Late relapse of germ cell tumors: Detection and treatment outcomes.

Abstract

5007 Background: Late relapse (LR) of germ cell tumors (GCT) is defined as relapsed disease > 2 years from initial treatment. LR remains a challenge both for optimal screening methods and treatment. We report the method of detection, treatments received, and outcomes in patients with LR GCT. Methods: The prospectively maintained Indiana University testicular cancer database was queried identifying 2712 pts with GCT treated at Indiana University from January 2000 to January 2019. Method of detection of LR was recorded along with site, treatment received, chemo-naive vs chemo-exposed LR, and survival outcomes. Results: 90 pts with LR were identified. Median age at LR was 35.2 yr (range, 19.2-56.8). Primary tumor site was testis in 88 (98%), retroperitoneum in 1 (1%), and mediastinum in 1 (1%). Chemo-exposed accounted for 42 (47%) and chemo-naïve for 48 (53%) of cases. Table compares clinical characteristics and survival outcomes of chemo-exposed vs. chemo-naïve late relapse. 62% of chemo-exposed LR were diagnosed with elevated AFP. For the 42 chemo-exposed LR pts, 2-yr PFS based on treatment: surgery vs. chemo vs surgery+chemo was 48% vs 10% vs 45% (p = 0.105). For the 48 chemo-naïve LR pts, 2-yr PFS based on treatment: surgery vs. chemo vs. surgery+chemo was 100% vs 74% vs 37% (p = 0.004). Next generation sequencing was available for 9 patients. No actionable findings were found. Tumor mutational burden was low in all patients where genomic testing was available. Conclusions: Most pts with chemo-exposed LR will be diagnosed with an elevated AFP. GCT pts require lifetime follow-up with annual physical exam and tumor markers. Surgical resection, when feasible, remains our preferred treatment for chemo-exposed LR as chemotherapy alone offers only brief responses. Pts with chemo-naïve LR have more chemo-sensitive biology.[Table: see text]