A meta-analysis on concordance between immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH) to detect HER2 gene overexpression in breast cancer

Real-world data on neoadjuvant chemotherapy with dual-anti HER2 therapy in HER2 positive breast cancer

BACKGROUND

Neoadjuvant chemotherapy with dual-targeted therapy is the standard treatment for human epidermal growth factor 2 (HER2)-positive breast cancer. Although the dual-targeted therapy has significantly improved the pathological complete response (pCR) rate, further investigation is needed to identify biomarkers that predict the response to neoadjuvant therapy.

METHODS

This retrospective study analyzed 353 patients with HER2-positive breast invasive ductal carcinoma. The correlation between clinicopathological factors and pCR rate was evaluated. A nomogram was constructed based on the results of the multivariate logistic regression analysis to predict the probability of pCR.

RESULTS

The breast pCR (b-pCR) rate was 56.1% (198/353) and the total pCR (t-pCR) rate was 52.7% (186/353). Multivariate analysis identified ER status, PR status, HER2 status, Ki-67 index, and neoadjuvant chemotherapy regimens as independent indicators for both b-pCR and t-pCR. The nomogram had an area under the receiver operating characteristic curve (AUC) of 0.73 (95% CI: 0.68-0.78). According to the nomogram, the t- pCR rate was highest in the ER-PR- HER2-positive patients (131/208) and lowest in the ER + PR + HER2-positive patients (19/73). The subgroup analyses showed that there was no significant difference in pCR rate among the neoadjuvant chemotherapy regimens in ER positive, PR positive, HER2 IHC 2 + , Ki67 index < 30% population. However, for ER-PR-HER2-positive patients, the neoadjuvant chemotherapy regimen has a great influence on the pCR rates.

CONCLUSIONS

Patients with ER-negative, PR-negative, HER2 3 + and high KI-67 index were more likely to achieve pCR. THP may be used as an alternative to AC-THP or TCbHP in selected HER2-positive patients.

Evaluating Low HER2 Status in Invasive Breast Carcinoma via HER2 Immunohistochemistry, with HER2 FISH Correlation: A Cohort of 112 Patients

Introduction

Recent trials demonstrated clinically significant benefits in HER2-nonamplified breast cancer with HER2-low expression using novel anti-HER2 antibody-drug conjugates. Thus, HER2-low breast cancer was proposed as a separate diagnostic entity. Herein, we reclassify HER2-negative cancers according to the new HER2-low category using a modified system and further investigate HER2-very-low expression.

Methods

114 HER2 immunohistochemistry (IHC)-negative invasive breast tumors were identified from the pathology database of Mayo Clinic, Jacksonville, FL, between January 2019 and August 2022. Two blinded breast pathologists (BP) independently rescored HER2 IHC slides at 200x and 400x magnification. Discordant cases between the two BPs were rescored together. The most recent 2018 ASCO/CAP HER2 scoring criteria were used. HER2 (0) was subdivided into HER2 (absent) and HER2 (very low). HER2 FISH testing was performed in all cases.

Results

The cohort comprised of 38 (33.3%) HER2 (0) and 76 (66.7%) HER2 (1+) tumors. The first round of rescoring at 200x and 400x magnification resulted in 17 (14.9%) HER2 (absent), 31 (27.2%) HER2 (very low), and 64 (56.2%) HER2 (1+) and 2 (1.8%) HER2 (2+) tumors by BP1 and 20 (17.5%) HER2 (absent), 33 (28.9%) HER2 (very low), and 61 (53.5%) HER2 (1+) tumors by BP2. The combined final rescoring by BP1 and BP2 was as follows: 15 (13.2%) HER2 (absent), 35 (30.7%) HER2 (very low), 63 (55.3%) HER2 (1+), and 1 (0.9%) HER2 (2+) cases. A comparison of the first round of rescoring between two BPs showed substantial agreement with Cohen's kappa value of 0.67. Both comparisons of first rescoring by BP1 and by BP2 to combined final rescoring showed almost perfect agreement with Cohen's kappa value of 0.83.Follow-up FISH studies showed one amplified tumor.

Conclusion

Our data support the need for finer granularity, classification, and understanding of HER2-low breast cancers. We also show that reproducibility between trained BP can be obtained, albeit with scoring at high power and low threshold for showing challenging interpretations.

Low and Ultra-Low HER2 in Human Breast Cancer: An Effort to Define New Neoplastic Subtypes

HER2-low and ultra-low breast cancer (BC) have been recently proposed as new subcategories of HER2 BC, supporting a re-consideration of immunohistochemical negative scores of 0, 1+ and the 2+/in situ hybridization (ISH) negative phenotype. In the present review, we outline the criteria needed to exactly distinguish HER2-low and ultra-low BC. Recent clinical trials have demonstrated significant clinical benefits of novel HER2 directing antibody-drug conjugates (ADCs) in treating these groups of tumors. In particular, trastuzumab-deruxtecan (T-Dxd), a HER2-directing ADC, has been recently approved by the US Food and Drug Administration as the first targeted therapy to treat HER2-low BC. Furthermore, ongoing trials, such as the DESTINY-Breast06 trial, are currently evaluating ADCs in patients with HER2-ultra low BC. Finally, we hope that new guidelines may help to codify HER2-low and ultra-low BC, increasing our knowledge of tumor biology and improving a targetable new therapeutical treatment.

Comprehensive Analysis of Human Epidermal Growth Factor Receptor 2 Through DNA, mRNA, and Protein in Diverse Malignancies

PURPOSE

Human epidermal growth factor receptor 2 (HER2) expression (protein immunohistochemistry [IHC] or gene amplification [copy-number variation, CNV]) predicts anti-HER2 therapy responsiveness, although recently it was shown that even low HER2-expressing breast cancers benefit from trastuzumab-deruxtecan. Little is known about HER2 transcriptomic (mRNA) expression, and comparisons between genomic, mRNA, and protein HER2 assays.

METHODS

HER2 status was evaluated using clinical-grade IHC (protein), quantitative reverse transcription polymerase chain reaction (mRNA), and next-generation sequencing (NGS; amplifications).

RESULTS

Multi-institutional HER2 testing was performed on 5,305 diverse cancers including non-small-cell lung (n = 1,175), breast (n = 1,040), and colon cancers (n = 566; N = 3,926 tested for CNV; N = 1,848, mRNA; N = 2,533, IHC). Overall, 4.1% (161/3,926) had NGS HER2 amplification; 33.3% (615/1,848) had mRNA overexpression; and 9.3% (236/2,533) were IHC-positive. In 723 patients with all three tests (CNV/mRNA/IHC), various amplification/expression patterns occurred: 7.5% (54/723) had all three HER2 tests positive; 62.8% (454/723) had all three tests negative. Discrepant patterns between amplification and overexpression emerged. For instance, 20% (144/723) of patients had mRNA overexpression alone with negative CNV and IHC. A range in values for only mRNA+ cases occurred in different tumor types (eg, 16.9%, breast; 5%, hepatobiliary). There were 53 patients with various tumors from our institution who had all three assays attempted; 22 tested positive for HER2, and seven received anti-HER2 therapy: two patients achieved response: one (esophageal cancer), complete response (≥42 months); one (cholangiocarcinoma), who only had HER2 mRNA positivity (tissue was inadequate for IHC and CNV assessment), partial response (≥24 months) on HER2-based regimens.

CONCLUSION

We demonstrate variability of HER2 (protein and mRNA) expression and amplification using comprehensive assays (CNV, mRNA, and IHC) among diverse cancers. As HER2-targeted therapy indications expand, the relative importance of these modalities merits further evaluation.

HER2 Amplification Level Predicts Pathological Complete Response in the Neoadjuvant Setting of HER2-Overexpressing Breast Cancer: A Meta-Analysis and Systematic Review

Anti-HER2 therapies have dramatically improved the prognosis of human epidermal growth factor receptor 2 (HER2)-overexpressing cancers. However, the correlation between the HER2 copy number and the response rate to anti-HER2 remains unclear. Here, following the PRISMA method, we performed a meta-analysis in the neoadjuvant setting in breast cancer to study the association between the HER2 amplification level and the pathological complete response (pCR) to anti-HER2 therapies. Nine articles (four clinical trials, five observational studies) were retrieved after full-text screening, involving 11,238 women with locally advanced breast cancer in the neoadjuvant setting. The median HER2/CEP17 ratio cut-off value was 5.0 ± 5.0 (min-max = 1.0-14.0). For the overall population, the median pCR rate was 48% using the random effect model. The studies were categorized in quartiles as follows: ≤2 (Class 1); 2.1 to 5.0 (Class 2); 5.1 to 7.0 (Class 3); and >7.0 (Class 4). After grouping, the pCR rates were 33%, 49%, 57%, and 79%, respectively. When we excluded the study by Greenwell et al., which accounted for 90% of the patients, using the same quartiles, we still observed an increasing rate of pCR as the HER2/CEP17 ratio increased. This is the first meta-analysis demonstrating the relationship between the HER2 amplification level and the percentage of pCR in the neoadjuvant setting among women with HER2-overexpressing breast cancer, with potential therapeutic applications.

Multicentricity in Different Molecular Subtypes of Breast Cancer: A Cross-sectional Study in Isfahan

Background

Breast cancer is the most common cancer leading to death in women. Women with multicentric breast cancer were reported more likely to have poor prognosis. Here, we decided to study and compare the frequency distribution of multicentricity in different subtypes of breast cancer.

Materials and Methods

This is a cross-sectional study that was performed in 2019-20 on medical records and breast pathology reports of 250 patients who undergone mastectomy due to breast cancer. Demographic data of all patients including age, along with other medical data such as menstruation condition, breast cancer grade, multicentricity status, stage, and expression of estrogen receptor (ER), progesterone (PR), and human epidermal growth factor receptor 2 (HER2) receptors were collected from medical records. Samples were divided into four subtypes of Luminal B, Luminal A, HER2 expressing, and basal-like.

Results

The mean age of patients was 50.21 ± 11.15 years. Ninety-five patients (38%) had multicentricity and HER2 expressing (48.5%) and Luminal A (41.4%) were most common in patients with multicentricity. In addition, basal-like group presented with least multicentricity (13.5%) among the subtypes (P = 0.008). We also showed significant increased chances of multicentricity in Luminal B (odds ratio [OR] = 3.782) (P = 0.033), Luminal A (OR = 5.164) (P = 0.002), and HER2-expressing group (OR = 5.393) (P = 0.011).

Conclusions

Taken together, we showed significantly increased chances of multicentricity in patients with HER2-expression, Luminal A, and Luminal B groups compared to basal-like group or triple negative. These results were in line with most previous studies; however, we showed higher rates of multicentricity among our population compared to some previous reports.

Anesthesia With Propofol Sedation Reduces Locoregional Recurrence in Patients With Breast Cancer Receiving Total Mastectomy Compared With Non-Propofol Anesthesia

Purpose

We examined locoregional recurrence (LRR) in patients with breast invasive ductal carcinoma (IDC) receiving total mastectomy (TM) under propofol-based paravertebral block-regional anesthesia (PB-RA) versus sevoflurane-based inhalational general anesthesia (INHA-GA) without propofol. All-cause death and distant metastasis were secondary endpoints.

Patients and Methods

Patients with breast IDC receiving TM were recruited through propensity score matching and categorized into INHA-GA with sevoflurane and PB-RA with propofol groups. Cox regression analysis was performed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

Results

In the multivariate Cox regression analysis, the adjusted HR (aHR; 95% CI) of LRR for the PB-RA with propofol group was 0.52 (0.28–0.96) compared with the INHA-GA with sevoflurane group. The aHRs of LRR for differentiation grade II, grade III, the American Joint Committee on Cancer clinical stage II, stage III, pathological tumor (pT) stage 2, pT stage 3–4, pathological nodal (pN) stage 1, and pN stage 2–3 were 1.16 (1.04–2.08), 1.28 (1.07–2.12), 3.71 (1.82–7.59), 4.67 (1.65–13.18), 1.09 (1.02–1.21), 1.17 (1.03–2.16), 1.10 (1.03–1.33), and 1.22 (1.06–2.41), respectively, compared with differentiation grade I, clinical stage I, pT1, and pN0. The aHR of LRR for adjuvant RT was 0.88 (0.64–0.94) compared with that for no adjuvant RT.

Conclusion

PB-RA with propofol might be beneficial for reducing LRR in women with breast IDC receiving TM compared with INHA-GA without propofol.

Survival Impact of Long-Term Tramadol Use on Breast Cancer for Patients with Chronic Pain: A Propensity Score-Matched Population-Based Cohort Study

Purpose: The impact of tramadol analgesic use before breast cancer diagnosis on survival in patients with chronic pain is unclear. Therefore, we designed a propensity score-matched population-based cohort study to compare the breast cancer-related survival of patients with chronic pain who received long-term tramadol analgesic treatment with that of those who did not receive such treatment. Patients and Methods: We included patients with chronic pain and categorized them into two groups according to their analgesic use, comparing their breast cancer-related survival; patients with breast cancer and chronic pain who were prescribed ≥180 defined daily doses (DDDs) of tramadol analgesics per year >3 months before breast cancer diagnosis comprised the case group, and those who were prescribed non-tramadol analgesics before breast cancer diagnosis comprised the control group. Patients in both groups were matched at a ratio of 1:5. Results: The matching process yielded a final cohort of 624 patients (104 and 520 in the case and control groups, respectively) who were eligible for further analysis. According to both univariate and multivariate Cox regression analyses, the adjusted hazard ratio for all-cause death in the case group compared with in the control group was 3.45 (95% confidence interval = 2.36−5.04; p < 0.001). Conclusion: Long-term tramadol analgesic use prior to breast cancer diagnosis might be associated with poor overall survival in patients with chronic pain compared with such patients that did not receive long-term tramadol analgesic treatment.

HER2 changes to positive after neoadjuvant chemotherapy in breast cancer: A case report and literature review

BACKGROUND

As the most common cancer in women, breast cancer is the leading cause of death. Most patients are initially diagnosed as stage I-III. Among those without distant metastases, 64% are local tumors and 27% are regional tumors. Patients in stage IIA-IIIC and those who meet the breast-conserving criterion with the exception of tumor size can consider neoadjuvant chemotherapy (NACT). It is worth noting that the status of tumor cell biomarkers is not consistently static. Endocrine-related estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) encoded by erythroblastic leukemia viral oncogene homolog 2 gene can all alter from positive to negative or vice versa, especially in luminal B subtype after NACT. In addition, determination of HER2 status currently mainly relies on immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH), but FISH is commonly used when the result of IHC is uncertain. HER2 is regarded as negative when the IHC result is 0/1+ without the addition of FISH. To the best of our knowledge, this is the first report of a case harboring HER2 status transformation and IHC1+ with positive amplification by FISH after NACT.

CASE SUMMARY

A 49-year-old woman discovered a mass in her right breast and underwent diagnostic workup. Biopsies of the right breast lesion and axillary lymph nodes were obtained. The results pointed to invasive ductal carcinoma with the IHC result for ER (80%), PR (60%), Ki-67 (20%) and ambiguous expression of HER2 (IHC 2+) with negative amplification by FISH (HER2/CEP17 ratio of 1.13). She underwent surgery after NACT. The pathological findings of the surgically resected sample supported invasive ductal carcinoma with the tumor measuring 1.1 cm × 0.8 cm × 0.5 cm and had spread to one of fifteen dissected lymph nodes. Retesting of the specimen showed that the tumor was positive for ER (2+, 85%) and PR (2+, 10%) but negative for HER2 by IHC (1+). Also Ki-67 had dropped to 2%. The patient was regularly monitored every 3 mo without evidence of recurrence.

CONCLUSION

Biomarker status should be reassessed after NACT especially in luminal subtypes.

Targeting HER2 protein in individual cells using ICP-MS detection and its potential as prognostic and predictive breast cancer biomarker

The human epidermal growth factor receptor 2 (HER2) is a transmembrane protein that has become one of the most specific prognostic and predictive biomarker of breast cancer. Its early detection is key for optimizing the patient clinical outcome. This work is focused on the detection of HER2 in individual cells using an antibody containing lutetium (Lu) as reporter group that is monitored by introducing the individual cells into the inductively coupled plasma mass spectrometer (ICP-MS). This Lu-containing antibody probe is used to label different breast cancer cell lines considered HER2 negative (MDA-MB-231) and positive (SKBR-3 and BT-474). Optimizations regarding the amount of the probe necessary to ensure complete labelling reactions are conducted in the different cell models. Concentrations in the range of 0.006 fg Lu/cell and 0.030 fg Lu/cell could be found in the HER2 negative and HER2 positive cells, respectively. In addition, the selectivity of the labelling reaction is tested by using two different metal-containing antibody probes for HER2 (containing Lu) and for transferrin receptor 1 (containing Nd), respectively, within the same cell population. Finally, the methodology is applied to the targeting of HER2 positive cells in complex cell mixtures containing variable amounts of BT-474 and MDA-MB-231 cells. The obtained results showed the excellent capabilities of the proposed strategy to discriminate among cell populations. This finding could help for scoring HER2 positive tumors improving existing technologies.

Looking for more reliable biomarkers in breast cancer: Comparison between routine methods and RT-qPCR

PURPOSE

Decades of quality control efforts have raised the standards of immunohistochemistry (IHC), the principle method used for biomarker testing in breast cancer; however, computational pathology and reverse transcription quantitative PCR (RT-qPCR) may also hold promise for additional substantial improvements.

METHODS

Herein, we investigated discrepancies in the assessment of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and marker of proliferation Ki67 comparing routinely obtained IHC (and FISH) data (ORI) with the results of manual (REV) and semi-automated (DIA) re-evaluation of the original IHC slides and then with RNA expression data from the same tissue block using the MammaTyper® (MT) gene expression assay.

RESULTS

Correlation for ER and PR was high between ORI IHC and the other three study methods (REV, DIA and RT-qPCR). For HER2, 10 out of 96 discrepant cases can be detected between ORI and REV that involved at least one call in the equivocal category (except for one case). For Ki67, 22 (29.1%) cases were categorized differently by either REV alone (n = 17), DIA alone (n = 15) or both (n = 10) and 28 cases (29.2%) for RT-qPCR. Most of the discrepant Ki67 cases changed from low to high between the original and following assessment and belonged to the intermediate Ki67 expression range (between 9 and 30%).

CONCLUSIONS

Determination of the breast cancer biomarkers ER, PR, HER2 and Ki67 at the mRNA level shows high degree of correlation with IHC and compares well with correlations between original with subsequent independent manual or semi-automated IHC assessments. The use of methods with wider dynamic range and higher reproducibility such as RT-qPCR may offer more precise assessment of endocrine responsiveness, improve Ki67 standardization and help resolve HER2 cases that remain equivocal or ambiguous by IHC/FISH. In summary, our findings seem to configure RT-qPCR as a complementary method to be used in cases of either equivocal results or presenting, at the traditional determination assays, biomarkers expressions close to the cut-off values.

Paravertebral block in regional anesthesia with propofol sedation reduces locoregional recurrence in patients with breast cancer receiving breast conservative surgery compared with volatile inhalational without propofol in general anesthesia

PURPOSE

We examined locoregional recurrence (LRR) in patients with breast invasive ductal carcinoma (IDC) receiving breast conservative surgery (BCS) under propofol-based paravertebral block-regional anesthesia (PB-RA) versus sevoflurane-based inhalational general anesthesia (INHA-GA) without propofol. All-cause death and distant metastasis were secondary endpoints.

PATIENTS AND METHODS

Patients with breast IDC receiving BCS were recruited through propensity score matching and categorized into INHA-GA with sevoflurane and PB-RA with propofol groups. Cox regression analysis was performed to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

In the multivariate Cox regression analysis, the adjusted HR (aHR; 95% CI) of LRR for the PB-RA with propofol group was 0.67 (0.46-0.99) compared with the INHA-GA with sevoflurane group. The aHRs of LRR for differentiation grade II, grade III, the American Joint Committee on Cancer clinical stage II, stage III, pathological tumor (pT) stage 2, pT stage 3-4, pathological nodal (pN) stage 2-3, and Her-2 positivity were 1.87 (1.03-3.42), 2.31 (1.20-4.44), 1.67 (1.09-2.56), 2.43 (1.18-4.97), 1.17 (1.03-1.19), 1.28 (1.13-2.24), 1.20 (1.05-2.22), and 1.59 (1.01-2.51), respectively, compared with those for differentiation grade I, clinical stage I, pT1, pN0, and HER-2 negativity. The aHR of LRR for adjuvant radiotherapy was 0.60 (0.38-0.97) compared with that for no adjuvant radiotherapy.

CONCLUSION

PB-RA with propofol might be beneficial for reducing LRR in women with breast IDC receiving BCS compared with INHA-GA without propofol.

Impact of Smoking-Related Chronic Obstruction Pulmonary Disease on Mortality of Invasive Ductal Carcinoma Patients Receiving Standard Treatments: Propensity Score-Matched, Nationwide, Population-Based Cohort Study

Simple Summary

This study is the first to estimate the impact of smoking-related chronic obstructive pulmonary disease (COPD) on invasive ductal carcinoma (IDC) patients receiving standard treatments. Smoking-related COPD was not a significant independent risk factor for all-cause mortality in women with stage I–III IDC receiving standard treatments. The frequency of hospitalization for COPD with at least one acute exacerbation within one year before breast surgery was highly associated with high mortality for women with IDC receiving standard treatments.

Abstract

Purpose: the survival effect of smoking-related chronic obstructive pulmonary disease (COPD) and COPD with acute exacerbation (COPDAE) is unclear for patients with invasive ductal carcinoma (IDC) receiving standard treatments. Methods: we recruited women with clinical stage I–III IDC from the Taiwan Cancer Registry Database who had received standard treatments between 1 January 2009 and 31 December 2018. The time-dependent Cox proportional hazards model was used to analyze all-cause mortality. To reduce the effects of potential confounders when all-cause mortality between Groups 1 and 2 were compared, 1:2 propensity score matching (PSM) was performed. We categorized the patients into two groups based on COPD status to compare overall survival outcomes: Group 1 (current smokers with COPD) and Group 2 (nonsmokers without COPD group). Results: PSM yielded 2319 patients with stage I–III IDC (773 and 1546 in Groups 1 and 2, respectively) eligible for further analysis. In the multivariate time-dependent Cox regression analyses, the adjusted hazard ratio (aHR; 95% confidence interval (CI)) of all-cause mortality for Group 1 compared with Group 2 was 1.04 (0.83–1.22). The aHRs (95% CIs) of all-cause mortality for ≥1 hospitalization for COPDAE within one year before breast surgery was 1.51 (1.18–2.36) compared with no COPDAE. Conclusion: smoking-related COPD was not a significant independent risk factor for all-cause mortality in women with stage I–III IDC receiving standard treatments. Being hospitalized at least once for COPDAE within one year before breast surgery is highly associated with high mortality for women with IDC receiving standard treatments. The severity of smoking-related COPD before treatments for breast cancer might be an important prognostic factor of survival. Thus, the information of the severity of COPD before treatment for breast cancer might be valuable for increasing the survival rate in treatment of breast cancer, especially in the prevention of progress from COPD to COPDAE.

Discordance Between Immunohistochemistry and In Situ Hybridization to Detect HER2 Overexpression/Gene Amplification in Breast Cancer in the Modern Age: A Single Institution Experience and Pooled Literature Review Study

BACKGROUND

Human epidermal growth factor 2 (HER2) amplification and/or overexpression occurs in 12% to 25% of breast cancers. Accurate detection of HER2 is critical in predicting response to HER2-targeted therapy. Both immunohistochemistry (IHC) and in situ hybridization (ISH) are FDA-approved methods for detecting HER2 status because its protein overexpression is largely attributable to gene amplification. However, variable discordant results between IHC and ISH have been reported.

METHODS

We determined the frequency of HER2 IHC/ISH discordance in these patients and also performed a pooled literature review analysis.

RESULTS

Of the 1125 consecutive primary or metastatic breast cancers with HER2 IHC and ISH performed simultaneously between 2015 and 2020, 84.6% had an unequivocal HER2 status. Discordance was found in 30 cases from 26 patients, including 13 IHC^-/ISH⁺ and 17 IHC⁺/ISH^-, representing 1.6% and 11.9% of IHC^- and IHC⁺ cases, respectively. Review of the literature between 2001 and 2020 identified 46 relevant studies, with a total of 43,468 cases with IHC and ISH performed. The IHC^-/ISH+ and IHC⁺/ISH^- discordances were seen in all antibody clones and ISH methods used. The IHC⁺/ISH^- discordance was significantly higher than IHC^-/ISH⁺ (13.8% vs. 3%, P < .0001). The overall discordance constituted 4% of all cases and 5.4% of those with an unequivocal IHC status. Significantly lower incongruities for both IHC^-/ISH⁺ and IHC⁺/ISH^- were found in those published after 2018. The discordances probably reflect altered biology of HER2 oncogene/oncoprotein. Routinely performing both IHC and ISH may uncover such cases to prevent denial of potentially beneficial targeted therapy.

Neoadjuvant Chemotherapy or Endocrine Therapy for Invasive Ductal Carcinoma of the Breast With High Hormone Receptor Positivity and Human Epidermal Growth Factor Receptor 2 Negativity

IMPORTANCE

Although neoadjuvant endocrine therapy (NET) is an alternative to chemotherapy for strongly hormone receptor (HR)-positive and human epidermal growth factor receptor 2 (ERBB2)-negative breast cancer, evidence is currently lacking regarding the probable survival outcomes of NET in comparison with those of neoadjuvant chemotherapy (NACT) for this cancer.

OBJECTIVE

To evaluate all-cause mortality among patients with strongly HR-positive and ERBB2-negative breast cancer treated with NET vs NACT.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study included patients with a diagnosis of invasive ductal carcinoma (IDC) with strong HR positivity and ERBB2 negativity, treated between January 1, 2009, and December 31, 2016, with follow-up from the index date (ie, date of IDC diagnosis) to December 31, 2018. The data came from the Taiwan Cancer Registry Database. Data were analyzed from January to November 2020.

EXPOSURES

NET vs NACT for IDC with strong HR positivity and ERBB2 negativity.

MAIN OUTCOMES AND MEASURES

The primary end point was all-cause mortality. Propensity score matching was performed, and Cox proportional hazard models were used to analyze all-cause mortality among patients undergoing different neoadjuvant treatments.

RESULTS

A total of 640 patients (297 [46.4%] aged 20-49 years) undergoing NET (145 patients [22.7%]) or NACT (495 patients [77.3%]) were eligible for further analysis. In the multivariate Cox regression analyses, the adjusted hazard ratio (aHR) for all-cause mortality among the NET cohort compared with the NACT cohort was 2.67 (95% CI, 1.95-3.51; P < .001). The aHRs for age were 1.13 (95% CI, 1.03-2.24), 1.25 (95% CI, 1.13-2.45), and 1.37 (95% CI, 1.17-3.49) for all-cause mortality among patients aged 50 to 59, 60 to 69, and 70 years or older, respectively, compared with those aged 20 to 49 years (P = .002); the aHR for all-cause mortality among premenopausal women was 1.35 (95% CI, 1.13-1.56) compared with postmenopausal women (P < .001); and that of patients with a Charlson Comorbidity Index score of 2 or greater was 1.77 (1.37-2.26) compared with those with a score of 0 (P < .001). The aHRs of all-cause mortality for clinical tumor stage 2, 3, and 4 compared with 1 were 1.84 (95% CI, 1.07-3.40), 1.97 (95% CI, 1.03-3.77), and 2.49 (95% CI, 1.29-4.81), respectively (P = .009). The aHRs for all-cause mortality by clinical nodal (cN) stages were 1.49 (95% CI, 1.13-1.99) and 1.84 (95% CI, 1.31-2.61) for cN stage 1 and cN stages 2 or 3, respectively, compared with cN stage 0 (P = .005); those for differentiation were 1.77 (95% CI, 1.24-2.54) and 2.31 (95% CI, 1.61-3.34) for differentiation grade 2 and differentiation grade 3, respectively, compared with differentiation grade 1 (P < .001).

CONCLUSIONS AND RELEVANCE

The findings of this study suggest that for patients with strongly HR-positive and ERBB2-negative IDC, NACT may be considered the first choice for neoadjuvant treatment.

Assessment of HER2 using the 2018 ASCO/CAP guideline update for invasive breast cancer: a critical look at cases classified as HER2 2+ by immunohistochemistry

In 2018, the American Society of Clinical Oncology/College of American Pathologists revised the criteria for HER2 immunohistochemistry (IHC) equivocal (2+) classification in their updated guideline. We reviewed invasive breast cancer specimens originally classified as equivocal (2+) under the 2018 guideline that underwent HER2 fluorescence in situ hybridization (FISH) testing from August 2018 to August 2019 at our Canadian reference hospital to investigate cases with ambiguous staining patterns between the 1+ and 2+ definitions. Demographics, pathologic features, and pre-analytic conditions were recorded. The H&E and corresponding HER2 IHC slides were reviewed to confirm tumor type and grade, and classify as HER2 indeterminate, 0, 1+, 2+, or "Intermediate" (staining features between the 1+ and 2+ classifications). FISH testing was performed on 289 cases and 273 met inclusion criteria. The FISH-amplified rate was 12.1%. Upon IHC review, 44.7% (122/273) of cases were reclassified as Intermediate. These cases had incomplete staining with moderate intensity (43/122, 35.3%) and/or <10% complete weak or moderate staining (102/122, 83.6%). Intermediate cases had a significantly lower frequency of amplified FISH results than 2+ cases (p < 0.0001), with only four (3.3%) FISH positive and two (1.6%) FISH heterogeneous. Our study highlights the ambiguity in the current guideline for classifying some HER2 IHC patterns. As the rate of gene amplification in these cases was low (4.9%), we recommend adhering to the 2018 HER2 2+ criteria for reflex FISH testing. However, cases with <10% moderate complete staining and certain heterogeneous patterns warrant special consideration. Further descriptive clarification of 1+ criteria is needed.

Real-world Evidence of Diagnostic Testing and Treatment Patterns in US Patients With Breast Cancer With Implications for Treatment Biomarkers From RNA Sequencing Data

OBJECTIVE/BACKGROUND

We performed a retrospective analysis of longitudinal real-world data (RWD) from patients with breast cancer to replicate results from clinical studies and demonstrate the feasibility of generating real-world evidence. We also assessed the value of transcriptome profiling as a complementary tool for determining molecular subtypes.

METHODS

De-identified, longitudinal data were analyzed after abstraction from records of patients with breast cancer in the United States (US) structured and stored in the Tempus database. Demographics, clinical characteristics, molecular subtype, treatment history, and survival outcomes were assessed according to strict qualitative criteria. RNA sequencing and clinical data were used to predict molecular subtypes and signaling pathway enrichment.

RESULTS

The clinical abstraction cohort (n = 4000) mirrored the demographics and clinical characteristics of patients with breast cancer in the US, indicating feasibility for RWE generation. Among patients who were human epidermal growth factor receptor 2-positive (HER2⁺), 74.2% received anti-HER2 therapy, with ∼70% starting within 3 months of a positive test result. Most non-treated patients were early stage. In this RWD set, 31.7% of patients with HER2⁺ immunohistochemistry (IHC) had discordant fluorescence in situ hybridization results recorded. Among patients with multiple HER2 IHC results at diagnosis, 18.6% exhibited intra-test discordance. Through development of a whole-transcriptome model to predict IHC receptor status in the molecular sequenced cohort (n = 400), molecular subtypes were resolved for all patients (n = 36) with equivocal HER2 statuses from abstracted test results. Receptor-related signaling pathways were differentially enriched between clinical molecular subtypes.

CONCLUSIONS

RWD in the Tempus database mirrors the overall population of patients with breast cancer in the US. These results suggest that real-time, RWD analyses are feasible in a large, highly heterogeneous database. Furthermore, molecular data may aid deficiencies and discrepancies observed from breast cancer RWD.

Pathologic response rates for breast cancer stages as a predictor of outcomes in patients receiving neoadjuvant chemotherapy followed by breast-conserving surgery

PURPOSE

To determine easy-to-use predictors of overall survival (OS), locoregional recurrence (LRR), and distant metastasis (DM) in patients with breast invasive ductal carcinoma (IDC) receiving neoadjuvant chemotherapy (NACT) followed by breast-conserving surgery (BCS), we obtained pathologic response rates (PRRs) for combined primary and nodal diseases (American Joint Committee on Cancer [AJCC] stages) from clinical and pathologic reports, and we used these as predictors.

PATIENTS AND METHODS

We enrolled patients with IDC who had received NACT followed by BCS. Cox regression analysis was used to calculate hazard ratios (HRs) and confidence intervals (CIs) for the patients' PRRs; other independent predictors were controlled for or stratified in the analysis.

RESULTS

We analyzed 1047 patients with IDC (611, 260, and 176 patients in clinical stages IIB, IIIA, and IIIB-C, respectively) receiving NACT and BCS. After multivariate Cox regression analyses, the adjusted HRs (aHRs; 95% CI) in patients with pathologic complete response (ypT0N0) were 0.26 (0.13-0.56), 0.36 (0.15-0.85), and 0.15 (0.08-0.31) for all-cause mortality, LRR, and DM, respectively. The aHRs (95% CI) in patients with downstaging of AJCC stages were 0.55 (0.35-0.89), 0.91 (0.62-0.96), and 0.63 (0.43-0.91) for all-cause mortality, LRR, and DM, respectively. The aHRs (95% CI) in patients with upstaging of AJCC stages were 1.77 (1.06-2.24), 1.08 (1.03-1.82), and 1.19 (1.07-2.01) for all-cause mortality, LRR, and DM, respectively.

CONCLUSION

The impacts of AJCC-stage PRRs are useful predictive tools and strong predictors for OS, LRR, and DM in patients with breast IDC receiving NACT followed by BCS.

Effect of pathologic stages on postmastectomy radiation therapy in breast cancer receiving neoadjuvant chemotherapy and total mastectomy: A Cancer Database Analysis

PURPOSE

To use pathologic indicators to determine which patients benefit from postmastectomy radiation therapy (PMRT) for breast cancer after neoadjuvant chemotherapy (NACT) and total mastectomy (TM).

PATIENTS AND METHODS

We enrolled 4236 patients with breast invasive ductal carcinoma who received NACT followed by TM. Cox regression analysis was used to calculate hazard ratios (HRs) and confidence intervals; independent predictors were controlled for or stratified in the analysis.

RESULTS

After multivariate Cox regression analyses, the adjusted HRs derived for PMRT for all-cause mortality were 0.65 (0.52-0.81, P < 0.0001) and 0.58 (0.47-0.71, P < 0.0001) in postchemotherapy pathologic tumor stages T2-4 (ypT3-4) and postchemotherapy pathologic nodal stages N2-3 (ypN2-3), respectively. Moreover, adjusted HRs derived for PMRT with all-cause mortality were 0.51 (0.38-0.69, P < 0.0001), 0.60 (0.40-0.88, P = 0.0096), and 0.64 (0.48-0.86, P = 0.0024) in pathological stages IIIA, IIIB, and IIIC, respectively. Additionally, the PMRT group showed significant locoregional control irrespective of the pathologic response, even ypT0, ypN0, or pathological complete response (pCR), compared with the No-PMRT group. The multivariate analysis showed no statistical differences between the PMRT and No-PMRT groups for distant metastasis-free survival in any pathologic response of ypT0-4, ypN0-3, and pathologic American Joint Committee on Cancer stages pCR to IIIC.

CONCLUSION

For patients with breast cancer ypT3-4, ypN2-3, or pathologic stages IIIA-IIIC receiving NACT and TM, benefit from PMRT if it is associated with OS benefits, regardless of the clinical stage of the disease. Compared with No-PMRT, PMRT improved locoregional recurrence-free survival, even pCR, in patients with breast cancer receiving NACT and TM.

CDKN2A and MTAP Are Useful Biomarkers Detectable by Droplet Digital PCR in Malignant Pleural Mesothelioma: A Potential Alternative Method in Diagnosis Compared to Fluorescence In Situ Hybridisation

Background

The diagnosis of malignant pleural mesothelioma (MPM) can be difficult, in part due to the difficulty in distinguishing between MPM and reactive mesothelial hyperplasia (RMH). The tumor suppressor gene, CDKN2A, is frequently silenced by epigenetic mechanisms in many cancers; in the case of MPM it is mostly silenced via genomic deletion. Co-deletion of the CDKN2A and methylthioadenosine phosphorylase (MTAP) genes has been researched extensively and discovered to be a highly specific characteristic of MPM. Most studies have used FISH to detect the deletion of CDKN2A and IHC for MTAP as a surrogate for this. In this study, we aim to investigate and validate droplet digital PCR (ddPCR) as an emerging alternative and efficient testing method in diagnosing MPM, by particularly emphasizing on the loss of MTAP and CDKN2A.

Methods

This study included 75 formalin fixed paraffin embedded (FFPE) MPM tissue, and 12 normal pleural tissue and 10 RMH as control. Additionally, primary MPM cell lines and normal pleural samples were used as biomarker detection controls, as established in our previous publication. All FFPE specimens were processed to isolate the DNA, that was subsequently used for ddPCR detection of CDKN2A and MTAP. FFPE samples were also analyzed by fluorescence in situ hybridization (FISH) for CDKN2A and MTAP deletion, and for MTAP IHC expression. Concordance of IHC and ddPCR with FISH were studied in these samples.

Results

95% and 82% of cases showed co-deletion of both MTAP and CDKN2A when determined by FISH and ddPCR respectively. ddPCR has a sensitivity of 72% and specificity of 100% in detecting CDKN2A homozygous loss in MPM. ddPCR also has a concordance rate of 92% with FISH in detecting homozygous loss of CDKN2A. MTAP IHC was 68% sensitive and 100% specific for detecting CDKN2A homozygous loss in MPM when these losses were determined by ddPCR.

Conclusion

Our study confirms that MTAP is often co-deleted with CDKN2A in MPM. Our in-house designed ddPCR assays for MTAP and CDKN2A are useful in differentiating MPM from RMH, and is highly concordant with FISH that is currently used in diagnosing MPM. ddPCR detection of these genetic losses can potentially be utilized as an alternative method in the diagnosis of MPM and for the future development of a less-invasive MPM-specific detection technique on MPM tumor tissue DNA.

Breast-conserving surgery with or without irradiation in women with invasive ductal carcinoma of the breast receiving preoperative systemic therapy: A cohort study

Purpose

To investigate the outcomes of adjuvant whole breast radiation therapy (WBRT) in patients with invasive ductal carcinoma of the breast (breast IDC) receiving preoperative systemic therapy (PST) and breast-conserving surgery (BCS), and their prognostic factors, considering overall survival (OS), locoregional recurrence (LRR), distant metastasis (DM), and disease-free survival.

Patients and methods

Patients diagnosed as having breast IDC and receiving PST followed by BCS were recruited and categorized by treatment into non-breast radiation therapy [BRT] (control) and WBRT (case) groups, respectively. Cox regression analysis was used to calculate hazard ratios (HRs) and confidence intervals (CIs).

Results

Multivariate Cox regression analyses indicated that non-BRT, cN3, and pathologic residual tumor (ypT2–4) or nodal (ypN2–3) stages were poor prognostic factors for OS. The adjusted HRs (aHRs; 95% CIs) of the WBRT group to non-BRT group for all-cause mortality were 0.14 (0.03–0.81), 0.32 (0.16–0.64), 0.43 (0.23–0.79), 0.23 (0.13–0.42), 0.52 (0.20–1.33), and 0.34 (0.13–0.87) in the ypT0, ypT1, ypT2–4, ypN0, ypN1, and ypN2–3 stages, respectively. The aHRs (95% CIs) of the WBRT group to non-BRT group for all-cause mortality were 0.09 (0.00–4.07), 0.46 (0.26–0.83), 0.18 (0.06–0.51), 0.28 (0.06–1.34), 0.25 (0.10–0.63), 0.47 (0.23–0.88), and 0.32 in the cT0–1, cT2, cT3, cT4, cN0, cN1, and cN2–3 stages, respectively. The WBRT group exhibited significantly better LRR-free and DM-free survival than the non-BRT group, regardless of the clinical T or N stage or pathologic response after PST.

Conclusion

WBRT might lead to superior OS and LRR-free and DM-free survival compared with the non-BRT group, regardless of the initial clinical TN stage or pathologic response.

•

Outcome patterns of adjuvant RT for patients with breast cancer receiving preoperative systemic therapy and breast-conserving surgery.

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Non-breast radiation therapy, cN3, pathologic residual tumor (ypT2–4), or nodal (ypN2–3) stages are poor prognostic factors for survival.

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The beneficial effects of RT are superior OS and LRR-free and DM-free survival compared with the non-RT group.

Oncogenic Addiction to ERBB2 Signaling Predicts Response to Trastuzumab in Urothelial Cancer

Urothelial carcinoma (UC) is a common and frequently lethal cancer. Despite the presence of genomic alterations creating dependency on particular signaling pathways, the use of targeted therapies in advanced and metastatic UC has been limited. We performed an integrated analysis of whole-exome and RNA sequencing of primary and metastatic tumors in a patient with platinum-resistant UC. We found a strikingly high ERBB2 mRNA expression and enrichment of downstream oncogenic ERBB2 signaling in this patient's tumors compared with tumors from an unselected group of patients with UC (N=17). This patient had an exceptional sustained response to trastuzumab. Our findings show that oncogenic addiction to ERBB2 signaling potentially predicts response to ERBB2-directed therapy of UC.

HER2 testing across practices-Have we come to a consensus on the ideal method of testing? A systematic literature review

Human epidermal growth factor (HER2) is an oncogene that codes for HER2 protein. The gene is amplified, and protein is overexpressed in 20% of patients and carries a poor prognosis. HER2-positive tumors tend to be more aggressive and highly proliferative. In 2006, trastuzumab, a monoclonal antibody targeting HER2, was approved for use with chemotherapy as an adjuvant treatment for women with HER2-positive breast cancer. The drug has shown improved survival rates for women with HER2-positive breast cancer. As promised for survival in HER2-positive patients continues with new research, and as novel drug approvals emerge, HER2 assessment plays a significant role in adjuvant and in metastatic setting. HER2 assays approved by the US Food and Drug administration include immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), and bright field dual in situ hybridization (DISH). Accuracy of HER2 testing across laboratories has an impact on treatment as false-negative testing can deprive the patients of trastuzumab therapy. The current review will focus on the variability of HER2 testing across laboratories and the potential impact on treatment.

Digital Assessment of Stained Breast Tissue Images for Comprehensive Tumor and Microenvironment Analysis

Current histopathological diagnosis involves human expert interpretation of stained images for diagnosis. This process is prone to inter-observer variability, often leading to low concordance rates amongst pathologists across many types of tissues. Further, since structural features are mostly just defined for epithelial alterations during tumor progression, the use of associated stromal changes is limited. Here we sought to examine whether digital analysis of commonly used hematoxylin and eosin-stained images could provide precise and quantitative metrics of disease from both epithelial and stromal cells. We developed a convolutional neural network approach to identify epithelial breast cells from their microenvironment. Second, we analyzed the microenvironment to further observe different constituent cells using unsupervised clustering. Finally, we categorized breast cancer by the combined effects of stromal and epithelial inertia. Together, the work provides insight and evidence of cancer association for interpretable features from deep learning methods that provide new opportunities for comprehensive analysis of standard pathology images.

Relationship Study of The Verified H uman Epidermal Growth Factor Receptor 2 Amplification with Other Tumor Markers and Clinicohistopathological Characteristics in Patients with Invasive Breast Cancer, Using Chromogenic In Situ Hybridization

Objective

Human epidermal growth factor receptor 2 (HER-2), as a crucial factor involved in about 20% of breast cancer cases, is one of the most reliable tumor markers to determine prognosis and therapeutic trend of this disease. This marker is generally assessed by immunohistochemistry (IHC) technique. In the cases that result of IHC test cast doubt (+2), the test should be repeated or validated by applying in situ hybridization techniques, like chromogenic in situ hybridization (CISH). In this regard, the goal of current study was to figure out the link between different clinicopathological characteristics of patients suffering from invasive breast cancer, using tumor markers, hormone receptor (HR) and HER-2. Comparing IHC and CISH techniques for evaluating diagnostic value and usefulness of HER-2 were also the other objective of this study.

Materials and Methods

Based on this retrospective study, histological markers of 113 individuals suffering from invasive breast cancer -such as estrogen receptor (ER), progesterone receptor, HER-2 receptor, E-cadherin, CK5/6, vimentin and Ki67 were examined by IHC technique. HER-2 amplification of all patients was also evaluated by CISH. Clinicopathological information of the patients was also extracted from medical documents and their associations with tumor markers were statistically evaluated.

Results

There is a significant relationship between tumor size, CK5/6 and tumor grade with HR status. Similar relationship was observed between HER-2 status and HR status, as well as vascular invasion (P<0.05). The comparison of HER-2 amplification showed no complete concordance of the result obtained from these two techniques, with score +3.

Conclusion

Since the status of HER-2 is very important in decision making of the treatment process, CISH technique is recommended in the malignant conditions as the primary test, instead of IHC. In this study, we also determined that HER-2 expression is greatly correlated with ER- and PR- status. This might propose a better prognosis for HER-2⁺ patients.

A fluorescent aptasensor for the femtomolar detection of epidermal growth factor receptor-2 based on the proximity of G-rich sequences to Ag nanoclusters

Human epidermal growth factor receptor-2 (HER2) has been recognized as an important biomarker for the early diagnosis and management of breast cancer. However, there is still challenge in the clinical detection of HER2. In this work, a simple strategy for "turn on" fluorescent detection of HER2 with ultra-sensitivity and high specificity was developed. Herein, HER2-binding aptamer (HApt) and DNA2 containing G-rich sequences, templated sequences for Ag nanoclusters (AgNCs), and complementary bases at both ends were involved to achieve the double stranded DNA templated AgNCs (dsDNA-AgNCs) as a fluorescence probe for HER2 detection. In the presence of HER2, the highly specific binding of HER2 to HApt caused HApt separating from dsDNA-AgNCs, resulting in the folding of DNA2-AgNCs because of the complementary bases at both ends, which led to AgNCs' proximity to G-rich sequences, and therefore the enhanced fluorescence intensity. By monitoring the change in fluorescence signal (ΔF), HER2 was measured, and a linear range from 8.5 fM to 225 fM with a limit of detection (LOD) 0.0904 fM was obtained. More significantly, the detection of HER2 in serum samples was achieved with high accuracy, and the breast cancer patients were successfully discriminated from healthy persons. In summary, this strategy is simple, time-saving, cost-effective, ultrasensitive, specific, universal and more applicable for the detection of HER2. Therefore, we expect this present aptasensor can be used in the clinical detection of biomakers, which lays a potential foundation for the early diagnosis of cancer.

Concordance analysis between HER2 immunohistochemistry and in situ hybridization in non-small cell lung cancer

PURPOSE

This study aimed to elucidate the concordance between human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) and in situ hybridization (ISH) and the diagnostic accuracy of HER2 IHC in non-small cell lung cancer (NSCLC) through a meta-analysis and diagnostic test accuracy review.

METHODS

Seven eligible studies and 1,217 patients with NSCLC were included in the review. The concordance between HER2 IHC and ISH was analyzed. To confirm the diagnostic accuracy of HER2 IHC, the sensitivity and specificity were analyzed and the area under the curve (AUC) in the summary receiver operating characteristic (SROC) curve was calculated.

RESULTS

The concordance rate between HER2 IHC and ISH was 0.795 (95% confidence interval [CI] 0.534-0.929). In the HER2 IHC-negative (score 0/1+) subgroup, the concordance rate was 0.975 (95% CI 0.854-0.996). The concordance rates of the HER2 IHC score 2+ and 3+ subgroups were 0.091 (95% CI 0.039-0.197) and 0.665 (95% CI 0.446-0.830), respectively. In diagnostic test accuracy review, the pooled sensitivity and specificity were 0.67 (95% CI 0.54-0.78) and 0.89 (95% CI 0.87-0.91), respectively. The AUC in the SROC curve was 0.891 and the diagnostic odds ratio was 16.99 (95% CI 5.08-56.76).

CONCLUSIONS

HER2 IHC was largely in agreement with ISH in cases of HER2 IHC score 0/1+. Because the concordance rates of HER2 IHC score 2/3+ cases were lower than that of HER2 IHC score 0/1+ cases, further studies for detailed analysis criteria for HER2 IHC score 2+ or 3+ are required.

3D Imaging Detection of HER2 Based in the Use of Novel Affibody-Quantum Dots Probes and Ratiometric Analysis

Patients with breast cancer (BC) overexpressing HER2 (HER2+) are selected for Trastuzumab treatment, which blocks HER2 and improves cancer prognosis. However, HER2+ diagnosis, by the gold standard, immunohistochemistry, could lead to errors, associated to: a) variability in sample manipulation (thin 2D sections), b) use of subjective algorithms, and c) heterogeneity of HER2 expression within the tissue. Therefore, we explored HER2 3D detection by multiplexed imaging of Affibody-Quantum Dots conjugates (Aff-QD), ratiometric analysis (RMAFI) and thresholding, using BC multicellular tumor spheroids (BC-MTS) (~120 μm of diameter) as 3D model of BC. HER2+, HER2- and hybrid HER2+/- BC-MTS (mimicking heterogeneous tissue) were incubated simultaneously with two Aff-QD probes (anti-HER2 and negative control (NC), respectively, (1:1)). Confocal XY sections were recorded along the Z distance, and processed by automatized RMAFI (anti-HER2 Aff-QD/ NC). Quantifying the NC fluorescence allowed to predict the fraction of non-specific accumulation of the anti-HER2 probe within the thick sample, and resolve the specific HER2 level. HER2 was detected up to 30μm within intact BC-MTS, however, permeabilization improved detection up to 70μm. Specific HER2 signal was objectively quantified, and HER2 3D-density of 9.2, 48.3 and 30.8% were obtained in HER2-, HER2+ and hybrid HER2+/- permeabilized BC-MTS, respectively. Therefore, by combining the multiplexing capacity of Aff-QD probes and RMAFI, we overcame the challenge of non-specific probe accumulation in 3D samples with minimal processing, yielding a fast, specific spatial HER2 detection and objective quantification.

TRKA expression and NTRK1 gene copy number across solid tumours

AIMS

Neurotrophic Tropomyosin Kinase Receptor 1 (NTRK1) gene encodes for the protein Tropomyosin-related kinase A (TRKA). Deregulated activity of TRKA has been shown to have oncogenic potential. We present here the results of an immunohistochemical (IHC) observational cohort study of TRKA expression together with gene copy number (GCN) assessment in various solid tumours.

METHODS

Formalin-fixed, paraffin-embedded consecutive samples of different tumour types were tested for TRKA expression. Samples showing TRKA IHC staining in at least 10% of cells were analysed by fluorescence in situ hybridisation to assess NTRK1 gene rearrangements and/or individual GCN gain. All patients underwent this molecular assessment within the phase I ALKA-001 clinical trial.

RESULTS

1043 samples were tested and annotation for histology was available in 1023. Most of the samples were colorectal adenocarcinoma (CRC) (n=550, 52.7%) and lung adenocarcinoma (n=312, 29.9%). 24 samples (2.3%) were biliary tract carcinoma (BTC). Overall, 17 (1.6%) samples were characterised by TRKA IHC expression (four weak, eight moderate, five strong): 9/17 lung adenocarcinoma, 3/17 CRC, 3/17 BTC, 1/17 thyroid cancer and 1/17 cancer of unknown primary. Of these, 1/17 with strong TRKA IHC staining displayed NTRK1 gene rearrangement and 15/17 NTRK1 GCN gain by FISH. No correlation was found between intensity of TRKA IHC staining and number of copies of NTRK1.

CONCLUSIONS

TRKA expression can be found in 1.6% of solid tumours and can be paralleled by NTRK1 gene rearrangements or mostly GCN gain. The prognostic and translational therapeutic impact of the latter remains to be established.

The Assessment of HER2 Gene Status by Fluorescence In Situ Hybridization in Invasive Breast Carcinomas With Equivocal HER2 Immunostaining: Experience From a Single Institution

Background. A subset of breast carcinomas harbors overexpression of the human epidermal growth factor receptor 2 (HER2). Fluorescence in situ hybridization (FISH) should be performed in breast carcinomas with equivocal HER2 immunostaining (immunohistochemistry [IHC] HER2 2+). The aim of our study is to investigate clinicopathologic factors associated with HER2 status in breast invasive carcinomas with IHC HER2 2+ through FISH analysis. Methods. This is a retrospective study including the FISH analysis of 111 patients with invasive breast carcinomas with equivocal HER2 immunostaining. Results. The mean age was 49.51 ± 10.48 years, and invasive breast carcinoma of no special type was the most histological type in our study (96.4%). Most patients had tumors positive for hormones receptors (88.2% positive for estrogen receptor and 81.4% for progesterone receptor). On FISH, the HER2 amplification rate was 22.5%. There was no significant association of HER2 status with any clinicopathologic factors ( P > .05). Conclusions. Our study shows that there are no reliable clinicopathologic factors to predict the HER2 status in breast tumors with equivocal HER2 immunostaining, supporting the necessary usage of FISH in such circumstances.

The prognostic value of HER2 in ovarian cancer: A meta-analysis of observational studies

BACKGROUND

The prognostic role of human epidermal growth factor receptor 2 (HER2) in ovarian cancer has been investigated in previous studies, but the results remain controversial. Here we present a meta-analysis to systematically review the association between HER2 expression and ovarian cancer prognosis.

METHOD

Observational studies published until July 2017 were searched in Pubmed, Embase, and Cochrane library databases. Hazard ratios (HRs) for survival with 95% confidence intervals (CIs), subgroup analyses, publication bias and sensitivity analyses were implemented under a standard manner. Estimates of overall survival (OS), progress-free survival (PFS) and disease-free survival (DFS) were weighted and pooled using Der Simonian-Laird random-effect model.

RESULT

Thirty-four studies that include 5180 ovarian cancer patients were collected for analysis. Expression of HER2 was negatively correlated with clinical prognosis of overall survival (HR = 1.57, 95% CI: 1.31 to 1.89, P < 0.001) and disease-free survival / progress-free survival (HR = 1.26, 95% CI = 1.06 to 1.49) in ovarian cancers. The association between HER2 expression and poor ovarian cancer prognosis in overall survival was also statistically significant in subgroups of unclassified ovarian cancer, Caucasian population and Asian population, while irrespective of detection method.

CONCLUSION

HER2 expression was related with poor prognosis in ovarian cancer patients and can be used as a predicting cancer prognostic biomarker in ovarian cancer patients.

Lapatinib

The human epidermal growth factor receptor (HER) family of receptor tyrosine kinases plays an important role in the biology of many cancers. In breast and gastrointestinal cancer, and at lower rates also in additional tumor types, HER2 and its homo- or heterodimerization with HER1 or HER3 are essential for cancer cell growth and survival. Breast cancer patients overexpressing HER2 have a more aggressive course of their disease. The poor prognosis associated with HER2 overexpression can be substantially improved by adding HER2-targeted therapy to standard of care using the monoclonal antibody trastuzumab. Lapatinib, an oral dual tyrosine kinase inhibitor, blocks HER1 and HER2 tyrosine kinase activity by binding to the ATP-binding site of the receptor's intracellular domain, resulting in inhibition of tumor cell growth. Lapatinib is generally well tolerated with diarrhea being the most common adverse effect. However, although being mainly of mild to moderate severity, interruption or discontinuation of treatment has been reported in a substantial proportion of patients in clinical trials. In 2007, lapatinib has been approved in combination with capecitabine in patients with advanced HER2-positive breast cancer upon progressive disease following standard therapy with anthracyclines, taxanes, and trastuzumab. In 2013, the approval was extended to a chemotherapy-free combination with trastuzumab for patients with metastatic HER2-positive, hormone receptor-negative breast cancer progressing on prior trastuzumab and chemotherapy. Since 2010, lapatinib is approved in combination with letrozole in the treatment of postmenopausal women with advanced HER2- and hormone receptor-positive breast cancer. In contrast, in first-line cytotoxic-based therapy of both early and advanced HER2-positive breast cancer, data from clinical trials did not provide evidence of additional benefit of lapatinib compared to trastuzumab. Moreover, over the past few years, novel HER2-targeted drugs, either alone or as a combined anti-HER2 approach, have been extensively evaluated, demonstrating a more favorable outcome. Also, neither in first- nor second-line treatment of advanced gastric cancer, lapatinib has been proven to be superior compared to trastuzumab as hitherto standard of care HER2 blockade. Therefore, lapatinib has become somewhat less important in patients with HER2-positive breast cancer during the past 10 years since its first introduction. Nevertheless, consideration of treatment with lapatinib appears to be reasonable in selected patients not only in the approved applications but also beyond, and further indications such as HER2-positive refractory metastatic colorectal cancer may arise in future. Also, lapatinib may have distinct advantages over antibodies in targeting truncated HER2 and crossing the blood-brain barrier. Finally, the favorable cardiac toxicity profile of lapatinib makes it an attractive alternative to trastuzumab-based regimens in patients at risk for cardiac events.

High concordance of a closed-system, RT-qPCR breast cancer assay for HER2 mRNA, compared to clinically determined immunohistochemistry, fluorescence in situ hybridization, and quantitative immunofluorescence

Historically, mRNA measurements have been tested on several commercially available platforms, but none have gained broad acceptance for assessment of HER2. An mRNA measurement, as a continuous value, has the potential for use in adjudication of the equivocal category. Here we use a real-time quantitative reverse transcription polymerase chain reaction (RT-qPCR) assay in a closed, single-use cartridge, automated system. Multiple cores (1 mm in diameter) were retrospectively collected from 80 formalin-fixed paraffin-embedded (FFPE) tissue blocks with invasive breast cancer seen by Yale Pathology Labs between 1998 and 2011. Tissue cores were processed with a FFPE lysis kit to create lysates that were tested with the automated RT-qPCR assay. Results for IHC and FISH were extracted from the pathology reports and quantitative immunofluorescence (QIF) for each case was measured as previously described. Quality control testing showed that the GX platform RT-qPCR shows no case to case cross contamination on material from routine histology practices. Concordance between RT-qPCR and IHC/FISH was 91.25% (sensitivity=0.87; specificity=0.94; PPV=0.89; NPV=0.92) using a pre-defined delta Ct cut-off (dCt≥-1) for HER2. Concordance (OPA) between RT-qPCR and QIF was 94% (sensitivity=0.90; specificity=0.96; PPV=0.93; NPV=0.94) using dCt≥-1 and a previously defined cut-point for positivity by QIF. In conclusion, the closed system RT-qPCR assay shows >90% concordance with the ASCO/CAP HER2 IHC/FISH scoring. Additionally, the RT-qPCR assay is highly concordant (94%) with the continuous variable HER2 QIF assay, and may better reflect the true continuum of HER2 receptor status in invasive breast cancer. These initial results suggest that fast, closed system molecular assays may have future value for the adjudication of the ASCO/CAP HER2 equivocal category or possibly routine usage in time constrained or low resource settings.

CD74 and intratumoral immune response in breast cancer

CD74 (invariant chain) plays a role in MHC class II antigen presentation. We assessed CD74 and MHCII expression in tumor cells, as well as CD8, CD4, and CD68 tumor infiltrating leucocyte (TIL) density by immunohistochemistry in a cohort of 492 breast cancer patients. CD74 expression was associated with poor prognostic markers including patient age, tumor grade, ER status, non-Luminal A subtypes, and with MHCII expression and higher TIL densities, particularly in the Basal-like subgroup. Univariate analysis showed a favorable prognostic effect of CD74 (Hazard ratio = 0.46, 95% CI = 0.26–0.89, p = 0.022) and for combined CD74/MHCII (Hazard ratio = 0.26, 95% CI = 0.17–0.81, p = 0.014) positive status for overall survival that was only manifested in the Basal-like subgroup. CD74 and MHCII expression is associated with patient survival in Basal-like breast cancer, and the association with TIL may reflect an effective intratumoral immune response.

Clinicopathological significance and diagnostic accuracy of HER2 immunohistochemistry in colorectal cancer: a meta-analysis

INTRODUCTION

The aim of this study was to elucidate the clinicopathological significance of HER2 expression and the diagnostic accuracy of HER2 immunohistochemistry (IHC) in colorectal cancer (CRC). A total of 2,573 CRC cases from 13 eligible studies were included.

METHODS

We performed a meta-analysis to examine the correlations between HER2 expression and clinicopathological characteristics in CRC. Concordance analysis between HER2 IHC and in situ hybridization (ISH) and diagnostic test accuracy review was conducted.

RESULTS

The estimated rate of HER2 IHC overexpression was 0.162 (95% confidence interval [CI] 0.106-0.240). HER2 IHC overexpression was significantly correlated with lymph node metastasis and distant metastasis but not tumor depth. HER2 IHC overexpression was not correlated with overall survival. The concordance rates between IHC and ISH were 0.968 (95% CI 0.881-0.992), 0.377 (95% CI 0.225-0.557) and 0.780 (95% CI 0.390-0.952) for HER2 IHC scores of 0/1+, 2+ and 3+, respectively. The diagnostic test accuracy review of HER2 IHC revealed that the pooled sensitivity and specificity were 0.71 (95% CI 0.58-0.82) and 0.96 (95% CI 0.94-0.97), respectively. The diagnostic odds ratio and area under the summary receiver operating characteristic curve were 51.34 (95% CI 3.82-690.54) and 0.9704, respectively.

CONCLUSIONS

HER2 IHC overexpression was significantly correlated with lymph node metastasis and distant metastasis. CRC cases with HER2 IHC scores of 0/1+ exhibited good agreement with the ISH data. However, additional ISH analysis is needed to confirm HER2 status in cases with IHC scores of 2+ or 3+.

ALK Immunohistochemistry for ALK Gene Rearrangement Screening in Non-Small Cell Lung Cancer: A Systematic Review and Meta-Analysis

Introduction

The aim of this study was to investigate the diagnostic accuracy of anaplastic lymphoma kinase (ALK) immunohistochemistry (IHC) for ALK gene rearrangement in non-small cell lung cancer (NSCLC) through systematic review, meta-analysis and diagnostic test accuracy review.

Methods

The current study included 11,806 NSCLC cases in 42 eligible studies. We performed concordance analyses between ALK IHC and fluorescence in situ hybridization (FISH). The diagnostic accuracy of ALK IHC was analyzed based on ALK IHC criteria and antibodies.

Results

The overall ALK IHC results were positive in 13.2%. The overall concordance rate between ALK IHC and FISH was 0.950 (95% confidence interval [CI], 0.927-0.966). In the ALK IHC-positive and negative groups, the concordance rates were 0.805 (95% CI 0.733-0.861) and 0.985 (95% CI 0.978-0.990), respectively. The ALK FISH-positive rates were 0.009 (95% CI 0.004-0.023), 0.378 (95% CI 0.217-0.572), 0.628 (95% CI 0.420-0.796) and 0.900 (95% CI 0.840-0.939) in the ALK IHC 0, 1+, 2+ and 3+ groups, respectively. In diagnostic test accuracy review for ALK IHC, the pooled sensitivity and specificity were 0.92 (95% CI 0.89-0.94) and 0.91 (95% CI 0.90-0.91), respectively. The diagnostic odds ratio and the area under the curve on the summary receiver operating characteristic curve were 266.56 (95% CI 110.83-641.14) and 0.983, respectively.

Conclusions

Our results suggested that ALK IHC equivocal (score 1+ and 2+) cases should not be considered as IHC-negative in screening for ALK gene rearrangement. Additional detailed criteria for ALK IHC equivocal cases are necessary to determine how to best apply this approach in daily practice.

Influence of decalcification procedures on immunohistochemistry and molecular pathology in breast cancer

Distant breast cancer metastases are nowadays routinely biopsied to reassess receptor status and to isolate DNA for sequencing of druggable targets. Bone metastases are the most frequent subgroup. Decalcification procedures may negatively affect antigenicity and DNA quality. We therefore evaluated the effect of several decalcification procedures on receptor status and DNA/RNA quality. In 23 prospectively collected breast tumors, we compared ERα, PR and HER2 status by immunohistochemistry in (non-decalcified) tissue routinely processed for diagnostic purposes and in parallel tissue decalcified in Christensen's buffer with and without microwave, EDTA and Formical-4. Furthermore, HER2 fluorescence in situ hybridization and DNA/RNA quantity and quality were assessed. We found that the percentage of ERα-positive cells were on average lower in EDTA (P=0.049) and Formical-4 (P=0.047) treated cases, compared with controls, and PR expression showed decreased antigenicity after Christensen's buffer treatment (P=0.041). Overall, a good concordance (weighted kappa) was seen for ERα, PR and HER2 immunohistochemistry when comparing the non-decalcified control tissues with the decalcified tissues. For two patients (9%), there was a potential influence on therapeutic decision making with regard to hormonal therapy or HER2-targeted therapy. HER2 fluorescence in situ hybridization interpretation was seriously hampered by Christensen's buffer and Formical-4, and DNA/RNA quantity and quality were decreased after all four decalcification procedures. Validation on paired primary breast tumor specimens and EDTA-treated bone metastases showed that immunohistochemistry and fluorescence in situ hybridization were well assessable and DNA and RNA yield and quality were sufficient. With this, we conclude that common decalcification procedures have only a modest negative influence on hormone and HER2 receptor immunohistochemistry in breast cancer. However, they may seriously affect DNA/RNA-based diagnostic procedures. Overall, EDTA-based decalcification is therefore to be preferred as it best allows fluorescence in situ hybridization and DNA/RNA isolation.

Clinicopathological significance and concordance analysis of c-MET immunohistochemistry in non-small cell lung cancers: A meta-analysis

OBJECTIVE

The aim of this study was to investigate the clinicopathological significance and concordance rate of c-MET immunohistochemistry (IHC) in non-small cell lung cancer (NSCLC) through meta-analysis and diagnostic test accuracy review.

METHODS

The current study included 4454 NSCLC cases of 22 eligible studies. The meta-analysis examined the correlation between c-MET IHC expression and clinicopathological parameters. We investigated concordance rate between c-MET IHC and genetic alteration and performed subgroup analysis based on c-MET IHC cut-off value.

RESULTS

The estimated positive rate of c-MET IHC was 0.440 (95% confidence interval [CI] 0.355-0.529). The positive rate of c-MET IHC was significantly high in non-squamous cell carcinomas and tumors with stage III-IV. However, there was no significant difference between c-MET IHC positivity and sex, smoking, and lymph node metastasis. The c-MET IHC positivity was significantly correlated with poor overall survival (hazard ratio 1.551, 95% CI 1.101-2.184). In c-MET IHC-positive and negative groups, the concordance rate was 0.941 (95% CI 0.885-0.971) and 0.300 (95% CI 0.196-0.429), respectively. The pooled sensitivity and specificity of the high cut-off subgroup for c-MET IHC was 1.00 (95% CI 0.92-1.00) and 0.78 (95% CI 0.75-0.81), respectively. The diagnostic odds ratio and the area under curve on summary receiver operating characteristic curve were 76.56 (95% CI 8.23-712.41) and 0.9949, respectively.

CONCLUSION

The c-MET IHC could be useful for screening of c-MET genetic alteration in NSCLC patients. Detailed criteria for c-MET IHC evaluation are necessary to determine how to best apply this approach in daily practice.

Digital image analysis outperforms manual biomarker assessment in breast cancer

In the spectrum of breast cancers, categorization according to the four gene expression-based subtypes 'Luminal A,' 'Luminal B,' 'HER2-enriched,' and 'Basal-like' is the method of choice for prognostic and predictive value. As gene expression assays are not yet universally available, routine immunohistochemical stains act as surrogate markers for these subtypes. Thus, congruence of surrogate markers and gene expression tests is of utmost importance. In this study, 3 cohorts of primary breast cancer specimens (total n=436) with up to 28 years of survival data were scored for Ki67, ER, PR, and HER2 status manually and by digital image analysis (DIA). The results were then compared for sensitivity and specificity for the Luminal B subtype, concordance to PAM50 assays in subtype classification and prognostic power. The DIA system used was the Visiopharm Integrator System. DIA outperformed manual scoring in terms of sensitivity and specificity for the Luminal B subtype, widely considered the most challenging distinction in surrogate subclassification, and produced slightly better concordance and Cohen's κ agreement with PAM50 gene expression assays. Manual biomarker scores and DIA essentially matched each other for Cox regression hazard ratios for all-cause mortality. When the Nottingham combined histologic grade (Elston-Ellis) was used as a prognostic surrogate, stronger Spearman's rank-order correlations were produced by DIA. Prognostic value of Ki67 scores in terms of likelihood ratio χ(2) (LR χ(2)) was higher for DIA that also added significantly more prognostic information to the manual scores (LR-Δχ(2)). In conclusion, the system for DIA evaluated here was in most aspects a superior alternative to manual biomarker scoring. It also has the potential to reduce time consumption for pathologists, as many of the steps in the workflow are either automatic or feasible to manage without pathological expertise.

Her2-neu score as a prognostic factor for outcome in patients with triple-negative breast cancer

PURPOSE

Triple-negative breast cancer (TNBC) is characterized by a strong heterogeneity with regard to tumour biology as well as in the clinical course of the disease. This study aimed to analyse whether there are any prognostic factors enabling prediction of the clinical outcome in patients with TNBC. Particularly, the impact of Her2-neu score 0 versus Her2-neu score 1 and 2 on survival was investigated.

MATERIALS AND METHODS

We retrospectively studied a cohort of 1013 patients with TNBC, diagnosed at seven hospitals between May 2002 and February 2015. We studied the impact of Her2-neu scores (0 vs. 1 or 2 with negative FISH) on disease-free survival (DFS) and overall survival (OS).

RESULTS

1013 patients were included in this study. 447 (44.13 %) of them had a T2-4 tumour. A total of 314 (31.00 %) were nodal-positive and 714 (70.48 %) had high-grade tumours. The Her2-neu score of all participating patients was determined. 588 (58.05 %) of them had a Her2-neu score 0, and 425 (41.95 %) had a score of 1 or 2. This study shows that TNBC patients with a Her2-neu score 0 had a significantly poorer outcome regarding DFS (p = 0.0001) and OS (p = 0.0051) compared to a score of 1 or 2. In contrast, grading did not seem to have any prognostic value for women with TNBC.

CONCLUSION

The Her2-neu score 0 might be considered as an innovative prognostic factor for patients with TNBC indicating poor clinical outcome.

HER2 expression status in diverse cancers: review of results from 37,992 patients

Human epidermal growth factor receptor 2 (HER2) amplification/overexpression is an effective therapeutic target in breast and gastric cancer. Although HER2 positivity has been reported in other malignancies, previous studies generally focused on one cancer type, making it challenging to compare HER2 positivity across studies/malignancies. Herein, we examined 37,992 patient samples for HER2 expression (+/- amplification) in a single laboratory. All 37,992 patients were tested by immunohistochemistry (IHC); 21,642 of them were also examined for HER2 amplification with either fluorescent in situ hybridization (FISH) (11,670 patients) or chromogenic in situ hybridization (CISH) (9,972 patients); 18,262 patients had tumors other than breast or gastric cancer. All tissues were analyzed in a Clinical Laboratory Improvement Amendments (CLIA) laboratory (Caris Life Sciences) at the request of referring physicians. HER2 protein overexpression was found in 2.7 % of samples. Over-expressed HER2 was detected predominantly in malignancies of epithelial origin; for cancers derived from mesenchyme, neuroendocrine tissue, central nervous system, and kidney, HER2 expression and amplification were remarkably rare or non-existent. Bladder carcinomas, gallbladder, extrahepatic cholangiocarcinomas, cervical, uterine, and testicular cancers showed HER2 positivity rates of 12.4, 9.8, 6.3, 3.9, 3.0, and 2.4 %, respectively. HER2 overexpression and/or amplification is frequently found across tumor types. These observations may have significant therapeutic implications in cancers not traditionally thought to benefit from anti-HER2 therapies.

Clinicopathological variables predicting HER-2 gene status in immunohistochemistry-equivocal (2+) invasive breast cancer

BACKGROUND AND OBJECTIVE

Human epidermal growth factor receptor-2 (HER-2) gene status is crucial to guide treatment decisions regarding the use of HER-2-targeted therapies in breast cancer. An invasive breast cancer with HER-2 2+ score is regarded as HER-2 status equivocal and should further determine by fluorescent in situ hybridization (FISH), which is considered the standard test for HER-2 status. Here, we aimed to establish a risk score to allow for prediction of the presence of HER-2 gene status.

METHODS

A total of 182 HER-2 2+ by immunohistochemistry (IHC) invasive breast cancer cases were enrolled in this study. The association between clinicopathological variables like age, sex, tumor grade, hormone receptor (HR) status, P53 and proliferation index (Ki67), and FISH result using US Food and Drug Administration (FDA) criteria was evaluated. Also, we compared the HER-2 FISH results using FDA criteria and 2013 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guideline.

RESULTS

The study population had a median age of 48 years (range, 29-78 years). Estrogen receptor (ER) was expressed in 131 (72.0%) patients. 73.1% of patients (133/182) were progesterone receptor (PR) positive. The median Ki67 value was 20% (range, 3-90%). There was good agreement between the FDA and 2013 ASCO/CAP guideline. Sixty-three of all patients were HER-2 FISH amplified (positive) based on FDA criteria. Tumors with HER-2 amplified were more likely to harbor ER negative (58.8% vs. 25.2%, P<0.001) or PR negative (57.1% vs. 26.3%, P<0.001) or P53 negative (44.8% vs. 29.8%, P=0.048). A significant high level of Ki67 was detected in HER-2 amplified groups (P=0.006). We created a risk score that comprised HR, P53 and Ki67. A significant association between risk score and HER-2 FISH amplification was observed (χ(2)=30.41, P<0.001).

CONCLUSIONS

This novel immunohistochemical risk score could be highly useful to predict the presence of HER-2 gene status in invasive breast cancer.