Preoperative core needle biopsy is accurate in determining molecular subtypes in invasive breast cancer

Intertumoral heterogeneity of bifocal breast cancer: a morphological and molecular study

PURPOSE

To analyze concordance rates between individual foci of bifocal BC for histological grade, type and intrinsic subtype based on immunohistochemical (IHC) and mRNA-testing using MammaTyper.

METHODS

We evaluated histological grade and type as well as intrinsic subtype based on IHC status for estrogen and progesterone receptors, HER2 and the mitotic activity index in 158 individual foci of 79 bifocal BC. A subgroup of 31 cases additionally underwent mRNA-based subtyping using the MammaTyper (MT) test. We calculated concordance rates between individual foci, as well as Cohen's Kappa (K).

RESULTS

For 79 bifocal BC, concordance rates between individual foci for grade, histological type, and IHC-based subtype were 69.6% (K=0.53), 92.4% (K=0.81), and 74.7% (K=0.62), respectively. In the MT subgroup of 31 bifocal BC, concordance rates between individual foci for grade, histological type, IHC-based and mRNA-based intrinsic subtype were 87.1% (K=0.78), 90.3% (K=0.73), 87.1% (K=0.82), and 87.1% (K=0.7), respectively. Overall concordance between IHC- and mRNA-based subtype in the MT subgroup was 79% (K=0.7). In 6/79 cases (7.6%), testing of the smaller focus added clinically relevant information either on IHC- or mRNA-level: four cases showed high hormonal receptor expression while the expression in the larger focus was negative or low, warranting additional endocrine treatment; two cases presented with higher proliferative activity in the smaller focus, warranting additional chemotherapy.

CONCLUSION

In bifocal BC, intertumoral heterogeneity on the morphological, immunohistochemical and molecular level is common, with discordant intrinsic subtype in up to 25% between individual foci, with about 8% clinically relevant discordances.

The Clinical and Biological Significance of Estrogen Receptor-Low Positive Breast Cancer

Estrogen receptor (ER) status in breast cancer (BC) is determined using immunohistochemistry (IHC) with nuclear expression in ≥1% of cells defined as ER-positive. BC with 1%-9% expression (ER-low-positive), is a clinically and biologically unique subgroup. In this study, we hypothesized that ER-low-positive BC represents a heterogeneous group with a mixture of ER-positive and ER-negative tumor, which may explain their divergent clinical behavior. A large BC cohort (n = 8171) was investigated and categorized into 3 groups: ER-low-positive (1%-9%), ER-positive (≥10%), and ER-negative (<1%) where clinicopathological and outcome characteristics were compared. A subset of ER-low-positive cases was further evaluated using IHC, RNAscope, and RT-qPCR. PAM50 subtyping and ESR1 mRNA expression levels were assessed in ER-low-positive cases within The Cancer Genome Atlas data set. The reliability of image analysis software in assessment of ER expression in the ER-low-positive category was also assessed. ER-low-positive tumors constituted <2% of BC cases examined and showed significant clinicopathological similarity to ER-negative tumors. Most of these tumors were nonluminal types showing low ESR1 mRNA expression. Further validation of ER status revealed that 45% of these tumors were ER-negative with repeated IHC staining and confirmed by RNAscope and RT-qPCR. ER-low-positive tumors diagnosed on needle core biopsy were enriched with false-positive ER staining. BCs with 10% ER behaved similar to ER-positive, rather than ER-negative or low-positive BCs. Moderate concordance was found in assessment of ER-low-positive tumors, and this was not improved by image analysis. Routinely diagnosed ER-low-positive BC includes a proportion of ER-negative cases. We recommend repeat testing of BC showing 1%-9% ER expression and using a cutoff ≥10% expression to define ER positivity to help better inform treatment decisions.

Ki67 increase after core needle biopsy associated with worse disease outcome in HER2-negative breast cancer patients

Ki67 would change after core needle biopsy (CNB) in invasive breast cancer. However, whether Ki67 alteration (ΔKi67) influences disease outcomes remains unclear. Here we aim to evaluate the prognostic value of ΔKi67. Patients with paired CNB and open excision biopsy (OEB) samples between January 2009 and June 2016 were retrospectively analyzed. ΔKi67 was calculated as the absolute difference between Ki67 level in CNB and OEB samples, and the median value of 5% was adopted to category patients into high- and low ΔKi67 groups. Disease-free survival (DFS) and overall survival (OS) were compared between different ΔKi67 groups. Overall, 2173 invasive breast cancer patients were included. Median Ki67 was higher in OEB than CNB samples: 25.00% versus 20.00% (P < 0.001). Axillary nodal status, STI, histological grading, and molecular subtype were independently associated with ΔKi67 (P < 0.05). In the whole population, patients with low ΔKi67 showed superior 5-year DFS (89.6% vs 87.0%, P = 0.026), but similar OS (95.8% vs 94.3%, P = 0.118) compared to those with high ΔKi67. HER2 status at surgery was the only significant factor interacting with ΔKi67 on both DFS (P = 0.026) and OS (P = 0.007). For patients with HER2-negative disease, high ΔKi67 was associated with worse 5-year DFS (87.2% vs 91.2%, P = 0.004) as well as impaired 5-year OS (93.9% vs 96.8%, P = 0.010). ΔKi67 had no significant impact on survival of HER2-positive patients. Ki67 increase after CNB was significantly associated with worse disease outcomes in HER2-negative, but not in HER2-positive patients, which warrants further study.

Diagnostic value of core needle biopsy for determining HER2 status in breast cancer, especially in the HER2-low population

PURPOSE

The status of human epidermal growth factor receptor 2 (HER2) is important for treatment decision-making of breast cancer and was commonly determined by core needle biopsy (CNB). The concordance of CNB with surgical excision biopsy (SEB) has been verified, but remain unclear according to the newly developed classification of HER2 status. Our study aimed to re-evaluate the diagnostic value of CNB for determining HER2 status in breast cancer, especially in the HER2-low population.

METHODS

Eligible breast cancer patients in West China Hospital between January 1, 2007 and December 31, 2021 were enrolled consecutively and data were extracted from the Hospital Information System. The agreement of HER2 status between CNB and SEB was calculated by concordance rate and κ statistics, as well as the sensitivity, specificity, positive, and negative predictive values (PPV & NPV). Logistic models were used to explore potential factors associated with the discordance between both tests.

RESULTS

Of 1829 eligible patients, 1097 (60.0%) and 1358 (74.2%) were consistent between CNB and SEB by pathological and clinical classifications, respectively, with κ value being 0.46 (0.43-0.49) and 0.57 (0.53-0.60). The sensitivity (50.9%-52.7%) and PPV (50.5%-55.2%) of CNB were especially low among IHC 1+ and 2+/ISH - subgroups by pathological classifications; however, it showed the highest sensitivity (77.5%) and the lowest specificity (73.9%) in HER2-low population by clinical classifications. Advanced N stages might be a stable indicator for the discordance between both tests.

CONCLUSION

The diagnostic value of CNB was limited for determining HER2 status in breast cancer, especially in HER2-low population.

HER2-Low Status Is Not Accurate in Breast Cancer Core Needle Biopsy Samples: An Analysis of 5610 Consecutive Patients

Background: HER2-Low status is found in approximately half of breast cancer patients and shows potential benefits from novel antibody−drug conjugates (ADCs). Data on the accuracy of HER2-Low status between core needle biopsy (CNB) and surgical excision specimen (SES) samples are lacking. We aimed to investigate the accuracy of HER2-Low status diagnosis between CNB and SES samples. Methods: Consecutive early-stage breast cancer patients who underwent surgery from January 2009 to March 2022 with paired CNB and SES samples were retrospectively reviewed. HER2-Low was defined as IHC 1+ or IHC2+ and FISH-negative. Concordance rates were analyzed by the Kappa test. Further clinicopathological characteristics were compared among different HER2 status and their changes. Results: A total of 5610 patients were included, of whom 3209 (57.2%) and 3320 (59.2%) had HER2-Low status in CNB and SES samples, respectively. The concordance rate of HER2 status in the whole population was 82.37% (Kappa = 0.684, p < 0.001), and was 76.87% in the HER2-Negative patients (Kappa = 0.372, p < 0.001). Among 1066 HER2-0 cases by CNB, 530 patients were classified as HER2-Low tumors. On the contrary, in 3209 patients with HER2-Low tumor by CNB, 387 were scored as HER2-0 on the SES samples. ER-negative or Ki67 high expression tumor by CNB had a high concordance rate of HER2-Low status. Conclusions: A relatively low concordance rate was found when evaluating HER2-Low status between CNB and SES samples in HER2-Negative breast cancer patients, indicating the necessity of retesting HER2 low status at surgery, which may guide further therapy in the era of anti-HER2 ADCs.

Systematically higher Ki67 scores on core biopsy samples compared to corresponding resection specimen in breast cancer: a multi-operator and multi-institutional study

Ki67 has potential clinical importance in breast cancer but has yet to see broad acceptance due to inter-laboratory variability. Here we tested an open source and calibrated automated digital image analysis (DIA) platform to: (i) investigate the comparability of Ki67 measurement across corresponding core biopsy and resection specimen cases, and (ii) assess section to section differences in Ki67 scoring. Two sets of 60 previously stained slides containing 30 core-cut biopsy and 30 corresponding resection specimens from 30 estrogen receptor-positive breast cancer patients were sent to 17 participating labs for automated assessment of average Ki67 expression. The blocks were centrally cut and immunohistochemically (IHC) stained for Ki67 (MIB-1 antibody). The QuPath platform was used to evaluate tumoral Ki67 expression. Calibration of the DIA method was performed as in published studies. A guideline for building an automated Ki67 scoring algorithm was sent to participating labs. Very high correlation and no systematic error (p = 0.08) was found between consecutive Ki67 IHC sections. Ki67 scores were higher for core biopsy slides compared to paired whole sections from resections (p ≤ 0.001; median difference: 5.31%). The systematic discrepancy between core biopsy and corresponding whole sections was likely due to pre-analytical factors (tissue handling, fixation). Therefore, Ki67 IHC should be tested on core biopsy samples to best reflect the biological status of the tumor.

Association of Ki-67 Change Pattern After Core Needle Biopsy and Prognosis in HR+/HER2− Early Breast Cancer Patients

Background

To investigate the association of Ki-67 change pattern after core needle biopsy (CNB) and prognosis in HR+/HER2− early breast cancer patients.

Method

Eligible patients were categorized into three groups: Low group, Elevation group, and High group. Chi-square test and logistic regression analysis were used to compare the clinic-pathological characteristics. Kaplan–Meier method was used to estimate the rates of recurrence-free interval (RFI) and breast cancer-specific survival (BCSS), which were compared via the Log-rank test. Cox proportional hazard analysis was performed to investigate independent prognostic factors.

Results

A total of 2,858 patients were included: 1,179 (41.3%), 482 (16.9%), and 1,197 (41.8%) patients were classified into the low, elevation, and high groups, respectively. Age, tumor size, histological grade, lymph-vascular invasion (LVI), and ER level status were associated with Ki-67 change pattern after CNB. With a median follow-up of 53.6 months, the estimated 5-year RFI rates for the low group, elevation, and high groups were 96.4%, 95.3% and 90.9%, respectively (P < 0.001). And 5-year BCSS rates were 99.3%, 98.3% and 96.8%, respectively (P = 0.001). Compared with patients in the low group, patients in the high group had significantly worse RFI (hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.16–2.54) in multivariate analysis.

Conclusions

Ki-67 change after CNB was associated with prognosis in HR+/HER2− early breast cancer. Patients with Ki-67 high or elevation after CNB had an inferior disease outcome, indicating the necessity of re-evaluating Ki-67 on surgical specimens after CNB.

Association of Molecular Biomarker Heterogeneity With Treatment Pattern and Disease Outcomes in Multifocal or Multicentric Breast Cancer

Purpose

This study aimed to evaluate the rates of estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki67 heterogeneity in multifocal or multicentric breast cancer (MMBC) and its association with treatment pattern and disease outcomes.

Methods

MMBC patients with ER, PR, HER2, and Ki67 results for each tumor focus were retrospectively analyzed using Kappa test and categorized into the homogeneous group (Homo group) and the heterogeneous group (Hetero group). Chi-square tests were performed to compare the clinical features and treatment options between the groups. Disease-free survival (DFS) and overall survival (OS) rates were estimated from Kaplan–Meier curves and compared between two groups.

Results

A total of 387 patients were included, and 93 (24.0%) were classified into the Hetero group. Adjuvant endocrine therapy was more frequently assigned for patients in the Hetero group than in the Homo group (84.9% vs. 71.7%, p = 0.046). There was no difference in terms of adjuvant anti-HER2 therapy (28.3% vs. 19.6%, p = 0.196) and chemotherapy (69.9% vs. 69.8%, p = 0.987) usage between the two groups. At a median follow-up of 36 months, DFS rates were 81.2% for the Hetero group and 96.5% for the Homo group (p = 0.041; adjusted HR, 2.95; 95% CI, 1.04–8.37). The estimated 3-year OS rates for the groups were 95.8% and 99.5%, respectively (p = 0.059; adjusted HR, 5.36; 95% CI, 0.97–29.69).

Conclusion

Heterogeneity of ER, PR, HER2, or Ki67 was present in 24.0% patients with MMBC. Biomarkers heterogeneity influenced adjuvant endocrine therapy usage and was associated with worse disease outcomes, indicating further clinical evaluation.

Concordance of breast cancer biomarker testing in core needle biopsy and surgical specimens: A single institution experience

BACKGROUND

Accurate diagnostic biomarker testing is crucial to treatment decisions in breast cancer. Biomarker testing is performed on core needle biopsies (CNB) and is often repeated in the surgical specimen (SS) after resection. As differences between CNB and SS testing may alter treatment decisions, we evaluated concordance between CNB and SS as well as associated changes in treatment and clinical outcomes.

METHODS

We performed a retrospective analysis of breast cancer patients at our institution between January 2010 and May 2020. Concordance between CNB and SS was assessed for estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) by immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH). Survival in patients, including recurrence, metastatic recurrence, and death, were assessed using chi-squared likelihood ratio.

RESULTS

In total, 961 patients met eligibility criteria. Concordance, minor discordance, total concordance (concordance plus minor discordance), and major discordance between CNB and SS were reported for ER (87.7%, 9.2%, 90.8%, and 2.9%), PR (58.1%, 29.1%, 87.2%, and 12.8%), and HER2 IHC (52.5%, 20.9%, 73.4%, 26.6%), respectively. HER2 FISH concordance and major discordance were 58.5% and 1.2%, respectively. Of major discordance, ER (48.2%, p < 0.001) and HER2 FISH (50.0%) led to more management changes than HER2 IHC (2.4%, p = 0.04) and PR (1.6%, p = 0.10). Patients with ER major discordance had increased risk of death (6.7% concordance vs. 22.2% major discordance, p = 0.004).

CONCLUSION

Overall, retesting ER and HER2 was more clinically beneficial than retesting PR. To aid decision-making and minimize healthcare costs, we propose patient-centered guidelines on retesting biomarker profiles.

Heterogeneity between Core Needle Biopsy and Synchronous Axillary Lymph Node Metastases in Early Breast Cancer Patients-A Comparison of HER2, Estrogen and Progesterone Receptor Expression Profiles during Primary Treatment Regime

Simple Summary

All initial therapeutic decisions in early breast cancer are commonly based on the intrinsic subtype consisting of estrogen (ER), progesterone (PR), the human epidermal growth factor 2 (HER2) receptors and the proliferation marker Ki67. However, breast cancer is a very heterogeneous disease, and receptor expression is reported to change during progression. Little is known about receptor changes at the primary site. In a German single center study, we retrospectively analyzed a mostly therapy naive cohort of 215 primary breast cancer patients with axillary synchronous lymph node metastases (LNM). We compared core needle biopsy tissue of the primary tumor (t-CNB) to axillary LNM and detected receptor discordance for all three receptors at the primary site.

Abstract

In breast cancer therapeutic decisions are based on the expression of estrogen (ER), progesterone (PR), the human epidermal growth factor 2 (HER2) receptors and the proliferation marker Ki67. However, only little is known concerning heterogeneity between the primary tumor and axillary lymph node metastases (LNM) in the primary site. We retrospectively analyzed receptor profiles of 215 early breast cancer patients with axillary synchronous LNM. Of our cohort, 69% were therapy naive and did not receive neoadjuvant treatment. Using immunohistochemistry, receptor status and Ki67 were compared between core needle biopsy of the tumor (t-CNB) and axillary LNM obtained during surgery. The discordance rates between t-CNB and axillary LNM were 12% for HER2, 6% for ER and 20% for PR. Receptor discordance appears to already occur at the primary site. Receptor losses might play a role concerning overtreatment concomitant with adverse drug effects, while receptor gains might be an option for additional targeted or endocrine therapy. Hence, not only receptor profiles of the tumor tissue but also of the synchronous axillary LNM should be considered in the choice of treatment.

Pathological underestimation and biomarkers concordance rates in breast cancer patients diagnosed with ductal carcinoma in situ at preoperative biopsy

Ductal carcinoma in situ (DCIS) often upgrade to invasive breast cancer at surgery. The current study aimed to identify factors associated with pathological underestimation and evaluate concordance rates of biomarkers between biopsy and surgery. Patients diagnosed with DCIS at needle biopsy from 2009 to 2020 were retrospectively reviewed. Univariate and multivariate analyses were performed to identify factors associated with pathological underestimation. Concordance rates between paired biopsy samples and surgical specimens were evaluated. A total of 735 patients with pure DCIS at biopsy were included, and 392 patients (53.3%) underwent pathological underestimation at surgery. Multivariate analysis demonstrated that tumor size > 5.0 cm [odds ratio (OR) 1.79], MRI BI-RADS ≥ 5 categories (OR 2.03), and high nuclear grade (OR 2.01) were significantly associated with pathological underestimation. Concordance rates of ER, PR, HER2 status and Ki-67 between biopsy and surgery were 89.6%, 91.9%, 94.8%, and 76.4% in lesions without pathological underestimation, and were 86.4%, 93.2%, 98.2% and 76.3% for in situ components in lesions with pathological underestimation. Meanwhile, in situ components and invasive components at surgery had concordance rates of 92.9%, 93.8%, 97.4%, and 86.5% for those biomarkers, respectively. In conclusion, lesions diagnosed as DCIS at biopsy have a high rate of pathological underestimation, which was associated with larger tumor size, higher MRI BI-RADS category, and higher nuclear grade. High concordances were found in terms of ER, PR, and HER2 status evaluation between biopsy and surgery, regardless of the pathological underestimation.

High concordance of 70-gene recurrence risk signature and 80-gene molecular subtyping signature between core needle biopsy and surgical resection specimens in early-stage breast cancer

BACKGROUND AND OBJECTIVES

With increased neoadjuvant therapy recommendations for early-stage breast cancer patients due to the COVID-19 pandemic, it is imperative that molecular diagnostic assays provide reliable results from preoperative core needle biopsies (CNB). The study objective was to determine the concordance of MammaPrint and BluePrint results between matched CNB and surgical resection (SR) specimens.

METHODS

Matched tumor specimens (n = 121) were prospectively collected from women enrolled in the FLEX trial (NCT03053193). Concordance is reported using overall percentage agreement and Cohen's kappa coefficient. Correlation is reported using Pearson correlation coefficient.

RESULTS

We found good concordance for MammaPrint results between matched tumor samples (90.9%, κ = 0.817), and a very strong correlation of MammaPrint indices (r = 0.94). The concordance of BluePrint subtyping in matched samples was also excellent (98.3%).

CONCLUSIONS

CNB samples demonstrated high concordance with paired SR samples for MammaPrint risk classification and BluePrint molecular subtyping, suggesting that physicians are provided with accurate prognostic information that can be used to guide therapy decisions.

Concordance between core needle biopsy and surgical excision specimens for Ki-67 in breast cancer - a systematic review of the literature

AIMS

The biomarkers oestrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) are routinely measured in patients with breast cancer with international consensus on how they should be interpreted. There is evidence to support use of other biomarkers to give more detailed predictive and prognostic information. Ki-67 is one example, and measures the proliferative activity of cancer cells. It is important that this can be performed at diagnosis of breast cancer for patients who do not have initial surgical treatment (mainly older women) and those receiving neoadjuvant therapies.

METHODS AND RESULTS

A systematic review was performed to assess concordance of measurement of Ki-67 between core needle biopsy (CNB) samples and surgical excision (SE) samples in patients with invasive breast cancer. MEDLINE and Embase databases were searched. Studies were eligible if performed within the last 10 years; included quantitative measurement of Ki-67 in both CNB and SE samples with no prior breast cancer treatment; measured concordance between two samples; and had full text available. A total of 22 studies, including 5982 paired CNB and SE samples on which Ki-67 was measured, were appraised. Overall, there appeared to be concordance; however, reliability was unclear. Where given, the Cohen's kappa coefficient (κ) of correlation between samples ranged from 0.261 to 0.712. The concordance rate between CNB and SE where measured as a percentage had a range from 70.3 to 92.7% CONCLUSIONS: Assessment of level of concordance of Ki-67 between CNB and SE samples is hampered by different methodologies. International consensus on Ki-67 measurement is urgently needed.

Clinical characteristics and disease outcomes in ER+ breast cancer: a comparison between HER2+ patients treated with trastuzumab and HER2- patients

Background

Trastuzumab has changed the prognosis of HER2+ breast cancer. We aimed to investigate the prognosis of ER+/HER2+ patients treated with trastuzumab, thus to guide escalation endocrine treatment in ER+ breast cancer.

Methods

ER-positive early breast cancer patients operated at Ruijin Hospital between Jan. 2009 and Dec. 2017 were retrospectively included. Eligible patients were grouped as HER2-negative (HER2-neg) or HER2-positive with trastuzumab treatment (HER2-pos-T). Kaplan-Meier analysis and Cox proportional hazards model were used to compare the disease-free survival (DFS) and overall survival (OS) between these two groups.

Results

A total of 3761 patients were enrolled: 3313 in the HER2-neg group and 448 in the HER2-pos-T group. Patients in the HER2-pos-T group were associated with pre/peri-menopause, higher histological grade, LVI, higher Ki-67 level, lower ER and PR levels (all P <  0.05). At a median follow-up of 62 months, 443 DFS events and 191 deaths were observed. The estimated 5-year DFS rate was 89.7% in the HER2-neg group and 90.2% in the HER2-pos-T group (P = 0.185), respectively. Multivariable analysis demonstrated that patients in the HER2-pos-T group had a better DFS than patients in the HER2-neg group (HR 0.52, 95% CI: 0.37–0.73, P <  0.001). The estimated 5-year OS rates were 96.0% and 96.3% in the two groups, respectively (P = 0.133). Multivariate analysis found that HER2-pos-T group was still associated with significantly better OS compared with the HER2-neg group (HR 0.38, 95% CI: 0.22–0.67, P = 0.037).

Conclusion

ER+/HER2+ breast cancer patients treated with trastuzumab were associated with superior outcome compared with ER+/HER2- patients, indicating HER2-positivity itself may not be an adverse factor for ER+ patients in the era of trastuzumab.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-021-08555-4.

Does Specimen Type Have an Impact on HER2 Status in Endometrial Serous Carcinoma? Discordant HER2 Status of Paired Endometrial Biopsy and Hysterectomy Specimens in the Presence of Frequent Intratumoral Heterogeneity

A recent clinical trial showed prolonged progression-free survival in human epidermal growth factor receptor 2 (HER2)-positive advanced stage and recurrent endometrial serous carcinomas when trastuzumab was added to traditional chemotherapy. Approximately one third of these tumors are HER2-positive and have been described to show unique characteristics of HER2 protein expression and gene amplification, including significant intratumoral heterogeneity, in recent studies. However, currently, there are no standard protocols for the selection of optimal specimen type or algorithm for HER2 testing in endometrial serous carcinomas. The current study aimed to evaluate the concordance of HER2 status between endometrial biopsy/curettage and subsequent hysterectomy specimens in endometrial serous carcinoma. A total of 57 patients with endometrial serous carcinoma with available HER2 status were identified during the study period, 14 of which (14/57, 25%) were HER2-positive by immunohistochemistry and/or fluorescent in situ hybridization (FISH). The final study cohort consisted of 40 paired endometrial biopsies/curettings and hysterectomies to include all 14 HER2-positive tumors and 26 selected HER2-negative tumors to represent an equal distribution of HER2 immunohistochemical scores. HER2 FISH was performed on all tumors with an immunohistochemical score of 2+. HER2 immunohistochemical scores, heterogeneity of HER2 expression, FISH results, and the overall HER2 status were compared between the 2 specimen types. HER2 status was successfully assigned in both specimen types in 37 cases, as three specimens showed inadequate FISH signals. Concordant HER2 status was observed in 84% of cases (31/37), with identical HER2 immunohistochemical scores in 65% (26/40) of tumors. Among the 6 tumors with a discordant HER2 status, 2 were HER2 negative in the biopsy and positive in the hysterectomy, and 4 were HER2-positive in the biopsy and negative in the hysterectomy. The false-negative rate would be 15.4% and 26.7% if only the biopsy or only the hysterectomy would be the basis for the result, respectively. Intratumoral heterogeneity of HER2 protein expression was present in 22 tumors (55%), including all cases with a discordant HER2 status. The concordance rate of HER2 status between paired endometrial biopsies/curettings and hysterectomies of endometrial serous carcinoma is lower than the reported rates of breast cancer, and comparable to those of gastric carcinomas. Frequent heterogeneity of HER2 protein expression combined with the possibility of a spatially more heterogenous sampling of endometrial cavity in biopsies and curettings, and the potential differences in specimen handling/fixation between the 2 specimen types may explain our findings. HER2 testing of multiple specimens may help identify a greater proportion of patients eligible for targeted trastuzumab therapy and should be taken into account in future efforts of developing endometrial cancer-specific HER2 testing algorithm.

Concordance of the molecular subtype classification between core needle biopsy and surgical specimen in primary breast cancer

BACKGROUND

Molecular profiling of breast cancer (BC) classifies several intrinsic subtypes based on different patterns of gene expression. Multigene assays estimate the risk of recurrence and help to select high-risk patients for adjuvant chemotherapy. However, these tests are associated with significant costs. Immunohistochemistry (IHC) offers a surrogate classification for molecular subtypes by determining estrogen (ER) and progesterone receptors (PR), human epidermal growth factor (Her2neu), as well as the proliferation marker Ki67. Core needle biopsy (CNB) is well established in BC diagnosis and allows a pre-operative assessment of biomarkers. The aim of this study was to analyze the concordance of these markers between CNB and surgical specimens to assess whether re-testing of the surgical specimen is mandatory.

MATERIALS AND METHODS

Within a 3-year period, patients with primary BC and paired samples of CNB and surgical specimens were analyzed retrospectively. Concordance rates of ER, PR, Her2neu, Ki67, and the surrogate classification for molecular subtypes were calculated using the Landis and Koch agreement grades.

RESULTS

Out of 2254 patients with primary breast cancer, 1307 paired specimens without pre-operative treatment were available for analysis Concordance rates for ER, PR, Her2neu, and Ki67 status showed substantial-to-almost perfect agreement grades (κ = 0.91, 0.75, 0.89, and 0.61, respectively). Though substantial concordance was also found for the subtype classification (κ = 0.70), the molecular subtype changed in 18.5% of patients based on the testing of the surgical specimen, mainly from luminal A-like to luminal B-like.

CONCLUSIONS

Though the concordance rates for single markers were convincing, a significant proportion of the molecular subtypes differed between CNB and the surgical specimen. Re-testing of PR and Ki67 is mandatory to ensure optimal treatment decisions. Further research is necessary to define safe, efficient, and cost-effective predictive models in adjuvant breast cancer therapy.

HER2 positivity is not associated with adverse prognosis in high-risk estrogen receptor-positive early breast cancer patients treated with chemotherapy and trastuzumab

Co-expression of human epidermal growth factor receptor-2 (HER2) and hormone receptor (HR) predicted worse prognosis in early breast cancer before trastuzumab was developed. We aimed to investigate whether HER2 positivity was still associated with worse outcome in high-risk estrogen receptor (ER) positive patients treated with trastuzumab and chemotherapy. In the present study, 227 ER+/HER2+ patients treated with trastuzumab and chemotherapy (HER2-pos-T group) and 1097 ER+/HER2-patients treated with chemotherapy alone (HER2-neg group) during 2009 and 2015 were retrospectively enrolled for the comparison of disease-free survival (DFS) and overall survival (OS). At a median follow-up of 59 months, 174 DFS events and 69 deaths were observed. The estimated 5-year DFS rate was 94.2% in the HER2-pos-T group and 87.4% in the HER2-neg group (Log-rank P = 0.014). HER2-pos-T group was associated with significantly better DFS in multivariate analysis (HR 0.38, 95% CI: 0.22–0.67, Log-rank P = 0.001). The estimated 5-year OS rates for the two groups were 97.2% and 95.7%, respectively (Log-rank P = 0.183). In multivariable analysis, patients in the HER2-pos-T group had significantly better OS compared with those in the HER2-neg group (HR 0.40, 95% CI: 0.17–0.95, Log-rank P = 0.037). We concluded that high-risk ER+/HER2+ breast cancer patients treated with chemotherapy and trastuzumab had superior prognosis compared with ER+/HER2-patients. Therefore, HER2 positivity itself may not be considered as an unfavorable factor for ER + patients in the era of trastuzumab.

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ER+/HER2+ early breast cancer patients treated with trastuzumab-based chemotherapy had superior prognosis.

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ER+/HER2+ early breast cancer patients had distinct patterns of relapse or death from those of ER+/HER2-patients.

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HER2 positivity itself may not be considered as an unfavorable factor for ER + patients in the era of trastuzumab.

Factors influencing agreement of breast cancer luminal molecular subtype by Ki67 labeling index between core needle biopsy and surgical resection specimens

Reliable determination of Ki67 labeling index (Ki67-LI) on core needle biopsy (CNB) is essential for determining breast cancer molecular subtype for therapy planning. However, studies on agreement between molecular subtype and Ki67-LI between CNB and surgical resection (SR) specimens are conflicting. The present study analyzed the influence of clinicopathological and sampling-associated factors on agreement. Molecular subtype was determined visually by Ki67-LI in 484 pairs of CNB and SR specimens of invasive estrogen receptor (ER)-positive, human epidermal growth factor (HER2)-negative breast cancer. Luminal B disease was defined by Ki67-LI > 20% in SR. Correlation of molecular subtype agreement with age, menopausal status, CNB method, Breast Imaging Reporting and Data System imaging category, time between biopsies, type of surgery, and pathological tumor parameters was analyzed. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using the Kaplan-Meier method. CNB had a sensitivity of 77.95% and a specificity of 80.97% for identifying luminal B tumors in CNB, compared with the final molecular subtype determination after surgery. The correlation of Ki67-LI between CNB and SR was moderate (ROC-AUC 0.8333). Specificity and sensitivity for CNB to correctly define molecular subtype of tumors according to SR were significantly associated with tumor grade, immunohistochemical progesterone receptor (PR) and p53 expression (p < 0.05). Agreement of molecular subtype did not significantly impact RFS and OS (p = 0.22 for both). The identified factors likely mirror intratumoral heterogeneity that might compromise obtaining a representative CNB. Our results challenge the robustness of a single CNB-driven measurement of Ki67-LI to identify luminal B breast cancer of low (G1) or intermediate (G2) grade.

Surrogate Molecular Classification of Invasive Breast Carcinoma: A Comparison Between Core Needle Biopsy and Surgical Excision, With and Without Neoadjuvant Therapy

Surrogate molecular classification identifies different subtypes of invasive breast carcinoma on the basis of their immunohistochemical markers. The purpose of the study is to verify whether the immunohistochemical markers and surrogate molecular subtypes can be correctly assessed on the core needle biopsy (CNB) when compared with the corresponding surgical excision (SE), with or without neoadjuvant treatment (NAT). Cases with invasive carcinomas identified on both CNB and SE were retrospectively selected. With immunohistochemistry for estrogen receptors (ER), progesterone receptors (PgR), Ki67, human epidermal growth factor receptor 2 (Her2), and molecular analysis for Her2, surrogate molecular classification was determined in 4 and 5 groups, according to the 2013 St Gallen consensus. A total of 1067 cases was considered and complete data for surrogate molecular classification were available for 988 cases (655 without NAT, 333 with NAT). Without NAT, concordance was strong for ER and Her2, moderate for PgR, and weak for Ki67; concordance for surrogate molecular classification was moderate. After NAT, lower concordance rates were recorded, with significant reduction of PgR (P<0.001) and Ki67 (P<0.001). Without NAT, the surrogate molecular subtypes of breast carcinoma can be reliably assessed on CNB; Ki67 and/or PgR may be repeated on SE when values are close to cutoffs to avoid tumor subtype misclassification. After NAT, it seems advisable to repeat at least Ki67 and PgR.

A Prospective Study on Level of Concordance Between Core Needle Biopsy and Surgical Specimen for Assessing Oestrogen Receptor, Progesterone Receptor, and Her2/Neu Receptor Status in Carcinoma Breast and Its Implications on Treatment Decisions

A prospective study on the level of concordance between core needle biopsy specimen (CNB) and surgical specimen (SS) assesses the oestrogen receptor (ER), progesterone receptor (PR) and Her2/Neu receptor status in Carcinoma breast and its implications on treatment decisions. Ninety consecutive treatment naive operable breast cancer patients treated between September 2015 and April 2017 were included in our prospective study. All patients underwent core needle biopsy prior to definitive surgery. Immunohistochemistry (IHC) studies for ER, PR, and Her2/Neu receptor assay were done in both the CNB specimen and SS. The concordances between CNB specimen and SS for ER, PR, and Her2/Neu receptor were 92%, 88%, and 78% respectively. In our study, overall discordance for ER, PR, and Her2/Neu status based on IHC tests on CNB specimen and its corresponding SS was 41% (37 out of total 90 patients), which was mostly for Her2/Neu (20 patients). Altogether, there was a change in treatment decision based on IHC test results of CNB specimen for 14 out of 37 discordant tests, translating to 15% of the overall study group. Four patients received adjuvant hormonal therapy, and 10 patients got adjuvant Traztuzumab added to their protocol. There is almost perfect to substantial concordance between CNB specimen and SS of IHC tests for ER and PR status. However, the concordance for Her2/Neu receptor is only moderate. Her2/Neu receptor assay by IHC is more sensitive in CNB specimen than in SS.

Predictive Value of Molecular Subtypes in Premenopausal Women with Hormone Receptor-positive Early Breast Cancer: Results from the ABCSG Trial 5

PURPOSE

To assess the predictive value of molecular breast cancer subtypes in premenopausal patients with hormone receptor-positive early breast cancer who received adjuvant endocrine treatment or chemotherapy.

EXPERIMENTAL DESIGN

Molecular breast cancer subtypes were centrally assessed on whole tumor sections by IHC in patients of the Austrian Breast and Colorectal Cancer Study Group Trial 5 who had received either 5 years of tamoxifen/3 years of goserelin or six cycles of cyclophosphamide, methotrexate, and fluorouracil (CMF). Luminal A disease was defined as Ki67 <20% and luminal B as Ki67 ≥20%. The luminal B/HER2-positive subtype displayed 3+ HER2-IHC or amplification by ISH. Recurrence-free survival (RFS) and overall survival (OS) were analyzed using Cox models adjusted for clinical and pathologic factors.

RESULTS

185 (38%), 244 (50%), and 59 (12%) of 488 tumors were classified as luminal A, luminal B/HER2-negative and luminal B/HER2-positive, respectively. Luminal B subtypes were associated with poor outcome. Patients with luminal B tumors had a significantly shorter RFS [adjusted HR for recurrence: 2.22; 95% confidence interval (CI), 1.41-3.49; P = 0.001] and OS (adjusted HR for death: 3.51; 95% CI, 1.80-6.87; P < 0.001). No interaction between molecular subtypes and treatment was observed (test for interaction: P = 0.84 for RFS; P = 0.69 for OS).

CONCLUSIONS

Determination of molecular subtypes by IHC is an independent prognostic factor for recurrence and death in premenopausal women with early-stage, hormone receptor-positive breast cancer but is not predictive for outcome of adjuvant treatment with tamoxifen/goserelin or CMF.See related commentary by Hunter et al., p. 5543.

Do YOU know the Ki-67 index of your breast cancer patients? Knowledge of your institution's Ki-67 index distribution and its robustness is essential for decision-making in early breast cancer

OBJECTIVES

The proliferative activity of the Ki-67 index is important in decision-making of adjuvant treatments in early breast cancer. Its reliability can be reduced by inter-observer variability. This analysis' objective is to evaluate the robustness of Ki-67 values within one center over 5 years and to compare its distribution with a published dataset.

MATERIALS AND METHODS

Ki-67 indices of early breast cancers treated at St. Gallen Breast Center were collected (2010-2014; 1154 patients). Distribution of Ki-67 values was analyzed for each year, along with histologic subtype and grading. Tumors were classified into intrinsic subtypes using two definitions: 2013 St. Gallen Consensus and the refined definition by Maisonneuve ("Milano Group"). Our institution's Ki-67 cut-off value was adjusted to obtain the same distribution of luminal subtypes as published data of the Milano Group.

RESULTS

Ki-67 index frequency distributions were comparable between years (mean 26-30%, median 22-26%). Shape and position of the distribution curves were nearly identical. Ki-67 values correlated with tumor grade (median Ki-67: G1: 12.0%, G2: 21%, G3: 38%). Standard deviation of Ki-67 increased with higher grading (G1: 6.9; G2: 9.2; G3: 18.2; p < 0.001). According to the 2013 definition (and refined definition respectively), there were 35% (41%) luminal A-like and 65% (59%) luminal B-like tumors. To obtain the same distribution as the Milano group, Ki-67 cut-off needed to be elevated to 22%.

CONCLUSIONS

Ki-67 index assessment was comparable over many years. Knowledge of one's institution's Ki-67 value distribution is essential for clinical decision-making of adjuvant therapies in early breast cancer.

Luminal A versus luminal B breast cancer: MammaTyper mRNA versus immunohistochemical subtyping with an emphasis on standardised Ki67 labelling-based or mitotic activity index-based proliferation assessment

AIMS

Proliferation assessment by the use of Ki67 is a crucial component in intrinsic subtyping of luminal breast cancers (BCs), but suffers from variability between laboratories, observers, and methods. MammaTyper is a quantitative molecular tool that measures mRNA levels of ERBB2, ESR1, PGR and MKI67 in BC, and interprets the results according to the St Gallen 2013 consensus recommendations. We compared MammaTyper with immunohistochemistry (IHC)-based subtypes, with a focus on standardised proliferation assessment.

METHODS AND RESULTS

We analysed the agreement in assigning subtypes between MammaTyper and receptor IHC in 101 unifocal luminal HER2-negative early BCs of no special type. Two Ki67 counting protocols, Ki67-Global (Ki67-G) and Ki67-HotSpot (Ki67-H), recommended by the International Ki67 in BC Working Group, and the mitotic activity index (MAI) were used for proliferation assessment. The proportions of BCs identified as luminal A and as luminal B were 55% and 45% for MammaTyper, 55% and 45% for IHC + Ki67-G, 36% and 64% for IHC + Ki67-H, and 56% and 44% for IHC + MAI. The levels of agreement between MammaTyper-based and IHC-based subtyping were 84% (κ = 0.679) for IHC + Ki67-G, 72% (κ = 0.462) for IHC + Ki67-H, and 89% (κ = 0.779) for IHC + MAI.

CONCLUSIONS

High rates of agreement between mRNA-based and IHC-based intrinsic subtyping of luminal HER2-negative BC can be achieved. However, the agreement between IHC-based and MammaTyper-based luminal subtypes depends on the proliferation assessment method, and was highest when the MAI was used. Further comparative clinical studies are needed to determine which method is to be preferred, including analysis of cost-effectiveness.

Imaging breast cancer using hyperpolarized carbon-13 MRI

Our purpose is to investigate the feasibility of imaging tumor metabolism in breast cancer patients using 13C magnetic resonance spectroscopic imaging (MRSI) of hyperpolarized 13C label exchange between injected [1-13C]pyruvate and the endogenous tumor lactate pool. Treatment-naïve breast cancer patients were recruited: four triple-negative grade 3 cancers; two invasive ductal carcinomas that were estrogen and progesterone receptor-positive (ER/PR+) and HER2/neu-negative (HER2-), one grade 2 and one grade 3; and one grade 2 ER/PR+ HER2- invasive lobular carcinoma (ILC). Dynamic 13C MRSI was performed following injection of hyperpolarized [1-13C]pyruvate. Expression of lactate dehydrogenase A (LDHA), which catalyzes 13C label exchange between pyruvate and lactate, hypoxia-inducible factor-1 (HIF1α), and the monocarboxylate transporters MCT1 and MCT4 were quantified using immunohistochemistry and RNA sequencing. We have demonstrated the feasibility and safety of hyperpolarized 13C MRI in early breast cancer. Both intertumoral and intratumoral heterogeneity of the hyperpolarized pyruvate and lactate signals were observed. The lactate-to-pyruvate signal ratio (LAC/PYR) ranged from 0.021 to 0.473 across the tumor subtypes (mean ± SD: 0.145 ± 0.164), and a lactate signal was observed in all of the grade 3 tumors. The LAC/PYR was significantly correlated with tumor volume (R = 0.903, P = 0.005) and MCT 1 (R = 0.85, P = 0.032) and HIF1α expression (R = 0.83, P = 0.043). Imaging of hyperpolarized [1-13C]pyruvate metabolism in breast cancer is feasible and demonstrated significant intertumoral and intratumoral metabolic heterogeneity, where lactate labeling correlated with MCT1 expression and hypoxia.

Assessment of Ki67 in Breast Cancer: A Comparison Between the Eye-10 Method, Stepwise Counting Strategy, and International System of Ki67 Evaluation

Background & Objective:

Ki-67 evaluation is an essential tool to define luminal A and B breast cancers, which is not yet systematized. The International Ki67 in Breast Cancer Working Group suggests the counting of 500 or 1000 cancer cells, which is a time-consuming process. Therefore, novel methods, such as the Eye-10 method and stepwise counting strategy, are proposed to facilitate measurement.

Methods:

Immunohistochemical staining of Ki67 was performed on 100 hormone-receptor-positive invasive ductal carcinoma specimens. Ki67LI was evaluated for each case, and then results were dichotomized by a cut-off point of 20%. Next, for each sample, an expert pathologist visually assessed percentages of Ki67-positive cells in 10% intervals at a glance (Eye-10 method). Finally, by using a dynamic process with rejection regions, Ki67 was defined so if the estimate belonged to the upper or lower rejection region, the Ki67 status had been determined and if the rejection region could not be reached after counting the maximum number of 400 tumor cells, the specimen was regarded as equivocal (stepwise counting strategy).

Results:

The comparison between Eye-10 and Ki67LI revealed almost perfect agreement (kappa coefficient =0.889), and the concordance between the stepwise counting strategy and Ki67LI was substantial (kappa coefficient =0.639).

Conclusion:

Both two methods left some results in the gray/intermediate zone, which is unavoidable. Both methods are much faster and simpler than evaluation of Ki67LI and are also reliable. Regarding the gray zone in both methods, further improvements in the methodology, as well as more analytical studies, are needed.

Identifying breast cancer patients who require a double-check of preoperative core needle biopsy and postoperative surgical specimens to determine the molecular subtype of their tumor

Purpose

Core needle biopsy (CNB) is a widely used procedure for breast cancer diagnosis and analyzing results of immunohistochemistry (IHC). Several studies have shown concordance or discordance in IHC results between CNB and surgical specimens (SS). A double-check (CNB and SS) is inefficient and costly to perform a double-check on all patients. Therefore, it is important to determine which patients would benefit from a double-check.

Methods

We collected the medical records of patients who underwent breast cancer surgery at Pusan National University Yangsan Hospital between April 2009 and June 2018 (n = 620). Molecular subtypes were classified as follows by hormone receptors (HR) and human epidermal growth factor receptor-2 (HER2): HR+/HER2+, HR+/HER2−, HR−/HER2+, HR−/HER2−. Clinicopathological factors including age, obesity, histological grade, preoperative CEA, CA15-3, T stage, N stage, and menopausal status were assessed to determine whether they were associated with subtype change.

Results

Increasing histological grade (P < 0.001; odds ratio [OR], 3.693; 95% confidence interval [CI], 1.941–7.025), preoperative CEA ≥ 5 ng/mL (P =0.042; OR, 2.399; 95% CI, 1.009–5.707) and higher T stage (P = 0.015; OR, 2.241; 95% CI, 1.152–4.357) were significantly associated with subtype change. On multivariable analyses, subtype changes were more common in high-grade breast cancer (P < 0.001; OR, 1.077; 95% CI, 1.031–1.113) and CEA ≥ 5 (P = 0.032; OR, 2.658; 95% CI, 1.088–6.490).

Conclusion

Patients with moderate- to high-grade tumors or CEA ≥ 5 ng/mL are required a double-check to determine the molecular subtype of breast cancer.

Analysis of the molecular subtypes of preoperative core needle biopsy and surgical specimens in invasive breast cancer

Background

Accurate molecular classification of breast core needle biopsy (CNB) tissue is important for determining neoadjuvant systemic therapies for invasive breast cancer. The researchers aimed to evaluate the concordance rate (CR) of molecular subtypes between CNBs and surgical specimens.

Methods

This study was conducted with invasive breast cancer patients who underwent surgery after CNB at Seoul St. Mary’s Hospital between December 2014 and December 2017. Estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki67 were analyzed using immunohistochemistry. ER and PR were evaluated by Allred score (0–8). HER2 was graded from 0 to +3, and all 2+ cases were reflex tested with silver in situ hybridization. The labeling index of Ki67 was counted by either manual scoring or digital image analysis. Molecular subtypes were classified using the above surrogate markers.

Results

In total, 629 patients were evaluated. The CRs of ER, PR, HER2, and Ki67 were 96.5% (kappa, 0.883; p<.001), 93.0% (kappa, 0.824; p<.001), 99.7% (kappa, 0.988; p<.001), and 78.7% (kappa, 0.577; p<.001), respectively. Digital image analysis of Ki67 in CNB showed better concordance with Ki67 in surgical specimens (CR, 82.3%; kappa, 0.639 for digital image analysis vs. CR, 76.2%; kappa, 0.534 for manual counting). The CRs of luminal A, luminal B, HER2, and triple negative types were 89.0%, 70.0%, 82.9%, and 77.2%, respectively.

Conclusions

CNB was reasonably accurate for determining ER, PR, HER2, Ki67, and molecular subtypes. Using digital image analysis for Ki67 in CNB produced more accurate molecular classifications.

21-Gene Recurrence Score and Adjuvant Chemotherapy Decision for Breast Cancer Patients with Positive Lymph Nodes

The 21-gene recurrence score (RS) assay is prognostic and predictive for hormone receptor (HR)+/HER2-/node- breast cancer (BC) patients. However, its clinical value in node + patients hasn’t been elucidated. HR+/HER2-/pN1 patients operated in Comprehensive Breast Health Center, Shanghai Ruijin Hospital from January 2014 to December 2018, with available RS results were retrospectively included. Clinico-pathological characteristics were compared. Adjuvant chemotherapy recommendations pre-/post- RS assay and actual usage were analyzed. A total of 303 patients were included, with 59, 178, 66 RS < 18, 18–30 and ≥ 31. Age (P < 0.001), comorbidity (P = 0.013), and RS category (P < 0.001) were independently associated with chemotherapy recommendation. Compared with low RS patients, those with intermediate (OR 6.58, 95% CI 2.37–18.31, P < 0.001) or high (OR 54.14, 95% CI 3.77–776.54, P = 0.003) RS were more likely to be recommended with chemotherapy. RS independently influence chemotherapy decision in postmenopausal population as well. Chemotherapy recommendation changed for 9.57% patients after RS assay. Patient adherence rate to chemotherapy recommendation was 94.72% (287/303). The 21-gene RS independently influenced chemotherapy recommendation in pN1 BC patients, which could provide additional information to guide chemotherapy decision with relatively good treatment adherence rate.

Clinicopathological Features and Disease Outcome in Breast Cancer Patients with Hormonal Receptor Discordance between Core Needle Biopsy and Following Surgical Sample

Background

There are limited data about how to manage patients with discordant hormonal receptor (HR) status between core needle biopsy (CNB) and following surgical sample (FSS). This study aimed to evaluate clinicopathological features and disease outcome for these HR discordance patients.

Patients and Methods

Invasive breast cancer patients with paired HR between CNB and FSS were retrospectively analyzed, being classified into three groups: HR positive, HR negative, and HR discordance. Patient characteristics, treatment decisions, and disease outcome were compared among above groups.

Results

A total of 1710 patients (1233 HR positive, 417 HR negative, and 60 HR discordance patients) were enrolled. Compared with the HR positive group, HR discordance patients were associated with more human epidermal growth factor receptor 2 positivity (P < 0.001) and higher Ki67 level (P = 0.001) tumors. The fraction of patients receiving adjuvant chemotherapy was 95.0% and 93.8% in the HR discordance or HR negative groups, much higher than in the HR positive group (66.7%, P < 0.001). Of 60 HR discordance patients, 34 (56.7%) received adjuvant endocrine therapy. The 5-year disease-free survival (DFS) rate was 90.4% for HR discordant patients, showing no statistical difference compared with HR positive (87.0%, P = 0.653) or HR negative (83.2%, P = 0.522) groups. For HR discordance patients, there was no difference in DFS between patients who received adjuvant endocrine therapy or not (P = 0.259).

Conclusions

HR discordance patients had similar tumor characteristics, adjuvant chemotherapy treatment, and DFS compared with HR negative patients. The benefit of endocrine therapy in these HR discordance patients is uncertain and deserves further clinical evaluation.

Electronic supplementary material

The online version of this article (10.1245/s10434-019-07480-y) contains supplementary material, which is available to authorized users.

Efficacy of an RNA-based multigene assay with core needle biopsy samples for risk evaluation in hormone-positive early breast cancer

BACKGROUND

Gene expression profiling provides key information for prognosis of breast cancer to establish treatment strategy. However, the genetic assessment should be available before induction of treatment to be useful for clinical practice. To evaluate the reliability of using needle biopsy samples for gene assays, we compared gene-expression profiling results between core needle biopsy (CNB) samples and surgical specimens in breast cancer.

METHODS

Thirty-one paired, formalin-fixed, paraffin-embedded CNB and surgical specimen samples were selected from patients with hormone receptor-positive breast cancer. Total RNA was extracted from the samples and the risk classifications based on GenesWell BCT scores were compared.

RESULTS

The BCT scores correlated between CNB samples and surgical specimens of hormone receptor-positive breast cancer (Pearson r = 0.66). The overall concordance rate of risk classification (high/low risk) was 83.9%. However, when the breast cancer does not contain intratumoral microcalcification, the concordance rate increased as 92.0%. And, when the breast cancer formed a solitary nodule (non-multifocal), the concordance rate increased up to 95.8%.

CONCLUSION

Risk classification using the GenesWell BCT multigene kit with CNB samples could be considered reliable, when the breast cancer is a solitary nodule without intratumoral microcalcification. Such genetic profiling results should be helpful for establishing a treatment plan for hormone receptor-positive breast cancer before treatment induction.

Breast cancer global tumor biomarkers: a quality assurance study of intratumoral heterogeneity

Biomarker analysis of invasive breast carcinoma is useful for prognosis, as surrogate for molecular subtypes of breast cancer, and prediction of response to adjuvant and neoadjuvant systemic therapies. Breast cancer intratumoral heterogeneity is incompletely studied. Comprehensive biomarker analysis of estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 labeling index was performed on each tissue block of 100 entirely submitted breast tumors in 99 patients. Invasive carcinoma and in situ carcinoma was scored using semiquantitative histologic score (H-score) for ER and PR, HER2 expression from 0 to 3+, and percentage positive cells for Ki67. Core biopsy results were compared with surgical excision results, invasive carcinoma was compared with in situ carcinoma, and interblock tumoral heterogeneity was assessed using measures of dispersion (coefficient of variation and quartile coefficient of dispersion). Overall concordance between core biopsy and surgical excision was 99% for ER and 95% for PR. Mean histologic score of ER was significantly lower in invasive carcinoma between core biopsy and surgical excision (p = 0.000796). Intratumoral heterogeneity was higher for PR than for ER (mean coefficient of variation for ER 0.08 stdv 0.13 vs. PR 0.26 stdv 0.41). Ki67 labeling index was significantly higher in invasive carcinoma as compared with associated ductal carcinoma in situ on surgical resection specimen (p ≤ 0.0001). Ki67 hotspots were identified in 47% of cases. Of 52 HER2 negative cases on core biopsy, 10 were scored as equivocal on surgical resection. None (0/10) were amplified by Her-2/neu fluorescence in situ hybridization. Overall, biomarkers on core biopsy showed concordance with the surgical excision specimen in the vast majority of cases. Biomarker expression of in situ closely approximates associated invasive carcinoma. Intratumoral heterogeneity of PR is greater than ER. Biomarker expression on diagnostic core biopsy or single tumor block is representative of breast carcinoma as a whole in most cases and is appropriate for clinical decision-making.

Re-testing of predictive biomarkers on surgical breast cancer specimens is clinically relevant

PURPOSE

The accuracy of predictive and prognostic biomarker assessment in breast cancer is paramount since these guide therapy decisions. The aim was to investigate the concordance of biomarkers and immunohistochemical (IHC)-based surrogate tumor subtypes between core needle biopsies (CNB) and consecutive paired breast cancer surgical resections.

METHODS

This retrospective study comprised two cohorts of patients with primary breast cancer diagnosed between 2016 and 2017: one treated with primary surgery (n = 526) and one with neoadjuvant chemotherapy (NAC) (n = 216). The agreement between preoperative CNB and paired tumor specimens regarding the assessment of biomarkers and surrogate tumor subtypes was evaluated in both cohorts.

RESULTS

In the primary surgery cohort, the concordance rates and kappa values for estrogen receptor (ER), progesterone receptor (PR) and Ki67 were 98.6% (κ = 0.917), 89.3% (κ = 0.725) and 78.8% (κ = 0.529), respectively. Importantly, human epidermal growth factor receptor 2 (HER2) IHC assessment showed only moderate agreement (κ = 0.462). HER2 status combining IHC and in situ hybridization was discordant in 3.6% of cases, potentially impacting on indications for HER2-targeted therapy. The concordance rate for IHC-based surrogate tumor subtypes was only 73.2-78.3%. Generally lower concordance rates for ER, PR and HER2 were observed in the NAC cohort. Here, HER2 status was discordant in 7.4%.

CONCLUSIONS

The agreement of HER2 and Ki67 between CNB and paired surgical specimen in primary breast cancer is insufficient. Limited agreement of surrogate tumor subtypes indicates a significant clinical value of biomarker re-testing on surgical specimens.

Association Between Shear Wave Elastography of Virtual Touch Tissue Imaging Quantification Parameters and the Ki-67 Proliferation Status in Luminal-Type Breast Cancer

OBJECTIVES

To evaluate the association between shear wave elastography parameters using virtual touch tissue imaging quantification (VTIQ) and the Ki-67 index in luminal-type breast cancer.

METHODS

Eighty-one patients with 82 lesions of pathologic confirmed luminal-type breast cancer underwent virtual touch tissue imaging quantification examination before surgery between December 2015 and June 2016. Patients were divided into 2 groups according to the Ki-67 index (≥14% versus < 14%), which is used to define luminal type B and luminal type A, respectively. The mean shear wave velocity (SWV_mean ) and lesion-to-adjacent tissues ratio (SWV ratio) were calculated for each lesion.

RESULTS

The SWV_mean , SWV ratio, histologic grade, axillary lymph node involvement, and lymphovascular invasion showed a significant positive association with a high Ki-67 index (all P < .05). Receiver operating characteristic curve analysis for the differential diagnosis between high (≥14%) and low (<14%) Ki-67 groups displayed that the optimal cutoff value for SWV_mean and SWV ratio were 3.99 meters per second and 2.861, with sensitivity 94% and 72%, specificity 40.6% and 56.2%, and area under the receiver operating characteristic curve of 0.689 and 0.651, respectively. Univariate analysis showed that SWV_mean (P = .005), SWV ratio (P = .029), histologic grade (P = .011), presence of axillary node involvement (P = .004), and lymphovascular invasion (P = .008) were significantly associated with high Ki-67 status. Multivariable analysis displayed that SWV_mean (hazard ratio [HR], 1.459, 95% confidence interval [CI], 1.028-2.072; P = .035), histologic grade (HR, 4.105; 95% CI, 1.142-14.763; P = .031), and presence of axillary node involvement (HR, 3.75; 95% CI, 1.228-11.453; P = .020) maintained significance for predicting high Ki-67 status.

CONCLUSIONS

The SWV_mean using the virtual touch tissue imaging quantification method showed significant correlation with the Ki-67 index, suggesting the potential to assess tumor proliferation status in luminal-type breast cancer with a noninvasive manner.

Core needle biopsy as an alternative to whole section in IHC4 score assessment for breast cancer prognostication

AIMS

IHC4 score, based on expression of four routine markers (oestrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) and proliferation marker, Ki67), is a recently developed, cost-effective prognostic tool in breast cancer. Possibly, the score may be useful also in advanced diseases where only core needle biopsy (CNB) is available and neoadjuvant therapy. However, its studies on CNB are scant. This study examined whether IHC4 score assessment on CNB is comparable to that from whole section (WS).

METHODS

Immunohistochemical (IHC) analysis was performed for ER, PR, HER2 and Ki67 on 108 paired CNB and WS to evaluate IHC4 score (with follow-up range 1-230 months and 5 relapse/death). Concordance between the two was examined. Factors that affected the concordance were analysed. Additionally, IHC4 score was compared with Nottingham Prognostic Index (NPI).

RESULTS

There was moderate concordance between IHC4 score on CNB and WS (all cases: κ=0.699, p<0.001; ER+ cases: κ=0.595, p<0.001). Among the IHC4 components, concordance for HER2 was the poorest (κ=0.178, p<0.001 in all cases; ER+ cases: κ=0.082, p<0.097). Significant factors affecting concordance between CNB and WS included number of cores, total core length and percentage of tumour cells in cores (p≤0.030), indicating the importance of sufficient sampling. Interestingly, the concordance was also affected by patients' age (p=0.039). There was poor agreement between IHC4 score and NPI (κ≤0.160).

CONCLUSION

Our results suggested that IHC4 score can be used on adequately sampled CNB. Its poor agreement with NPI highlights the independence of the two factors.

Negative Conversion of Progesterone Receptor Status after Primary Systemic Therapy Is Associated with Poor Clinical Outcome in Patients with Breast Cancer

Purpose

Alteration of biomarker status after primary systemic therapy (PST) is occasionally found in breast cancer. This study was conducted to clarify the clinical implications of change of biomarker status in breast cancer patients treated with PST.

Materials and Methods

The pre-chemotherapeutic biopsy and post-chemotherapeutic resection specimens of 442 breast cancer patients who had residual disease after PST were included in this study. The association between changes of biomarker status after PST and clinicopathologic features of tumors, and survival of the patients, were analyzed.

Results

Estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status changed after PST in 18 (4.1%), 80 (18.1%), and 15 (3.4%) patients,respectively. ER and PR mainly underwent positive to negative conversion,whereas HER2 status underwent negative to positive conversion. Negative conversion of ER and PR status after PST was associated with reduced disease-free survival. Moreover, a decline in the Allred score for PR in post-PST specimens was significantly associated with poor clinical outcome of the patients. HER2 change did not have prognostic significance. In multivariate analyses, negative PR status after PST was found to be an independent adverse prognostic factor in the whole patient group, in the adjuvant endocrine therapy-treated subgroup, and also in pre-PST PR positive subgroup.

Conclusion

ER and HER2 status changed little after PST, whereas PR status changed significantly. In particular, negative conversion of PR status was revealed as a poor prognostic indicator, suggesting that re-evaluation of basic biomarkers is mandatory in breast cancer after PST for proper management and prognostication of patients.

Evaluation of Ki-67 Index in Core Needle Biopsies and Matched Breast Cancer Surgical Specimens

Context.—

The Ki-67 index is strongly prognostic and is used as a surrogate marker to distinguish luminal A from luminal B breast cancer types.

Objective.—

To investigate differences in Ki-67 index between core needle biopsy samples and matched surgical samples in breast cancer.

Design.—

We included patients with invasive breast cancer who did not receive neoadjuvant therapy. A total of 89 pairs of core needle biopsies and surgical specimens were collected, and the Ki-67 index was assessed in hot spot areas using an image analyzer. We applied a 14% Ki-67 index to define low versus high groups.

Results.—

The Ki-67 index was significantly higher in core needle biopsies than in surgical specimens (P &lt; .001), with a median absolute difference of 3.5%. When we applied 14% as a cutoff, 16 of 89 cases (18%) showed discrepancy. Thirteen cases showed a high Ki-67 index in core needle biopsies but a low Ki-67 index in surgical samples. There were 10 cases (11.2%) that showed discordant luminal A/B types between core needle biopsy and the matched surgical specimen. The reasons for the discordance were poor staining of MIB1 accompanied by fixation issues and intratumoral heterogeneity of the Ki-67 index.

Conclusions.—

A significant difference in the Ki-67 index between core biopsy and surgical specimens was observed. Our findings indicate that it may be better to perform the Ki-67 assay on the core needle biopsy and the surgical specimen than on only one sample.

The Reliability of Core-Needle Biopsy in Assessment of Hormone Receptor, HER2, and Ki-67 in Breast Carcinoma

Objective:

The purpose of this study was to compare the estrogen receptor (ER), progesterone receptor (PgR), and human epidermal growth factor receptor 2 (HER2) status and Ki-67 index by immunohistochemical (IHC) analysis in breast carcinoma to determine the level of concordance between core-needle biopsy (CNB) and surgical specimens.

Summary of Background:

Accurate preoperative diagnosis of a breast lesion has recently been considered essential to the treatment strategy to achieve optimal treatment without delay. However, the reliability of using CNB specimens for IHC assessment is in relatively small number of cases and differing results between previous studies.

Methods:

The patients included in this study were 255 patients with primary breast carcinoma who had CNB and subsequent surgical resection at the Hospital of Dokkyo Medical University between 2010 and 2016. We compare the ER, PgR, HER2 status, and Ki-67 index by IHC analysis in breast carcinoma between CNB and surgical specimens.

Results:

There was a concordance rate between the ER, PgR, HER2, and Ki-67 IHC assessment of CNB and surgical specimens in 99.0%, 92.1%, 86.3%, and 91.5%, respectively. We also found small numbers of discordant cases in the estimation for which a discrepancy in determination led to a change in treatment.

Conclusions:

Our results do not entirely invalidate the use of CNB for assessment if they are the only source of tumor tissue available, but suggest a more cautious approach in their interpretation when clinical decisions are being made.

Comparison of Core Needle Biopsy and Surgical Specimens in Determining Intrinsic Biological Subtypes of Breast Cancer with Immunohistochemistry

PURPOSE

We evaluated the concordance between core needle biopsy (CNB) and surgical specimens on examining intrinsic biological subtypes and receptor status, and determined the accuracy of CNB as a basic diagnostic method.

METHODS

We analyzed breast cancer patients with paired CNB and surgical specimen samples during 2014. We used monoclonal antibodies for nuclear staining, and estrogen receptor (ER) and progesterone receptor (PR) status evaluation. A positive test was defined as staining greater than or equal to 1% of tumor cells. Human epidermal growth factor receptor 2 (HER2) was graded by immunohistochemistry and scored as 0 to 3+ according to the recommendations of the American Society of Clinical Oncology/College of American Pathologists. Ki-67 immunostaining was performed using the monoclonal antibody Ki-67, and the results were divided at 10% intervals. The cutoff value for high Ki-67 was defined as 20%. Concordance analysis of ER, PR, HER2, Ki-67, and five intrinsic biological subtypes was performed on CNB and surgical specimens. Statistical analysis for concordance was calculated using κ-tests.

RESULTS

We found very good agreement for ER and PR with a concordance of 96.7% for ER (κ=0.903), and 94.3% for PR (κ=0.870). HER2 and Ki-67 showed concordance rates of 84.8% (κ=0.684) and 83.5% (κ=0.647), respectively, which were interpreted as good agreement. Five subgroups analysis showed 85.8% agreement and κ-value of 0.786, also indicating good agreement.

CONCLUSION

CNB showed high diagnostic accuracy compared with surgical specimens, and good agreement for ER, PR, HER2, and Ki-67. Our findings reaffirmed the recommendation of CNB as an initial procedure for breast cancer diagnosis, and the assessment of receptor status and intrinsic biological subtypes to determine further treatment plans.

Can Clinically Node-Negative Breast Cancer Patients with Suspicious Axillary Lymph Nodes at Ultrasound But Negative Fine-Needle Aspiration Be Approached as Having Node-Negative Disease?

BACKGROUND

Few data exist to elucidate whether patients with a suspicious axillary lymph node (ALN) at ultrasound but a negative fine-needle aspiration result (FNA group) can be managed as having ultrasound node-negative disease (AUN group). This study compared various ALN statuses between the AUN and FNA groups to guide further ALN management.

METHODS

Patients who had clinical T1-2N0 breast cancer treated with sentinel lymph node (SLN) biopsy were retrospectively analyzed. The ALN metastasis status, SLN status, and non-SLN metastasis rates in the entire population and the patients with one or two positive SLNs were compared between the AUN and FNA groups.

RESULTS

A total of 1007 patients (886 AUN and 121 FNA patients) were eligible for the final analysis: The incidence of ALN metastasis did not differ between the AUN group (16.5%) and the FNA group (21.5%) (P = 0.170). In addition, three or more metastases were found in only 2.4% of the AUN patients and 3.3% of the FNA patients (P = 0.405). The non-SLN metastasis rate was 22.6% (33/146) in the AUN group and 19.2% (5/26) in the FNA group (P = 0.699). For the patients with one or two positive SLNs, the rate of non-SLN metastasis was similar between the AUN group (19.6%, 27/138) and the FNA group (12.5%, 3/24) (P = 0.591).

CONCLUSIONS

Patients with a suspicious ALN at ultrasound but a negative FNA result had ALN statuses similar to those of the ultrasound node-negative patients, indicating that these patients can be treated as having ultrasound node-negative disease.

Comparison of Core Needle Biopsy and Excision Specimens for the Accurate Evaluation of Breast Cancer Molecular Markers: a Report of 1003 Cases

In this study, we compared the accuracy of marker evaluation in core needle biopsy (CNB) specimens versus excision specimens (ESs) from breast cancer patients. This retrospective study used data collected from the breast cancer database at the West China Hospital, China. Immunohistochemistry (IHC) results from CNB specimens and ESs were compared, using estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), and Ki-67 as markers. Molecular subtyping and endocrine therapy usage correlations based on CNB samples and ESs were evaluated. The results obtained from CNB samples and ESs exhibited substantial agreement for the detection of ER (κ = 0.522), PR (κ = 0.441), and HER2 (κ = 0.451), and also influenced endocrine therapy usage. Fair and poor correlations were observed for Ki-67 staining and molecular subtyping (κ = 0.195), respectively. This disagreement might be attributable to a combination of heterogeneity and large tumor size. This study indicates that the discordance rate in molecular marker staining between CNB specimens and ESs is significant enough that results obtained with CNB specimens should be used cautiously or verified using ESs.

Reliability of the Ki67-Labelling Index in Core Needle Biopsies of Luminal Breast Cancers is Unaffected by Biopsy Volume

BACKGROUND

Assessing prognostic and predictive factors like the Ki67 labelling index (Ki67-LI) in breast cancer core needle biopsies (CNB) may be hampered by undersampling. Our aim was to arrive at a representative assessment of Ki67-LI in CNB of luminal breast cancers by defining optimal cutoffs and establishing the minimum CNB volume needed for highest concordance of Ki67-LI between CNB and subsequent surgical excision biopsy (SEB).

METHODS

We assessed the Ki67-LI in CNB and subsequent SEB of 170 luminal breast cancers according to two counting methods recommended by the International Ki67 in Breast Cancer Working Group and applied the cutoffs to distinguish low and high proliferation given by the St Gallen 2013 and 2015 consensus, respectively. We then compared CNB volume characteristics for cases with concordant and discordant Ki67-LI between CNB versus SEB.

RESULTS

Highest concordance (75%, κ = 0.44) between CNB and SEB was achieved using the method that assesses the average tumor Ki67-LI and a cutoff of 20%. No significant differences were found between cases with concordant and discordant Ki67-LI in CNB versus SEB for number of biopsy cores, total core length, tumor tissue length, or total CNB or tumor tissue area size in the CNB for two various cutoffs.

CONCLUSIONS

A concordance of 75% between CNB and SEB can be achieved for the Ki67-LI using a method assessing average Ki67-LI at the threshold of 20%. Increasing CNB volume did not result in improved agreement rates, indicating that reliability of Ki67 levels in CNB of luminal breast cancers is unaffected by CNB volume.

Impact of molecular subtypes classification concordance between preoperative core needle biopsy and surgical specimen on early breast cancer management: Single-institution experience and review of published literature

BACKGROUND

Core needle biopsy (CNB) plays a crucial role as diagnostic tool for breast cancer (BC). The characterization of biomarkers status before surgical treatment is crucial when primary systemic therapy is a therapeutic option. The aim of this analysis was to report concordance between preoperative CNB and surgical specimen (SS) in evaluating biomarkers and molecular subtypes.

METHODS

Data have been collected from a cohort of 101 patients affected by early BC treated at Careggi Florence University Hospital, between January 2014 and March 2015. The conformity between molecular subtype classification was tested using kappa (κ) test.

RESULTS

Mean age was 57.5 years (range 29-86). There was concordance between the estrogen receptor (ER) assessment on CNB and SS in 95 cases (94.1%). Concordance of the progesterone receptor (PgR) assessment was observed in 89 cases (88.1%). Concordance for detecting immunohistochemistry-assessed BC molecular subtypes was 87.1% (κ = 0.78). Concerning Ki-67 evaluation, we report a concordance rate of 88.1% (κ = 0.68). The evaluation of luminal A plus luminal B/HER negative subgroup showed a κ-value of 0.65.

CONCLUSIONS

CNB showed good accuracy in evaluating hormonal receptors status, HER2, and BC molecular subtypes. Evaluation of Ki67 status was less accurate than other biomarkers; therefore, we recommend that it should be detected both on CNB and SS samples, especially in hormonal positive HER2 negative tumors, in order to avoid a misclassification of tumor subtypes that could lead to an omission of potential effective systemic therapy.

Risk Factors Associated with Discordant Ki-67 Levels between Preoperative Biopsy and Postoperative Surgical Specimens in Breast Cancers

PURPOSE

The Ki-67 labelling index is significant for the management of breast cancer. However, the concordance of Ki-67 expression between preoperative biopsy and postoperative surgical specimens has not been well evaluated. This study aimed to find the correlation in Ki-67 expression between biopsy and surgical specimens and to determine the clinicopathological risk factors associated with discordant values.

PATIENTS AND METHODS

Ki-67 levels were immunohistochemically measured using paired biopsy and surgical specimens in 310 breast cancer patients between 2008 and 2013. ΔKi-67 was calculated by postoperative Ki-67 minus preoperative levels. The outliers of ΔKi-67 were defined as [lower quartile of ΔKi-67-1.5 × interquartile range (IQR)] or (upper quartile + 1.5 × IQR) and were evaluated according to clinicopathological parameters by logistic regression analysis.

RESULTS

The median preoperative and postoperative Ki-67 levels were 10 (IQR, 15) and 10 (IQR, 25), respectively. Correlation of Ki-67 levels between the two specimens indicated a moderately positive relationship (coefficient = 0.676). Of 310 patients, 44 (14.2%) showed outliers of ΔKi-67 (range, ≤-20 or ≥28). A significant association with poor prognostic factors was found among these patients. Multivariate analysis determined that significant risk factors for outliers of ΔKi-67 were tumor size >1 cm, negative progesterone receptor (PR) expression, grade III cancer, and age ≤35 years. Among 171 patients with luminal human epidermal growth factor receptor 2-negative tumors, breast cancer subtype according to preoperative or postoperative Ki-67 levels discordantly changed in 46 (26.9%) patients and a significant proportion of patients with discordant cases had ≥1 risk factor.

CONCLUSION

Ki-67 expression showed a substantial concordance between biopsy and surgical specimens. Extremely discordant Ki-67 levels may be associated with aggressive tumor biology. In patients with luminal subtype disease, clinical application of Ki-67 values should be cautious considering types of specimens and clinicopathological risk factors.

Surgery time interval and molecular subtype may influence Ki67 change after core needle biopsy in breast cancer patients

Background

To investigate the accuracy of core needle biopsy (CNB) in evaluating breast cancer estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 status and to identify factors which might be associated with Ki67 value change after CNB.

Methods

A retrospective study was carried out on 276 patients with paired CNB and surgically removed samples (SRS). Clinico-pathological factors as well as the surgery time interval (STI) between CNB and surgery were analyzed to determine whether there were factors associated with Ki67 value change after CNB. Five tumor subtypes were classified as follows: Luminal A, Luminal B-HER2-, Luminal B-HER2+, Triple Negative (TN), and HER2+. Ki67 value change was calculated as SRS minus CNB.

Results

Mean STI after CNB was 4.5 (1-37) days. Good agreement was achieved for ER, PR, and HER2 evaluation between CNB and SRS. However, Ki67 expression level was significantly higher in SRS compared with CNB samples: 29.1 % vs. 26.2 % (P < 0.001). Both univariate and multivariate analysis demonstrated that STI and molecular subtype were associated with a Ki67 change after CNB. Luminal A tumors experienced more Ki67 elevation than Luminal B-HER2- diseases (6.2 % vs -0.1 %, P = 0.014). Patients with longer STI after CNB had a higher Ki67 increase: -1.1 % within 1-2 days, 2.1 % with 3-4 days, and 5.6 % more than 4 days, respectively (P = 0.007). For TN and HER2+ tumors, the Ki67 change was apt to be 0 with STI ≤ 4 days, while a >7 % Ki67 increase was noticed in patients with STI ≥ 5 days.

Conclusion

CNB was accurate in evaluating ER, PR, HER2, and molecular subtype status. Ki67 value significantly increased after CNB, which was associated with STI and molecular subtype. Further translational research needs to consider Ki67 changes following CNB among different breast cancer molecular subtypes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1853-1) contains supplementary material, which is available to authorized users.

Prediction of Response to Neoadjuvant Chemotherapy Using Core Needle Biopsy Samples with the Prosigna Assay

PURPOSE

Most hormone receptor (HR)(+)/HER2(-) breast cancer patients respond unfavorably to neoadjuvant chemotherapy (NAC); however, genomic tests may identify those patients who are likely to benefit. Using the Prosigna assay, we first evaluated the technical performance of core needle biopsy (CNB) tissues. We then determined whether Prosigna risk of relapse (ROR) score and intrinsic subtype predicted response to NAC in HR(+)/HER2(-) patients using CNB samples.

EXPERIMENTAL DESIGN

Using the NanoString's nCounter Dx analysis system and a development tissue sample set, we established tissue requirements and assay output variance. We then evaluated the concordance in subtype and correlation in ROR between CNBs and corresponding surgical resection specimens (SRS) in a second independent sample set. Finally, we analyzed 180 independent CNB samples from HR(+)/HER2(-) patients who were treated with NAC and correlated ROR and intrinsic subtype with pathologic response.

RESULTS

Intra- and interbiopsy variabilities were 2.2 and 6.8 ROR units, respectively. Subtype concordance within multiple CNBs was high for the 4- and 3-subtype classifications (k = 0.885 and 0.889, respectively). Correlation in Prosigna ROR score observed between paired CNBs and SRS was high (r ≥ 0.90), and subtype concordance was also high for the 4- and 3-subtype classifications (kappa = 0.81 and 0.91, respectively). Prosigna results obtained from the HR(+)/HER2(-) patient samples showed that both ROR (P = 0.047) and intrinsic subtype (OR LumA vs. non-LumA = 0.341, P = 0.037) were significant predictors of response to NAC.

CONCLUSIONS

Prosigna ROR and intrinsic subtype are readily obtained from CNB samples in normal practice and reliably predict response to NAC in HR(+)/HER2(-) patients.

Evaluation of Ki67 expression across distinct categories of breast cancer specimens: a population-based study of matched surgical specimens, core needle biopsies and tissue microarrays

Introduction

Tumor cell proliferation in breast cancer is strongly prognostic and may also predict response to chemotherapy. However, there is no consensus on counting areas or cut-off values for patient stratification. Our aim was to assess the matched level of proliferation by Ki67 when using different tissue categories (whole sections, WS; core needle biopsies, CNB; tissue microarrays, TMA), and the corresponding prognostic value.

Methods

We examined a retrospective, population-based series of breast cancer (n = 534) from the Norwegian Breast Cancer Screening Program. The percentage of Ki67 positive nuclei was evaluated by visual counting on WS (n = 534), CNB (n = 154) and TMA (n = 459).

Results

The median percentage of Ki67 expression was 18% on WS (hot-spot areas), 13% on CNB, and 7% on TMA, and this difference was statistically significant in paired cases. Increased Ki67 expression by all evaluation methods was associated with aggressive tumor features (large tumor diameter, high histologic grade, ER negativity) and reduced patient survival.

Conclusion

There is a significant difference in tumor cell proliferation by Ki67 across different sample categories. Ki67 is prognostic over a wide range of cut-off points and for different sample types, although Ki67 results derived from TMA sections are lower compared with those obtained using specimens from a clinical setting. Our findings indicate that specimen specific cut-off values should be applied for practical use.

Brief fixation does not hamper the reliability of Ki67 analysis in breast cancer core-needle biopsies: a double-centre study

AIMS

Immunohistochemical assessment of Ki67 expression in core-needle biopsies (CNBs) is increasingly playing a role in therapeutic decision-making for breast cancer patients. Within the framework of same-day diagnosis of breast lesions, fixation times are markedly decreased. We therefore attempted to validate Ki67 analysis in briefly fixed breast cancer CNBs.

METHODS AND RESULTS

CNBs of 136 consecutive patients with invasive breast cancer diagnosed through the same-day diagnosis programme of both the University Medical Centre Utrecht (UMCU) and the Radboud University Medical Centre (RUMC) were included. CNBs were fixed in formaldehyde for approximately 45 min at the UMCU and for between 60 and 90 min at the RUMC. Immunohistochemistry for Ki67 expression was compared between the briefly fixed CNBs and conventionally fixed resection specimens of the same tumour. The overall agreement between CNBs and resections was 122 of 142 (85.9%) (κ = 0.71; 95% CI 0.60-0.83). Positive and negative predictive values were 79.7% (95% CI 67-88%) and 91.0% (95% CI 82-96%), respectively.

CONCLUSIONS

Overall agreement for Ki67 expression was good between briefly fixed CNBs and conventionally fixed resection specimens, and within the range of studies comparing conventionally fixed CNBs and resections.