Tamoxifen Chemoprevention Treatment and Time to First Diagnosis of Estrogen Receptor-Negative Breast Cancer
Open Access
- 7 October 2008
- journal article
- research article
- Published by Oxford University Press (OUP) in JNCI Journal of the National Cancer Institute
- Vol. 100 (20), 1448-1453
- https://doi.org/10.1093/jnci/djn320
Abstract
Tamoxifen’s effect of reducing the risk of estrogen receptor (ER)–positive breast cancer is well established. Its effect on the time to first diagnosis of breast cancer has not been reported. We used information from the randomized, placebo-controlled Breast Cancer Prevention Trial (BCPT) to make that evaluation. A total of 13 388 women enrolled in BCPT, of whom 174 were diagnosed with ER-positive tumors and 69 were diagnosed with ER-negative tumors. A flexible semiparametric cure rate model was used to assess the effects of tamoxifen vs placebo treatment on the time to disease diagnosis. Multivariable logistic regression, adjusted for age and tumor size at diagnosis, was used to assess the association between the mammography detection rate and treatment with tamoxifen. All statistical tests were two-sided. The median times to diagnosis of ER-positive tumors were similar in both treatment groups (43 months for the placebo arm and 51 months for the treatment arm). Times to diagnosis of ER-negative tumors, however, differed between treatment groups, with median times to diagnosis of 36 months in the placebo arm vs 24 months in the tamoxifen arm (difference = 12 months, 95% confidence interval [CI] = 3 to 17 months, P = .037). ER-negative breast cancers in the tamoxifen arm were more likely than those in the placebo arm to be detected by mammography than by clinical breast examination alone after adjustment for age and tumor size, but the increase was only marginally statistically significant (odds ratio for mammography detection = 4.68, 95% CI = 0.86 to 25.32, P = .073). No differences were found in the mammography detection rates for ER-positive tumors by treatment arm. Although tamoxifen treatment does not reduce the incidence of ER-negative breast cancer, it may have advanced detection of such tumors by approximately 1 year, compared with that in the placebo arm. The time to diagnosis of ER-positive breast cancer was similar in both treatment arms.Keywords
This publication has 25 references indexed in Scilit:
- Inference of Tamoxifen's Effects on Prevention of Breast Cancer From a Randomized Controlled TrialJournal of the American Statistical Association, 2007
- Longitudinal Measurement of Clinical Mammographic Breast Density to Improve Estimation of Breast Cancer RiskJNCI Journal of the National Cancer Institute, 2007
- Mammographic Density and the Risk and Detection of Breast CancerNew England Journal of Medicine, 2007
- Influence of Patterns of Hormone Replacement Therapy Use and Mammographic Density on Breast Cancer DetectionCancer Epidemiology, Biomarkers & Prevention, 2006
- RESPONSE: Re: Tamoxifen for the Prevention of Breast Cancer: Current Status of the National Surgical Adjuvant Breast and Bowel Project P-1 StudyJNCI Journal of the National Cancer Institute, 2006
- Re: Tamoxifen for the Prevention of Breast Cancer: Current Status of the National Surgical Adjuvant Breast and Bowel Project P-1 StudyJNCI Journal of the National Cancer Institute, 2006
- Progress in chemoprevention of breast cancerCritical Reviews in Oncology/Hematology, 2004
- Italian Randomized Trial Among Women With Hysterectomy: Tamoxifen and Hormone-Dependent Breast Cancer in High-Risk WomenJNCI Journal of the National Cancer Institute, 2003
- Overview of the main outcomes in breast-cancer prevention trialsThe Lancet, 2003
- Breast Density as a Predictor of Mammographic Detection: Comparison of Interval- and Screen-Detected CancersJNCI Journal of the National Cancer Institute, 2000