Impact In Prognosis Of Residual Masses In Germ Cell Tumors.

e15617 Background: Residual masses (RM) after treatment with orchiectomy and chemotherapy in patients with germ cell tumors (GCT) may be positive for tumoral cells, necrosis or teratoma and might be implicated in the prognosis of the disease. Methods: We analyzed retrospectively 161 male patients diagnosed of GCT treated between 1974 and 2012 in our hospital with a median follow up of 8.1 years. We compared the evolution of patients with RM with those without. Results: 159 had testicular and 2 extragonadal tumors.41.5% were seminomas and 59.5% non seminomatous.16% of patients diagnosed at stage I had RM, 15% in stage II, whereas 50% in III and 46% in IV (p<0,001). BEP (Cisplatin, etoposide, bleomicine) was the most frecuent chemotherapy scheme used. 89.4% had complete responses, 7.5% parcial responses with negative tumoral markers and 1.9%. with positive markers. 27 (16.8%) of the 161 had RM detected in computed tomography: In 22 were resected, in 5 watchful waiting was decided. In 40% the histology was malignant tumor (MT) , in 32% teratoma, in 27% necrosis or other findings. No histological differences (linfovascular, rete testis or albugineal invasion) were found in those with MT (p=0.13). The finding of teratoma in primary tumor (PT) was not associated with the presence of RM (p=0.31). Median time to diagnosis of PT in the group without RM was 1.2 months, and in the RM group 2.1. (p=0.04). Intermediate or bad prognosis (GCT risk classification), was associated to the presence of RM (55% vs 11.3%, p<0.001). In the group without RM, 27 (20.3%) relapsed whereas 13 (48.1%) did it in the RM group (p=0.001). Progression free survival (PFS) without and with RM after two and ten years was 83% and 57% and 77% and 33% respectively p<0.001 HR:3.1 (CI95% 1.7-5.6). Ten-year overall survival (OS) was 92% and 81% respectively p=0.07 HR:2.5 (CI95% 0.9-6.9). Conclusions: 40% of RM were malignant tumors but we did not find any histological marker that may predict this. Bad or intermediate prognosis and advanced stages as well as elapsed time to diagnosis of PT were associated with the presence of RM. These patients had a raised risk of relapse and a lower rate of PFS but no differences were found in OS. In this serie, the finding of teratoma in primary tumor was not a predictor of residual masses.