Passive Smoking is an Independent Risk Factor for Cervical Cancer in Northeast Thai women

Abstract

Backgrounds and Objectives: Cancer of the cervix is the most common cancer in Thai women with an estimated 16.4% of all cancer in females. It has been proposed that cigarette smoking among HPV positive women is one of the co-factors which likely influence the risk of cervical cancer progression. The association between cervical cancer development and the duration or the dose of cigarette smoking of the family members, however, was still unclear. This study is determined to evaluate the association between passive smoking as well as other factors such as HPV infection and cervical cancer in Northeastern Thai women.

Methods: A case–control study was undertaken with 55 cases of SCCA and 55 age-matched healthy controls. HPV DNA was analyzed in cervical specimens with the GP5+/6+ primers. The information regarding sexual behaviors, reproductive history, contraceptive use, and history of smoking were collected from all subjects. This study was approved by the Ethics Committee of Khon Kaen University No. HE 450333.

Results: HPV infection, prolong oral contraceptive pills use, age at first delivery, number of sexual partners and smoking status of partners revealed statistical different increase risk for cervical cancer with the odds ratio of 38.74, 12.72, 11.10 and 4.92-fold respectively with p<0.001. Statistical higher risk for cervical cancer was observed in present smoker 4.68-fold (p<0.01). Smoking duration more than 20 years of partners increased the risk of cervical cancer 3.05 with p<0.05. Multiple sexual partners showed 4.09-fold increased in the risk for HPV infection with p<0.01.

Conclusions: The data suggest that HPV infection, oral contraceptive pills use, age at first delivery were associated with cervical carcinogenesis among Northeastern Thai women. Moreover, smoking status and duration of smoke of partners also affect on cervical cancer. This indicated that, passive smoking may affect cervical cells abnormality, consequently cervical cancer development directly in this population. Therefore, to prevent cervical cancer or HPV infection, administration of knowledge on sexual behaviors and effects of smoking into public health program is important and, at the same time, a nation-wide screening scheme for the cervical abnormalities including HPV-typing is awaited in Thailand.

Key Words: Cervical cancer, Passive smoking, Risk factor, HPV