BACKGROUND: Hormonal and reproductive history has been associated with risk of some @entity1583 , but their role in @entity5 ( @entity5 ) is largely unknown. METHODS: Using a population-based cohort study, we evaluated the association of these factors with risk of @entity5 overall, and for @entity4407 ( @entity4407 ) and @entity6582 vera (PV) specifically. Incident @entity5 cases from 1993 to 2004 were identified via linkage to Medicare. RR and 95% confidence intervals (CI) were estimated utilizing Cox proportional hazard regression. RESULTS: After >250,000 @entity1 -years of follow-up, 257 cases of @entity5 were identified (172 @entity4407 , 64 PV). Ever use of @entity34 ( @entity34 ) was associated with an increased risk of @entity4407 (RR = 1.63; 95% CI, 1.19-2.23) but a decreased risk of PV (RR = 0.58; 95% CI, 0.34-0.98). There were no statistically significant associations of oral contraceptives or reproductive factors with @entity5 risk overall, or by @entity5 subtype. Bilateral oophorectomy was associated with increased risk of @entity4407 (RR = 1.58; 95% CI, 1.11-2.25) and decreased risk of PV (RR = 0.32; 95% CI, 0.12-0.88). There was no association of ovulatory years with @entity4407 risk; however, there was increased risk of PV (RR = 1.68 for >36.8 compared with  <=27.6 years; P trend = 0.045). Adjustment for potential confounding factors did not alter these associations. CONCLUSIONS: @entity34 use and bilateral oophorectomy had opposite associations for @entity4407 and PV. Except for ovulatory years and PV risk, reproductive history did not appear to play a role in the etiology of @entity5 . IMPACT: This study suggests different mechanistic impacts of @entity172 , and perhaps distinct etiologies, for the two major @entity5 subtypes. Cancer Epidemiol Biomarkers Prev; 25(1); 1-7.   2015 AACR.

Hormonal and Reproductive Factors and Risk of Myeloproliferative Neoplasms in Postmenopausal XXXX .

@entity1 :: ('9606', 'Species') :: ['person'] @entity6582 :: ('MESH:D011086', 'Disease') :: ['polycythemia'] @entity172 :: ('MESH:D004967', 'Chemical') :: ['estrogen'] @entity5 :: ('MESH:D009369', 'Disease') :: ['myeloproliferative neoplasms', 'MPN'] @entity1583 :: ('MESH:D019337', 'Disease') :: ['hematologic malignancies'] @entity4407 :: ('MESH:D013920', 'Disease') :: ['ET', 'essential thrombocythemia'] @entity34 :: ('MESH:D016609', 'Disease') :: ['hormone therapy', 'HT']
@entity1 :: (9606,Species) :: ['Women']
