No need for contralateral lung surgery in case of evidence of post-chemotherapy necrosis alone in residual lung masses in patients with disseminated non seminomatous germ cell tumors

Abstract

4524 Background: Resection of residual lesions after primary chemotherapy and normalization of serum tumor markers is part of the multimodality treatment of advanced non seminomatous germ cell tumors (NSGCT). Multiple resections are currently recommended in case of multiple sites of residual disease. Methods: A multicenter retrospective study of 71 pts with thoracic residual masses after first-line cisplatin-based chemotherapy for disseminated NSGCT. Results: The histologic findings in residual lesions included complete necrosis, teratoma, and viable cancer in 31%, 55%, and 14% of patients, respectively. Discordant histopathologic findings were evidenced between retroperitoneal lymph node and thoracic (lung or mediastinal lymph nodes) residual masses in 31% of cases (n= 52). For example, 3 of the 15 pts with necrosis (20%) alone in RPLND had either teratoma or viable cancer in their lung metastases. In contrast, only 2 of 39 patients (5%) who had a bilateral pulmonary resection had discordant histological findings between the 2 lungs. Of 20 patients with necrosis alone in residual masses in the first lung, 19 (95%) also had necrosis alone in residual masses in their contralateral lung. Only one patient had necrosis alone in the first lung and some mature teratoma in the contralateral lung. Conclusions: These results support published data on discordant histopathologic findings between retroperitoneal and thoracic residual masses. Most importantly, they show that the pathologic concordance rate between the 2 lungs is high. Therefore, we recommend avoiding contralateral lung surgery when only necrosis is found in the first lung after primary chemotherapy for NSGCT. No significant financial relationships to disclose.