Effect of Oral Contraceptives on Risk of Cervical Cancer
Natthakan Vanakankovit MD*, Surasak Taneepanichskul MD*
Affiliation : * Department of Obstetrics and Gynecology, Faculty of Medicine, King Chulalongkorn Memorial Hospital, Chulalongkorn University, Bangkok
Objective : To assess the risk of oral contraceptives on the occurrence of cervical cancer.
Material and Method: A hospital-based case-control study was conducted. Sixty women patients with histo-
logically confirmed invasive cervical cancer and 180 healthy women as the control group who attended the
King Chulalongkorn Memorial Hospital, Bangkok, Thailand were recruited. Information about the use of
oral contraceptives and other cervical cancer risk factors were obtained from personal interviews. The risk
factors were evaluated by using odds ratio (OR).
Results : 60 women with invasive cervical cancer and 180 healthy controls were interviewed by the investigator.s
Compared with non-users, patients who had ever used or currently used oral contraceptive had an increased
risk of cervical cancer (OR 1.45; 95% CI 0.79-2.64). However, the risk was not statistically significant.
Considering the duration of use, patients who had used oral contraceptives for 3 years or less did not have an
increased risk of cervical cancer (OR 0.78; 95% CI 0.39-1.77). Nevertheless, the odds ratio of oral contracep-
tive pill use for more than 3 years was 2.57 (95% CI 1.22-5.49) which was statistically significant.
Conclusion : Long-term use of oral contraceptive might be a cofactor that increases the risk of cervical
carcinoma. Further investigations should be conducted to confirm this risk. However, Pap smear has to be
done routinely in long-term oral pill users.
Keywords : Oral contraceptives, Cervical cancer
