Title: Postmenopausal circulating levels of 2- and 16ýý-hydroxyestrone and risk of endometrial cancer.
Authors: Zeleniuch-Jacquotte, A; Shore, R E; Afanasyeva, Y; Lukanova, A; Sieri, S; Koenig, K L; Idahl, A; Krogh, V; Liu, M; Ohlson, N; Muti, P; Arslan, A A; Lenner, P; Berrino, F; Hallmans, G; Toniolo, P; Lundin, E
Published In Br J Cancer, (2011 Oct 25)
Abstract: It has been suggested that the relative importance of oestrogen-metabolising pathways may affect the risk of oestrogen-dependent tumours including endometrial cancer. One hypothesis is that the 2-hydroxy pathway is protective, whereas the 16ýý-hydroxy pathway is harmful.We conducted a case-control study nested within three prospective cohorts to assess whether the circulating 2-hydroxyestroneýýý:ýýý16ýý-hydroxyestrone (2-OHE1ýýý:ýýý16ýý-OHE1) ratio is inversely associated with endometrial cancer risk in postmenopausal women. A total of 179 cases and 336 controls, matching cases on cohort, age and date of blood donation, were included. Levels of 2-OHE1 and 16ýý-OHE1 were measured using a monoclonal antibody-based enzyme assay.Endometrial cancer risk increased with increasing levels of both metabolites, with odds ratios in the top tertiles of 2.4 (95% CI=1.3, 4.6; P(trend)=0.007) for 2-OHE1 and 1.9 (95% CI=1.1, 3.5; P(trend)=0.03) for 16ýý-OHE1 in analyses adjusting for endometrial cancer risk factors. These associations were attenuated and no longer statistically significant after further adjustment for oestrone or oestradiol levels. No significant association was observed for the 2-OHE1ýýý:ýýý16ýý-OHE1 ratio.Our results do not support the hypothesis that greater metabolism of oestrogen via the 2-OH pathway, relative to the 16ýý-OH pathway, protects against endometrial cancer.
PubMed ID: 21952628
MeSH Terms: Aged; Case-Control Studies; Endometrial Neoplasms/epidemiology*; Estrogens/metabolism; Female; Humans; Hydroxyestrones/blood*; Middle Aged; Prospective Studies