The present invention relates to a 1-phenylpropanone compound of formula (I), wherein X is CH2 or an atom selected from the group consisting of O, S and Se, n is an integer from 4 to 6, A is a substituent selected from the group consisting of 4-morpholyl, 1-piperidinyl, 4-methyl-1-piperazinyl, A being optionally substituted with a (C1-C3)alkyl or (C1-C3)acyl substituent, with the proviso that when X is CH2, n is equal to 5, for use as an antitumoral agent in the treatment of breast cancer, chronic lymphatic leukemia or neuroblastoma. The invention also concerns new 1-phenylpropanone compounds, and compounds as antitumoral agents.