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Impact of Estrogen on Myeloproliferative Neoplasms
Assessing its effect on essential thrombocythemia and polycythemia vera
Estrogen has different mechanistic impacts, and perhaps distinct etiologies, on the 2 major subtypes of myeloproliferative neoplasms (MPNs), according to a study of 257 postmenopausal women with MPNs, including 172 with essential thrombocythemia (ET) and 64 with polycythemia vera (PV). Researchers found:
• Ever use of hormone therapy was associated with increased risk of ET (RR=1.63), but decreased risk of PV (RR=0.58).
• Oral contraceptives and reproductive factors had no statistically significant associations with MPN risk overall, or by MPN subtype.
• Bilateral oophorectomy was associated with increased risk of ET (RR=1.58) and decreased risk of PV (RR=0.32).
• No associations were seen with ovulatory years for ET risk; but there was increased risk of PV (RR=1.68) for >36.8 years vs ≤ 27.6 years.
• Adjustment for potential confounding factors did not alter these associations.
Citation: Leal AD, Thompson CA, Wang AH, et al. Hormonal and reproductive factors and risk of myeloproliferative neoplasms in postmenopausal women. [Published online ahead of print November 12, 2015]. Cancer Epidemiol Biomarkers Prev. doi: 10.1158/1055-9965.EPI-15-0613.