REVIEW: Circulating Tumor DNA And Its Potential Applications for Assessing Effectiveness of Neoadjuvant Drug Therapy in the Breast Cancer Patients

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Tatiana M. Zavarykina^1,2,a*, Irina V. Pronina^1,2, Polina S. Mazina^1,2, Svetlana V. Khokhlova², and Gennady T. Sukhikh²

¹N. M. Emanuel Institute of Biochemical Physics, Russian Academy of Science, 119334 Moscow, Russia

²B. I. Kulakov National Medical Research Center of Obstetrics, Gynecology and Perinatology, Ministry of Health of the Russian Federation, 117997 Moscow, Russia

^* To whom correspondence should be addressed.

Received: July 18, 2025; Revised: October 8, 2025; Accepted: October 15, 2025

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The review discusses main characteristics and analytical features of the circulating tumor DNA (ctDNA), which accounts for a minor fraction of the cell-free DNA (cfDNA) in cancer patients. Currently, ctDNA is considered to be a promising biomarker for assessing treatment efficacy, prognosis, and disease monitoring in oncology, including breast cancer (BC). A significant proportion of BC patients receive neoadjuvant drug therapy, effectiveness of which largely determines necessity and extent of subsequent treatment. Determination of ctDNA could be the most sensitive method for evaluating response to neoadjuvant therapy, as it enables real-time monitoring of molecular changes during the treatment, prediction of therapeutic response, and assessment of recurrence risk. This approach could become an additional tool for personalization of BC therapy.

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KEY WORDS: circulating tumor DNA, breast cancer, neoadjuvant chemotherapy, pathologic response of tumor, relapse

DOI: 10.1134/S0006297925602187

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