Molecular Detection of HPV and Chlamydia trachomatis Infections in Brazilian Women with Abnormal Cervical Cytology

Abstract

Abstract. The question of whether Chlamydia trachomatis (Ct) is a cofactor for human Papillomavirus (HPV) in cervical carcinogenesis is still controversial. We conducted a molecular detection study of both infections in 622 Brazilian women, including 252 women with different grades of abnormal cervical cytology and cervical cancer (CC; cases) and 370 women with normal cytology (controls). Although Ct infection did not seem related to CC carcinogenicity, women with abnormal cytology had a significant high rate of Ct infection. Therefore, it is important to adopt protocols for diagnosis and treatment of this bacterium in conjunction with screening for CC in this population.At present, cervical cancer (CC) is the second leading cause of cancer affecting women, 1,2 preceded only by breast cancer; it develops over a long period through precursor lesions that can be detected by cytological screening.3 Its frequency varies in different regions of the world, and it is much higher in underdeveloped or developing than developed countries.1 In Brazil, CC is the third most common cancer among women, with 17,000-18,000 new cases annually. 4 It is well-established that persistent infection by high-risk (HR) human Papillomavirus (HPV) is a necessary but not sufficient cause of CC.5 Considering that a small proportion of HR-HPV-infected women actually develop CC, 6 additional risk factors that may be involved in the development of the disease have been investigated.Among other sexually transmitted infections (STIs) that can increase the risk of CC, Chlamydia trachomatis (Ct) is among the leading factors. Some investigators have proposed that Ct infection could affect HPV acquisition and persistence, increase the rate of transformation to early precursor lesions, and also increase the likelihood that precursor lesions lead to CC.7 However, the association of Ct as a cofactor for HPV in cervical carcinogenesis is still controversial. 8 This information directly affects the adoption of efforts to control CC, because a Ct-HPV association would require not only HPV vaccination but also adoption of protocols for diagnosis and treatment of the bacteria. Considering that, in Brazil and Latin America in general, few studies have examined this possibility, we conducted a molecular detection study of HPV and Ct infections in Brazilian women with different grades of abnormal cervical cytology and CC in an attempt to contribute to elucidating the involvement of Ct in cervical carcinogenesis.Six hundred twenty-two women of low socioeconomic status, ages 15-83 years, were recruited between August 1, 2009 and March 31, 2012 in three cities of the state of Paraná , southern Brazil: Maringá , Paiçandú , and Uniã o da Vitó ria. The epidemiological characteristics were obtained through the analysis of data from a standard registration form for each woman. Each woman involved signed the authorization, and the execution of this project was approved by the Committee for Ethics in Research Involving Humans at the State University of Maringá /Paraná , ...

Frequency of Chlamydia trachomatis infection in cervical intraepithelial lesions and the status of cytological p16/Ki-67 dual-staining

“…When assessing other demographic factors, such as years of schooling, marital status and smoking, there was no positive association with Ct presence, similar to what has been reported in other national studies [13]. …”

“…A study conducted in the city of Manaus had a higher prevalence of 20.7%, and may be explained by regional or socioeconomic reasons [4, 13–15]. …”

Prevalência da infecção endocervical de Chlamydia trachomatis em universitárias do estado do Pará, Região Amazônica, Brasil

“…A prevalência da infecção não difere significativamente das encontradas em outros estudos do Brasil, os quais foram realizados em populações femininas urbanas, com variados graus de instrução, como nos estados do Rio Grande do Norte (10,9%) 13 , Goiás (9,6%) 14 , Paraná (12,7%) 17 e Rio Grande do Sul (11,0%) 15 . Apenas nos estados da Bahia (31,0%) 18 e de Pernambuco (23,8%) 16 foram registradas prevalências maiores, porém com tamanho amostral inferior ao utilizado neste estudo.…”

“…No Brasil, a prevalência de infecções por C. trachomatis varia entre 4,3% e 31,0%, conforme estudos de base populacional/comunitária de grandes centros urbanos e estudos de base clínica, realizados com participantes frequentadoras de ambulatórios e clínicas ginecológicas 10,11,12,13,14,15,16,17,18,19 . Nas comunidades amazônicas, há escassez de conhecimento sobre a epidemiologia da infecção endocervical por C. trachomatis, o que impossibilita a criação de diretrizes que estabeleçam o rastreio e controle dessa infecção.…”

Lack of Significant Effects of Chlamydia trachomatis Infection on Cervical Cancer Risk in a Nested Case-Control Study in North-East Thailand

“…Thus, although infection did not seem related to cervical cancer in one study in Brazil, women with abnormal cytology had a significant high rate of C. trachomatis (de Abreu et al, 2012). A positive Chlamydia test was also significantly associated with the risk of having an abnormal cervical cytology in Puerto Rican pregnant women (Seda et al, 2011) and in Greece (Peitsidis et al, 2012).…”