Study: Smoking Increases Risk of Cervical Cancer in Women with HPV (dateline February 9, 2003)
A new study finds that women with HPV , a common sexually transmitted disease, are at significantly higher risk of developing cervical cancer if they smoke. The study also examined the use of oral contraceptives and childbirth on cervical cancer risk, but found that smoking was the only factor associated with a higher risk of cancer in the HPV-positive women. According to the researchers, the studys findings have important implications for public health officials and may be particularly relevant in developing countries where women have poor access to cervical cancer screening and treatment.
HPV (human papillomavirus) is very common sexually transmitted disease; there are over 80 different strains of HPV, affecting more than 40 million Americans. While the majority of HPV strains do not pose any health risks, a few strains increase the risk for cervical cancer. Annual Pap smears help screen women for cervical cancer and have contributed to 75% decrease in cervical cancer deaths in the U.S since the mid-1950s.
To study the effects of oral contraceptive use, smoking, and childbirth on cervical cancer risk, Philip E. Castle, PhD of the National Cancer Institute and his colleagues followed 1812 women who were enrolled in 10-year study on cervical cell growth at Kaiser Permanente in Portland, Oregon. All of the women had tested positive for HPV. For Dr. Castles study, the women filled out questionnaires about their smoking habits, use of birth control pills, and their number of children.
After 10 years, Dr. Castle and his colleagues found that the women who had smoked one or more packs of cigarettes a day were four times more likely to develop pre-cancerous or cancerous cervical cells compared to non-smokers. Thus, the researchers conclude that women who smoke are at significantly higher risk of developing cervical cancer. Oral contraceptive use and childbirth had no effect on the risk of cervical cancer.
Dr. Castle and his team say the study has an important message for women and public health officials. Particularly in developing countries where women have poor access to Pap smear screening and treatment, smoking may contribute significantly to the number of cases of cervical cancer and ultimately to the number of cancer deaths.
In the United States, cervical cancer screening has become increasingly routine. Approximately 50 million Pap smears are performed each year in the United States. The increased use of Pap smear is largely responsible for a significant reduction in the number of deaths from cervical cancer over the years (a decrease of 74% from 1955 to 1992).
The International Agency for Research on Cancer estimates that nearly 380,000 women are diagnosed with cervical cancer worldwide each year. The number of cases and number of deaths from cervical cancer are higher in less developed countries where routine screening is not widespread.
- The report, "A Prospective Study of High-Grade Cervical Neoplasia Risk Among Human Papillomavirus-Infected Women," is published in the September 18, 2002 issue of the Journal of the National Cancer Institute, http://jncicancerspectrum.oupjournals.org/
- To learn more about cervical cancer and HPV, please visit http://www.imaginis.com/cervical-cancer/