Clinical and pathological response in “aggressive” immunohistochemical types of breast cancer: impact on the choice of oncoplastic or reconstructive surgery tactics, and the role of tumor biological characteristics

Ermoschenkova M.V., Mglinets M.P., Galkin V.N., Reshetov I.V., Kuzmina E.S., Arkova S.A.

1) Oncology Center No. 1, S.S. Yudin City Clinical Hospital, Moscow, Russia; 2) I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia

Background: Breast cancer is characterized by pronounced molecular heterogeneity, which determines differences in prognosis, sensitivity to therapy, and the potential for breast-preserving and reconstructive interventions. The most aggressive course is observed in triple-negative and Her2/neu-positive breast cancer types, which justifies the need for a comprehensive assessment of factors influencing the effectiveness of neoadjuvant treatment and the choice of surgical approach.
Objective: Evaluation of the impact of immunohistochemical (IHC) subtype and neoadjuvant drug treatment regimens on clinical and pathological response, as well as their relationship with the choice of surgical intervention in patients with prognostically unfavorable forms of breast cancer (BC).
Materials and methods: A retrospective study of 500 patients with stage II–III breast cancer was conducted. IHC types, neoadjuvant therapy regimens, clinical response, residual cancer burden (RCB), and the nature of surgical treatment were analyzed. Nonparametric statistical methods and categorical data analysis were used.
Results: Statistically significant differences were found between the subtypes in terms of Ki-67 levels, differentiation grade, and disease stage (p<0.05). The rate of complete pathological response (RCB-0) was highest in the Her2/neu-positive subtype (70.2%) and lower in the triple-negative and luminal B, Her2/neu-positive subtypes (46.9 and 46.5%, respectively). Clinical response did not differ between the groups (p=0.312). The type of surgical intervention did not achieve statistically significant differences between the groups (p=0.066), but a tendency towards differences was noted. Differences were also found in the choice of specific oncoplastic and reconstructive techniques (p=0.021).
Conclusion: IHC subtype is a significant predictor of pathological response, but does not independently influence the choice of the extent of surgical intervention, which is determined primarily by clinical and anatomical factors. The obtained data substantiate the need to consider RCB when assessing therapy efficacy and planning treatment.

For citations: Ermoschenkova M.V., Mglinets M.P., Galkin V.N., Reshetov I.V., Kuzmina E.S., Arkova S.A. Clinical and pathological response in «aggressive» immunohistochemical types of breast cancer: impact on the choice of oncoplastic or reconstructive surgery tactics, and the role of tumor biological characteristics. Pharmateca. 2026;33(4):229-236. (In Russ.). DOI: https://dx.doi.org/10.18565/pharmateca.2026.4.229-236

Authors’ contribution: M.V. Ermoschenkova – scientific concept of the study, critical revision of the article, editing and approval of the final version of the manuscript. M.P. Mglinets – study design, statistical analysis, writing and preparation of the article. V.N. Galkin – participation in the interpretation of the results, advisory support in developing the methodological part of the study. I.V. Reshetov – general scientific supervision, development of the study concept, supervision of the clinical and oncological focus of the work. E.S. Kuzmina – participation in the collection of clinical material, verification of morphological data. S.A. Arkova – collection and processing of clinical and morphological data
Conflicts of interest: The authors confirm that they have no conflicts of interest to declare.
Funding: The study was conducted without any sponsorship.
Ethical Approval: The study protocol was approved by the local ethics committee (protocol No. 01-25 dated 23.01.2025).
Patient Consent for Publication: All patients provided informed consent for the publication of their data.
Authors’ Data Sharing Statement: The data supporting the findings of this study are available upon request from the corresponding author after approval from the principal investigator.

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About the Authors

M.V. Ermoschenkova, Dr. Sci. (Med.), Head of the 1st Oncology Department (Oncomammology and Reconstructive Plastic Surgery), Oncology Center No. 1, S.S. Yudin City Clinical Hospital, Moscow Healthcare Department; Professor, Department of Oncology, Radiotherapy, and Reconstructive Surgery, N.V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; maryerm@mail.ru; ORCID: https://orcid.org/0000-0002-4178-9592
Maria P. Mglinets, Postgraduate Student, Department of Oncology, Radiotherapy, and Reconstructive Surgery, N.V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; m.mglinets@inbox.ru; ORCID:
https://orcid.org/0009-0001-1114-2296 (corresponding author)
V.N. Galkin, Dr. Sci. (Med.), Chief Physician, S.S. Yudin City Clinical Hospital, Moscow Healthcare Department; Professor, Department of Oncology, Radiotherapy, and Reconstructive Surgery, N N.V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; vsgalkin@gmail.com; ORCID: https://orcid.org/0000-0002-6619-6179
I.V. Reshetov, Dr. Sci. (Med.), Professor, Academician of the Russian Academy of Sciences, Head of the Department of Oncology, Radiotherapy, and Plastic Surgery, N.V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Director of the L.L. Levshin Institute of Cluster Oncology (Sechenov University), Moscow, Russia; reshetoviv@mail.ru; ORCID: https://orcid.org/0000-0002-0909-6278
E.S. Kuzmina, Cand. Sci. (Med.), Head of Chemotherapy Department No. 2, Day Hospital for Antitumor Drug Therapy No. 2, Oncology Center No. 1, S.S. Yudin City Clinical Hospital, Moscow, Russia; KuzminaES1@zdrav.mos.ru; ORCID: https://orcid.org/0009-0007-2856-5176
S.A. Arkova, 4th-year student, N.V. Sklifosovsky Institute of Clinical Medicine, I.M. Sechenov First Moscow State Medical University (Sechenov University), Moscow, Russia; sophaarkova@gmail.com; ORCID: https://orcid.org/0000-0002-1843-8743

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