Management Of Stage I Seminomatous Germ-Cell Cancer (Sgcc): Results From 4 Different Risk-Adapted Strategies In A Single Institution.

e16047 Background: Management of stage I SGCC depends on pathological findings after orchiectomy. Four risk-adapted strategies were sequentially applied in a single institution during a 24-year (yr) period according to national guidelines. Here, we compare treatment burden and outcomes of each of them. Methods: From 1/1994 to 1/2018, 208 patients with stage I SGCC were prospectively included in 4 cohorts. Those without risk criteria underwent close surveillance. Patients received active treatment as follow: Group 1: 1994-1999, only patients with T > pT1 received 2 cycles of carboplatin (CBDCA AUC7 x2); Group 2: 1999-2003, patients received CBDCA AUC7 x2 if either tumor size > 4cm or rete testis invasion; Group 3 : 2004-2009, CBDCA AUC7 x2 if both tumor size > 4cm and rete testis invasion were present; Group 4 : ≥2010, CBDCA AUC7 x1 if either tumor size > 4cm or rete testis invasion. Kaplan Meier and log-rank tests were used to evaluate disease-free survival (DFS), Kruskal-Wallis test to compare amount of chemotherapy received per patient. Results: At a median follow-up of 108 months [range 3-423], 19 (9.1%) relapses had occurred. Global 3 and 5-yr DFS were 92.3% and 90%. All relapsing patients were rendered disease-free with 4 cycles of cisplatin (CDDP) - etoposide. Table 1 summarizes results by cohort: Conclusions: A risk-adapted program provided an overall specific survival of 100%. A clinically significant difference in RR was observed when 1 or 2 courses of CBDCA were given. In our series and considering treatment burden, vascular invasion was a better criteria for patient selection to adjuvant chemotherapy, showing a similar DFS but a lower no of total platinum cycles per patient.[Table: see text]