BACKGROUND: High parity is associated with reduced risk of ovarian cancer. One hypothesis is that pregnancy is associated with clearance of a fraction of the genetically modified (premalignant) cells from the ovaries. METHODS: We evaluated this hypothesis using a model that estimates the cell clearance fraction at first and second pregnancy according to age at pregnancy. The model was fitted using reproductive history data from a cohort of 1.5 million Danish women born between 1935 and 1978 and followed for 28.7 million person-years. During this follow-up period, 2,035 developed invasive ovarian cancer. RESULTS: We found the model to have a satisfactory fit despite the very few parameters involved. The model estimated similar cell clearance fractions for the first and second pregnancy and decreasing clearance with later age at pregnancy. CONCLUSION: The relation of pregnancy history to risk of ovarian cancer can be well described by a cell clearance model that allows the cell clearance fraction to decrease with age at pregnancy.
BACKGROUND: High parity is associated with reduced risk of ovarian cancer. One hypothesis is that pregnancy is associated with clearance of a fraction of the genetically modified (premalignant) cells from the ovaries. METHODS: We evaluated this hypothesis using a model that estimates the cell clearance fraction at first and second pregnancy according to age at pregnancy. The model was fitted using reproductive history data from a cohort of 1.5 million Danish women born between 1935 and 1978 and followed for 28.7 million person-years. During this follow-up period, 2,035 developed invasive ovarian cancer. RESULTS: We found the model to have a satisfactory fit despite the very few parameters involved. The model estimated similar cell clearance fractions for the first and second pregnancy and decreasing clearance with later age at pregnancy. CONCLUSION: The relation of pregnancy history to risk of ovarian cancer can be well described by a cell clearance model that allows the cell clearance fraction to decrease with age at pregnancy.
Authors: Gustavo C Rodriguez; James Kauderer; Jessica Hunn; Larry G Thaete; William G Watkin; Samantha Russell; Michael Yozwiak; Jack Basil; Jean Hurteau; Shashikant Lele; Susan C Modesitt; Oliver Zivanovic; Hao Helen Zhang; Peter H Bartels; David S Alberts Journal: Cancer Prev Res (Phila) Date: 2019-04-23
Authors: M G M Braem; N C Onland-Moret; P A van den Brandt; R A Goldbohm; P H M Peeters; R F P M Kruitwagen; L J Schouten Journal: Am J Epidemiol Date: 2010-09-22 Impact factor: 4.897