Prognostic Impact of Combined Oral Contraceptive Use Among Ovarian Cancer Patients in Addis Ababa, Ethiopia: A Cohort Study
Abrham Tesfaye Habteyes, Fekadeselassie Teferi Mekonen, Temesgen Ashagrie HaileIntroduction
Globally, ovarian cancer is the third most common gynecological malignancy, following cervical and uterine cancers. The protective effect of combined oral contraceptive (COC) use against the development of primary ovarian cancer is well-established. However, little is known about the potential prognostic benefit of COC use among patients already diagnosed with ovarian cancer. Therefore, this study aimed to evaluate the association of COC use on ovarian cancer survival in oncology centers in Addis Ababa, Ethiopia.
Methods
A hospital-based, retrospective cohort study was conducted among a total of 436 ovarian cancer patients, comprising 109 COC users and 327 non-users. Kaplan–Meier survival curves and the log-rank test were used to assess differences in overall survival. The incidence density rate of mortality was calculated for each group. The effect of COC use on time to death following an ovarian cancer diagnosis was estimated using Cox proportional hazards regression, with a significance level of 5%.
Results
The mortality incidence density rate among ovarian cancer patients with prior COC use was 5.55 per 1,000 person-years (95% CI: 3.69–8.35), compared with 13.95 per 1,000 person-years (95% CI: 11.89–16.35) among non-users. The 5-year overall survival rate was higher among COC users (66.18%; 95% CI: 53.07–76.41) than among non-users (37.65%; 95% CI: 31.26–44.01). The median overall survival time for the cohort was 49.80 months. After adjustment for potential confounders, prior COC use was associated with a lower hazard of mortality compared with non-use (adjusted hazard ratio [AHR] = 0.37; 95% CI: 0.24–0.59).
Conclusions
In the present study, prior COC use was associated with improved overall survival among women diagnosed with ovarian cancer. These findings provide preliminary evidence of a possible prognostic association; however, further studies are needed to confirm these findings and clarify the underlying mechanisms.