Genomic characterization of testis cancer: Association of alterations with outcome of clinical stage 1 mixed germ cell nonseminomatous germ cell tumor of the testis

Objective: To identify genomic markers that are reliable in predicting lymph node metastases in clinical stage 1 non-seminomatous germ cell tumors (NSGCTs). Methods: Comparative genomic array technology was used to identify regions of genomic amplification or deletion in clinical stage 1 NSGCTs. Twelve stage 1 mixed germ cell testicular tumors were analyzed, which were obtained from 8 patients who had no evidence of nodal metastasis when retroperitoneal lymph node dissection (RPLND) had been performed (ie, were RPLND negative) and 4 patients who had nodal metastases (ie, were RPLND positive). Results: Differences between the genomic alterations associated with the two classes of tumors were identified. Genomic alterations previously reported in other subtypes of testicular tumors were observed in both metastatic and nonmetastatic cases. Statistically suggestive differences in mean copy number of the Y chromosome were found between metastatic and nonmetastatic cases (P =.0142). Conclusion: This finding suggests the presence of chromosome Y deletions to be a potential genetic marker for prediction of mixed germ cell tumor progression. This is a first step toward identifying chromosomal markers of progression in testicular cancer in clinical stage 1 mixed germ cell NSGCT.