RESUMEN
BACKGROUND: History of breast cancer has been reported as a risk factor for colorectal cancer in women. In view of the ambiguous nature of existing evidence and the growing interest in targeted colorectal cancer prevention, we sought to quantify this risk. METHODS: We used the Surveillance Epidemiology and End Results (SEER) database to estimate risk of colorectal cancer after breast-cancer diagnosis in women with first incident breast cancer between 1974 and 1995. Observed colon and rectal cancer risk was compared with that expected in the general population. We stratified comparisons by age at breast-cancer diagnosis, stage of cancer, ethnic origin of patient, and follow-up time. FINDINGS: Overall, women with previous breast cancer were 5% less likely (95% CI 1-9) to develop colon and 13% less likely (6-19) to develop rectal cancer than women in the general population. Stratified analyses suggested that the risk reductions observed for colon and rectal cancer were most pronounced for women with breast cancer diagnosed after age 65 years, in white women, women with local stage breast cancer, and women diagnosed in the later study years (1990-94). INTERPRETATIONS: Breast cancer does not increase subsequent colorectal cancer risk, and reduced risk was seen for certain subgroups of women. Because no biologically plausible endogenous protective factor has been identified, we suggest that reduced risk could stem from an accumulation of exposures that increase breast-cancer frequency but protect against colorectal cancer.
Asunto(s)
Neoplasias de la Mama/complicaciones , Neoplasias Colorrectales/etiología , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Estudios de Cohortes , Neoplasias del Colon/etiología , Bases de Datos como Asunto/estadística & datos numéricos , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Vigilancia de la Población , Neoplasias del Recto/etiología , Factores de RiesgoRESUMEN
The position of a retained root for preservation of a ridge requires modification of the design of a distal-extension removable partial denture on the side of the retained root. A model with silicone rubber over the ridges and simulated retained roots was fabricated. A framework with mesial rests, distal proximal plates, and I-bar clasp arms was fitted to it. A pencil lead was attached to the framework to record the arcs of rotation of the I-bar clasp arm. The movements and the fulcrums of the prosthesis were changed by the presence of simulated retained roots posterior to the distal abutment.