RESUMEN
BACKGROUND: Electrical impedance scanning (EIS) measures changes in breast tissue associated with breast cancer (Br-Ca) development. The T-Scan(tm2000 (ED is designed to use EIS to identify women ages 30-39 with elevated risk of breast cancer (i.e., T-Scan+ women). AIM: To estimate the relative probability of breast cancer in a T-Scan+ woman compared to a randomly selected young woman. METHODS: A prospective, two-cohort trial was conducted in pre-menopausal women. The Specificity (S(p))-Cohort evaluated T-Scan specificity in 1,751 asymptomatic women ages 30-39. The Sensitivity)S(n))-Cohort evaluated T-Scan sensitivity in 390 women ages 45-30 scheduled for biopsy. Specificity, sensitivity, and conservative estimate of disease prevalence were used to calculate relative probability. RESULTS: In the S(p)-Cohort, 93 of 1,751 women were T-Scan+ (S(p) = 94.7%; 95% CI: 93.7-95.7%). In the S(n)-Cohort, 23 of 87 biopsy-proven cancers were T-Scan+ (S(n) = 26.4%; 95% CI: 17.4-35.4%). Given S(p) = 94.7%, S(n) = 26.4% and prevalence of 1.5 cancers/1,000 women (ages 30-39), the relative probability of a T-Scan+ woman having Br-Ca is 4.95: (95% CI: 3.16-7.14). CONCLUSION: EIS can identify a subset of young women with a relative probability of breast cancer almost five times greater than in the population of young women at-large. T-Scan+ women have a sufficiently high risk of Br-Ca to warrant further surveillance or imaging.
Asunto(s)
Neoplasias de la Mama/diagnóstico , Mama/patología , Impedancia Eléctrica , Adulto , Biopsia , Estudios de Cohortes , Electrodiagnóstico/instrumentación , Electrodiagnóstico/métodos , Femenino , Humanos , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Premenopausia/fisiología , Probabilidad , Estudios Prospectivos , Medición de Riesgo , Sensibilidad y EspecificidadRESUMEN
PURPOSE: To evaluate the feasibility and patient satisfaction with electrical impedance scanning (EIS) for early detection of breast cancer in young women. METHODS: Women undergoing screening clinical breast examination, imaging, or biopsy were eligible for EIS examination with T-Scan 2000ED (Mirabel Medical Systems, Austin, TX). Multiple logistic regression analysis evaluated the association between clinical variables and EIS performance. Patients completed a screening EIS satisfaction questionnaire (1 = least satisfied to 5 = most satisfied). RESULTS: Twenty-nine cancers were identified among 1,103 women. Sixty-six percent (19 of 29) of cancers were nonpalpable and 55% (16 of 29) were in women age < or = 50 years. EIS sensitivity and specificity in women younger than 40 years was 50% and 90%, respectively. Exogenous estrogen use (P < .001) and menopausal status (P = .007) correlated significantly with EIS performance. False-positive rates were increased in postmenopausal women and those taking exogenous hormones. No correlation was evident between EIS performance and family history, prior breast cancer, breast density, or palpability. EIS-positive women younger than age 40 were 4.5 times more likely to have breast carcinoma than were women randomly selected from the general population. Patients were highly satisfied with the comfort, speed, and reporting of EIS screening (mean score, 4.8). CONCLUSION: EIS seems promising for early detection of breast cancer, and identification of young women at increased risk for having the disease at time of screening. Positive EIS-associated breast cancer risk compares favorably with relative risks of conditions commonly used to justify early breast cancer screening. Patients are satisfied with a screening paradigm involving breast EIS.