ejaculation was preserved in 80.9%. In the worst histology of post-chemotherapy retroperitoneal lymph node dissection or extraretroperitoneal mass resection in 156 patients, 5-year disease-free survival was 93.2% for necrosis, 79.0% for teratoma and 63.4% for viable cancer (log-rank, P < 0.001). Independent prognostic factors for disease-free survival were presence of viable cancer in retroperitoneal lymph node histology and salvage chemotherapy.

Conclusion: The presence of viable cancer at the retroperitoneal lymph node is an independent predictor of disease recurrence. In approximately one-third of cases, there is a histological discordance between retroperitoneal lymph node and extraretroperitoneal mass. Resection of residual retroperitoneal lymph node and extraretroperitoneal masses remains an important procedure in the management of advanced germ cell tumors.