镉是已知的人类致癌物质，在多个层面上深刻影响着男性生殖功能，通过发挥内分泌和非内分泌作用。然而，在睾丸癌症病因中镉的潜在作用在人类中研究得很少，目前可用的流行病学观察研究对此无法得出确定性结论。相反，实验动物研究显示，镉是睾丸肿瘤的强烈诱导剂，主要表现为良性Leydig细胞腺瘤；此外，也有报道称在少数动物中发现了恶性转化，随着镉治疗的进行。早期动物实验研究提出了镉诱发睾丸肿瘤的内分泌依赖机制；然而，最新的细胞无液相分析、体外研究和短期体内研究的发现表明，镉也可能通过早期发生的内分泌非依赖机制，包括睾丸内异常基因表达和基因毒性效应，提供了对睾丸肿瘤发生之时机之前镉的贡献。然而，这些内分泌非依赖机制迄今为止尚未直接在受影响的镉处理动物的睾丸肿瘤样本中进行研究。本综述侧重于镉暴露与睾丸癌之间的关系，通过报告少数可用的流行病学观察人类研究并提供基于动物的实验证据，详细讨论镉在睾丸肿瘤发生和发展中的相关性。此外，还将通过批判性地评估可用数据的优点和不足，广泛讨论实验动物研究与人类镉暴露的相关性和实验结果的翻译潜力。

Cadmium is a known human carcinogen, and has been shown to profoundly affect male reproductive function, at multiple levels, by exerting both endocrine and non-endocrine actions. Nevertheless, the potential role of cadmium in the etiology of testis cancer has been scantly investigated in humans, and, currently, available epidemiological observational studies are insufficient to draw definitive conclusions in this regard. On the contrary, experimental studies in laboratory animals demonstrated that cadmium is a strong inducer of testis tumors, mostly represented by benign Leydig cell adenoma; moreover, malignant transformation was also reported in few animals, following cadmium treatment. Early experimental studies in animals proposed an endocrine-dependent mechanism of cadmium-induced testis tumorigenesis; however, more recent findings from cell-free assays, in vitro studies, and short-term in vivo studies, highlighted that cadmium might also contribute to testis tumor development by early occurring endocrine-independent mechanisms, which include aberrant gene expression within the testis, and genotoxic effects, and take place well before the timing of testis tumorigenesis. These endocrine-independent mechanisms, however, have not been directly investigated on testis tumor samples retrieved from affected, cadmium-treated animals so far. The present review focuses on the relationship between cadmium exposure and testis cancer, by reporting the few epidemiological observational human studies available, and by providing animal-based experimental evidences of cadmium implication in the pathogenesis and progression of testis tumor. Moreover, the relevance of experimental animal studies to human cadmium exposure and the translational potential of experimental findings will be extensively discussed, by critically addressing strengths and weaknesses of available data.