日前，著名的柳叶刀医学杂志～肿瘤学分册（The Lancet Oncology）发表了一篇关于宫内节育器（Intrauterine contraceptive device）与子宫颈癌发病率之关系的文献回顾性研究，结果提示植入宫内节育器虽然并不能够预防人乳头状病毒之感染（human papillomavirus infection），但确有助于预防子宫颈人乳头状病毒感染后进一步发展为宫颈癌。该报告还指出，植入宫内节育器的时间与其宫颈癌的预防效果并无直接的关系，其预防宫颈癌之机理可能是“植入宫内节育器之过程中损伤了子宫内膜，继而启动了长期的免疫反应有关”。更多资讯，请参阅原文。

IUDs May Lower Women's Risk for Cervical Cancer: Study

Intrauterine contraceptive device appears to prevent progression of HPV to cervical cancer, researchers say

By Mary Elizabeth Dallas

MONDAY, Sept. 12 (HealthDay News) -- Intrauterine devices (IUDs) may reduce a woman's risk of cervical cancer, a new study contends.

"Our data suggest that use of IUDs significantly reduces the risk of cervical cancer and that this effect does not seem to be due to differences in screening histories between users and non-users," said the Spanish researchers who authored the study.

While the study found an apparent association between IUD use and cervical cancer risk, it did not prove a cause-and-effect.

The study, published online Sept. 13 in The Lancet Oncology, said that although IUDs did not affect women's risk for HPV (human papillomavirus) infection -- the virus that causes cervical cancer -- the plastic devices inserted into the uterus may prevent HPV from progressing to cervical cancer.

In conducting what they called the largest epidemiological study to date, researchers from the Institut Catala d'Oncologia in Catalonia, Spain, examined 26 previous studies involving more than 20,000 women who were followed for a decade.

While past studies suggest that IUDs can reduce the odds of endometrial cancer, research on cervical cancer and IUDs has been mixed, the researchers said in a journal news release.

IUDs, the research showed, were associated with a lower risk of two major types of cervical cancer for up to 10 years. Women who used IUDs had a 44 percent lower risk for squamous-cell carcinoma or a 54 percent reduced risk for adenosquamous carcinoma, the study said. In the first year of use, the risk of cervical cancer was reduced by nearly half, the study authors said.

How long the women used the IUDs did not have an impact on their risk for the disease, the researchers said, and they suggested that inserting or removing the contraceptive device may destroy precancerous lesions or trigger a long-term immune response that offers protection against HPV progression.

While the IUD is a popular method of birth control around the world, just 2 percent of American women use one. The reason: many women are afraid to use an IUD because one older type -- the Dalkon shield -- posed significant health problems, including infertility, and was withdrawn from the market in 1975.

Today's IUDs are safe and more effective due to design changes, according to the American College of Obstetricians and Gynecologists.

SOURCE: The Lancet, news release, Sept. 12, 2011