Higher Quality of Molecular Testing, an Unfulfilled Priority
2014; Elsevier BV; Volume: 16; Issue: 3 Linguagem: Inglês
10.1016/j.jmoldx.2014.01.003
ISSN1943-7811
AutoresLien Tembuyser, Marjolijn J. L. Ligtenberg, Nicola Normanno, Sofie Delen, J. Han van Krieken, Elisabeth Dequeker,
Tópico(s)Genetic factors in colorectal cancer
ResumoPrecision medicine is now a key element in clinical oncology. RAS mutational status is a crucial predictor of responsiveness to anti–epidermal growth factor receptor agents in metastatic colorectal cancer. In an effort to guarantee high-quality testing services in molecular pathology, the European Society of Pathology has been organizing an annual KRAS external quality assessment program since 2009. In 2012, 10 formalin-fixed, paraffin-embedded samples, of which 8 from invasive metastatic colorectal cancer tissue and 2 artificial samples of cell line material, were sent to more than 100 laboratories from 26 countries with a request for routine KRAS testing. Both genotyping and clinical reports were assessed independently. Twenty-seven percent of the participants genotyped at least 1 of 10 samples incorrectly. In total, less than 5% of the distributed specimens were genotyped incorrectly. Genotyping errors consisted of false negatives, false positives, and incorrectly genotyped mutations. Twenty percent of the laboratories reported a technical error for one or more samples. A review of the written reports showed that several essential elements were missing, most notably a clinical interpretation of the test result, the method sensitivity, and the use of a reference sequence. External quality assessment serves as a valuable educational tool in assessing and improving molecular testing quality and is an important asset for monitoring quality assurance upon incorporation of new biomarkers in diagnostic services. Precision medicine is now a key element in clinical oncology. RAS mutational status is a crucial predictor of responsiveness to anti–epidermal growth factor receptor agents in metastatic colorectal cancer. In an effort to guarantee high-quality testing services in molecular pathology, the European Society of Pathology has been organizing an annual KRAS external quality assessment program since 2009. In 2012, 10 formalin-fixed, paraffin-embedded samples, of which 8 from invasive metastatic colorectal cancer tissue and 2 artificial samples of cell line material, were sent to more than 100 laboratories from 26 countries with a request for routine KRAS testing. Both genotyping and clinical reports were assessed independently. Twenty-seven percent of the participants genotyped at least 1 of 10 samples incorrectly. In total, less than 5% of the distributed specimens were genotyped incorrectly. Genotyping errors consisted of false negatives, false positives, and incorrectly genotyped mutations. Twenty percent of the laboratories reported a technical error for one or more samples. A review of the written reports showed that several essential elements were missing, most notably a clinical interpretation of the test result, the method sensitivity, and the use of a reference sequence. External quality assessment serves as a valuable educational tool in assessing and improving molecular testing quality and is an important asset for monitoring quality assurance upon incorporation of new biomarkers in diagnostic services. Precision medicine has become a key element in clinical oncology. Specific molecular aberrations within a tumor guide the administration of therapy that targets oncogenic pathways. Several targeted therapies have become available for various cancer types and a growing number of clinically important biomarkers has been discovered and implemented in routine practice to predict response. For metastatic colorectal cancer (mCRC), testing of KRAS codon 12 and 13 mutations has been established as essential for the selection of patients who can benefit from anti–epidermal growth factor receptor (EGFR) agents. Recently, less common mutations in exons 3 and 4 of the KRAS gene and in exons 2, 3, and 4 of the NRAS gene were shown to be equally important. In fact, mutations in KRAS and NRAS have been shown to predict a detrimental effect of panitumumab and cetuximab when combined with oxaliplatin-based therapy in mCRC.1De Roock W. Claes B. Bernasconi D. De Schutter J. Biesmans B. Fountzilas G. et al.Effects of KRAS, BRAF, NRAS, and PIK3CA mutations on the efficacy of cetuximab plus chemotherapy in chemotherapy-refractory metastatic colorectal cancer: a retrospective consortium analysis.Lancet Oncol. 2010; 11: 753-762Abstract Full Text Full Text PDF PubMed Scopus (1711) Google Scholar, 2Loupakis F. Ruzzo A. Cremolini C. Vincenzi B. Salvatore L. Santini D. Masi G. Stasi I. Canestrari E. Rulli E. Floriani I. Bencardino K. Galluccio N. Catalano V. Tonini G. Magnani M. Fontanini G. Basolo F. Falcone A. Graziano F. KRAS codon 61, 146 and BRAF mutations predict resistance to cetuximab plus irinotecan in KRAS codon 12 and 13 wild-type metastatic colorectal cancer.Br J Cancer. 2009; 101: 715-721Crossref PubMed Scopus (479) Google Scholar, 3Peeters M. Oliner K.S. Parker A. Siena S. Van Cutsem E. Huang J. Humblet Y. Van Laethem J.L. Andre T. Wiezorek J. Reese D. Patterson S.D. Massively parallel tumor multigene sequencing to evaluate response to panitumumab in a randomized phase III study of metastatic colorectal cancer.Clin Cancer Res. 2013; 19: 1902-1912Crossref PubMed Scopus (204) Google Scholar, 4Oliner K.S. Douillard J.Y. Siena S. Tabernero J. Burkes R.L. Barugel M.E. Analysis of KRAS/NRAS and BRAF mutations in the phase III PRIME study of panitumumab (pmab) plus FOLFOX versus FOLFOX as first-line treatment (tx) for metastatic colorectal cancer (mCRC) (abstract 3511).J Clin Oncol. 2013; 31Google Scholar, 5Schwartzberg L.S. Rivera F. Karthaus M. Fasola G. Canon J.L. Yu H. Oliner K.S. Analysis of KRAS/NRAS mutations in PEAK: a randomized phase II study of FOLFOX6 plus panitumumab (pmab) or bevacizumab (bev) as first-line treatment (tx) for wild-type (WT) KRAS (exon 2) metastatic colorectal cancer (mCRC) (abstract 3631).J Clin Oncol. 2013; 31Google Scholar, 6Stintzing S. Jung A. Rossius L. Modest D.P. Fischer von Weikersthal L. Decker T. Möhler M. Scheithauer W. Kirchner T. Heinemann V. Late Breaking Abstract: analysis of KRAS/NRAS and BRAF mutations in FIRE-3: a randomized phase III study of FOLFIRI plus cetuximab or bevacizumab as first-line treatment for wild-type (WT) KRAS (exon 2) metastatic colorectal cancer (mCRC) patients. Presented at the European Cancer Congress, 2013 September 27–October 1, Amsterdam, The Netherlands. European Cancer Organization, Amsterdam2013Google Scholar These additional sites of mutations now have to be tested. In keeping up with these rapid developments, many medical diagnostic laboratories increasingly are performing molecular tests in daily practice. Of course, results must be accurate and highly reliable. Moreover, taking into account the growing complexity of oncologic biomarker testing, the need for clear and concise written reports that are readily interpretable by clinicians is apparent. Clinical interpretation of test results needs to be integrated into each clinical report because it is essential in guiding patient-management decisions. As discussed previously, a quality assurance program is a necessary part of the quality framework of medical diagnostic laboratories that perform KRAS testing, in addition to an established quality management system as required by the International Organization for Standardization (ISO 15189) or by Clinical Laboratory Improvement Amendments in the United States.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar, 8Organisation for Economic Co-operation and DevelopmentOECD guidelines for quality assurance in molecular genetic testing. OECD, Paris2007Google Scholar, 9Garcia-Alfonso P. Salazar R. Garcia-Foncillas J. Musulen E. Garcia-Carbonero R. Paya A. Perez-Segura P. Ramon y Cajal S. Navarro S. Guidelines for biomarker testing in colorectal carcinoma (CRC): a national consensus of the Spanish Society of Pathology (SEAP) and the Spanish Society of Medical Oncology (SEOM).Clin Transl Oncol. 2012; 14: 726-739Crossref PubMed Scopus (19) Google Scholar, 10Lindeman N.I. Cagle P.T. Beasley M.B. Chitale D.A. Dacic S. Giaccone G. Jenkins R.B. Kwiatkowski D.J. Saldivar J.S. Squire J. Thunnissen E. Ladanyi M. Molecular testing guideline for selection of lung cancer patients for EGFR and ALK tyrosine kinase inhibitors: guideline from the College of American Pathologists, International Association for the Study of Lung Cancer, and Association for Molecular Pathology.J Mol Diagn. 2013; 15: 415-453Abstract Full Text Full Text PDF PubMed Scopus (373) Google Scholar In Europe, the approval of anti-EGFR agents has not been linked to an in vitro companion diagnostic device. Because a wide variety of methods can be used for mutation analysis, it is highly important that laboratories can verify the robustness and accuracy of their methods. Therefore, the European Society of Pathology (ESP) established a European external quality assessment (EQA) network that includes programs for molecular testing in colorectal cancer and in non-small cell lung cancer.11van Krieken J.H. Jung A. Kirchner T. Carneiro F. Seruca R. Bosman F.T. Quirke P. Flejou J.F. Plato Hansen T. de Hertogh G. Jares P. Langner C. Hoefler G. Ligtenberg M. Tiniakos D. Tejpar S. Bevilacqua G. Ensari A. KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program.Virchows Arch. 2008; 453: 417-431Crossref PubMed Scopus (270) Google Scholar, 12Thunnissen E. Bubendorf L. Dietel M. Elmberger G. Kerr K. Lopez-Rios F. Moch H. Olszewski W. Pauwels P. Penault-Llorca F. Rossi G. EML4-ALK testing in non-small cell carcinomas of the lung: a review with recommendations.Virchows Arch. 2012; 461: 245-257Crossref PubMed Scopus (188) Google Scholar These programs monitor laboratory performance, allow interlaboratory comparisons, and ensure that laboratories that perform these tests provide results according to accepted predefined standards of quality.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar Diagnostic and clinical reality is reflected as closely as possible within the EQA program, and, in doing so, analytical as well as pre-analytical and postanalytical phases of the laboratory process are assessed. Importantly, by making the results public, patients and clinicians are aided in their choice of a laboratory for testing. The ESP KRAS EQA scheme was organized since 2009 to evaluate the reliability and accurateness of genotyping and result reporting in KRAS mutation testing in CRC. This article summarizes the findings of the 2012 data to reflect the status of routine diagnostic practices and to validate whether reporting practices in molecular pathology fulfill international guidelines, which is especially important now that KRAS testing is replaced by the more elaborate RAS testing. This study describes the current state of the testing quality in molecular diagnostic laboratories and seeks to increase the awareness of the occurrence of errors in routine clinical testing. We further stress the importance of providing clear laboratory reports and the need for well-implemented quality assurance systems. The ESP KRAS EQA scheme is organized on a yearly basis at the University of Leuven (EQA provider) with the aid of a medical and technical expert from the Radboud University Medical Center and with the support of the ESP Quality Assurance Working Group. Sample preparation and distribution for the 2012 scheme was assigned to 10 regional scheme organizers. Each participant received three consecutive unstained sections from eight formalin-fixed, paraffin-embedded invasive colorectal carcinoma tissues. The last three cut sections of each case were validated independently by a reference laboratory. One section was to be used for H&E staining and analysis of neoplastic cell content, the other sections were used for DNA extraction and mutation analysis. In addition, two artificial samples from Horizon Diagnostics (Cambridge, UK) were included in the sample set, provided in sample tubes containing one formalin-fixed, paraffin-embedded sample of cell line material. The neoplastic load of the artificial samples was supplied to the participants in advance.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar Mock clinical information was provided for three cases, for which the delivery of a full written report was requested. Participants were asked to use their routine testing procedures and to submit results within 14 days after sample receipt. A central database was used for submission of the results. Participants were expected to complete an EQA questionnaire with information on which mutations were tested, the methods used, analytical sensitivity, the percentage of neoplastic cells present, and the results that were obtained. Written reports, scans of the H&E-stained sections, and optional raw data should be uploaded. Results of the EQA scheme were evaluated independently by two assessors and discussed during an assessment meeting to obtain final consensus scores. Participants received individual feedback and a general report with aggregated scheme results. Genotyping marks were assigned in agreement with a recently published EQA guideline7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar (Table 1). Harmonization in genotypes across the subschemes (labeled A through J) was aimed for as much as possible. A maximum of two points per genotype could be obtained. It was assumed that test methods had undergone thorough internal validation before they were offered for diagnostic purposes and before participation in the EQA. However, a test failure could occur and reporting of failures was essential. Therefore, 0.50 points were awarded for test failures. Exceptions were made for two samples for which the reference laboratory confirmed a problem with the specimen (the neoplastic cell content was too low in the last cut sections in one case and loss of sections during H&E staining in the other case), and for an artificial sample mimicking a neoplastic cell content of 10% (specimen KRAS12.109), for these cases full marks were awarded in case of test failures. For laboratories reporting a failure in one of the other samples, the uploaded scans of H&E-stained slides were reviewed and compared with the scans of the laboratories that received the previous and subsequent sections. This enabled us to assess the sample adequacy and evaluate the cause of the error.Table 1Marking Criteria for the Genotyping ResultsScoring codeMarking criteriaMarksaThe sample was assigned correctly2.000The sample was assigned incorrectly0.00bThe sample mutation was not screened2.00cVariant of unknown significance was detected (mutation that is not classified as an activating mutation and has no influence on therapy advice)Ignored in scoringdSamples likely were switched0.00eThe sample mutation was filled in incorrectly on the datasheet, but was correct on raw data and/or reports0.00fTechnical error occurred: no or not enough amplified product for a reliable result•0.50•2.00 for KRAS12.108 samples in subschemes E and F•2.00 for KRAS12.109 samples if the sensitivity of the method was not sufficient and a comment about this was made in the datasheetgThe laboratory indicated that a mutation was detected, but with the technique used the exact nucleotide change could not be determined2.00 Open table in a new tab Written reports were evaluated for the presence and correctness of 29 elements, based on established standards and guidelines on reporting.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar, 11van Krieken J.H. Jung A. Kirchner T. Carneiro F. Seruca R. Bosman F.T. Quirke P. Flejou J.F. Plato Hansen T. de Hertogh G. Jares P. Langner C. Hoefler G. Ligtenberg M. Tiniakos D. Tejpar S. Bevilacqua G. Ensari A. KRAS mutation testing for predicting response to anti-EGFR therapy for colorectal carcinoma: proposal for an European quality assurance program.Virchows Arch. 2008; 453: 417-431Crossref PubMed Scopus (270) Google Scholar, 13International Organization for StandardizationISO 15189:2007 Medical laboratories - particular requirements for quality and competence. ISO, Geneva2007Google Scholar, 14Gulley M.L. Braziel R.M. Halling K.C. His E.D. Kant J.A. Nikiforova M.N. Nowak J.A. Ogino S. Oliveira A. Polesky H.F. Silverman L. Tubbs R.R. Van Deerlin V.M. Vance G.H. Versalovic J. Clinical laboratory reports in molecular pathology.Arch Pathol Lab Med. 2007; 131: 852-863PubMed Google Scholar, 15International Organization for StandardizationISO 15189:2012 Medical laboratories - particular requirements for quality and competence. ISO, Geneva2012Google Scholar Nine essential elements were marked to determine a reporting score (Table 2), and relative weights were assigned in agreement with the EQA guideline, emphasizing accurate patient identification, clear statement of the test result, and correct clinical interpretation.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar Marks were awarded if the item was correctly present or if it was present but unclearly defined. No marks were awarded if the item was incorrect or absent.Table 2Marking Criteria for the Written ReportsMarking criteriaMarksCorrect name and first name of the patient was provided without clerical errors1.00Date of birth was provided without any error1.00Result is provided0.50Explanation of how to interpret the result is provided0.25Clinical interpretation is provided (eg, prediction of effect of genotype on therapy response)0.50Reference sequence and version was used correctly throughout the report0.25Specification of the molecular assay used was provided0.125Aberrations detected by the assay (or regions/exons covered) were stated0.125Limitations of the assay and/or sensitivity of the test was stated0.25 Open table in a new tab In total, 1050 samples were analyzed by 105 laboratories from 26 different countries (primarily European Union countries). The majority of the laboratories were set in a hospital (60%) or a university hospital (15%) environment. Ten percent of the participants were private laboratories. The analysis was performed mainly under the authority of the Department of Pathology (78%). The most frequently used DNA extraction method was the QIAmp DNA FFPE Tissue Kit (Qiagen DxS, Hilden, Germany) (by 30% of the participating laboratories). The most frequently used mutation detection methods were dideoxy sequencing (43%), the Therascreen KRAS PCR Kit (Qiagen DxS) (11%), and the Cobas KRAS Mutation Test (Roche Diagnostics, Basel, Switzerland) (11%). Table 3 illustrates the genotypes and the distribution of the category scores for each sample. Genotyping errors consisted of false positives and false negatives, as well as incorrectly identified mutations. In the entire scheme, 9 false positives and 29 false negatives occurred. Ten cases were assigned a positive mutational status, but with an incorrect mutation reported. Thus, in total, 48 of 1050 samples (4.57%) were identified incorrectly (Table 3). Sixteen of 29 false negatives were assigned for sample KRAS12.109 (10% neoplastic cell content). Eighteen percent of laboratories made a genotyping error for this specimen and 12% reported insufficient sensitivity of the test for reliable mutation detection.Table 3Genotypes and Distribution of the Category Scores per Sample Included in the SchemeSample number and genotypeScoring code and criterion12.10112.10212.10312.10412.10512.106 (scheme A–H, J)12.106 (scheme I)12.107 (scheme A–C, E–J)12.107 (scheme D)12.10812.10912.110Total per scoring criterionWtc.38G > Ap.Gly13Aspc.35G > Tp.Gly12ValWtWtc.35G > Ap.Gly12AspWtWtc.183A > Tp.Gln61Hisc.34G > Tp.Gly12Cysc.34G > Cp.Gly12Argc.34G > Ap.Gly12SeraCorrect10296921021018489538866939300FP, FN, wrong mutation134335110519348bMutation not screened0000000060006cVUS reported1000000000001dSamples switched0000000000000eClerical error0000000000011fTechnical error, no result102010000614226gNo exact genotype06700700066638Total per sample105105105105105969969105105105n = 1050 Open table in a new tab Twenty-six samples resulted in a technical failure (Table 3) (score f), 14 of which involved case KRAS12.109. Six of nine samples harboring the codon 61 mutation for case 7 in subscheme D were not screened for this specific mutation (score b). One laboratory made a clerical error for case 10 by indicating the wrong genotype in the datasheet (score e). Twenty-eight of 105 laboratories (27%) made genotyping errors. Eighteen laboratories (17%) genotyped 1 of 10 samples incorrectly. Two or more of the 10 samples were genotyped incorrectly by 10 laboratories (10%). Twenty-one laboratories (20%) reported a technical error (no result) for one or more samples. Five laboratories made a combination of genotyping and technical errors. The average genotyping score was 18.97 of 20 (95%). The criterion for successful participation was set on a genotyping score of 18 or greater of 20. In a setting of 10 cases, this results in an upper limit of the 90% CI (Bayesian confidence interval) greater than 95%, implicating a 90% chance that between 63.6% and 96.7% of the routine analysis will be correct.7van Krieken J.H. Normanno N. Blackhall F. Boone E. Botti G. Carneiro F. Celik I. Ciardiello F. Cree I.A. Deans Z.C. Edsjo A. Groenen P.J. Kamarainen O. Kreipe H.H. Ligtenberg M.J. Marchetti A. Murray S. Opdam F.J. Patterson S.D. Patton S. Pinto C. Rouleau E. Schuuring E. Sterck S. Taron M. Tejpar S. Timens W. Thunnissen E. van de Ven P.M. Siebers A.G. Dequeker E. Guideline on the requirements of external quality assessment programs in molecular pathology.Virchows Arch. 2013; 462: 27-37Crossref PubMed Scopus (62) Google Scholar Based on this limit, 94 of 105 laboratories participated successfully. Seventy-two laboratories obtained the maximum score. Reports were sent by 102 of 105 participating laboratories. The average reporting score was 2.9 of 4 (score, 73%), with a SD of 1.02 points. The lower and upper quartiles were 2.75 and 3.75, respectively. Figure 1 illustrates the presence of the nine marking criteria in the written reports. Essential elements such as information on the method of sensitivity, a specification of the mutations detected by the assay, and an interpretation stating the putative clinical impact of the found genotype were missing in 44%, 19%, and 48% of the reports, respectively. A genotype-specific clinical interpretation was included more often in cases with a positive KRAS mutational status (10% difference). In 87% of the written reports, the percentage of neoplastic cells present in the specimen was stated clearly. To specify the genotype, the gene name (KRAS or KRAS) and the reference sequence (NM_004985.3 and NM_033360.2) were used correctly in 67% and only 17% of the reports, respectively. Substantial variation occurred in the use of correct standardized Human Genome Variation Society nomenclature, with both incorrect and inconsistent use observed. Seven laboratories only mentioned the presence of a mutation in codon 12 and 13 without specifying the exact genotype. All except one of these were using a technique that did not distinguish between mutations in the same codon. Patient history and the indication for testing were present in no more than 57% and 63% of the reports, respectively. The sample identification number and the sample nature were cited correctly in 95% and 77%, respectively. Page number and the total number of pages were present in only 48% and 42% of the reports, respectively. Precision medicine constitutes a promising approach for maximizing treatment efficacy and minimizing toxicity, for facilitating efficient health care delivery, and generating cost savings.16Heinemann V. Douillard J.Y. Ducreux M. Peeters M. Targeted therapy in metastatic colorectal cancer - an example of personalised medicine in action.Cancer Treat Rev. 2013; 39: 592-601Abstract Full Text Full Text PDF PubMed Scopus (102) Google Scholar Current developments in cancer treatment focus on novel classes of therapeutic agents targeting specific molecules expressed by cancer cells. Two EGFR monoclonal antibodies (cetuximab and panitumumab) and two small-molecule EGFR tyrosine kinase inhibitors (gefitinib and erlotinib) have been evaluated extensively and have been approved by the Food and Drug Administration and the European Medicines Agency for the treatment of CRC, non-small cell lung cancer, carcinoma of the head and neck, and pancreatic cancer.17Vecchione L. Jacobs B. Normanno N. Ciardiello F. Tejpar S. EGFR-targeted therapy.Exp Cell Res. 2011; 317: 2765-2771Crossref PubMed Scopus (90) Google Scholar Mutations of the KRAS gene are found in 30% to 40% of colorectal carcinomas and are observed most frequently in codons 12, 13, and less commonly in codons 59, 61, 117, and 146.3Peeters M. Oliner K.S. Parker A. Siena S. Van Cutsem E. Huang J. Humblet Y. Van Laethem J.L. Andre T. Wiezorek J. Reese D. Patterson S.D. Massively parallel tumor multigene sequencing to evaluate response to panitumumab in a randomized phase III study of metastatic colorectal cancer.Clin Cancer Res. 2013; 19: 1902-1912Crossref PubMed Scopus (204) Google Scholar, 18Edkins S. O'Meara S. Parker A. Stevens C. Reis M. Jones S. Greenman C. Davies H. Dalgliesh G. Forbes S. Hunter C. Smith R. Stephens P. Goldstraw P. Nicholson A. Chan T.L. Velculescu V.E. Yuen S.T. Leung S.Y. Stratton M.R. Futreal P.A. Recurrent KRAS codon 146 mutations in human colorectal cancer.Cancer Biol Ther. 2006; 5: 928-932Crossref PubMed Scopus (190) Google Scholar, 19Normanno N. Tejpar S. Morgillo F. De Luca A. Van Cutsem E. Ciardiello F. Implications for KRAS status and EGFR-targeted therapies in metastatic CRC.Nat Rev Clin Oncol. 2009; 6: 519-527Crossref PubMed Scopus (358) Google Scholar, 20Igbokwe A. Lopez-Terrada D.H. Molecular testing of solid tumors.Arch Pathol Lab Med. 2011; 135: 67-82PubMed Google Scholar, 21Vaughn C.P. Zobell S.D. Furtado L.V. Baker C.L. Samowitz W.S. Frequency of KRAS, BRAF, and NRAS mutations in colorectal cancer.Genes Chromosomes Cancer. 2011; 50: 307-312Crossref PubMed Scopus (299) Google Scholar Since 2008, the European Medicines Agency has approved the use of cetuximab and panitumumab only for mCRC patients carrying a wild-type KRAS gene. The genotypes included in the 2012 scheme complied with this recommendation and belong to the most common KRAS mutations. Profiling tumors of all patients with mCRC for mutations in KRAS codons 12 and 13, particularly the seven most common mutations, has been standard practice since 2008.21Vaughn C.P. Zobell S.D. Furtado L.V. Baker C.L. Samowitz W.S. Frequency of KRAS, BRAF, and NRAS mutations in colorectal cancer.Genes Chromosomes Cancer. 2011; 50: 307-312Crossref PubMed Scopus (299) Google Scholar Recently, the European Medicines Agency specified that wild-type RAS (KRAS exons 2, 3, and 4, and NRAS exons 2, 3, and 4) status is required before initiating treatment with cetuxim
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