ABSTRACT
CONTEXT.: The College of American Pathologists (CAP), a laboratory accreditation organization with deemed status under the Clinical Laboratories Improvement Amendments of 1988 administers accreditation checklists. Checklists are used by laboratories to ensure regulatory compliance. Peer-level laboratory professionals audit laboratory records during inspections to assess compliance. OBJECTIVE.: To identify the most frequently cited deficiencies for molecular oncology laboratories undergoing CAP accreditation inspections and describe laboratory improvement opportunities. DESIGN.: The CAP Molecular Oncology Committee (MOC), which is involved in maintaining the Molecular Pathology checklist, reviewed data and inspector comments associated with the most frequently observed citations related to molecular oncology testing from laboratories inspected by the CAP during a 2-year period (2018-2020). RESULTS.: Of 422 molecular oncology laboratories that underwent accreditation inspections, 159 (37.7%) were not cited for any molecular oncology-related deficiencies. For the All Common (COM) and Molecular Pathology checklists, there were 364 and 305 deficiencies, corresponding to compliance rates of 98.8% and 99.6%, respectively. The most frequently cited deficiencies are described. The COM checklist deficiencies were associated most often with the analytic testing phase; the MOL checklist deficiencies were more evenly distributed across the preanalytic, analytic, and postanalytic phases of testing. CONCLUSIONS.: Molecular oncology laboratories demonstrated excellent compliance with practices that support high-quality results for patients and the health care providers who use those test results in patient management. This review includes a critical assessment of opportunities for laboratories to improve compliance and molecular oncology testing quality.
Subject(s)
Clinical Laboratory Services , Laboratories , Humans , Societies, Medical , Accreditation , Medical OncologyABSTRACT
Recent studies have shown that immunohistochemical evaluation of MYC protein expression in diffuse large B-cell lymphoma is a useful prognostic tool with high concordance rate among pathologists. Concordance in these studies was assessed among few pathologists from one institution by scoring tissue microarrays. In daily practice, MYC evaluation is performed on entire tumor sections by a diverse group of pathologists. In our study, nine hematopathologists from two institutions scored whole-tissue sections of two sets of cases. The training set included 13 cases of diffuse large B-cell lymphoma and 4 cases of Burkitt lymphoma. The validation set included 18 cases of diffuse large B-cell lymphoma and 1 case of Burkitt lymphoma. MYC positivity was defined as ≥40% of tumor cells demonstrating nuclear staining similar to prior studies. The mean score for each case was used to determine MYC status with discrepant cases defined as having any score causing a different MYC status designation. Discrepant cases from the training set were characterized by staining heterogeneity, extensive necrosis or crush artifact and had mean scores within 15 percentage points of 40%. Cases from the validation set that demonstrated any of these features were scored twice on two different days. Overall concordance was moderate (Kappa score: 0.68, P-value<0.001) with no significant change between the two sets (Kappa scores: 0.69 vs 0.67). Thirty-nine percent of cases were discrepant. The findings indicate that a significant number of diffuse large B-cell lymphomas are inherently difficult to score due to staining heterogeneity. The effect of heterogeneity can be under-represented when concordance is measured among few pathologists scoring tissue microarrays. Careful scoring strategy in our study failed to improve concordance. In the absence of specific instructions on how to deal with heterogeneity, caution is advised when evaluating MYC expression in diffuse large B-cell lymphoma.
