A Primer on Chimeric Antigen Receptor T-cell Therapy: What Does It Mean for Pathologists?

CONTEXT.­: Chimeric antigen receptor T-cell (CAR-T) technology has shown great promise in both clinical and preclinical models in mediating potent and specific antitumor activity. With the advent of US Food and Drug Administration-approved CAR-T therapies for B-cell lymphoblastic leukemia and B-cell non-Hodgkin lymphomas, CAR-T therapy is poised to become part of mainstream clinical practice. OBJECTIVE.­: To educate pathologists on CAR-T and chimeric antigen receptor-derived cellular therapy, provide a better understanding of their role in this process, explain important regulatory aspects of CAR-T therapy, and advocate for pathologist involvement in the delivery and monitoring of chimeric antigen receptor-based treatments. Much of the focus of this article addresses US Food and Drug Administration-approved therapies; however, more general issues and future perspectives are considered for therapies in development. DESIGN.­: A CAR-T workgroup, facilitated by the College of American Pathologists Personalized Health Care Committee and consisting of pathologists of various backgrounds, was convened to develop a summary guidance paper for the College of American Pathologists Council on Scientific Affairs. RESULTS.­: The workgroup identified gaps in pathologists' knowledge of CAR-T therapy, including uncertainty in the role of the clinical laboratory in supporting CAR-T therapy. The workgroup considered these issues and summarized the findings to assist pathologists to become stakeholders in CAR-T therapy administration. CONCLUSIONS.­: This manuscript serves to both educate pathologists on CAR-T therapy and serve as a point of initial discussions in areas of CAR-T science, clinical therapy, and regulatory issues as CAR-T therapies continue to be introduced into clinical practice.

Evaluating the Adoption of Laboratory Practice Guidelines.

CONTEXT.­: To date, the College of American Pathologists (CAP) has developed 17 laboratory practice guidelines (LPGs) including updates. In 2013, the CAP was awarded a 5-year cooperative agreement grant from the United States Centers for Disease Control and Prevention to increase the effectiveness of LPGs. OBJECTIVE.­: To assess the awareness and adoption of 2 CAP LPGs: immunohistochemical (IHC) assay validation and initial workup of acute leukemia. DESIGN.­: Baseline surveys for each LPG were conducted in 2010 and 2015, respectively. To measure the adoption of guideline recommendations and inform future updates, a follow-up study consisting of surveys, telephone interviews, and focus group sessions was conducted in laboratories that indicated they perform IHC testing. A follow-up study for the acute leukemia LPG is planned. RESULTS.­: For the IHC Validation LPG, a total of 1624 survey responses, 40 telephone interviews, and discussions with 5 focus group participants were analyzed. The response rate for the aforementioned 3 modalities was 46%, 13%, and 3%, respectively. All modalities indicated most respondents were aware of the LPG and had adopted most or all of its recommendations. Respondents expressed needs for continued communication, increased specificity, and more prescriptive recommendations when the guideline is updated. CONCLUSIONS.­: While data-driven development of evidence-based LPGs requires significant resources, active data collection to identify gaps and assess adoption contributes to improved laboratory testing practices in support of patient care. The CAP identified sustainable modalities to track metrics and developed multiple tools that should improve guideline development, adoption, and implementation. Of these modalities, written or electronic surveys were the most logistically feasible and had the highest response rate.

Collection and Handling of Thoracic Small Biopsy and Cytology Specimens for Ancillary Studies: Guideline From the College of American Pathologists in Collaboration With the American College of Chest Physicians, Association for Molecular Pathology, American Society of Cytopathology, American Thoracic Society, Pulmonary Pathology Society, Papanicolaou Society of Cytopathology, Society of Interventional Radiology, and Society of Thoracic Radiology.

CONTEXT.­: The need for appropriate specimen use for ancillary testing has become more commonplace in the practice of pathology. This, coupled with improvements in technology, often provides less invasive methods of testing, but presents new challenges to appropriate specimen collection and handling of these small specimens, including thoracic small biopsy and cytology samples. OBJECTIVE.­: To develop a clinical practice guideline including recommendations on how to obtain, handle, and process thoracic small biopsy and cytology tissue specimens for diagnostic testing and ancillary studies. METHODS.­: The College of American Pathologists convened an expert panel to perform a systematic review of the literature and develop recommendations. Core needle biopsy, touch preparation, fine-needle aspiration, and effusion specimens with thoracic diseases including malignancy, granulomatous process/sarcoidosis, and infection (eg, tuberculosis) were deemed within scope. Ancillary studies included immunohistochemistry and immunocytochemistry, fluorescence in situ hybridization, mutational analysis, flow cytometry, cytogenetics, and microbiologic studies routinely performed in the clinical pathology laboratory. The use of rapid on-site evaluation was also covered. RESULTS.­: Sixteen guideline statements were developed to assist clinicians and pathologists in collecting and processing thoracic small biopsy and cytology tissue samples. CONCLUSIONS.­: Based on the systematic review and expert panel consensus, thoracic small specimens can be handled and processed to perform downstream testing (eg, molecular markers, immunohistochemical biomarkers), core needle and fine-needle techniques can provide appropriate cytologic and histologic specimens for ancillary studies, and rapid on-site cytologic evaluation remains helpful in appropriate triage, handling, and processing of specimens.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology.

CONTEXT: In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing. OBJECTIVE: To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update. DESIGN: The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations. RESULTS: Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline. CONCLUSIONS: The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes (ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology.

CONTEXT: In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing. OBJECTIVE: To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update. DESIGN: The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations. RESULTS: Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline. CONCLUSIONS: The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes (ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Updated Molecular Testing Guideline for the Selection of Lung Cancer Patients for Treatment With Targeted Tyrosine Kinase Inhibitors: Guideline From the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology.

CONTEXT: - In 2013, an evidence-based guideline was published by the College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology to set standards for the molecular analysis of lung cancers to guide treatment decisions with targeted inhibitors. New evidence has prompted an evaluation of additional laboratory technologies, targetable genes, patient populations, and tumor types for testing. OBJECTIVE: - To systematically review and update the 2013 guideline to affirm its validity; to assess the evidence of new genetic discoveries, technologies, and therapies; and to issue an evidence-based update. DESIGN: - The College of American Pathologists, the International Association for the Study of Lung Cancer, and the Association for Molecular Pathology convened an expert panel to develop an evidence-based guideline to help define the key questions and literature search terms, review abstracts and full articles, and draft recommendations. RESULTS: - Eighteen new recommendations were drafted. The panel also updated 3 recommendations from the 2013 guideline. CONCLUSIONS: - The 2013 guideline was largely reaffirmed with updated recommendations to allow testing of cytology samples, require improved assay sensitivity, and recommend against the use of immunohistochemistry for EGFR testing. Key new recommendations include ROS1 testing for all adenocarcinoma patients; the inclusion of additional genes ( ERBB2, MET, BRAF, KRAS, and RET) for laboratories that perform next-generation sequencing panels; immunohistochemistry as an alternative to fluorescence in situ hybridization for ALK and/or ROS1 testing; use of 5% sensitivity assays for EGFR T790M mutations in patients with secondary resistance to EGFR inhibitors; and the use of cell-free DNA to "rule in" targetable mutations when tissue is limited or hard to obtain.

Analytic Validation of Immunohistochemistry Assays: New Benchmark Data From a Survey of 1085 Laboratories.

CONTEXT: - A cooperative agreement between the College of American Pathologists (CAP) and the United States Centers for Disease Control and Prevention was undertaken to measure laboratories' awareness and implementation of an evidence-based laboratory practice guideline (LPG) on immunohistochemical (IHC) validation practices published in 2014. OBJECTIVE: - To establish new benchmark data on IHC laboratory practices. DESIGN: - A 2015 survey on IHC assay validation practices was sent to laboratories subscribed to specific CAP proficiency testing programs and to additional nonsubscribing laboratories that perform IHC testing. Specific questions were designed to capture laboratory practices not addressed in a 2010 survey. RESULTS: - The analysis was based on responses from 1085 laboratories that perform IHC staining. Ninety-six percent (809 of 844) always documented validation of IHC assays. Sixty percent (648 of 1078) had separate procedures for predictive and nonpredictive markers, 42.7% (220 of 515) had procedures for laboratory-developed tests, 50% (349 of 697) had procedures for testing cytologic specimens, and 46.2% (363 of 785) had procedures for testing decalcified specimens. Minimum case numbers were specified by 85.9% (720 of 838) of laboratories for nonpredictive markers and 76% (584 of 768) for predictive markers. Median concordance requirements were 95% for both types. For initial validation, 75.4% (538 of 714) of laboratories adopted the 20-case minimum for nonpredictive markers and 45.9% (266 of 579) adopted the 40-case minimum for predictive markers as outlined in the 2014 LPG. The most common method for validation was correlation with morphology and expected results. Laboratories also reported which assay changes necessitated revalidation and their minimum case requirements. CONCLUSIONS: - Benchmark data on current IHC validation practices and procedures may help laboratories understand the issues and influence further refinement of LPG recommendations.

Analytic Validation of Immunohistochemical Assays: A Comparison of Laboratory Practices Before and After Introduction of an Evidence-Based Guideline.

CONTEXT: - Laboratories must demonstrate analytic validity before any test can be used clinically, but studies have shown inconsistent practices in immunohistochemical assay validation. OBJECTIVE: - To assess changes in immunohistochemistry analytic validation practices after publication of an evidence-based laboratory practice guideline. DESIGN: - A survey on current immunohistochemistry assay validation practices and on the awareness and adoption of a recently published guideline was sent to subscribers enrolled in one of 3 relevant College of American Pathologists proficiency testing programs and to additional nonsubscribing laboratories that perform immunohistochemical testing. The results were compared with an earlier survey of validation practices. RESULTS: - Analysis was based on responses from 1085 laboratories that perform immunohistochemical staining. Of 1057 responses, 65.4% (691) were aware of the guideline recommendations before this survey was sent and 79.9% (550 of 688) of those have already adopted some or all of the recommendations. Compared with the 2010 survey, a significant number of laboratories now have written validation procedures for both predictive and nonpredictive marker assays and specifications for the minimum numbers of cases needed for validation. There was also significant improvement in compliance with validation requirements, with 99% (100 of 102) having validated their most recently introduced predictive marker assay, compared with 74.9% (326 of 435) in 2010. The difficulty in finding validation cases for rare antigens and resource limitations were cited as the biggest challenges in implementing the guideline. CONCLUSIONS: - Dissemination of the 2014 evidence-based guideline validation practices had a positive impact on laboratory performance; some or all of the recommendations have been adopted by nearly 80% of respondents.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology.

OBJECTIVES: - To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens. METHODS: - The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted. RESULTS: - Twenty-one guideline statements were established. CONCLUSIONS: - Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and the American Society of Clinical Oncology.

Purpose Molecular testing of colorectal cancers (CRCs) to improve patient care and outcomes of targeted and conventional therapies has been the center of many recent studies, including clinical trials. Evidence-based recommendations for the molecular testing of CRC tissues to guide epidermal growth factor receptor (EGFR) -targeted therapies and conventional chemotherapy regimens are warranted in clinical practice. The purpose of this guideline is to develop evidence-based recommendations to help establish standard molecular biomarker testing for CRC through a systematic review of the literature. Methods The American Society for Clinical Pathology (ASCP), College of American Pathologists (CAP), Association for Molecular Pathology (AMP), and the American Society of Clinical Oncology (ASCO) convened an Expert Panel to develop an evidence-based guideline to help establish standard molecular biomarker testing, guide targeted therapies, and advance personalized care for patients with CRC. A comprehensive literature search that included over 4,000 articles was conducted to gather data to inform this guideline. Results Twenty-one guideline statements (eight recommendations, 10 expert consensus opinions and three no recommendations) were established. Recommendations Evidence supports mutational testing for genes in the EGFR signaling pathway, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize molecular testing for predictive and prognostic molecular biomarkers involve selection of assays, type of specimens to be tested, timing of ordering of tests and turnaround time for testing results. Additional information is available at: www.asco.org/CRC-markers-guideline and www.asco.org/guidelineswiki.

Molecular Biomarkers for the Evaluation of Colorectal Cancer.

Objectives: To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens. Methods: The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted. Results: Twenty-one guideline statements were established. Conclusions: Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented.

Molecular Biomarkers for the Evaluation of Colorectal Cancer: Guideline From the American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology.

OBJECTIVES: To develop evidence-based guideline recommendations through a systematic review of the literature to establish standard molecular biomarker testing of colorectal cancer (CRC) tissues to guide epidermal growth factor receptor (EGFR) therapies and conventional chemotherapy regimens. METHODS: The American Society for Clinical Pathology, College of American Pathologists, Association for Molecular Pathology, and American Society of Clinical Oncology convened an expert panel to develop an evidence-based guideline to establish standard molecular biomarker testing and guide therapies for patients with CRC. A comprehensive literature search that included more than 4,000 articles was conducted. RESULTS: Twenty-one guideline statements were established. CONCLUSIONS: Evidence supports mutational testing for EGFR signaling pathway genes, since they provide clinically actionable information as negative predictors of benefit to anti-EGFR monoclonal antibody therapies for targeted therapy of CRC. Mutations in several of the biomarkers have clear prognostic value. Laboratory approaches to operationalize CRC molecular testing are presented. Key Words: Molecular diagnostics; Gastrointestinal; Histology; Genetics; Oncology.

The Cancer Genomics Resource List 2014.

CONTEXT: Genomic sequencing for cancer is offered by commercial for-profit laboratories, independent laboratory networks, and laboratories in academic medical centers and integrated health networks. The variability among the tests has created a complex, confusing environment. OBJECTIVE: To address the complexity, the Personalized Health Care (PHC) Committee of the College of American Pathologists proposed the development of a cancer genomics resource list (CGRL). The goal of this resource was to assist the laboratory pathology and clinical oncology communities. DESIGN: The PHC Committee established a working group in 2012 to address this goal. The group consisted of site-specific experts in cancer genetic sequencing. The group identified current next-generation sequencing (NGS)-based cancer tests and compiled them into a usable resource. The genes were annotated by the working group. The annotation process drew on published knowledge, including public databases and the medical literature. RESULTS: The compiled list includes NGS panels offered by 19 laboratories or vendors, accompanied by annotations. The list has 611 different genes for which NGS-based mutation testing is offered. Surprisingly, of these 611 genes, 0 genes were listed in every panel, 43 genes were listed in 4 panels, and 54 genes were listed in 3 panels. In addition, tests for 393 genes were offered by only 1 or 2 institutions. Table 1 provides an example of gene mutations offered for breast cancer genomic testing with the annotation as it appears in the CGRL 2014. CONCLUSIONS: The final product, referred to as the Cancer Genomics Resource List 2014, is available as supplemental digital content.

Developing precision medicine in a global world.

Advances in understanding the biology of cancer, as well as advances in diagnostic technologies, such as the advent of affordable high-resolution DNA sequencing, have had a major impact on the approach to identification of specific alterations in a given patient's cancer that could be used as a basis for treatment selection, and hence the development of companion diagnostics. Although there are now several examples of successful development of companion diagnostics that allow identification of patients who will achieve the greatest benefit from a new therapeutic, the path to coapproval of a diagnostic test along with a new therapeutic is complex and often inefficient. This review and the accompanying articles examine the current state of companion diagnostic development in the United States and Europe from academic, industry, regulatory, and economic perspectives. See all articles in this CCR Focus section, "The Precision Medicine Conundrum: Approaches to Companion Diagnostic Co-development."

Summary of microsatellite instability test results from laboratories participating in proficiency surveys: proficiency survey results from 2005 to 2012.

CONTEXT: The College of American Pathologists surveys are the largest laboratory peer comparison programs in the world. These programs allow laboratories to regularly evaluate their performance and improve the accuracy of the patient test results they provide. Proficiency testing is offered twice a year to laboratories performing microsatellite instability testing. These surveys are designed to emulate clinical practice, and some surveys have more challenging cases to encourage the refinement of laboratory practices. OBJECTIVE: This report summarizes the results and trends in microsatellite instability proficiency testing from participating laboratories from the inception of the program in 2005 through 2012. DESIGN: We compiled and analyzed data for 16 surveys of microsatellite instability proficiency testing during 2005 to 2012. RESULTS: The number of laboratories participating in the microsatellite instability survey has more than doubled from 42 to 104 during the 8 years analyzed. An average of 95.4% of the laboratories correctly classified each of the survey test samples from the 2005A through 2012B proficiency challenges. In the 2011B survey, a lower percentage of laboratories (78.4%) correctly classified the specimen, possibly because of overlooking subtle changes of microsatellite instability and/or failing to enrich the tumor content of the specimen to meet the limit of detection of their assay. CONCLUSIONS: In general, laboratories performed well in microsatellite instability testing. This testing will continue to be important in screening patients with colorectal and other cancers for Lynch syndrome and guiding the management of patients with sporadic colorectal cancer.

Revisiting oversight and regulation of molecular-based laboratory-developed tests: a position statement of the Association for Molecular Pathology.

Since 2006, the US Food and Drug Administration, Congress, and other policymakers have explored the appropriate way to guarantee the clinical and analytical validity of laboratory-developed tests. In the past, the Association for Molecular Pathology has publicly urged the Food and Drug Administration to exercise caution in implementing regulatory changes that could potentially hinder innovation or interfere with the practice of medicine. In 2012, the Association for Molecular Pathology Professional Relations Committee chose to develop this paper with the goal of outlining the best methods for ensuring appropriate oversight and validation of molecular diagnostic procedures. At the conclusion of this process, the workgroup reaffirmed the Association's previous position that the Centers for Medicare and Medicaid Services Clinical Laboratory Improvement Amendments program can provide the appropriate level of oversight for the vast majority of diagnostic tests.

Relevance, pathogenesis, and testing algorithm for mismatch repair-defective colorectal carcinomas: a report of the association for molecular pathology.

Loss-of-function defects in DNA mismatch repair (MMR), which manifest as high levels of microsatellite instability (MSI), occur in approximately 15% of all colorectal carcinomas (CRCs). This molecular subset of CRC characterizes patients with better stage-specific prognoses who experience no benefit from 5-fluorouracil chemotherapy. Most MMR-deficient (dMMR) CRCs are sporadic, but 15% to 20% are due to inherited predisposition (Lynch syndrome). High penetrance of CRCs in germline MMR gene mutation carriers emphasizes the importance of accurate diagnosis of Lynch syndrome carriers. Family-based (Amsterdam), patient/family-based (Bethesda), morphology-based, microsatellite-based, and IHC-based screening criteria do not individually detect all germline mutation carriers. These limitations support the use of multiple concurrent tests and the screening of all patients with newly diagnosed CRC. This approach is resource intensive but would increase detection of inherited and de novo germline mutations to guide family screening. Although CRC prognosis and prediction of 5-fluorouracil response are similar in both the Lynch and sporadic dMMR subgroups, these subgroups differ significantly with regard to the implications for family members. We recommend that new CRCs should be classified into sporadic MMR-proficient, sporadic dMMR, or Lynch dMMR subgroups. The concurrent use of MSI testing, MMR protein IHC, and BRAF c.1799T>A mutation analysis would detect almost all dMMR CRCs, would classify 94% of all new CRCs into these MMR subgroups, and would guide secondary molecular testing of the remainder.