Reflex Estrogen Receptor (ER) and Progesterone Receptor (PR) Analysis of Ductal Carcinoma In Situ (DCIS) in Breast Needle Core Biopsy Specimens: An Unnecessary Exercise That Costs the United States $35 Million/y

Determinants of targeted cancer therapy use in community oncology practice: a qualitative study using the Theoretical Domains Framework and Rummler-Brache process mapping

BACKGROUND

Precision medicine holds enormous potential to improve outcomes for cancer patients, offering improved rates of cancer control and quality of life. Not all patients who could benefit from targeted cancer therapy receive it, and some who may not benefit do receive targeted therapy. We sought to comprehensively identify determinants of targeted therapy use among community oncology programs, where most cancer patients receive their care.

METHODS

Guided by the Theoretical Domains Framework, we conducted semi-structured interviews with 24 community cancer care providers and mapped targeted therapy delivery across 11 cancer care delivery teams using a Rummler-Brache diagram. Transcripts were coded to the framework using template analysis, and inductive coding was used to identify key behaviors. Coding was revised until a consensus was reached.

RESULTS

Intention to deliver precision medicine was high across all participants interviewed, who also reported untenable knowledge demands. We identified distinctly different teams, processes, and determinants for (1) genomic test ordering and (2) delivery of targeted therapies. A key determinant of molecular testing was role alignment. The dominant expectation for oncologists to order and interpret genomic tests is at odds with their role as treatment decision-makers' and pathologists' typical role to stage tumors. Programs in which pathologists considered genomic test ordering as part of their staging responsibilities reported high and timely testing rates. Determinants of treatment delivery were contingent on resources and ability to offset delivery costs, which low- volume programs could not do. Rural programs faced additional treatment delivery challenges.

CONCLUSIONS

We identified novel determinants of targeted therapy delivery that potentially could be addressed through role re-alignment. Standardized, pathology-initiated genomic testing may prove fruitful in ensuring patients eligible for targeted therapy are identified, even if the care they need cannot be delivered at small and rural sites which may have distinct challenges in treatment delivery. Incorporating behavior specification and Rummler-Brache process mapping with determinant analysis may extend its usefulness beyond the identification of the need for contextual adaptation.

Annual cost-savings with the implementation of estrogen-receptor-only testing on Ductal Carcinoma in Situ specimens

BACKGROUND

In DCIS, ER status is an important marker. The utility of concomitant PR testing remains unclear.

METHODS

A single-institution retrospective cohort study was performed with a comparative analysis of the NCDB to assess annual cost-savings with omission of routine PR testing. National Medicare payment standards determined PR staining costs to be $124.92.

RESULTS

150 institutional DCIS cases with receptor data were identified. 104 (69%) were ER+/PR+, 16 (11%) were ER+/PR-, and none were ER-/PR+. Omission of routine PR testing would have resulted in $18,738 saved annually. Within the NCDB, 34,100 DCIS cases had receptor data: 29,277 (85.9%) patients were ER+, and 26,008 (76%) were both ER/PR+. 211 (0.6%) patients were ER-/PR+. Annual national cost-savings with omission of routine PR-testing would have been $4.3 million.

CONCLUSION

PR testing for DCIS should be reserved only for patients with ER- DCIS undergoing breast conservation to determine the utility of adjuvant endocrine therapy.

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.

Problematic issues in breast core needle biopsies

Image-directed core needle biopsies of the breast are routinely used in current clinical practice for the initial assessment of non-palpable breast lesions. This article provides an update on several important issues regarding evaluation of breast core needle biopsies.

Precursor Lesions of the Low-Grade Breast Neoplasia Pathway

The nonobligate precursor lesions columnar cell change/hyperplasia and flat epithelial atypia, atypical ductal hyperplasia and atypical lobular hyperplasia, lobular carcinoma in situ, and low-grade ductal carcinoma in situ share morphologic, immunophenotypic, and molecular features supporting the existence of a low-grade breast neoplasia pathway. The practical implication for pathologists is that the identification of one of these lesions should prompt careful search for others. From a clinical management perspective, however, their designation as "precursor lesions" should not be overemphasized, as the risk of progression among the earliest lesions is exceedingly low. Factors determining which lesions will progress remain unknown.