Mohammad Abufaraj1,2, Shahrokh Shariat1,3,4, Marco Moschini1, Florian Rohrer5, Kyriaki Papantoniou5, Elizabeth Devore6, Monica McGrath7, Xuehong Zhang6, Sarah Markt8, Eva Schernhammer5,6,9. 1. Department of Urology, Medical University of Vienna, Vienna, Austria. 2. Division of Urology, Department of Special Surgery, Jordan University Hospital, The University of Jordan, Amman, Jordan. 3. Department of Urology, Weill Cornell Medical College, New York-Presbyterian Hospital, New York, NY, USA. 4. Department of Urology, University of Texas Southwestern Medical Center, Dallas, TX, USA. 5. Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria. 6. Channing Division of Network Medicine, Harvard Medical School, Boston, MA, USA. 7. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA. 8. Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, Cleveland, OH, USA. 9. Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.
Abstract
BACKGROUND: With three out of four new bladder cancer (BCa) cases occurring in men, an apparent gender disparity exists. We aimed to investigate the role of hormonal and reproductive factors in BCa risk using two large female US prospective cohorts. METHODS: Our study population comprised 118 256 and 115 383 female registered nurses who were recruited in the Nurses' Health Study (NHS) and NHS II, respectively. Reproductive and hormonal factors and other relevant data were recorded in biennial self-administered questionnaires. Cox-regression analyses were performed to estimate age- and multivariable-adjusted incidence risk ratios (IRRs) and 95% confidence intervals (CIs). Inverse-variance-weighted meta-analysis was used to pool estimates across cohorts. RESULTS: During up to 36 years of follow-up, 629 incident BCa cases were confirmed. In the NHS, 22 566 women (21.3%) were postmenopausal at baseline, compared with 2723 women (2.4%) in the NHS II. Among women in the NHS, younger age at menopause (≤45 years) was associated with an increased risk of BCa (IRR: 1.41, 95% CI: 1.11-1.81, Ptrend = 0.01) compared with those with menopause onset at age 50+ years, particularly among ever-smokers (IRR for age at menopause ≤45 years: 1.53, 95% CI: 1.15-2.04; PIntx = 0.16). Age at menarche and first birth, parity, oral-contraceptive use and postmenopausal hormone use were not associated with BCa risk. CONCLUSIONS: Overall, we found little support for an association between female reproductive factors and BCa risk in these prospective cohort studies. Earlier age at menopause was associated with a higher risk of BCa, particularly among smokers, indicating the potential for residual confounding.
BACKGROUND: With three out of four new bladder cancer (BCa) cases occurring in men, an apparent gender disparity exists. We aimed to investigate the role of hormonal and reproductive factors in BCa risk using two large female US prospective cohorts. METHODS: Our study population comprised 118 256 and 115 383 female registered nurses who were recruited in the Nurses' Health Study (NHS) and NHS II, respectively. Reproductive and hormonal factors and other relevant data were recorded in biennial self-administered questionnaires. Cox-regression analyses were performed to estimate age- and multivariable-adjusted incidence risk ratios (IRRs) and 95% confidence intervals (CIs). Inverse-variance-weighted meta-analysis was used to pool estimates across cohorts. RESULTS: During up to 36 years of follow-up, 629 incident BCa cases were confirmed. In the NHS, 22 566 women (21.3%) were postmenopausal at baseline, compared with 2723 women (2.4%) in the NHS II. Among women in the NHS, younger age at menopause (≤45 years) was associated with an increased risk of BCa (IRR: 1.41, 95% CI: 1.11-1.81, Ptrend = 0.01) compared with those with menopause onset at age 50+ years, particularly among ever-smokers (IRR for age at menopause ≤45 years: 1.53, 95% CI: 1.15-2.04; PIntx = 0.16). Age at menarche and first birth, parity, oral-contraceptive use and postmenopausal hormone use were not associated with BCa risk. CONCLUSIONS: Overall, we found little support for an association between female reproductive factors and BCa risk in these prospective cohort studies. Earlier age at menopause was associated with a higher risk of BCa, particularly among smokers, indicating the potential for residual confounding.
Authors: Marie M Cantwell; James V Lacey; Catherine Schairer; Arthur Schatzkin; Dominique S Michaud Journal: Int J Cancer Date: 2006-11-15 Impact factor: 7.396
Authors: M J Stampfer; W C Willett; F E Speizer; D C Dysert; R Lipnick; B Rosner; C H Hennekens Journal: Am J Epidemiol Date: 1984-05 Impact factor: 4.897
Authors: Harun Fajkovic; Joshua A Halpern; Eugene K Cha; Atessa Bahadori; Thomas F Chromecki; Pierre I Karakiewicz; Eckart Breinl; Axel S Merseburger; Shahrokh F Shariat Journal: World J Urol Date: 2011-06-09 Impact factor: 4.226
Authors: Armin Henning; Marlies Wehrberger; Stephan Madersbacher; Armin Pycha; Thomas Martini; Evi Comploj; Klaus Jeschke; Christian Tripolt; Michael Rauchenwald Journal: BJU Int Date: 2013-01-15 Impact factor: 5.588
Authors: Shahrokh F Shariat; John P Sfakianos; Michael J Droller; Pierre I Karakiewicz; Siegfried Meryn; Bernard H Bochner Journal: BJU Int Date: 2009-11-13 Impact factor: 5.588
Authors: Brittany M Charlton; Janet W Rich-Edwards; Graham A Colditz; Stacey A Missmer; Bernard A Rosner; Susan E Hankinson; Frank E Speizer; Karin B Michels Journal: BMJ Date: 2014-10-31