Cancer Science & Therapy

Progesterone Receptor Expression Level Within Immunohistochemically Determined Early Stage Node Negative Luminal-B Breast Cancer: Forecasting Implication, Outcome and Concordance to Oncotype-DX Recurrence Scores

Abstract

Hala Ahmed Zaghloul*, Lulwah Abduljabbar, Karim Abdel Halim and Miral Mashhour

Purpose: To depict Progesterone Receptor (PR) expression exerted modulations on Oncotype-DX Recurrence Scores (RS) in immunehistochemically determined node-negative luminal-B-like breast cancers with Ki67 between ≥ 14% and <30% alongside their potentials in forecasting the outcome.

Methods: The impact of PR variations on Oncotype-Dx RS alongside their implications to the different prognosticators, including adjuvant chemotherapy, local and distant Recurrence-Free Survival (RFS) were scrutinized. Additionally, the concordance of the Hormone Receptor (HR) quantifying approaches devising immune staining and Reverse Transcriptase-Polymerase Reaction (RT-PCR) were statistically particularized.

Results: We selected 250 surgically treated node-negative Luminal-B1 (Ki67 ≥ 14%-<20%) and Luminal-B2(Ki67 ≥20%-<30%) breast cancers who had Oncotype-DX RS analyzed. The PR ≤ 20% was linked to high-grades tumors (P=0.013, 0.012) and accentuated Oncotype-DX RS (P=0.003, 0.001) in both Luminal-B1and B2. Multivariate regression revealed that PR ≤ 20% was a substantial forecaster of the enhanced RS and the adjuvant chemotherapy use (P<0.0001, 0.002), respectively. The Cox regression divulged that the accentuated Oncotype-Dx RS alongside the PR ≤ 20% were independently attributed to lower RFS, with a hazard ratio of 1.84 (95% confidence interval [CI], 3.67-8.14) and 2.53 (95% CI, 2.62-6.12), respectively. Furthermore, ER and PR characterized by immune staining and RT-PCR were concordant in 98.2% and 86.7% of cases.

Conclusion: In node-negative luminal-B with Ki67 between ≥14% and <30% breast cancers, PR ≤ 20% was a robust prognosticator of enhanced RS and adjuvant chemotherapy. The accentuated RS and PR ≤ 20% were independently attributed to reduced recurrence-free survival. Furthermore, a substantial concordance was attained between HR status defined by immune staining and RT-PCR that mounted up to 98.2% and 86.7% for ER and PR, respectively.