Is quantitative oestrogen receptor expression useful in the evaluation of the clinical prognosis? Analysis of a homogeneous series of 797 patients with prospective determination of the ER status using simultaneous EIA and IHC

Higher ER load is not associated with better outcome in stage 1-3 breast cancer: a descriptive overview of quantitative HR analysis in operable breast cancer

Purpose

In breast cancer, hormone receptor (HR) status is generally a qualitative measure; positive or negative. Quantitatively measured oestrogen and progesterone receptors (ER and PR) are frequently proposed prognostic and predictive markers, some guidelines even provide different treatment options for patients with strong versus weak expression.

Aim

To evaluate quantitative HR load assessed by immunohistochemistry as a prognostic and predictive measure in stage 1–3 breast cancer.

Methods

We reviewed all the available literature on quantitatively measured HRs using immunohistochemistry.

Results

All included studies (n = 19) comprised a cohort of 30,754 patients. Only 2 out of 17 studies found a clear correlation between higher quantitative ER and better disease outcome. Only one trial examined quantitative ER both as prognostic and predictive marker and found no association between ER% and survival. Ten studies examined quantitative PR load, only two of those found a significant correlation between higher PR load and better disease outcome. Two trials examined quantitative PR both as prognostic and predictive marker, neither found any association between PR% and disease outcome.

Conclusions

There is no clear evidence for using quantitatively assessed ER and PR as prognostic nor predictive marker in patients with stage 1–3 breast cancer. We recommend only using a qualitative HR status in future guidelines and treatment considerations.

Electronic supplementary material

The online version of this article (10.1007/s10549-019-05233-9) contains supplementary material, which is available to authorized users.

Automated measurement of estrogen receptor in breast cancer: a comparison of fluorescent and chromogenic methods of measurement

Whereas FDA-approved methods of assessment of estrogen receptor (ER) are 'fit for purpose', they represent a 30-year-old technology. New quantitative methods, both chromogenic and fluorescent, have been developed and studies have shown that these methods increase the accuracy of assessment of ER. Here, we compare three methods of ER detection and assessment on two retrospective tissue microarray (TMA) cohorts of breast cancer patients: estimates of percent nuclei positive by pathologists and by Aperio's nuclear algorithm (standard chromogenic immunostaining), and immunofluorescence as quantified with the automated quantitative analysis (AQUA) method of quantitative immunofluorescence (QIF). Reproducibility was excellent (R(2)>0.95) between users for both automated analysis methods, and the Aperio and QIF scoring results were also highly correlated, despite the different detection systems. The subjective readings show lower levels of reproducibility and a discontinuous, bimodal distribution of scores not seen by either mechanized method. Kaplan-Meier analysis of 10-year disease-free survival was significant for each method (Pathologist, P=0.0019; Aperio, P=0.0053, AQUA, P=0.0026); however, there were discrepancies in patient classification in 19 out of 233 cases analyzed. Out of these, 11 were visually positive by both chromogenic and fluorescent detection. In 10 cases, the Aperio nuclear algorithm labeled the nuclei as negative; in 1 case, the AQUA score was just under the cutoff for positivity (determined by an Index TMA). In contrast, 8 out of 19 discrepant cases had clear nuclear positivity by fluorescence that was unable to be visualized by chromogenic detection, perhaps because of low positivity masked by the hematoxylin counterstain. These results demonstrate that automated systems enable objective, precise quantification of ER. Furthermore, immunofluorescence detection offers the additional advantage of a signal that cannot be masked by a counterstaining agent. These data support the usage of automated methods for measurement of this and other biomarkers that may be used in companion diagnostic tests.

Quantitative progesterone receptor expression and efficacy of anti-estrogen therapy in breast cancer

The central role of estrogen receptor (ER) presence in predicting which breast cancer patients are likely to benefit from anti-estrogen therapies is well-established, but the added benefit of progesterone receptor (PR) and in particular low levels of PR is less well understood. The objective of this study was to determine the quantitative relationship between borderline levels of PR and subsequent benefit from anti-estrogen therapy. We examined data from 447 patients, age 50 or older. ER and PR levels were quantitated by conventional ligand binding assay and Scatchard plot analysis or by enzyme-linked immunoassay. Comparison of clinical outcome in relation with ER and PR status was calculated using Kaplan-Meier actuarial survival analysis and the log-rank test. Subpopulation treatment effect pattern plot (STEPP) analysis was used to explore the interaction between treatment effects and ER or PR levels for the 409 patients with ER values greater than 0. For anti-estrogen treated patients, when the ER and PR positivity cut-off was set at 1.0 fmole/mg protein, there was a statistically significant advantage for patients with ER+PR+ over ER+ PR- tumors for both breast cancer-free interval (BCFI) and overall survival (OS). STEPP analysis found no overall interaction between treatment outcome (5 year survival probability) and levels of hormone receptor. However, patients with borderline PR levels did not appear to benefit from anti-estrogen therapy. PR levels above borderline in addition to the presence of ER predicts an increased probability of benefit from anti-estrogen therapy in breast cancer patients.

Quantum dots-based molecular classification of breast cancer by quantitative spectroanalysis of hormone receptors and HER2

The emerging molecular breast cancer (BC) classification based on key molecules, including hormone receptors (HRs), and human epidermal growth factor receptor 2 (HER2) has been playing an important part of clinical practice guideline. The current molecular classification mainly based on their fingerprints, however, could not provide enough essential information for treatment decision making. The molecular information on both patterns and quantities could be more helpful to heterogeneities understanding for BC personalized medicine. Here we conduct quantitative determination of HRs and HER2 by quantum dots (QDs)-based quantitative spectral analysis, which had excellent consistence with traditional method. Moreover, we establish a new molecular classification system of BC by integrating the quantitative information of HER2 and HRs, which could better reveal BC heterogeneity and identify 5 molecular subtypes with different 5-year prognosis. Furthermore, the emerging 5 molecular subtypes based on simple quantitative molecules information could be as informative as multi-genes analysis in routine practice, and might help formulate a more personalized comprehensive therapy strategy and prognosis prediction.

High estrogen receptor expression in early breast cancer: chemotherapy needed to improve RFS?

One of the most controversial questions in early breast cancer treatment is the need of chemotherapy in patients with estrogen receptor positive disease. Therefore, we analyzed a group of patients with high estrogen receptor (ER) expression to scrutinize the role of chemotherapy in this situation. To gauge the effect of chemotherapy on recurrence free survival (RFS) three treatment modalities were compared: endocrine treatment only, chemoendocrine treatment, and chemotherapy. 3,971 breast cancer patients whose treatment modalities as well as ER level were known, were included in this retrospective analysis. Their level of ER expression was documented as immunoreactive score (IRS). A high ER group was defined as ER IRS ≥ 9; primary endpoint was RFS. RFS was associated with ER, with the best outcome for strong and the worst result for negative expression. Adjusted to Nottingham prognostic index (NPI), RFS did not differ between the treatment cohorts of endocrine treatment and chemoendocrine treatment (P = 0.828) in the high ER group. Patients with chemotherapy alone fared significantly worse (P = 0.003). Even in high risk patients (according to NPI) the chemoendocrine and the endocrine treatment only groups did not differ significantly (HR = 1.15; 95% CI (0.56-2.34), P = 0.709). Omission of endocrine treatment led to significantly worse outcome (P = 0.013). In conclusion, RFS was significantly longer in patients with high ER expression than with weak or no ER expression. In the high expression group, there was no significant difference in RFS between endocrine treatment only and chemoendocrine therapy-even in high risk patients, for whom chemoendocrine treatment is routinely indicated. It seems insufficient for high ER patients to only consider tumor size, nodal status, and grading in order to decide which patient will benefit from adding chemotherapy to endocrine treatment.