The Effect of Progesterone Receptor Level on Treatment Response in Breast Cancer Patients Receiving Neoadjuvant Therapy

Clinicians face challenges in deciding on the use of neoadjuvant chemotherapy(NACT) for patients with estrogen receptor(ER)-positive breast cancer due to the potential for low efficacy. Progesterone receptor(PR) is a biomarker routinely evaluated in breast cancer patients prior to NACT, but there is a lack of sufficient clinical data and guideline recommendations regarding its role in treatment decision-making. This study aimed to evaluate the impact of PR status on pathological complete response in ER-positive breast cancer patients receiving NACT. Our study examined 52 ER-positive patients who received NACT. Participants were grouped into three cohorts based on PR levels: less than 1%, 1-9%, and 10% and above. The pathological complete response rate, an important indicator of overall survival, was compared across these three groups. The results of our study showed a statistically significant higher pathological complete response rate in patients with PR levels below 1%. These findings suggest that NACT may be more effective in this patient subgroup. The study findings indicate that PR status may play a role in the decision-making process for NACT in ER-positive breast cancer patients.