Bilateral testicular germ cell tumors.

Abstract

392 Background: Germ cell tumors (GCTs), both seminomatous and non-seminomatous, account for greater than 90% of testicular cancers. While bilateral testicular GCTs are rare, the incidence of bilateral tumors has increased over time. Methods: 668 cases of bilateral and 38,593 cases of unilateral testicular GCTs were reported between 1973 and 2011 by the SEER database. Patient characteristics and tumor features were analyzed. Results: The incidence of bilateral GCTs among men with testicular GCTs was 1.7% (668 of 39,261 total cases). Among the 668 men with bilateral GCTs, 53% (n=353) of second GCTs occurred within three years after the first cancer. 29% (n=196) of bilateral tumors occurred synchronously. Among patients with bilateral GCTs, 378 first GCTs and 466 second GCTs were seminomatous. 43% of bilateral cases were concordant seminomatous GCTs, 16% were concordant non-seminomas, and 41% were discordant histologies. 68% of unilateral GCTs, 70% of first GCTs, and 82% of second GCTs were staged as Localized disease. Testicular cancer was the cause of death for 4% (n=1,630) of men with a unilateral GCT and 1% (n=8) of men with bilateral GCTs. A second malignant neoplasm (SMN) was the cause of death for 2% (n=736) of men with a unilateral GCT and 2% (n=16) of men with bilateral GCTs. Conclusions: Among men with bilateral testicular GCTs, 59% had concordant histological diagnoses between their first and second tumor. Most (53%) second cancers among men with bilateral tumors occurred within three years after diagnosis of first cancers. Men who experience bilateral testicular GCTs do not appear to have an increased risk of death due to testicular cancer or a subsequent non-germ cell malignant neoplasm compared to men with a unilateral testicular GCT. [Table: see text]