Impact of combining the progesterone receptor and preoperative endocrine prognostic index (PEPI) as a prognostic factor after neoadjuvant endocrine therapy using aromatase inhibitors in postmenopausal ER positive and HER2 negative breast cancer

The preoperative endocrine prognostic index (PEPI) predicts survival after neoadjuvant endocrine therapy (NAE) using aromatase inhibitors (AIs) for women with postmenopausal estrogen receptor (ER)-positive breast cancer irrespective of the human epidermal growth factor receptor 2 (HER2) status. Although the progesterone receptor (PgR) is also a prognostic factor for ER-positive breast cancer, the PgR status was not considered a prognostic factor in the original PEPI scoring system. In this study, we investigated the utility of a modified PEPI including the PgR status (PEPI-P) as a prognostic factor after NAE for postmenopausal patients with ER-positive and HER2-negative breast cancer. We enrolled 107 patients with invasive ER-positive and HER2-negative breast cancer treated with exemestane for ≥4 months as NAE. We initially assessed PEPI and compared survival between the groups. Additionally, we obtained an effective cutoff for PgR through survival analysis. Then, we assessed the survival significance of PEPI-P. A PgR staining rate of 50% was the most significant cutoff for predicting recurrence-free survival (RFS) and cancer-specific survival (CSS). PEPI was a significant prognostic factor; moreover, PEPI-P was the most significant prognostic indicator for RFS and CSS. PEPI-P is a potent prognostic indicator of survival after NAE using AIs for postmenopausal patients with ER-positive and HER2-negative breast cancer. This modified PEPI may be useful for therapeutic decision-making regarding postmenopausal ER-positive and HER2-negative breast cancer after NAE.

术前内分泌预后指数（preoperative endocrine prognostic index, PEPI）可用于预测绝经后雌激素受体（estrogen receptor, ER）阳性乳腺癌女性接受芳香化酶抑制剂（aromatase inhibitors, AIs）新辅助内分泌治疗（neoadjuvant endocrine therapy, NAE）后的生存结局，且不受人表皮生长因子受体2（human epidermal growth factor receptor 2, HER2）状态影响。尽管孕激素受体（progesterone receptor, PgR）同样是ER阳性乳腺癌的预后因子，但在原始PEPI评分系统中，PgR状态并未被纳入预后评估范畴。本研究针对绝经后ER阳性且HER2阴性的乳腺癌患者，探讨了将PgR状态作为预后因子纳入改良版PEPI（命名为PEPI-P）在NAE治疗后预后评估中的应用价值。本研究纳入107例接受依西美坦作为NAE治疗≥4个月的侵袭性ER阳性且HER2阴性乳腺癌患者。我们首先对PEPI进行评估，并比较各组间的生存差异；此外，通过生存分析确定了PgR的有效截断值。随后，我们评估了PEPI-P的生存预后意义。结果显示，PgR染色率50%是预测无复发生存期（recurrence-free survival, RFS）与癌症特异性生存期（cancer-specific survival, CSS）的最优截断值。PEPI是显著的预后因子；而PEPI-P则是预测RFS与CSS的最显著预后指标。PEPI-P可作为绝经后ER阳性且HER2阴性乳腺癌患者接受AIs类药物NAE治疗后生存结局的有效预后指标。该改良版PEPI或可为绝经后ER阳性且HER2阴性乳腺癌患者在NAE治疗后的治疗决策提供参考依据。