Resistance or diminished response of a neoplasm to an antineoplastic agent in humans, animals, or cell or tissue cultures.

Synonyms: Antineoplastic Drug Resistance, Resistance, Antineoplastic Drug, Antineoplastic Agent Resistance, Drug Resistance, Antineoplastic, Antibiotic Resistance, Neoplasm, Neoplasm Drug Resistance, Drug Resistance, Neoplasm, Resistance, Antineoplastic Agent