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Kreimer A.R.,Infections and Immunoepidemiology Branch | Rodriguez A.C.,Proyecto Epidemiologico Guanacaste | Hildesheim A.,Infections and Immunoepidemiology Branch | Herrero R.,Proyecto Epidemiologico Guanacaste | And 10 more authors.
Journal of the National Cancer Institute

Background Three-dose regimens for human papillomavirus (HPV) vaccines are expensive and difficult to complete, especially in settings where the need for cervical cancer prevention is greatest. Methods We evaluated the vaccine efficacy of fewer than three doses of the HPV16/18 vaccine Cervarix in our Costa Rica Vaccine Trial. Women were randomly assigned to receive three doses of the HPV16/18 vaccine or to a control vaccine and were followed for incident HPV16 or HPV18 infection that persisted in visits that were 10 or more months apart (median follow-up 4.2 years). After excluding women who had no follow-up or who were HPV16 and HPV18 DNA positive at enrollment, 5967 women received three vaccine doses (2957 HPV vaccine vs 3010 control vaccine), 802 received two doses (422 HPV vs 380 control), and 384 received one dose (196 HPV vs 188 control). Reasons for receiving fewer doses and other pre-and post-randomization characteristics were balanced within each dosage group between women receiving the HPV and control vaccines.ResultsIncident HPV16 or HPV18 infections that persisted for 1 year were unrelated to dosage of the control vaccine. Vaccine efficacy was 80.9% for three doses of the HPV vaccine (95% confidence interval [CI] = 71.1% to 87.7%; 25 and 133 events in the HPV and control arms, respectively), 84.1% for two doses (95% CI = 50.2% to 96.3%; 3 and 17 events), and 100% for one dose (95% CI = 66.5% to 100%; 0 and 10 events).ConclusionFour years after vaccination of women who appeared to be uninfected, this nonrandomized analysis suggests that two doses of the HPV16/18 vaccine, and maybe even one dose, are as protective as three doses. © 2011 The Author. Source

Dallal C.M.,Hormonal and Reproductive Epidemiology Branch | Dallal C.M.,U.S. National Institutes of Health | Tice J.A.,University of California at San Francisco | Buist D.S.M.,Group Health Research Institute | And 11 more authors.

Although elevated circulating estrogens are associated with increased postmenopausal breast cancer risk, less is known regarding the role of estrogen metabolism in breast carcinogenesis. We conducted a case-cohort study within the Breast and Bone Follow-up to the Fracture Intervention Trial to assess serum estrogens and estrogen metabolites (EMs) in 407 incident breast cancer cases diagnosed during follow-up and a subcohort of 496 women. In 1992-93, women completed a baseline questionnaire and provided blood samples. Hazard ratios (HRs) and 95% confidence intervals (CIs), adjusted for geography and trial participation status, were estimated using Cox proportional hazard regression. Serum concentrations of EMs were measured by liquid chromatography-tandem mass spectrometry. EMs (quintiles, Q) were analyzed individually, as metabolic pathways (C-2, -4 or -16) and as ratios. Elevated circulating estradiol was associated with increased breast cancer risk (HRQ5vsQ1 = 1.86; 95% CI: 1.19-2.90; P trend = 0.04). An elevated ratio of the 2-hydroxylation pathway (HRQ5vsQ1 = 0.69; 95% CI: 0.46-1.05; P trend = 0.01) and 4-hydroxylation pathway (HRQ5vsQ1 = 0.61; 95% CI: 0.40-0.93; P trend = 0.004) to parent estrogens (estradiol and estrone) was inversely associated with risk. A higher ratio of the 2/16-hydroxylation pathways was associated with reduced risk (HRQ5vsQ1 = 0.60; 95% CI: 0.40-0.90; P trend = 0.002). Increased 2- or 4-hydroxylation of parent estrogens may lower risk of postmenopausal breast cancer. Analyses of metabolic pathways may help elucidate the role of estrogen metabolism in breast carcinogenesis. © The Author 2013. Published by Oxford University Press. All rights reserved. Source

Gierach G.L.,Hormonal and Reproductive Epidemiology Branch | Ichikawa L.,U.S. National Institutes of Health | Ichikawa L.,Group Health Research Institute | Kerlikowske K.,University of California at San Francisco | And 6 more authors.
Journal of the National Cancer Institute

Background Women with elevated mammographic density have an increased risk of developing breast cancer. However, among women diagnosed with breast cancer, it is unclear whether higher density portends reduced survival, independent of other factors.Methods We evaluated relationships between mammographic density and risk of death from breast cancer and all causes within the US Breast Cancer Surveillance Consortium. We studied 9232 women diagnosed with primary invasive breast carcinoma during 19962005, with a mean follow-up of 6.6 years. Mammographic density was assessed using the Breast Imaging Reporting and Data System (BI-RADS) density classification. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated by Cox proportional hazards regression; women with scattered fibroglandular densities (BI-RADS 2) were the referent group. All statistical tests were two-sided.Results A total of 1795 women died, of whom 889 died of breast cancer. In multivariable analyses (adjusted for site, age at and year of diagnosis, American Joint Committee on Cancer stage, body mass index, mode of detection, treatment, and income), high density (BI-RADS 4) was not related to risk of death from breast cancer (HR = 0.92, 95% CI = 0.71 to 1.19) or death from all causes (HR = 0.83, 95% CI = 0.68 to 1.02). Analyses stratified by stage and other prognostic factors yielded similar Results , except for an increased risk of breast cancer death among women with low density (BI-RADS 1) who were either obese (HR = 2.02, 95% CI = 1.37 to 2.97) or had tumors of at least 2.0cm (HR = 1.55, 95% CI = 1.14 to 2.09). Conclusions High mammographic breast density was not associated with risk of death from breast cancer or death from any cause after accounting for other patient and tumor characteristics. Thus, risk factors for the development of breast cancer may not necessarily be the same as factors influencing the risk of death after breast cancer has developed. © 2012 Oxford University Press. Source

Trabert B.,Hormonal and Reproductive Epidemiology Branch | Wentzensen N.,Hormonal and Reproductive Epidemiology Branch | Yang H.P.,Hormonal and Reproductive Epidemiology Branch | Sherman M.E.,Hormonal and Reproductive Epidemiology Branch | And 4 more authors.
British Journal of Cancer

Background: Women using unopposed estrogens during menopause are at increased risk of ovarian cancer. It is uncertain whether oestrogen plus progestin therapy exerts similar effects. Methods: We evaluated menopausal hormone use and incident ovarian cancer (n426) in 92 601 post-menopausal women enrolled in the National Institutes of Health-AARP (NIH-AARP) Diet and Health Study. Participants were administered questionnaires in 1996-1997 and followed through 2006. Hazard rate ratios (RR) and 95% confidence intervals (CIs) were estimated using Cox regression. Results: Increased risks were associated with long duration (10 years) use of unopposed oestrogen (RR 2.15, 95% CI: 1.30-3.57 among women with a hysterectomy) and oestrogen plus progestin (RR 1.68, 95% CI: 1.13-2.49 among women with intact uteri) therapy. Similar risks were associated with progestins that were used sequentially (15 days progestin per month) (RR 1.60, 95% CI: 1.10-2.33) or continuously (25 days progestin per month) (RR 1.43, 95% CI: 1.032-2.01; P-value for heterogeneity0.63).Conclusion:Our findings suggest that long duration use of both unopposed estrogens and oestrogen plus progestins are associated with increased risks of ovarian cancer, and that risk associated with oestrogen plus progestin use does not vary by regimen (sequential or continuous). © 2012 Cancer Research UK All rights reserved. Source

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