Several studies have shown an inverse relationship between acute infections and cancer development. On the other hand, there is a growing evidence that chronic infections may contribute significantly to the carcinogenesis. Factors responsible for increased susceptibility to infections may include modifications of normal defence mechanisms or impairment of host immunity due to altered immune function, genetic polymorphisms, ageing and malnourishment. Studies have demonstrated that children exposed to febrile infectious diseases show a subsequent reduced risk for ovarian cancer, melanoma and many other cancers, while common acute infections in adults are associated with reduced risks for melanoma, glioma, meningioma and multiple cancers. Chronic inflammation associated with certain infectious diseases has been suggested as a cause for the development of tumours. Mechanisms of carcinogenesis due to infections include cell proliferation and DNA replication by mitogen-activated protein kinase pathway, production of toxins that affect the cell cycle and lead to abnormal cell growth and inhibition of apoptosis. This review was aimed to summarize the available evidence on acute infections as a means of cancer prevention and on the role of chronic infections in the development and progression of cancer.

中文翻译：

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感染对癌症发病机制的影响

多项研究表明急性感染与癌症发展之间存在反比关系。另一方面，越来越多的证据表明慢性感染可能会显着促进癌变。导致感染易感性增加的因素可能包括正常防御机制的改变或由于免疫功能改变、遗传多态性、衰老和营养不良而导致的宿主免疫力受损。研究表明，接触发热传染病的儿童患卵巢癌、黑色素瘤和许多其他癌症的风险会降低，而成人常见的急性感染则与黑色素瘤、神经胶质瘤、脑膜瘤和多种癌症的风险降低有关。与某些传染病相关的慢性炎症已被认为是肿瘤发生的原因。感染引起的致癌机制包括细胞增殖和通过丝裂原激活蛋白激酶途径进行DNA复制、产生影响细胞周期并导致细胞异常生长和抑制细胞凋亡的毒素。本综述旨在总结关于急性感染作为癌症预防手段以及慢性感染在癌症发生和进展中的作用的现有证据。