Chlamydia trachomatis and cancer.(cervical and ovarian cancer)

Genital Chlamydia trachomatis infections have been recognised as a major public health problem. The World Health Organization (WHO) estimates that 50 million cases of C trachomatis infection occur each year worldwide. [1] C trachomatis is the major cause of mucopurulent cervicitis, pelvic inflammatory disease, tubal factor infertility, and ectopic pregnancy. [2-5] Thus, the healthcare costs due to complications caused by C trachomatis infections are enormous.

Cervical cancer is the most common cancer in women worldwide. Epidemiological studies have shown that early sexual activity is a risk factor for cervical cancer. [6] High risk human papillomavirus (HPV) types are found in practically all cervical carcinomas. [7] The evidence linking oncogenic HPV types in the aetiology of cervical carcinoma is beyond doubt. HPV DNA based longitudinal studies have confirmed the seroepidemiological findings that past HPV infection predisposes to the development of cervical carcinoma. [8,9] Since C trachomatis infection is also a marker of sexual activity, an association between C trachomatis and cervical cancer has been suggested. Previous case-control studies have found cytological or serological evidence of the role of C trachomatis in cervical neoplasia. [10-12] Recent longitudinal seroepidemiological studies also shown that C trachomatis infection is associated with cervical carcinoma. [13,14] This association remains after adjustment for smoking and serum antibodies to th e high risk HPV types. [15] The association was specific for squamous cell carcinoma, and not for adenocarcinoma. [15] Of specific C trachomatis serotypes, serotype G was most strongly associated with cervical squamous cell carcinoma. [16] Furthermore, the presence of serum IgG antibodies to more than one serotype increased the risk. [17] The link between C trachomatis and squamous cell carcinoma is unexpected since it is well known that the targets for C trachomatis are endocervical glandular cells, and that women with cervical ectopy are more susceptible to C trachomatis than women without cervical ectopy.…