Use of certain substituted caprolactams in treating tumors

A method of treating tumors selected from the group consisting of breast, non-small cell lung, colon and prostate comprising administering to a mammal in need of such treatment a therapeutically effective amount of a compound of formula I

• where
• R1 is (C1-6)alkyl or (C3-6)cycloalkyl;
• R2 is hydrogen or (C1-6)alkyl;
• X is (C1-12)alkylene;
• (C2-12)alkenylene;
• or (C2-12)alkynylene;
• m is 0 or 1;
• and
• R3 is (C3-8)cycloalkyl;
• or an aromatic ring system selected from II, III, IV and V:
• where
• R4 is hydrogen, chloro, or methoxy;
• R5 is hydrogen, chloro, (C1-18)alkyl or (C1-18)alkoxy;
• and Z is oxygen, sulfur, N—H, or N—CN3;
• or a pharmaceutically acceptable acid addition salt thereof, where possible.