Abstract
Epidemiological and experimental studies indicate a causative
role of viruses in malignancies. Recently, a link between bacterial
infections and the development of cancer has been suggested. The purpose
of this study was to evaluate the association between chlamydial
infection and cancer.
The association between C. trachomatis infection
and cervix cancer was analysed in a prospective study. The presence
of IgG antibodies to C. trachomatis and C. pneumoniae was determined from
the serum samples of 182 Nordic women with invasive cervical carcinoma
and 538 matched cancer-free controls by the microimmunofluorescence
(MIF) method. Serum antibodies to C. trachomatis were associated
with an increased risk for cervical squamous cell carcinoma (SCC)
(OR 2.2, 95% CI 1.3-3.5), but not for cervical adenocarcinoma
(OR 0.4, 95% CI 0.1-1.7). C.
trachomatis serotype G was highly significantly associated
with an increased risk for SCC (adjusted OR 6.6, 95% CI
1.6-27). The presence of serum IgG antibodies to more than one serotype
of C. trachomatis, on the other
hand, also increased the risk of SCC.
The association between C. pneumoniae infection
and lung cancer was analysed separately in men and women. C. pneumoniae-specific antibodies
and immune complexes (IC) were analysed from 230 Finnish smoking
males with lung cancer and their matched controls using serum samples
collected before the lung cancer diagnosis. Suggestive chronic C. pneumoniae infection was associated
with an increased risk for lung cancer (OR 1.6; 95% CI
1.0-2.3). The risk was increased especially in men younger than
60 years (OR 2.9; 95% CI 1.5-5.4), but not in the older
age group (OR 0.9; 95% CI 0.5-1.6).
Chlamydial antibodies and chlamydia-specific ICs were analysed
from serum samples of 29 Finnish women with lung cancer and 87 matched
cancer-free controls by MIF. The mean follow-up from serum sampling
to cancer diagnosis was 6.7 years. IgG class antibodies to C. pneumoniae were common in pregnant
Finnish women (66% among cases, 62% among controls),
whereas IC-bound C. pneumoniae IgG
antibodies were rare. No additional risk for lung cancer in association
with chlamydial antibodies was found among women.
The association between chlamydial infections and lymphomas
was evaluated in a cross-sectional study. Seventy-two lymphoma patients
from Tampere University Hospital and 72 matched controls were selected,
and IgG antibodies and ICs to C. pneumoniae and C. trachomatis were analysed from their
serum samples by MIF and enzyme immunoassay (EIA). The serological
markers suggesting chronic chlamydial infection were associated
with an increased risk for malignant lymphoma. The association was
most evident for the presence of C. pneumoniae-specific
ICs in non-Hodgkin's lymphoma (OR = 7.3, 95% CI
2.2-25) and appeared to be limited to men.
Infection with C. trachomatis was
found to increase the risk of subsequent development of invasive
cervical SCC. Chronic C. pneumoniae infection
was also found to be a new independent risk factor for lung cancer
in males. Serological markers suggestive of chronic chlamydial infection
were associated with lymphomas, proposing that chlamydial infection
may have a similar role as H. pylori in
the pathogenesis of lymphomas.
| Identifer | oai:union.ndltd.org:oulo.fi/oai:oulu.fi:isbn951-42-5533-X |
| Date | 19 January 2000 |
| Creators | Anttila, T. (Tarja) |
| Publisher | University of Oulu |
| Source Sets | University of Oulu |
| Language | English |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis, info:eu-repo/semantics/publishedVersion |
| Format | application/pdf |
| Rights | info:eu-repo/semantics/openAccess, © University of Oulu, 2000 |
| Relation | info:eu-repo/semantics/altIdentifier/pissn/0355-3221, info:eu-repo/semantics/altIdentifier/eissn/1796-2234 |
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