SUMMARY OBJECTIVE: The aim of this study was to investigate the predictive importance of the previously validated log(ER)*log(PgR)/Ki-67 predictive model in a larger patient population. METHODS: Patients with hormone receptor positive/HER-2 negative and clinical node positive before chemotherapy were included. Log(ER)*log(PgR)/Ki-67 values of the patients were determined, and the ideal cutoff value was calculated using a receiver operating characteristic curve analysis. It was analyzed with a logistic regression model along with other clinical and pathological characteristics. RESULTS: A total of 181 patients were included in the study. The ideal cutoff value for pathological response was 0.12 (area under the curve=0.585, p=0.032). In the univariate analysis, no statistical correlation was observed between luminal subtype (p=0.294), histological type (p=0.238), clinical t-stage (p=0.927), progesterone receptor level (p=0.261), Ki-67 cutoff value (p=0.425), and pathological complete response. There was a positive relationship between numerical increase in age and residual disease. As the grade of the patients increased, the probability of residual disease decreased. Patients with log(ER)*log(PgR)/Ki-67 above 0.12 had an approximately threefold increased risk of residual disease when compared to patients with 0.12 and below (odds ratio: 3.17, 95% confidence interval: 1.48–6.75, p=0.003). When age, grade, and logarithmic formula were assessed together, the logarithmic formula maintained its statistical significance (odds ratio: 2.47, 95% confidence interval: 1.07–5.69, p=0.034). CONCLUSION: In hormone receptor-positive breast cancer patients receiving neoadjuvant chemotherapy, the logarithmic model has been shown in a larger patient population to be an inexpensive, easy, and rapidly applicable predictive marker that can be used to predict response.

Abstract Introduction: Trastuzumab emtansine (T-DM1) is one of the effective treatment options in human epidermal growth factor receptor 2 (HER2) positive breast cancer patients. In this study, we aimed to find the effect of T-DM1 on survival, its tolerability and prognostic factors of T-DM1 treatment. Material and methods: The study was designed as a single-center, retrospective study that included patients treated in the oncology department of a university hospital in Turkey. HER2-positive patients with metastatic breast cancer who had a progression response to trastuzumab and taxane treatment and received T-DM1 treatment for at least 2 months between 2016-2022 were included in the study. Adverse events were defined according to the Common Terminology Criteria for Adverse Events v5.0 (CTCAE). Kaplan-Meier methodology and Cox proportional hazard modelling were used for survival analyses. Results: The median progression-free survival (mPFS) for T-DM1 was 10.4 months and the median overall survival (mOS) was 22 months. In the created univariate cox regression model, liver metastasis, ECOG performance status, and pre-treatment serum CA 15-3 were found to be factors associated with PFS. Liver metastasis (HR=2.54, p=0.019), ECOG performance status (HR=4.66, p=0.002), and serum CA 15-3 (HR= 2.55, p=0.041) maintained their statistical significance for PFS in the established multivariate analysis. In the regression analysis for OS, only ECOG performance status (HR= 2.61, p=0.023) was found to be prognostic. While toxicity occurred in 46 (82.1%) of the patients, grade 3-4 toxicity developed in 10 (17.9%) patients. The most common side effects were anemia, thrombocytopenia, fatigue and nausea. Conclusions: T-DM1 is a safe and tolerable agent that prolongs survival. Liver metastasis, ECOG performance status, and pre-treatment serum CA 15-3 levels are independent prognostic factors for patients using T-DM1.

Resumen Introducción: Trastuzumab emtansina (T-DM1) es una de las opciones de tratamiento eficaces en pacientes con cáncer de mama positivo para el receptor 2 del factor de crecimiento epidérmico humano (HER2). En este estudio, nuestro objetivo fue encontrar el efecto de T-DM1 en la supervivencia, su tolerabilidad y los factores pronósticos del tratamiento con T-DM1. Material y métodos: El estudio se diseñó como un estudio retrospectivo unicéntrico que incluyó pacientes tratados en el departamento de oncología de un hospital universitario en Turquía. Se incluyeron en el estudio pacientes HER2 positivas con cáncer de mama metastásico que tuvieron una respuesta progresiva al tratamiento con trastuzumab y taxanos y recibieron tratamiento con T-DM1 durante al menos 2 meses entre 2016 y 2022. Los eventos adversos se definieron de acuerdo con los Criterios de Terminología Común para Eventos Adversos v5.0 (CTCAE). Se utilizaron la metodología de Kaplan-Meier y el modelo de riesgos proporcionales de Cox para los análisis de supervivencia. Resultados: La mediana de supervivencia libre de progresión (mPFS) para T-DM1 fue de 10,4 meses y la mediana de supervivencia general (mOS) fue de 22 meses. En el modelo de regresión de cox univariable creado, se encontró que la metástasis hepática, el estado funcional ECOG y el CA 15-3 sérico previo al tratamiento son factores asociados con la SLP. La metástasis hepática (HR = 2,54, p = 0,019), el estado funcional ECOG (HR = 4,66, p = 0,002) y el suero CA 15-3 (HR = 2,55, p = 0,041) mantuvieron su significación estadística para la SLP en el estudio multivariable establecido. análisis. En el análisis de regresión para OS, solo se encontró que el estado funcional ECOG (HR= 2.61, p=0.023) era pronóstico. Si bien se produjo toxicidad en 46 (82,1 %) de los pacientes, se desarrolló toxicidad de grado 3-4 en 10 (17,9 %) pacientes. Los efectos secundarios más comunes fueron anemia, trombocitopenia, fatiga y náuseas. Conclusiones: T-DM1 es un agente seguro y tolerable que prolonga la supervivencia. La metástasis hepática, el estado funcional ECOG y los niveles séricos de CA 15-3 previos al tratamiento son factores pronósticos independientes para los pacientes que usan T-DM1.