JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us

Influence of CYP2D6 polymorphisms on tamoxifen side effects in patients with breast cancer

  • 0Department of Medicine, University of Granada, Granada, Spain. iblancas@ugr.es.
Clinical & Translational Oncology : Official Publication of the Federation of Spanish Oncology Societies and of the National Cancer Institute of Mexico +

|

April 11, 2025

|

April 11, 2025

View abstract on PubMed

Summary

This summary is machine-generated.

CYP2D6 genetic variations impact tamoxifen treatment for breast cancer. Patients with reduced CYP2D6 activity experienced more uterine changes, suggesting tailored monitoring for toxicity.

Area Of Science

  • Pharmacogenetics
  • Oncology
  • Drug Metabolism

Background

  • Tamoxifen is a crucial drug for hormone receptor-positive breast cancer.
  • CYP2D6 enzyme activity varies due to genetic polymorphisms, affecting tamoxifen's efficacy and toxicity.
  • Understanding these variations is key to personalizing breast cancer treatment.

Purpose Of The Study

  • To investigate the association between CYP2D6 genetic polymorphisms and tamoxifen-induced side effects in breast cancer patients.
  • To determine if CYP2D6 metabolic status influences the occurrence of specific adverse events.

Main Methods

  • Eighty-six breast cancer patients receiving tamoxifen were genotyped for CYP2D6 polymorphisms.
  • Patients were categorized into poor, intermediate, normal, and ultrarapid metabolizer groups.
  • Adverse events, including uterine changes, were analyzed using Kaplan-Meier and Cox regression, with a propensity score-matched subgroup analysis.

Main Results

  • Rapid CYP2D6 metabolizers (NM+UM) exhibited significantly fewer uterine changes compared to slow metabolizers (PM+IM).
  • This association between reduced CYP2D6 activity and uterine alterations was consistent across the entire cohort and the PSM subgroup.
  • No significant link was found between CYP2D6 phenotype and other side effects like joint pain, hot flashes, or asthenia.

Conclusions

  • Impaired CYP2D6 enzyme activity is associated with an increased risk of uterine alterations in breast cancer patients treated with tamoxifen.
  • CYP2D6 genotype does not appear to influence other common tamoxifen toxicities.
  • Close monitoring for uterine toxicity is recommended for patients with reduced CYP2D6 metabolic capacity.

Keywords:

Related Concept Videos

Nonlinear Pharmacokinetics: Dependence of Elimination Half-Life and Dose Clearance 01:23

50

The elimination half-life and drug clearance of drugs following nonlinear kinetics can vary with dosage. The Michaelis-Menten parameters and drug concentration influence these factors. As the dose increases, the elimination half-life tends to lengthen, resulting in a reduction in clearance and a disproportionately larger area under the curve. The total clearance can be derived from the Michaelis-Menten equation for drugs following a one-compartment model.
A study on guinea pigs examined the...

Factors Affecting Drug Biotransformation: Biological 01:19

83

Biological factors significantly impact drug metabolism, influencing drug clearance, efficacy, and potential toxicity.
Species differences: Variations in enzyme systems across species can cause disparities in drug metabolism. For instance, humans may metabolize certain drugs faster than rodents, altering therapeutic effects.
Strain differences: Genetic variations within a species can result in differing enzyme activity, impacting drug response and toxicity. For example, some mouse strains may...

Nonlinear Pharmacokinetics: Role of Transporters 01:27

19

A drug's nonlinear kinetics can be influenced by a diverse range of transporter proteins that serve as crucial players in drug distribution. These transporters, found within cells, can enhance or reduce local drug concentrations by facilitating the influx or efflux of drugs. For instance, the expression of xenobiotic transporters can be influenced by factors such as age and gender, potentially impacting the linearity of drug response.
Polymorphisms occurring in drug transporters can alter...

Chronopharmacokinetics: Circadian Rhythms and Influence on Drug Response 01:15

31

Circadian rhythms are cyclic changes that are crucial in plasma drug concentrations. Various standard circadian parameters, including core body temperature, heart rate, and other cardiovascular factors, directly impact disease states and the therapeutic response to drug therapy.
The time of drug administration is an important factor to consider, as it can influence the toxic dose of a drug. For example, a study conducted by Prins et al. in 1997 examined the effects of the timing of...

Treatment Resistant Cancers 02:56

3.2K

Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...

Factors Affecting Drug Response: Overview 01:21

1.7K

When it comes to infants and young children, they are typically administered smaller doses of medication in comparison to adults. This is primarily because their organ functions still need to fully develop, meaning their bodies are not as efficient at metabolizing or eliminating drugs. Additionally, their blood-brain barrier is more permeable than in adults. As a result, high concentrations of drugs can easily penetrate the central nervous system (CNS), potentially leading to neurological...