人類疣瘤病毒與子宮頸癌變之巢疊病例對照研究(3/3)

Cervical cancer is the most common cancer among women in Taiwan with an age
standardized incidence rate of 22.1 per 100,000 person-years compared to an average of 11.2
in developed countries. It is well established that the major cause of cervical cancer is
persistent infection with oncogenic genital human papillomavirus (HPV). To investigate the
possible role of interaction between human papillomavirus (HPV) types and past Chlamydia
trachomatis exposure in cervical carcinogenesis in a population with low sexual risk-taking
behavior, we performed a nested case-control study of invasive and in situ cervical cancer
within a community-based cohort of 13,595 Taiwanese women assembled in 1991. During a 9
year follow-up period (1991-2000) incident cases were identified through linkage with
nationwide cancer registry. Prevalent cases identified at the baseline cervical examination
were also included in the study. Baseline serum or plasma from 114 cases and 519 controls
matched for sex, age, area of residence, type of sample and date of enrolment were analyzed
for antibodies against HPV types 6, 16 and 18 and against C. trachomatis. HPV-16
seropositivity was strongly associated with cervical cancer OR= 6.33 (95% CI 3.45-11.62).
C. trachomatis was overall not associated with cervical cancer, but was associated with
cervical cancer in analyses restricted to incident cases of cancer OR:2.94 (95% CI
1.17-7.42)or to cases that had serum samples taken OR:3.13 (95% CI 1.16-8.47). We found
a tendency of antagonistic interaction between HPV-6 and -16 [Relative Excess Risk due to
Interaction (RERI):- 4.68 (95% CI –10.63 to 1.27)] and between HPV-16 and -18 [RERI:-3.27
(95% CI -7.71-1.18)]. Our results suggest that different HPV types might interfere in cervical
carcinogenesis, that C. trachomatis associates with cervical cancer in prospective studies and
support the notion that HPV-16 seropositivity is strongly associated with cervical cancer risk
in low sexual risk-taking populations.