Barrier methods of contraception and cervical intraepithelial neoplasia

Abstract

This North Carolina-based case-control study examined risk factors for cervical intraepithelial neoplasia (CIN). Cases were 103 women with biopsy-confirmed CIN II or III who were recruited from a referral dysplasia clinic. Controls were 258 family practice patients with normal cervical cytology. All subjects were interviewed regarding their sexual and reproductive history, Pap smear screening, active and passive cigarette exposures, and contraceptive use patterns. When compared with controls, cases were half as likely to have ever used barrier methods of contraception; the adjusted odds ratio was 0.5 (95% CI 0.2-0.9). The risk of CIN II/III decreased further with increasing years of barrier method use. Recency, latency, and age at first barrier method use were all associated with a reduced risk of CIN. Men and women should carefully consider the range of benefits of barrier method use as a means to reduce their risk of unwanted pregnancies, sexually transmitted diseases, and cervical neoplasia.

PIP: The risk of cervical intraepithelial neophasia (CIN II and III) and use of barrier methods was assessed in a case control study among 103 biopsy confirmed CIN II and II patients in a North Carolina hospital clinic. Determinants considered were 1) the ever use of any barrier method (condoms, spermicides, or diaphragms), 2) duration of use, 3) time since last use, 4) time since 1st use, 5) age at 1st use, and 6) ever use of each specific type of barrier method. The hypothesis was that barrier use prevented cervical neoplasia; also explored was the effect of ever use of each method separately. Confounding variables were age, race, current marital status, ever use of OCs, active cigarette smoking history, age at 1st sexual intercourse, lifetime number of male sex partners, number of Pap smears, history of ever having genital warts, SES (Hollingshead Index), and years of education. Multiple logistic regression was used to estimate the maximum likelihood estimates of the odds ratios and 95% confidence intervals. The results were that the adjusted risk of CIN II/III. SES did not affect the strength of the relationship. These findings support other findings, but differ in that spermicide use alone was not associated with a reduced risk. Other spermicide findings are discussed. Spermicides by definition were significantly associated with a reduced risk because of their use with the diaphragm. Another difference is the lack of support for SES effects. The lowest odds were found to among the lowest SES strata. Since the focus is on preinvasive cervical cancer, the results are not generalizable to studies of invasive cervical cancer. However, if a continuum is accepted with CIN at the beginning, then a clearer picture of etiologic factors is revealed. Misclassification of disease was reduced by using only biopsy confirmed cases of CIN II and III. The only controls that were used had normal cervical cytology at the time of enrollment. Respondents with any history of CIN were excluded. All laboratory tests were read in the same place. The small sample size is a limitation. Use of barrier methods may however reduce risks of unwanted pregnancies, sexually transmitted disease, and cervical neoplasia.