Abstract
KRAS mutation status has a significant role determining anti-epidermal growth factor receptor (anti-EGFR) treatment response in colon carcinoma patients. Malignant transformation is a dynamic process and therefore, it is conceivable that, at a certain point, the tumor cells’ mass might be heterogeneous for particular mutations. Therefore, the fraction of tumor cells carrying a particular mutation may be more relevant for treatment than the simple determination of presence or absence of mutation. The purpose of this study is to assess whether or not KRAS mutation status is heterogeneous and, if so, to what extent in colon carcinoma samples. Deoxyribonucleic acid was extracted from formalin-fixed paraffin-embedded samples of colon carcinoma and analyzed for the presence of KRAS mutation. The relative fraction of mutated versus wild-type KRAS alleles was evaluated by real-time polymerase chain reaction. Additionally, the relative fraction of cancer cells in the tissue sample was evaluated using computer assisted morphometric analysis. Using this data, we calculated the fraction of mutation containing cells in the samples. Colon carcinoma (169 cases) were analyzed, and a KRAS mutation was found in 75 cases (44%), of which 42 were available for morphometric analysis. In 41 (97.6%) of these cases, the fraction of mutation containing tumor cells was 50% or higher, indicating the absence of significant KRAS mutation status heterogeneity. There was a strong positive correlation (R = 0.66, P < 0.0001) between the fraction of mutated KRAS alleles and the fraction of cancer cells in the samples. The strong positive correlation between the fraction of mutated KRAS alleles and the fraction of cancer cells in the samples indicate homogeneity of KRAS mutation status in colorectal carcinoma.
Similar content being viewed by others
References
Leslie A, Carey FA, Pratt NR, Steele RJ (2002) The colorectal adenoma–carcinoma sequence. Br J Surg 89(7):845–860
Bos JL (1989) Ras oncogenes in human cancer: a review. Cancer Res 49(17):4682–4689
Giaretti W, Rapallo A, Sciutto A, Macciocu B, Geido E, Hermsen MA, Postma C, Baak JP, Williams RA, Meijer GA (2000) Intratumor heterogeneity of k-ras and p53 mutations among human colorectal adenomas containing early cancer. Anal Cell Pathol 21(2):49–57
Al-Mulla F, Going JJ, Sowden ET, Winter A, Pickford IR, Birnie GD (1998) Heterogeneity of mutant versus wild-type Ki-ras in primary and metastatic colorectal carcinomas, and association of codon-12 valine with early mortality. J Pathol 185(2):130–138
Cunningham D, Humblet Y, Siena S, Khayat D, Bleiberg H, Santoro A, Bets D, Mueser M, Harstrick A, Verslype C, Chau I, Van Cutsem E (2004) Cetuximab monotherapy and cetuximab plus irinotecan in irinotecan-refractory metastatic colorectal cancer. N Engl J Med 351(4):337–345
Karapetis CS, Khambata-Ford S, Jonker DJ, O’Callaghan CJ, Tu D, Tebbutt NC, Simes RJ, Chalchal H, Shapiro JD, Robitaille S, Price TJ, Shepherd L, Au HJ, Langer C, Moore MJ, Zalcberg JR (2008) K-ras mutations and benefit from cetuximab in advanced colorectal cancer. N Engl J Med 359(17):1757–1765
Allegra CJ, Jessup JM, Somerfield MR, Hamilton SR, Hammond EH, Hayes DF, McAllister PK, Morton RF, Schilsky RL (2009) American society of clinical oncology provisional clinical opinion: testing for KRAS gene mutations in patients with metastatic colorectal carcinoma to predict response to anti-epidermal growth factor receptor monoclonal antibody therapy. J Clin Oncol 27(12):2091–2096
Wang HL, Lopategui J, Amin MB, Patterson SD (2010) KRAS mutation testing in human cancers: the pathologist’s role in the era of personalized medicine. Adv Anat Pathol 17(1):23–32
Kotoula V, Charalambous E, Biesmans B, Malousi A, Vrettou E, Fountzilas G, Karkavelas G (2009) Targeted KRAS mutation assessment on patient tumor histologic material in real time diagnostics. PLoS One 4(11):e7746
Efrati E, Elkin H, Peerless Y, Sabo E, Ben-Izhak O, Hershkovitz D (2010) LNA-based PCR clamping enrichment assay for the identification of KRAS mutations. Cancer Biomark 8(2):89–94
Knijn N, Mekenkamp LJ, Klomp M, Vink-Borger ME, Tol J, Teerenstra S, Meijer JW, Tebar M, Riemersma S, van Krieken JH, Punt CJ, Nagtegaal ID (2011) KRAS mutation analysis: a comparison between primary tumours and matched liver metastases in 305 colorectal cancer patients. Br J Cancer 104(6):1020–1026
Cejas P, Lopez-Gomez M, Aguayo C, Madero R, de Castro Carpeno J, Belda-Iniesta C, Barriuso J, Moreno Garcia V, Larrauri J, Lopez R, Casado E, Gonzalez-Baron M, Feliu J (2009) KRAS mutations in primary colorectal cancer tumors and related metastases: a potential role in prediction of lung metastasis. PLoS One 4(12):e8199
Mariani P, Lae M, Degeorges A, Cacheux W, Lappartient E, Margogne A, Pierga JY, Girre V, Mignot L, Falcou MC, Salmon RJ, Delattre O, De Cremoux P (2010) Concordant analysis of KRAS status in primary colon carcinoma and matched metastasis. Anticancer Res 30(10):4229–4235
Park JH, Han SW, Oh DY, Im SA, Jeong SY, Park KJ, Kim TY, Bang YJ, Park JG (2011) Analysis of KRAS, BRAF, PTEN, IGF1R, EGFR intron 1 CA status in both primary tumors and paired metastases in determining benefit from cetuximab therapy in colon cancer. Cancer Chemother Pharmacol 68(4):1045–1055
Bouchahda M, Karaboue A, Saffroy R, Innominato P, Gorden L, Guettier C, Adam R, Levi F (2010) Acquired KRAS mutations during progression of colorectal cancer metastases: possible implications for therapy and prognosis. Cancer Chemother Pharmacol 66(3):605–609
Cortot AB, Italiano A, Burel-Vandenbos F, Martel-Planche G, Hainaut P (2010) KRAS mutation status in primary nonsmall cell lung cancer and matched metastases. Cancer 116(11):2682–2687
Monaco SE, Nikiforova MN, Cieply K, Teot LA, Khalbuss WE, Dacic S (2010) A comparison of EGFR and KRAS status in primary lung carcinoma and matched metastases. Hum Pathol 41(1):94–102
Goranova TE, Ohue M, Shimoharu Y, Kato K (2011) Dynamics of cancer cell subpopulations in primary and metastatic colorectal tumors. Clin Exp Metastasis 28(5):427–435
Bellon E, Ligtenberg MJ, Tejpar S, Cox K, de Hertogh G, de Stricker K, Edsjo A, Gorgoulis V, Hofler G, Jung A, Kotsinas A, Laurent-Puig P, Lopez-Rios F, Hansen TP, Rouleau E, Vandenberghe P, van Krieken JJ, Dequeker E (2011) External quality assessment for KRAS testing is needed: setup of a european program and report of the first joined regional quality assessment rounds. Oncologist 16(4):467–478
Author information
Authors and Affiliations
Corresponding author
Additional information
Farber and Efrati contributed equally to the project.
Rights and permissions
About this article
Cite this article
Farber, L., Efrati, E., Elkin, H. et al. Molecular morphometric analysis shows relative intra-tumoural homogeneity for KRAS mutations in colorectal cancer. Virchows Arch 459, 487–493 (2011). https://doi.org/10.1007/s00428-011-1158-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00428-011-1158-y