RESUMEN
Risk for breast cancer can be easily and rapidly assessed using validated, quantitative models. Multiple randomized studies show that the selective estrogen response modifiers (SERMs) tamoxifen and raloxifene can safely reduce the risk of invasive breast cancer in both pre- and postmenopausal women. Treatment resulted in a 38% reduction in breast cancer incidence, and 42 women would need to be treated to prevent one breast cancer event in the first 10 years of follow-up. Reduction was larger in the first 5 years of follow-up than in years 5 to 10, but no studies treated patients for longer than 5 years. Thromboembolic events were significantly increased with all SERMs, whereas vertebral fractures were reduced. Tamoxifen provides net benefit to all premenopausal women who are at increased risk, whereas raloxifene reduces risk nearly as much in postmenopausal women and offers increased safety. Both tamoxifen and raloxifene reduce the incidence of in situ cancers. Lasofoxifene reduced the risk of breast cancer by 79% in postmenopausal women with osteoporosis. The MAP3 trial showed a 65% reduction in the annual incidence of invasive breast cancer in postmenopausal women who were at moderately increased risk for breast cancer who took the aromatase inhibitor exemestane. The IBIS-II trial showed a 53% reduction in the risk of invasive breast cancer in postmenopausal women aged 40 to 70 who took the aromatase inhibitor anastrozole. Of the 50 million white women in the United States aged 35 to 79, 2.4 million would have a positive benefit/risk index for chemoprevention.
Asunto(s)
Anticarcinógenos/uso terapéutico , Inhibidores de la Aromatasa/uso terapéutico , Neoplasias de la Mama/prevención & control , Neoplasias Hormono-Dependientes/prevención & control , Moduladores Selectivos de los Receptores de Estrógeno/uso terapéutico , Adulto , Factores de Edad , Anciano , Anticarcinógenos/efectos adversos , Inhibidores de la Aromatasa/efectos adversos , Neoplasias de la Mama/epidemiología , Neoplasias de la Mama/metabolismo , Neoplasias de la Mama/patología , Medicina Basada en la Evidencia , Femenino , Humanos , Persona de Mediana Edad , Neoplasias Hormono-Dependientes/epidemiología , Neoplasias Hormono-Dependientes/metabolismo , Neoplasias Hormono-Dependientes/patología , Factores Protectores , Medición de Riesgo , Factores de Riesgo , Moduladores Selectivos de los Receptores de Estrógeno/efectos adversos , Factores Sexuales , Factores de Tiempo , Resultado del TratamientoRESUMEN
The combined results from the four tamoxifen prevention trials showed a 38% reduction in breast cancer incidence. The largest risk-reduction trial, the Breast Cancer Prevention Trial conducted by the National Surgical Adjuvant Breast and Bowel Project, revealed that tamoxifen reduced the risk of invasive breast cancer by 49%. Tamoxifen is currently approved for breast cancer risk reduction. However, because of side effects associated with tamoxifen, other agents are being investigated. The Study of Tamoxifen and Raloxifene is designed to compare the efficacy of tamoxifen and raloxifene in reducing breast cancer risk. Aromatase inhibitors are also being evaluated in the prevention setting. Other agents are being investigated for chemoprevention. Novel agents are especially required for estrogen receptornegative breast cancer. Ductal lavage is a non-invasive method utilized for individualized risk assessment. Future utility of ductal lavage may be as an adjunct to screening as well a way to evaluate intermediate biochemical markers for chemopreventive agents.
Los resultados combinados de los cuatro estudios sobre la prevención con tamoxifeno demostraron una disminución del 38% en la incidencia de cáncer de mama. El estudio más amplio acerca de la disminución del riesgo, el Breast Cancer Prevention Trial, realizado por el National Surgical Adjuvant Breast and Bowel Project, reveló que el tamoxifeno disminuía el riesgo de cáncer de mama invasor en un 49%. El tamoxifeno actualmente está aprobado para disminuir el riesgo de cáncer de mama. Sin embargo, debido a los efectos colaterales asociados, otros agentes están siendo investigados. El ensayo Study of Tamoxifen and Raloxifene fue diseñado para comparar su eficacia para disminuir el riesgo de cáncer de mama. Los inhibidores de la aromatasa también están siendo evaluados en el marco de la prevención. Otros agentes están siendo investigados para la quimioprevención. Se requieren especialmente nuevos agentes para el cáncer de mama con receptores de estrógeno negativos. El lavado ductal es un método no invasivo que se utiliza para una valoración del riesgo individualizada. Su utilidad futura puede ser tanto para auxiliar de la pesquisa como para evaluar los marcadores bioquímicos intermedios para agentes quimiopreventivos