The present invention relates to certain cortexolone derivatives of formula (I) and the use of the same as antitumor active ingredients for the curative or adjuvant, or neoadjuvant or palliative treatment of precancerous lesions, dysplasias, metaplasias and tumor diseases, including malignant neoplasias and metastasis. The present invention also relates to pharmaceutical compositions comprising cortexolone derivatives of formula (I) as active ingredients and at least one physiologically acceptable excipient, and to the use of the pharmaceutical compositions as antitumor medicinal products.