Comparison of core needle biopsy and surgical specimens in malignant breast lesions regarding histological features and hormone receptor expression

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.

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.

Assessment accuracy of core needle biopsy for hormone receptors in breast cancer: a meta-analysis

The concordance of hormone receptors (HR) status identified by core needle biopsy (CNB) compared with excisional biopsy (EB) has been widely reported, but results were extremely variable and underpowered. To derive a more precise estimation of assessment accuracy of CNB for HR in breast cancer, we conducted a meta-analysis of all eligible studies comparing concordance or disconcordance between CNB and EB for HR status. Eligible articles were identified by search of databases including PubMed, Web of Science, EMBASE, and Chinese Biomedical Literature database for the period up to November 2011, and the reference lists of identified studies, relevant reviews, meta-analyses, and abstracts from recent conference proceedings were reviewed as a augmented searching. Finally, a total of 21 articles involving 2,450 patients for estrogen receptor (ER) and 2,448 patients for progesterone receptor (PR) were included and analyzed in this analysis. Study quality was assessed using the Quality Assessment of Diagnostic Accuracy Studies checklist. The overall aggrement between CNB and EB were 92.8 % for ER (κ = 0.78) and 85.2 % for PR (κ = 0.66), indicating a good agreement in PR and a better result in ER. The pooled sensitivity and specificity were 97.3 % (95 % CI 96.0-98.2) and 82.0 % (95 % CI 68.2-90.6) for ER, and the corresponding values for PR were 92.3 % (95 % CI 88.2-95.1) and 76.5 % (95 % CI 64.6-85.3), respectively. The pooled positive likelihood ratios was 5.39 % (95 % CI 2.92-9.97) and the negative likelihood ratios was 0.03 % (95 % CI 0.02-0.05) for ER, the corresponding values for PR were 3.93 % (95 % CI 2.53-6.11) and 0.10 % (95 % CI 0.07-0.16), respectively. In summary, although a good agreement was observed between CNB and EB for both ER and PR, we still suggest that negative HR testing results should be interpreted with caution or repeated on EB.

Ki67 in breast cancer: prognostic and predictive potential

The leading parameters that define treatment recommendations in early breast cancer are oestrogen-receptor, progesterone-receptor, and human epidermal growth-factor status. Although some pathologists report Ki67 in addition to other biological markers, the existing guidelines of the American Society of Clinical Oncology do not include Ki67 in the list of required routine biological markers. The advent of new genetic tests has emphasised the role of proliferative genes, including Ki67, as prognostic and predictive markers. Additionally, randomised studies have retrospectively reviewed data and reported on the role of Ki67 in breast cancer. In light of new data, we have re-assessed evidence that could change guidelines to include Ki67 in the standard pathological assessment of early breast cancers. This review provides an update on the current knowledge on Ki67 and of the evidence in the published work about the prognostic and predictive role of this marker, and provides information on the laboratory techniques used to determine Ki67.