Chlamydial disease: a crossroad between chronic infection and development of cancer BACTERIA AND CANCER 2012, 79-116, DOI: 10.1007/978-94-007-2585-0_4

Chlamydia is an intracellular bacterium implicated as potentially oncogenic for its tendency to cause chronic and persistent infections. This organism has been frequently associated with several types of cancer including cervical dysplasia and cancer by C. trachomatis, lung cancer and cutaneous T-cell lymphoma by C. pneumoniae and a number of non-gastrointestinal MALT lymphomas such as ocular adnexal lymphoma by C. psittaci, suggesting a potential role. C. trachomatis, which causes ocular-genital infections in humans, was recently demonstrated at molecular and cultural level in patients with ocular cancer, thus implying also for this bacterium a role in the pathogenesis of the above malignancy. The pathophysiological processes and molecular mechanisms that lead to the development of chronic inflammatory disease, persistence, and ultimately cancer, still need to be clarified. This chapter describes the pathogenetic aspects of Chlamydial infections favouring the onset of chronic diseases and cancers as well as the diagnostic and clinical features in relation to Chlamydia species involved. The potential application of bacteria-eradicating therapy would certainly represent an exciting challenge for the next few years.