1. Introduction
  1.1 Background and significance
  1.2 Objectives of the study
2. Drug metabolism in breast cancer
  2.1 Role of drug-metabolizing enzymes
  2.2 Altered drug metabolism in breast cancer
3. Drug-metabolizing enzymes in breast cancer
  3.1 Cytochrome P450 enzymes
  3.2 UDP-glucuronosyltransferases
  3.3 Glutathione S-transferases
4. Impact of altered drug metabolism on drug response
  4.1 Drug efficacy in breast cancer
  4.2 Drug toxicity in breast cancer
5. Experimental methods
  5.1 Cell culture and treatment
  5.2 Expression analysis of drug-metabolizing enzymes
  5.3 Enzyme activity assays