The Clinical Significance of a Small Component of Choriocarcinoma in Testicular Mixed Germ Cell Tumor (MGCT).

ABSTRACT

The clinical significance of limited choriocarcinoma in a malignant mixed germ cell tumor (MGCT) is unknown. Men with a MGCT with ≤5% choriocarcinoma at radical orchiectomy (RO) between 2000 and 2016 from our consult service were studied. Of 50 men in our cohort, we had clinical information for 30 men. Median follow-up was 41 months (1 to 168 mo). Median tumor size was 4.5 cm (1.1 to 8.0 cm). In total, 22/30 (73%) cases were pT1, 6/30(20%) cases were pT2, and 2/30 (7%) cases were pT3. In total, 4/30(13%) cases had lymph node metastases and 2/30 (7%) cases had distant metastases at the time of RO. In 30 cases with RO we had information on immediate postorchiectomy treatment 14/30 (46.7%) active surveillance, 4/30 (13.3%) retroperitoneal lymph node dissection, 10/30 (33.3%) chemotherapy (chemotherapy), 1/30 (3.3%) retroperitoneal lymph node dissection followed by chemotherapy, and 1/30 (3.3%) resection of a distant metastasis. Preoperative serum human chorionic gonadotropin (hCG) levels ranged between 0.1 and 60,715 mIU/mL (mean, 4796; median, 485). One patient had an hCG level of 6367 mIU/mL and another 60,715 mIU/mL with the remaining cases <5000 mIU/mL. In total, 4/30 (13%) patients had elevated serum markers after surgery, 3 of them normalized following chemotherapy while the fourth one continued to have elevated serum alpha fetoprotein levels after chemotherapy. All patients were alive at last follow-up. In total, 7/30 (23.3%) patients subsequently developed metastatic disease to lymph nodes or distal organs, the histology of the metastasis consisted mainly of teratoma and yolk sac tumor. Embryonal carcinoma was present in 2 metastatic sites. One lung metastasis was suggestive for choriocarcinoma. Definitive choriocarcinoma was not present in any of the metastasis. A small component of choriocarcinoma in a MGCT is typically associated with relatively low-level elevations of serum hCG levels, and is not associated with aggressive disease. The presence of limited choriocarcinoma (≤5%) does not add to the prognostic information provided by standard TNM staging, which uses levels of serum markers (hCG, alpha fetoprotein, lactate dehydrogenase) as surrogates for extent of disease.