One might expect that if screening identifies cancers before they cause clinical symptoms, then the period of screening will be followed by a period of compensatory decline in cancer rates, either in annual population incidence rates or in incidence rates in older women. However, no compensatory drop in incidence rates has ever been seen following the adoption of screening, suggesting that screening leads to overdiagnosis—the identification of clinically insignificant cancers (refer to the Overdiagnosis section in the Harms of Screening section of this summary for more information).
Se podría esperar que, si los exámenes de detección identifican cánceres antes de que se produzcan síntomas clínicos, el período de los exámenes debería estar seguido de un período de disminución compensatoria de las tasas de cáncer, ya sea en las tasas anuales de incidencia en la población, o en las tasas de incidencia en las mujeres de edad avanzada.