Chlamydia Linked to Cervical Cancer Risk

C H I C A G O, Jan. 2, 2001 -- New research in Scandinavia supports a linkbetween the sexually transmitted disease chlamydia and cervicalcancer, suggesting that women infected with certain types ofchlamydia may be at heightened risk for malignancy.

Another common sexually transmitted disease, humanpapillomavirus or HPV, is the leading cause of cervical cancer, butdata on chlamydia are much less clear.

The new findings, based on 128 women with invasive cervicalcancer in Finland, Sweden and Norway, appear in Wednesday’s Journalof the American Medical Association.

Chlamydia and Cervical Cancer LinkageThe findings “suggest that cervical malignancy should be addedto the complications and costs associated with genital chlamydialinfections,” Dr. Jonathan Zenilman of Johns Hopkins School ofMedicine wrote in a JAMA editorial.

In some previous studies that found a link, HPV likely was thereal culprit, but the current research strongly suggests there isan independent relationship between chlamydia and cervical cancer,Zenilman said.

The authors, led by Dr. Tarja Anttila of Finland’s NationalPublic Health Institute, examined data on women diagnosed withcervical cancer at least a year after having blood tests duringhealth exams.

Certain Chlamydia Strains RiskierBlood was measured for exposure to 10 different types ofchlamydia. Three specific types were linked to cervical cancer, butone known as serotype G carried the highest risk. Women with thattype of chlamydia were about 6.5 times more likely to developcervical cancer than uninfected women.

The authors took into account the effects of HPV and smoking,another risk factor for cervical cancer.

How a bacterial infection such as chlamydia might cause canceris unclear, the authors said, but they noted that other researchhas linked abnormal cell changes with the body’s inflammatoryresponse to infection.

Unknown How Bacteria Increases Risk

In the editorial, Zenilman called the study intriguing but notconclusive since there may have been other behavioral or biologicalfactors that contributed to the cancer risk. Still, Zenilman said,the findings may provide “additional justification for expandingchlamydial infection screening.”

Chlamydia is the most common bacterial STD in the United States,with between 4 million and 8 million new cases reported yearly.Unlike HPV, it can be treated with antibiotics, but many women haveno symptoms and the disease can cause pelvic inflammatory diseaseand infertility.

About 13,000 cases of cervical cancer are diagnosed in theUnited States annually, and though Pap tests can detect many casesin early, treatable stages, it kills about 4,600 women each year.