| Autor: |
Steenaard RV; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands.; Department of Internal Medicine, Máxima MC, 5504 DB Veldhoven, The Netherlands.; CAPHRI School for Public Health and Primary Care, Ageing and Long-Term Care, Maastricht University, 6229 HX Maastricht, The Netherlands., Feelders RA; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands., Dogan F; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands., van Koetsveld PM; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands., Creemers SG; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands., Ettaieb MHT; Department of Internal Medicine, Tergooi MC, 1213 XZ Hilversum, The Netherlands., van Kemenade FJ; Department of Pathology, Erasmus Medical Center, 3015 CA Rotterdam, The Netherlands., Haak HR; Department of Internal Medicine, Máxima MC, 5504 DB Veldhoven, The Netherlands.; CAPHRI School for Public Health and Primary Care, Ageing and Long-Term Care, Maastricht University, 6229 HX Maastricht, The Netherlands.; Department of Internal Medicine, Division of General Internal Medicine, Maastricht University Medical Centre+, 6229 HX Maastricht, The Netherlands., Hofland LJ; Department of Internal Medicine, Division of Endocrinology, Erasmus Medical Center, 3015 CN Rotterdam, The Netherlands. |
| Abstrakt: |
The differentiation between benign and malignant adrenocortical tumors based on pathological assessment can be difficult. We present a series of 17 patients with unclear malignant tumors, of whom six had recurrent or metastatic disease. The assessment of the methylation pattern of insulin-like growth factor 2 ( IGF2 ) regulatory regions in fresh frozen material has shown to be valuable in determining the malignancy of adrenocortical tumors, although this has not been elaborately tested in unclear malignant tumors. Since fresh frozen tissue was only available in six of the patients, we determined the feasibility of using formalin-fixed paraffin-embedded (FFPE) tissue for this method. We isolated DNA from FFPE tissue and matched the fresh frozen tissue of three patients with adrenocortical carcinoma. Methylation patterns of IGF2 regulatory regions were determined by pyrosequencing using different amounts of bisulfite-converted DNA (5 ng, 20 ng, 40 ng). Compared to fresh frozen tissue, FFPE tissue had a higher failure rate (fresh frozen 0%; FFPE 18.5%) and poor-to-moderate replicability (fresh frozen rho = 0.89-0.99, median variation 1.6%; FFPE rho = -0.09-0.85, median variation 7.7%). There was only a poor-to-moderate correlation between results from fresh frozen and FFPE tissue (rho = -0.28-0.70, median variation 13.2%). In conclusion, FFPE tissue is not suitable for determining the IGF2 methylation score in patients with an unclear malignant adrenocortical tumor using the currently used method. We, therefore, recommend fresh frozen storage of resection material for diagnostic and biobank purposes. |
