Differentiating the dielectric properties of the breast between healthy and cancerous tissues is essential to contribute to the early detection studies of breast cancer. There are not many reports based on in vivo and ex vivo dielectric measurements on breasts with tumor. In addition, women show high variability of dielectric parameters between breast tissues (skin, fat, gland, and tumors). This study focuses on the measurement and analysis of breast and tumor tissues in vivo and ex vivo, over a frequency range of 1 to 8 GHz, based on dielectric protocol measurement, using an open coaxial probe. The result led to make a tumor classification (early, middle, and advanced), size and type. These measurements were made in mastectomy and lumpectomy surgeries, considering the same pressure for each group of measurements through a regulated pressure system, with a temperature varies from 22 to 27 degrees, all these measurement and parameters validated by a pathologist. As a result, some differences are observed in distinguishing breasts with tumors from healthy breasts in middle and advanced ages, under a controlled system protocol, that is, increases in real permittivity and conductivity in the breast over the areas where benign and malignant anomalies were located.