This article is more than 5 years old. Information may no longer be current.
Researchers link chlamydia to cervical cancer
Women with prior chlamydia infection are 2.2 times more likely to develop cervical cancer.
Click Here to Manage Email Alerts
OULU, Finland — Infection with Chlamydia trachomatis increases the risk of invasive cervical cancer, according to a study by Pentti Koskela, PhD, of the National Public Health Institute here. The association was independent of whether patients smoked cigarettes or tested positive for human papillomavirus (HPV), both of which are also known to increase the risk of cervical cancer.
Women who had serum antibodies to C. trachomatis were more likely to develop squamous cell carcinomas and more likely to have metastatic disease, according to Koskela’s study.
“C. trachomatis infections occur mostly without symptoms and have a tendency to cause persistent and chronic diseases,” said Koskela. “We hope screening for C. trachomatis would be started in young women to prevent later complications, including cervical carcinoma.”
Increased risk
|
Colposcopy of a woman with cervicitis caused by C. trachomatis |
Koskela identified 182 cases of cervical cancer from multinational databases. Twenty-six percent of cases had prior infection with C. trachomatis. The association between cervical cancer and C. trachomatis remained significant after adjusting for smoking, any HPV antibodies or smoking and HPV, according to Koskela.
The presence of C. trachomatis antibodies implied patients were more than twice as likely as non-C. trachmatis patients to develop cervical cancer. C. trachomatis antibodies were associated with increased risk for squamous cell carcinomas, but not for cervical adenocarcinoma, which was of some surprise to the researchers.
It is well known that endocervical glandular cells are targets for C. trachomatis,” said Koskela. “However, with increasing age, the endocervical epithelium undergoes metaplasia, and the metaplastic cells also are permissive to C. trachomatis.”
Risk of metastatic disease was higher than localized disease. The odds ratio for metastatic disease with C. trachomatis was 3.7. For localized disease, the odds ratio was 1.6.
Identifying cases and controls
The current study used data from three population-based serum banks holding serum samples from a total of 530,000 women in Finland, Norway and Sweden. The information was linked to national cancer registries, and 208 women with invasive cervical cancer were identified.
|
Cervical smear sample showing a lot of stained C. trachomatis particles against reddish background. Immunofluorescent staining. |
“This number is low among 530,000 women over five years,” said Koskela. “This is because most potential cases of cervical cancer were identified at a pre-invasive stage due to the effective screening programs in Nordic countries. Our study included only invasive cases.”
Twenty-six women did not have enough sera to be evaluated or could not be located for follow up. For each woman, researchers randomly selected three control cases who were free of cancer, but matched the woman’s age at serum sample, length of serum storage and country of residence.
Twenty-six percent of women with cervical cancer had prior infection with C. trachomatis, compared with 14% of the control population.
Of the 182 cervical cancer cases, 149, or 82%, were squamous cell carcinomas. The majority (107) were localized and 62 cases were metastatic. The mean age at diagnosis was 44 years. Mean lag time between serum sampling and diagnosis was 56 months.
For Your Information:
- Koskela P, Anttila T, Bjørge T, et al. Chlamydia trachomatis infection as a risk factor for invasive cervical cancer. Int J Cancer. 2000;85:35-39.