Progesterone Receptor Signaling in the Breast Tumor Microenvironment

PR status is a more decisive factor in efficacy of adding pertuzumab into neoadjuvant therapy for HER2-positive and lymph node-positive breast cancer than ER status: a real-world retrospective study in China

BACKGROUND

Although neoadjuvant trastuzumab and pertuzumab (HP)-based regimens are recommended for human epidermal receptor-positive (HER2 +)/lymph node-positive (N +) breast cancer (BC) patients according to NCCN guidelines, it is undeniable that many patients achieved pathological complete response (pCR) after trastuzumab (H)-based regimens without adding pertuzumab to treatment. Patients who specifically benefit from pertuzumab must be identified. The aim of this retrospective study was to evaluate progesterone receptor (PR) status as a predictor of response to the addition of pertuzumab in HER2 + /N + breast cancer.

METHODS

One hundred forty-two patients who were diagnosed as HER2 + /N + BC without distant metastasis and followed by neoadjuvant HP-based or H-based therapy were retrospectively included. The endpoints were pCR and disease-free survival (DFS) times.

RESULTS

In total, the pCR occurred in 25 of 87 patients (28.74%) in group H compared with 32 of 55 (58.18%) in group HP. The results revealed that hormone receptor (HR) status was significantly different on pCR in group HP. The odds of pCR for patients who have HR-positive tumors were 0.160 times (P = 0.011) that for patients with HR-negative tumors by multivariable analysis. Moreover, a similar probability of PR-positive (PR +) patients, whatever estrogen receptor (ER) status was, achieving pCR in group HP was observed. The ROC curves showed different anti-HER2 regimens provide worst predictive value in the PR + cohort (N = AUC = 0.521, 95% CI: 0.348-0.694, P = 0.813) compared with the overall cohort (AUC = 0.644, 95% CI: 0.550-0.738, P = 0.004) and ER + cohort (AUC: 0.559, 95% CI: 0.405-0.713, P = 0.451). And PR status (AUC = 0.760, 95% CI: 0.626-0.894, P = 0.001) had a greater predictive value than ER status (AUC = 0.658, 95% CI: 0.508-0.807, P = 0.048) in group HP. DFS analyses were done on 141 patients. Although ER and PR status did not show significant difference in group HP (P = 0.789 and 0.088, respectively), HP-based therapy contributed to better DFS in the ER - and PR - cohorts (P = 0.035 and 0.015, respectively).

CONCLUSIONS

Compared with ER status, PR status might be a more valuable factor predicting the efficacy of adding pertuzumab into neoadjuvant therapy for HER2 + /N + BC. PR + patients benefit little from the addition of pertuzumab.

TRPS1 regulates the opposite effect of progesterone via RANKL in endometrial carcinoma and breast carcinoma

Medroxyprogesterone (MPA) has therapeutic effect on endometrial carcinoma (EC), while it could promote the carcinogenesis of breast cancer (BC) by activating receptor activator of NF-kB ligand (RANKL). However, the selective mechanism of MPA in endometrium and breast tissue remains obscure. Multiomics analysis of chromatin immunoprecipitation sequencing (ChIP-seq) and RNA sequencing (RNA-seq) were performed in cell lines derived from endometrial cancer and mammary tumor to screen the differential co-regulatory factors of progesterone receptor (PR). Dual-luciferase assays and ChIP-PCR assays were used to validate the transcriptional regulation. Co-immunoprecipitation (Co-IP) and immunofluorescence assays were carried out to explore molecular interactions between PR, the cofactor transcriptional repressor GATA binding 1 (TRPS1), and histone deacetylase 2 (HDAC2). Subsequently, human endometrial cancer/breast cancer xenograft models were established to investigate the regulation effect of cofactor TRPS1 in vivo. In the current study, we found that MPA downregulated RANKL expression in a time- and dose-dependent manner in EC, while had the opposite effect on BC. Then PR could recruit cofactor TRPS1 to the promoter of RANKL, leading to histone deacetylation of RANKL to repress its transcription in EC, whereas MPA disassociated the PR/TRPS1/HDAC2 complex to enhance RANKL histone acetylation in BC. Therefore, TRPS1, the coregulator recruited by PR played a critical role in the selective mechanism of progesterone in EC and BC and could become a potential candidate for targeted therapy to improve the anticancer effect of MPA on EC and avoid its carcinogenic effect on BC.

Multiregional Radiomic Signatures Based on Functional Parametric Maps from DCE-MRI for Preoperative Identification of Estrogen Receptor and Progesterone Receptor Status in Breast Cancer

Radiomics based on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) has been used for breast estrogen receptor (ER) and progesterone receptor (PR) status evaluation. However, the radiomic features of peritumoral regions were not thoroughly analyzed. This study aimed to establish and validate the multiregional radiomic signatures (RSs) for the preoperative identification of the ER and PR status in breast cancer. A total of 443 patients with breast cancer were divided into training (n = 356) and validation (n = 87) sets. Radiomic features were extracted from intra- and peritumoral regions on six functional parametric maps from DCE-MRI. A two-sample t-test, least absolute shrinkage and selection operator regression, and stepwise were used for feature selections. Three RSs for predicting the ER and PR status were constructed using a logistic regression model based on selected intratumoral, peritumoral, and combined intra- and peritumoral radiomic features. The area under the receiver operator characteristic curve (AUC) was used to assess the discriminative performance of three RSs. The AUCs of intra- and peritumoral RSs for identifying the ER status were 0.828/0.791 and 0.755/0.733 in the training and validation sets, respectively. For predicting the PR status, intra- and peritumoral RSs resulted in AUCs of 0.816/0.749 and 0.806/0.708 in the training and validation sets, respectively. Multiregional RSs achieved the best AUCs among three RSs for evaluating the ER (0.851 and 0.833) and PR (0.848 and 0.763) status. In conclusion, multiregional RSs based on functional parametric maps from DCE-MRI showed promising results for preoperatively evaluating the ER and PR status in breast cancer patients. Further studies using a larger cohort from multiple centers are necessary to confirm the reliability of the established models before clinical application.