Presentation Authors: Ryan Speir*, Adam Calaway, Marcelo Barboza, Richard Foster, Clint Cary, Indianapolis, IN
Introduction: Choriocarcinoma tumors of the testis are rare and usually present with significantly elevated HCG levels and hematogenous metastasis. When curable, it is felt to be largely a result of chemotherapy with little role for RPLND. We sought to determine the histologic characteristics for those undergoing PC-RPLND and compare them with metastatic NSGCT patients with similarly elevated HCG levels.
Methods: We reviewed the medical records of men who underwent PC-RPLND between 1988-2017 with post-orchiectomy, pre-induction chemotherapy HCG levels greater than 20,000 mU/mL. They were stratified by primary tumor histology into two groups: pure choriocarcinoma and mixed NSGCT. Clinical, pathologic and serologic data were reported and logistic regression was used to assess for predictors of necrosis /fibrosis in the PC-RPLND specimen.
Results: Our cohort consisted of 152 men. The mixed group (N=129) had a median HCG of 108,001 mU/mL, a post chemotherapy node size of 4.45 cm, of whom 25.6% also received salvage chemotherapy prior to RPLND. The pure choriocarcinoma group (N=23) had a median HCG of 110,358 mU/mL, a post chemotherapy node size of 5.0 cm, of whom 30.4% received salvage chemotherapy prior to RPLND. In patients with pure choriocarcinoma, 87% had necrosis/fibrosis in the PC-RPLND specimen compared to only 29.5% of the mixed NSGCT group (p= < 0.0001, Figure 1). While controlling for receipt of salvage chemotherapy, pre-chemotherapy HCG levels, node size and marker status, pure choriocarcinoma patients were 20 fold more likely to have necrosis on RPLND specimen compared to mixed NSGCT group (OR 20.68 (95% CI 5.279-81.114). Of importance, 4 additional major procedures were performed concomitantly with PC-RPLND in the pure choriocarcinoma group (2 pulmonary resections, 1 hepatic wedge resection and 1 nephrectomy), 100% of which had necrosis in the final RPLND pathology. This contrasts with the mixed NSGCT group in that of the 48 patients who required additional procedures, only 8.3% were done in the setting of necrosis in the final RPLND specimen.
Conclusions: While PC-RPLND is appropriate in patients with residual masses after chemotherapy, patients with pure choriocarcinoma presenting with significantly elevated HCG levels represent a unique patient population where necrosis is found more often than anticipated.