The impacts of ribociclib on the post-treatment Tp-e interval and Tp-e/QTc ratio in breast cancer patients.

PURPOSE: The study aimed to assess the impacts of ribociclib on the post-treatment Tp-e interval and Tp-e/QTc ratio in breast cancer patients.

MATERIALS/

METHODS

A retrospective study was carried out with 40 breast cancer patients between October 2023 and February 2024 to reveal the impacts of ribociclib therapy (either alone or in combination with letrozole) on the post-treatment Tp-e interval and Tp-e/QTc ratio. ECGs obtained before the start of the treatment and on the 21st day of the 3rd course were used in the evaluation.

RESULTS

Patients' pre-treatment heart rate, WBC, AST, QRS (ms), Tp-e/QT, and Tp-e/JT values decreased after the treatment (p < 0.05). Patients' pre-treatment QT, JT (ms), JTc(ms), Tp-e(ms), Tp-e/Qtc, and Tp-e/JTc values increased after the treatment (p < 0.05). Patients' pre- and post-treatment ionized Ca/(Tpe/JTc) values showed statistically significant difference (p < 0.01). The pre-treatment ionized Ca/(Tpe/JTc) values of patients decreased significantly after the treatment. The ionized Ca/(Tpe/QTc) values of patients differed statistically significantly before and after the treatment (p < 0.01). Patients' pre-treatment ionized Ca/(Tpe/QTc) values decreased significantly after the treatment.

CONCLUSION

The potential arrhythmogenic effects of ribociclib suggest that serum calcium (Ca), ionized calcium, QT, QTc, Tp-e interval, and Tp-e/QTc ratio may be monitored throughout the treatment period.