Thoracic residual germ cell tumor resection after high-dose chemotherapy with autologous stem cell transplantation in relapsed patients

Abstract

Purpose: The pathological and patient outcomes after the resection of residual thoracic germ cell tumors following sequential high-dose chemotherapy with autologous stem cell transplantation (HDC + SC) have rarely been investigated.

Methods: We retrospectively analyzed 79 male patients who underwent resection for residual germ cell tumors after HDC + SC between 1999 and 2017. Patient information, tumor characteristics, and short-term outcomes were analyzed. Long-term outcomes and survival curves were analyzed via the Kaplan‒Meier-method.

Results: In the HDC + SC cohort, lung metastases were observed in 88.6% of patients, mediastinal metastases in 24.1%, retrocrural metastases in 8.9%, and cervical metastases in 7.6%. Among those with pulmonary involvement, 67.1% presented with bilateral disease. Additional metastatic sites treated in the HDC + SC setting included the retroperitoneum (32.9%), liver (8.9%), brain (21.5%), and bone (5.1%). Postoperative histology following thoracic resections revealed necrosis in 49.4% of cases, teratoma in 26.6%, and viable malignancy in 24%. In patients undergoing multiple thoracic resections, discordant histological findings between different sites were identified in 24.53%. The rates of minor and major morbidity were 6.3% and 10.1%, respectively, with no 90-day mortality observed. Median follow-up was 123 months, and the 5-year overall survival reached 76%.

Conclusions: After sequential high-dose chemotherapy with autologous stem cell transplantation and partly high tumor burden, thoracic residual tumor resection can be performed with low morbidity and good long-term survival. Only about half of the histologies following high-dose chemotherapy are complete necroses, and the high rate of discordant histologies emphasize the importance of complete and bilateral resection.

Keywords: Germ cell cancer; High-dose chemotherapy; Lung metastases; Metastasectomy; Stem cell transplantation.