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<article xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:ali="http://www.niso.org/schemas/ali/1.0/" article-type="research-article" dtd-version="1.2" xml:lang="en"><front><journal-meta><journal-id journal-id-type="publisher-id">Surgery and Oncology</journal-id><journal-title-group><journal-title xml:lang="en">Surgery and Oncology</journal-title><trans-title-group xml:lang="ru"><trans-title>Хирургия и онкология</trans-title></trans-title-group></journal-title-group><issn publication-format="electronic">2949-5857</issn><publisher><publisher-name xml:lang="en">Publishing House ABV Press</publisher-name></publisher></journal-meta><article-meta><article-id pub-id-type="publisher-id">905</article-id><article-id pub-id-type="doi">10.17650/2949-5857-2026-16-2-107-117</article-id><article-categories><subj-group subj-group-type="toc-heading" xml:lang="en"><subject>ORIGINAL REPORT</subject></subj-group><subj-group subj-group-type="toc-heading" xml:lang="ru"><subject>ОРИГИНАЛЬНОЕ ИССЛЕДОВАНИЕ</subject></subj-group><subj-group subj-group-type="article-type"><subject>Research Article</subject></subj-group></article-categories><title-group><article-title xml:lang="en">Predictive model for assessing probability of breast cancer biological subtype change during treatment</article-title><trans-title-group xml:lang="ru"><trans-title>Прогностическая модель для оценки вероятности изменения биологического подтипа рака молочной железы в процессе лечения</trans-title></trans-title-group></title-group><contrib-group><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-8854-2773</contrib-id><name-alternatives><name xml:lang="en"><surname>Shvedskiy</surname><given-names>M. S.</given-names></name><name xml:lang="ru"><surname>Шведский</surname><given-names>М. С.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>Shvedsky99@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib><contrib contrib-type="author"><name-alternatives><name xml:lang="en"><surname>Tamrazov</surname><given-names>R. I.</given-names></name><name xml:lang="ru"><surname>Тамразов</surname><given-names>Р. И.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>Shvedsky99@gmail.com</email><xref ref-type="aff" rid="aff2"/></contrib><contrib contrib-type="author"><contrib-id contrib-id-type="orcid">https://orcid.org/0000-0002-7262-3819</contrib-id><name-alternatives><name xml:lang="en"><surname>Gaysina</surname><given-names>E. A.</given-names></name><name xml:lang="ru"><surname>Гайсина</surname><given-names>Е. А.</given-names></name></name-alternatives><address><country country="RU">Russian Federation</country></address><email>Shvedsky99@gmail.com</email><xref ref-type="aff" rid="aff1"/></contrib></contrib-group><aff-alternatives id="aff1"><aff><institution xml:lang="en">Туumen State Medical University, Ministry of Health of Russia</institution></aff><aff><institution xml:lang="ru">ФГБОУ ВО «Тюменский государственный медицинский университет» Минздрава России</institution></aff></aff-alternatives><aff-alternatives id="aff2"><aff><institution xml:lang="en">Russian University of Medicine, Ministry of Health of Russia</institution></aff><aff><institution xml:lang="ru">ФГБОУ ВО «Российский университет медицины» Минздрава России</institution></aff></aff-alternatives><pub-date date-type="pub" iso-8601-date="2026-06-20" publication-format="electronic"><day>20</day><month>06</month><year>2026</year></pub-date><volume>16</volume><issue>2</issue><issue-title xml:lang="en"/><issue-title xml:lang="ru"/><fpage>107</fpage><lpage>117</lpage><history><date date-type="received" iso-8601-date="2026-01-26"><day>26</day><month>01</month><year>2026</year></date></history><permissions><copyright-statement xml:lang="en">Copyright ©; 2026, ABV-press</copyright-statement><copyright-statement xml:lang="ru">Copyright ©; 2026, АБВ-пресс</copyright-statement><copyright-year>2026</copyright-year><copyright-holder xml:lang="en">ABV-press</copyright-holder><copyright-holder xml:lang="ru">АБВ-пресс</copyright-holder><license><ali:license_ref xmlns:ali="http://www.niso.org/schemas/ali/1.0/">https://creativecommons.org/licenses/by/4.0/</ali:license_ref></license></permissions><self-uri xlink:href="https://onco-surgery.info/jour/article/view/905">https://onco-surgery.info/jour/article/view/905</self-uri><abstract xml:lang="en"><p><bold>Background. </bold>Breast cancer demonstrates significant biological heterogeneity, which determines disease prognosis and the choice of systemic therapy. In clinical practice, the molecular subtype of the tumor is traditionally considered a relatively stable characteristic; however, recent data indicate the possibility of its change during the course of treatment. Investigation of patterns of tumor biological transformation represents an important area of personalized oncology, as such changes may influence the efficacy and appropriateness of the administered therapy.</p> <p><bold>Aim.</bold> To develop a multiparametric prognostic model integrating histological, immunohistochemical, and clinical data for predicting changes in the molecular subtype of breast cancer.</p> <p><bold>Materials and methods.</bold> The retrospective study included 261 patients with histologically verified invasive breast cancer treated between 2006 and 2025 at the "Medical City" Multidisciplinary Clinical Medical Center (Tyumen). Depending on the presence or absence of a change in the tumor molecular subtype, defined as a change in the immunohistochemical subtype between sequential examinations, patients were divided into two groups: group 1 – patients with confirmed subtype change; group 2 – patients without subtype change.</p> <p><bold>Results.</bold> The developed prognostic model demonstrated AUC (area under curve, 0.779 (95 % confidence interval 0.71–0.82) with specificity of 85 % and sensitivity of 51 % at the standard cut-off threshold (&gt; 0.5). With optimized threshold of <italic>p</italic> = 0.32, sensitivity of the model reached 72.4 %, specificity – 71.3 %. Internal bootstrap validation (1000 repetitions) confirmed stability of the model: AUC 0.79 (95 % confidence interval 0.72–0.86). To improve predictive accuracy, additional machine learning methods were applied (Random Forest: AUC 0.79, F1 0.77; LASSO: AUC 0.81, F1 0.78), which confirmed robustness of the identified predictors and consistency of prognostic estimates.</p> <p><bold>Conclusion.</bold> Changes in the molecular subtype of breast cancer are a predictable event. The developed model enables identification of patients at high risk of tumor biological transformation, which may help optimize dynamic monitoring and ensure timely adjustment of therapeutic strategies.</p></abstract><trans-abstract xml:lang="ru"><p><bold>Введение. </bold>Рак молочной железы (РМЖ) обладает биологической гетерогенностью, определяющей прогноз заболевания и выбор лекарственной терапии. В клинической практике молекулярно-биологический подтип опухоли традиционно рассматривается как относительно стабильная характеристика, однако данные последних лет свидетельствуют о возможности его изменения в процессе лечения. Изучение закономерностей биологической трансформации опухоли представляет важное направление персонализированной онкологии, поскольку может влиять на эффективность и обоснованность проводимой терапии.</p> <p><bold>Цель исследования</bold> – разработать мультипараметрическую прогностическую модель, интегрирующую гистологические, иммуногистохимические и клинические данные для прогнозирования изменения подтипа РМЖ.</p> <p><bold>Материалы и методы.</bold> В исследование ретроспективно включены пациентки (<italic>n</italic> = 261) с верифицированным инвазивным РМЖ, получавшие лечение в период с 2006 по 2025 г. на базе Многопрофильного клинического медицинского центра «Медицинский город» (Тюмень). В зависимости от наличия или отсутствия изменения молекулярно-биологического подтипа опухоли, определяемого как смена иммуногистохимического статуса между последовательными исследованиями, пациенток разделили на 2 группы: с зафиксированным изменением подтипа (1-я группа) и без изменения (2-я группа).</p> <p><bold>Результаты.</bold> Разработанная прогностическая модель продемонстрировала площадь под ROC-кривой (area under curve, AUC), равную 0,779 (95 % доверительный интервал 0,71–0,82), специфичность 85 % и чувствительность 51 % при стандартном пороге отсечения (&gt; 0,5). При оптимизированном пороге <italic>p</italic> = 0,32 чувствительность модели достигла 72,4 % при специфичности 71,3 %. Внутренняя валидация методом bootstrap (1000 повторов) подтвердила устойчивость модели: AUC 0,79 (95 % доверительный интервал 0,72–0,86). Для повышения прогностической точности дополнительно применены методы машинного обучения Random Forest и LASSO, которые подтвердили устойчивость выявленных предикторов и согласованность прогностических оценок (AUC 0,79; F1 0,77 и AUC 0,81; F1 0,78 соответственно).</p> <p><bold>Заключение.</bold> Изменение молекулярно-биологического подтипа РМЖ – прогнозируемое событие. Разработанная модель позволяет идентифицировать пациенток с высоким риском биологической трансформации опухоли для оптимизации динамического наблюдения и своевременной коррекции терапии.</p></trans-abstract><kwd-group xml:lang="en"><kwd>breast cancer</kwd><kwd>biological subtype</kwd><kwd>immunohistochemical analysis</kwd><kwd>prognostic model</kwd><kwd>receptor dynamics</kwd><kwd>personalized therapy</kwd></kwd-group><kwd-group xml:lang="ru"><kwd>рак молочной железы</kwd><kwd>биологический подтип</kwd><kwd>иммуногистохимический анализ</kwd><kwd>прогностическая модель</kwd><kwd>динамика рецепторов</kwd><kwd>персонализированная терапия</kwd></kwd-group><funding-group/></article-meta></front><body></body><back><ref-list><ref id="B1"><label>1.</label><mixed-citation>Filho A.M., Bray F., Soerjomataram I. et al. The GLOBOCAN 2022 cancer estimates: data sources, methods, and a snapshot of the cancer burden worldwide. Int J Cancer 2025;156(7):1336–46. 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