Serotypes of Chlamydia trachomatis and risk for development of cervical squamous cell carcinoma.
BACKGROUND
Human papillomavirus (HPV) infection has been established as a cause of cervical cancer. Epidemiologic studies suggest that Chlamydia trachomatis infection also confers increased risk for cervical squamous cell carcinoma (SCC). Whether this risk is serotype-specific is unknown.


OBJECTIVE
To study the association between exposure to different C trachomatis serotypes and subsequent development of cervical SCC.


METHODS
Longitudinal, nested case-control study within a cohort of 530 000 women who provided samples to serum banks in Finland, Norway, and Sweden. The data files were linked to respective national cancer registries.


METHODS
One hundred twenty-eight women who had developed invasive cervical SCC at least 12 months following serum donation. Each case had 3 matched controls.


METHODS
Risk for the development of cervical SCC by IgG antibodies to 10 different C trachomatis serotypes, adjusted for antibodies to HPV types 16, 18, and 33 and for serum cotinine levels.


RESULTS
Of specific C trachomatis serotypes, serotype G was most strongly associated with SCC (adjusted odds ratio [OR], 6.6; 95% confidence interval [CI], 1. 6-27.0). Other serotypes associated with SCC were I (OR, 3.8; 95% CI, 1.3-11.0) and D (OR, 2.7; 95% CI, 1.3-5.6). Presence of serum IgG antibodies to more than 1 serotype increased the adjusted ORs for SCC (P<.001 for trend).


CONCLUSIONS
Chlamydia trachomatis serotype G is most strongly associated with subsequent development of cervical SCC. Increasing numbers of exposures to different C trachomatis serotypes also increases risk. Our results strengthen the evidence that there is a link between past C trachomatis infection and cervical SCC.
Anttila
T
T
Department of Obstetrics and Gynecology, University of Helsinki, Haartmaninkatu 2, 00290 Helsinki, Finland.
Saikku
P
P
Koskela
P
P
Bloigu
A
A
Dillner
J
J
Ikäheimo
I
I
Jellum
E
E
Lehtinen
M
M
Lenner
P
P
Hakulinen
T
T
Närvänen
A
A
Pukkala
E
E
Thoresen
S
S
Youngman
L
L
Paavonen
J
J
D000907:Antibodies, Bacterial / Q000097:blood; D002294:Carcinoma, Squamous Cell / Q000097:blood / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology; D016022:Case-Control Studies; D002690:Chlamydia Infections / Q000150:complications; D002692:Chlamydia trachomatis / Q000145:classification* / Q000235:genetics / Q000276:immunology; D003367:Cotinine / Q000097:blood; D004269:DNA, Bacterial; D005260:Female; D006801:Humans; D016015:Logistic Models; D008137:Longitudinal Studies; D027383:Papillomaviridae / Q000302:isolation & purification; D012042:Registries; D012307:Risk Factors; D012537:Scandinavian and Nordic Countries / Q000453:epidemiology; D012703:Serotyping; D002583:Uterine Cervical Neoplasms / Q000097:blood / Q000453:epidemiology / Q000382:microbiology* / Q000821:virology
D000907:Antibodies, Bacterial; D004269:DNA, Bacterial; D003367:Cotinine