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Intermediate Technical IVT

multidrug resistance

Cancer cell resistance to multiple chemotherapy agents simultaneously.

Full Definition

Multidrug resistance (MDR) is a phenomenon where cancer cells develop simultaneous resistance to multiple chemotherapy drugs with different mechanisms of action. This can occur through various mechanisms including overexpression of drug efflux pumps (particularly P-glycoprotein), altered drug metabolism, enhanced DNA repair capacity, or resistance to apoptosis. MDR represents a major obstacle in cancer treatment and can be either intrinsic (present before treatment) or acquired (developed during therapy). Understanding MDR mechanisms is crucial for developing strategies to overcome treatment resistance.

Usage

Usage note: Commonly abbreviated as MDR; specify mechanism when known.

In Context

  • "The tumor demonstrated multidrug resistance to standard chemotherapy regimens." — Clinical case report
  • "P-glycoprotein overexpression mediated multidrug resistance in these cell lines." — Research manuscript

Also known as

MDR cross-resistance

Contrasted with

drug sensitivity therapeutic susceptibility

Don't confuse with

drug resistance treatment failure

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