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- Fernebro, Eva, et al.
(författare)
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Evaluation of the tissue microarray technique for immunohistochemical analysis in rectal cancer.
- 2002
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Ingår i: Archives of pathology & laboratory medicine. - 0003-9985. ; 126:6, s. 702-705
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Immunohistochemical staining for tumor-associated proteins is widely used for the identification of novel prognostic markers. Recently, a tissue-conserving, high-throughput technique, tissue microarray, has been introduced. This technique uses 0.6-mm tissue core biopsy specimens, 500 to 1000 of which are brought into a new paraffin array block, which can be sectioned up to 100 times. METHODS: We evaluated the tissue microarray technique for immunohistochemical analysis in 20 rectal cancers. Immunohistochemical staining was performed for the proliferation marker Ki-67 and the tumor suppressor protein p53 in whole tissue sections and in tissue core biopsy specimens. RESULTS: The whole tissue sections were assessed by counting all cells in 10 high-power fields (x40), which resulted in a mean fraction of Ki-67-expressing tumor cells of 0.81 (range, 0.54-1.0). p53 expression assessed in whole tissue sections showed nuclear staining in 15 (75%) of 20 rectal carcinomas. For the tissue microarray technique, a median of 3 (range, 3-5) 0.6-mm tissue core biopsy specimens were studied from each of the 20 tumor specimens. The tissue microarray method gave a mean Ki-67 expression of 0.85 (range, 0.50-1.0) in tumor cell nuclei and showed p53 protein expression in the same 15 of 20 tumors as in the whole tissue sections. CONCLUSION: We conclude that the tissue microarray technique for immunohistochemical staining in rectal cancer yields staining of good quality and expression data for Ki-67 and p53 comparable to those obtained with whole tissue staining. The feasibility of tissue microarray thus enables time- and tissue-preserving studies of multiple markers in large tumor series.
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| 2. |
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| 3. |
- Fernebro, Eva, et al.
(författare)
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Prognostic importance of the soluble plasminogen activator receptor, suPAR, in plasma from rectal cancer patients
- 2001
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Ingår i: European Journal of Cancer. - 1879-0852. ; 37:4, s. 486-491
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer is one of the most common tumour types with approximately one third of the tumours located within the rectum. Rectal cancer differs somewhat from colon cancer, e.g. regarding the method of operation and the use of preoperative radiotherapy due to a tendency for local tumour recurrence. Proteolytic enzymes have been identified as key molecules in tumour invasion and metastasis, and factors within the urokinase-plasminogen activation (uPA) system have been associated with prognosis in several tumour types, including colorectal cancer. Recently, methods have been developed to analyse the soluble fraction of the plasminogen activator receptor (suPAR) in blood samples. An association between elevated suPAR levels and poor prognosis has recently been demonstrated in colorectal cancer. We have measured suPAR levels in pretreatment plasma samples from 173 rectal cancer patients in order to confirm its prognostic strength in this clinical entity. suPAR levels were determined in ethylenediamine tetraacetic acid (EDTA) plasma by a kinetic enzyme-linked immunosorbent assay (ELISA) and analysed with respect to sex, age, Dukes' stage, tumour differentiation grade and survival. In a univariate analysis, continuous suPAR plasma levels were associated with survival (P<0.001) with shorter survival among patients with high suPAR values. Patients with suPAR values within the upper quartile had significantly shorter survival (hazard ratio (HR) 2.2, 95% confidence interval (CI) 1.3-43.7, P=0.002). In a multivariate Cox analysis, increasing suPAR values predicted shorter survival independent from Dukes' stage and tumour differentiation grade with an adjusted HR of 2.2 per ng/ml suPAR (95% CI 1.2-4.0, P=0.01). This study thus confirms that measurement of suPAR in preoperative plasma samples gives independent prognostic information in rectal cancer patients, higher values being associated with shorter survival.
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| 4. |
- Fernebro, Eva
(författare)
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Rectal Cancer - Tumor Biology and Prognostic Markers
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal cancer is one of our most common malignancies and the second leading cause of cancer death worldwide. About 1/3 of the tumors are located in the rectum. Treatment advances such as the introduction of the standardized surgical technique total mesorectal excision (TME), pre-operative radiotherapy, and adjuvant chemotherapy have reduced the previously high local recurrence rates and improved survival in rectal cancer patients, but despite these advances about 40% of the patients still die from disseminated disease. Rectal cancer evolves through an accumulation of genetic alterations in the tumor cells, and although multiple such changes have been characterized, the molecular markers have not yet gained widespread clinical use. The prognostic markers currently available fail to identify patients at risk for tumor recurrencies, which implies a need for refined prognostic tools. This thesis focuses on analysis of different molecular events in rectal cancer with correlations to prognosis. Papers I-II evaluate the novel serological markers suPAR and TIMP-1 analyzed in pre-treatment plasma samples from patients with rectal cancer. High suPAR and TIMP-1 values were associated with shorter survival and these markers may thus be of potential prognostic use. In paper III, we evaluated the tissue microarray technique (TMA) for immunohistochemistry (IHC) using the markers p53 and Ki-67. Good quality staining was obtained and TMA could reproduce the results obtained from whole-tissue sections. Paper IV presents IHC tumor profiling using TMA in rectal cancer with correlations to prognosis using the markers Ki-67, p53, Bcl-2, EGFR, ß-catenin, E-cadherin, MLH1, and MSH2. The cell adhesion molecules ß-catenin and E-cadherin significantly correlated with metastatic disease, whereas the other markers did not. In paper V, we studied 30 cancers from patients younger than 50 years at diagnosis with respect to molecular alterations associated with the microsatellite instability (MSI) and the chromosomal instability (CIN) pathways for colorectal cancer development. We found that microsatellite stable (MSS), aneuploid tumors with increased expression of p53 and ß-catenin predominate also among young rectal cancer patients. Only 10% of the tumors displayed MSI, all of which showed loss of expression for MSH2, which suggests presence of a mutation associated with hereditary nonpolyposis colorectal cancer (HNPCC). In summary, this thesis presents confirmatory data on the plasma levels of suPAR and TIMP-1 as presumptive prognostic markers in rectal cancer. In addition, we have demonstrated that the TMA-technique allows high-throughput immunostaining in rectal cancer. A TMA-based molecular profiling demonstrated that aberrant expression patterns frequently occur, and that the expression of the cell-adhesion proteins ß-catenin and E-cadherin correlated with clinical outcome. Finally, the 5% of the rectal cancers that occur in young patients predominantly develop through the CIN pathway, whereas MSI is found in a small, HNPCC-related subset of the tumors. Hence, other mechanisms than defective MMR and HNPCC cause rectal cancer in the majority of young patients.
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