Factors Affecting Pathologic Complete Remission in Patients with Hormone Receptor-Positive and Human Epidermal Growth Factor Receptor 2-Negative Breast Cancer Receiving Neoadjuvant Chemotherapy

Abstract

<b><i>Introduction:</i></b> Pathological complete response (pCR) after neoadjuvant chemotherapy (NAC) is associated with improvement in survival outcomes. This study evaluated the pCR in patients with hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (HER2)-negative breast cancer after NAC. <b><i>Methods:</i></b> We evaluated 417 patients who were diagnosed with invasive breast cancer and treated with NAC followed by curative surgery between January 2007 and December 2020 and analyzed the pCR for HR-positive and HER2-negative breast cancer. <b><i>Results:</i></b> The median age at the time of surgery was 45.4 years, and 9.1% of patients (38 of 417) with HR-positive/HER2-negative status had pCR. Among patients with HR-positive/HER2-negative breast cancer, patients with single HR-positivity had a 20.2% pCR rate, and patients with double HR-positivity had a 4.4% pCR rate. Patients with a high Ki-67 index exhibited a higher pCR rate than those with a lower Ki-67 index (14.5% vs. 3.2%). Patients with single HR-positive and high Ki-67 values exhibited a significantly higher pCR rate than those with double HR-positive and low Ki-67 values (27.8% vs. 2.1%; <i>p</i> < 0.001). <b><i>Conclusion:</i></b> NAC could improve prognosis in patients with HR-positive/HER2-negative breast cancer with a single HR-positive and high Ki-67 values.

Conventional Tools for Predicting Satisfactory Response to Neoadjuvant Chemotherapy in HR+/HER2− Breast Cancer Patients

“…On the other hand, concordant with our findings, they also found that high Ki-67 level was significantly associated with more pCR in HR+/HER2- BC patients. In a large retrospective study, patients with tumors having single (either ER or PR) HR-positivity, and high Ki-67 expression had higher pCR rates than those with both ER and PR positivity and low Ki-67 expression [21]. Studies provided that increasing the threshold of high Ki-67 expression by over 30% resulted in more pCR in patients with ER+/HER2- BC [22, 23].…”

Прогностическая и предиктивная значимость маркера Ki67 при раке молочной железы

“…(2017), в котором высокий уровень Ki67 до начала терапии был ассоциирован с лучшим ответом на НАХТ в отношении полной патоморфологической ремиссии, причем оптимальным cut-off авторы считают 15-20 %, отмечая существенную гетерогенность пороговых уровней в разных исследованиях (от 14 до 50 %) [49]. Сходные результаты в отношении прогностической значимости Ki67 при химиотерапии показаны и в более поздних исследованиях, где пороговое значение находилось в диапазоне от 14 % до 20 % [50][51][52][53]. Кроме того, подтверждено прогностическое значение оценки уровня Ki67 после НАХТ в послеоперационных образцах [54,55].…”