The present invention provides certain cortexolone derivatives of formula (I), and the same for use 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. Another aspect of the invention 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 said pharmaceutical compositions as antitumor medicinal products.