Open Access

ARTICLE

Clinically atypical seminomas with yolk sac tumor features

Avik Som^1,2, Li Xiao³, Rui Zhu⁴, Charles C. Guo³, Lianchun Xiao⁵, Priya Rao³, Eleni Efstathiou¹, Angabin Matin⁴, Shi-Ming Tu¹

1 Department of Genitourinary Medical Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
2 The University of Texas MD Anderson Cancer Center Summer Research Program for Undergraduates, School of Health Professions, Houston, Texas, USA
3 Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
4 Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
5 Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
Address correspondence to Dr. Shi-Ming Tu, Department of Genitourinary Medical Oncology, Unit 1374, The University of Texas MD Anderson Cancer Center, 1155 Pressler Street, Houston, TX 77030-3721 USA

Canadian Journal of Urology 2013, 20(4), 6860-6867.

Abstract

Introduction: A small subset of young men die from seminoma. Studying these high risk, clinically atypical seminomas (CASs)—aggressive tumors with visceral metastases and chemotherapy resistance—may provide clues to the nature of drug resistance and the origin of testicular cancers. We explored the possibility that these seminomas are a unique clinical and biologic entity with intrinsic yolk sac tumor (YST) features.
Materials and methods: We assayed available archived tissue samples (n = 22) for chemotherapy-resistance markers found in YSTs. Specifically, we analyzed tissues and clinical histories from patients with CASs (those who had visceral metastases and recurrent disease), classical seminomas, and mixed germ-cell tumors containing YST. By using immunohistochemical testing, we evaluated the expression of bone morphogenetic protein 2, alpha fetoprotein, and glutathione S-transferase (pi) [GST (pi)].
Results: GST (pi) expression significantly predicted for overall survival (p = 0.036). In addition, according to the results of GST (pi) immunohistochemical staining, the CASs appeared to resemble YSTs more than they did classical seminomas (p = 0.043). Less-advanced tumors, both those that expressed GST (pi) and those that were negative for GST (pi), were more amenable to local therapies, and the patients who had those tumors had better clinical outcomes.
Conclusions: Results from this exploratory study suggest that certain CASs that express GST (pi) are more similar to YST than they are to classical seminomas, and that GST (pi) expression may be able to be used as a prognosticator of disease-specific survival. Such CASs thus may have a unique biologic origin that differs from that of classical seminomas. Additional studies are needed to determine the natural history and therapeutic implications of these CASs.

---

Keywords

---