The Impact of Parity on the Number of Ovarian Cortical Inclusion Cysts

Abstract

Objectives: Ovarian cancer is the most lethal gynecologic cancer. Understanding the origin and pathogenesis of epithelial ovarian cancers is one of the most challenging issues of gynecology. According to one of the theories, ovarian cortical inclusion cysts can cause epithelial ovarian cancer, but there are a lot of criticisms against the theory. In this study, the effect of oral contraceptive pills (OCP) on the number and type of inclusion cysts were investigated. Parity is a strong factor in the prevention of ovarian epithelial cancer. The base of this study is that if parity reduced the total number of cortical inclusion cysts (CIC) and tubal metaplasia, the theory would be strengthened. Materials and Methods: One hundred twenty-five patients under the total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH & BSO) due to causes other than conflict ovaries were considered for study. The patients were categorized in three groups based on their parity. Slides related to normal ovaries were considered for study by pathologist and the results analyzed. Results: The one-way analysis of variance (ANOVA) of total number of cysts revealed a statistically significant main effect, Welch's F (2, 55.09) = 3.51, P < 0.05, indicating that not all groups had the same number of total number of cysts. Also, the results indicated that patients with 0-2 parity had a significantly higher total number of cysts than patients with 6 and over (P < 0.05). Moreover, the results of Games-Howell post hoc procedure indicated that patients with 0-2 parity had a significantly higher number of inclusion cysts than patients with 6 and over (P < 0.05). Conclusion: Based on the results of this study, parity has significant effect on reducing total number of inclusions cysts, but number of tubal type inclusion cyst was not different.