Scientists from the Karolinska Institute in Stockholm have determined that women who smoke and carry human papillomavirus type 16 have bigger chances of developing "cervical cancer in situ" than the women who with only one of the two factors.

Cervical cancer in situ is a cancer that is confined to the surface layer of the cervix.

There are a few HPV types that lead to cervical cancer among over hundred HPV types.

Scientists have found that the risk of cancer in situ was very high in smokers with high levels of HPV 16. At first they thought that smoking could be an independent risk factor for this type of cancer. However, it turned out that both exposures, smoking and the presence of HPV 16, need to be present at the same time for there to be an interaction.
Women who smoked and had HPV 16 virus are 14 times more likely to develop the cancer than smokers who didn’t have the virus. Nonsmokers who had the HPV 16 had 5-6 times increased chances of having this type of cervical cancer.

The studies showed that there is even a correlation between smoking duration and HPV-16 positivity. The findings came as a shock to the researchers.

The women who belong to the risk group are advised to frequently monitor their conditions.