Metabolic syndrome is associated with increased cancer risk and progression at almost all sites, including the prostate in high-stage prostate cancer. However, several reports have described an inverse relationship between metabolic syndrome and its components and low-stage incident prostate cancer. Such anomalies in cancer research hamper efforts to fight cancer. Evidence suggests that metabolic syndrome and its components have two distinct effects in prostate cancer, concealing prostate cancer in low-stage disease and promoting progression to high-stage incident, nonlocalized, and lethal prostate cancer. The concealment of prostate cancer by metabolic syndrome and its components might be related to bias mechanisms that reduce PSA level and lead to a delayed diagnosis of low-stage prostate cancer, meaning that fewer men with metabolic syndrome are diagnosed with low-stage disease. The inverse link between metabolic syndrome and its components and low-stage incident prostate cancer might simply be the result of such bias and the shortcomings of the diagnostic procedure rather than being related to prostate cancer biology itself. The evidence summarized here supports the hypothesis that the link between metabolic syndrome and its components and incident prostate cancer is a two-way and stage-dependent one, a theory that requires further research.

代谢综合征与几乎所有部位（包括晚期前列腺癌中的前列腺）的癌症风险增加和进展有关。然而，一些报告描述了代谢综合征及其成分与低级事件性前列腺癌之间的反比关系。癌症研究中的此类异常妨碍了抗击癌症的努力。有证据表明，代谢综合症及其成分在前列腺癌中具有两种不同的作用，即将前列腺癌隐藏在低级疾病中，并促进其发展为高级别事件，非局限性和致命性前列腺癌。代谢综合症及其成分对前列腺癌的掩盖可能与降低PSA水平并导致低级前列腺癌的诊断延迟的偏倚机制有关，这意味着被诊断患有低级疾病的新陈代谢综合症男性人数减少。代谢综合症及其成分与低级事件性前列腺癌之间的反向关联可能仅仅是这种偏见和诊断方法的缺陷，而不是与前列腺癌生物学本身有关。此处总结的证据支持以下假设：代谢综合征及其成分与入射前列腺癌之间的联系是双向且依赖阶段的，这一理论需要进一步研究。