Research groups at the National Cancer Center, Keio University, and RIKEN are conducting the world's first prospective clinical trials on the effectiveness of genotype-based personalized therapy in breast cancer tamoxifen therapy.For patients with a genotype with low metabolic activity, no improvement in the therapeutic effect was observed by increasing the dose of tamoxifen, and it was concluded that dose individualization based on the genotype was unnecessary.
Tamoxifen is a hormone therapy drug that is used to control the recurrence of hormone receptor breast cancer after surgery and to control the disease of patients with metastases.However, when the CYP1D2 enzyme in the liver converts tamoxifen into an effective form after oral administration, it has an effect on cancer.There are ethnic and individual differences in the activity of this enzyme, and about 6% of the Japanese are genetically low in activity.Numerous past retrospective (based on past patient data) studies have shown conflicting results and inconclusive whether current tamoxifen doses are sufficient for low activity.
The research team, in collaboration with 54 institutions nationwide, conducted the world's first prospective (future follow-up) randomized controlled trial of the efficacy of genotype-based personalized therapy in breast cancer tamoxifen therapy. We prospectively compared conventional standard tamoxifen treatment with double-dose dose-increasing treatment in breast cancer patients with the CYP2D6 low metabolic activity gene to study the need for personalized treatment.
As a result, for patients with a genotype with low metabolic activity, no improvement in the therapeutic effect was observed by increasing the dose of tamoxiphen, and it was concluded that dose individualization based on the genotype was unnecessary. I confirmed that it was not.This time, he said that he was able to investigate the discussions that have a great impact on the Japanese in a prospective study that can obtain high evidence and disseminate it to the world.
