Passive smoking linked to cervical cancer

Exposure to secondhand smoke appears to increase the risk of cervical cancer, albeit to a lesser extent than active smoking, new research shows.

“There was good reason to think that passive smoking might be associated with cervical cancer, given the link with active smoking,” senior author Dr. Anthony J. Alberg, from Johns Hopkins University in Baltimore, told Reuters Health. “Findings from case-control and cross-sectional studies have supported the link, but there has been a lack of evidence from prospective studies.”To address this issue, Dr. Alberg’s team conducted a prospective cohort study involving 24,792 women who were surveyed about household smoking in 1963 and 26,381 who were surveyed in 1975. Cancer registry data were analyzed to determine the occurrence of cervical cancer in the former and latter groups between 1963 to 1978 and 1975 to 1994, respectively.The researchers’ findings appear in the January issue of Obstetrics and Gynecology.Exposure to passive smoking increased the risk of cervical cancer by 2.1- and 1.4-fold in the 1963 and 1975 cohorts, respectively. The corresponding risks for active smoking were 2.6- and 1.7-fold.”The twofold increased risk linked to passive smoking in the earlier cohort is almost too strong,” Dr. Alberg said. “I suspect the true risk lies somewhere between the risks seen in each cohort, probably closer to the 1.4-fold increased risk. Unfortunately, we don’t have a good explanation for why the risks differed so much between the cohorts.””I hope these results will stimulate other researchers to look at their data and see if the findings can be replicated in cohort studies,” Dr. Alberg noted. Aside from possible dose issues, there is really “no reason why passive smoking shouldn’t be associated with cervical cancer if active smoking is.”(Sourcec: Obstet Gynecol 2005;105:174-181: Reuters Health: Anthony J. Brown, MD: Oncolink: January 2005.)