| 1. |
- Dahlin, Anna M, 1979-, et al.
(författare)
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Colorectal cancer prognosis depends on T-cell infiltration and molecular characteristics of the tumor
- 2011
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Ingår i: Modern Pathology. - : Elsevier BV. - 0893-3952 .- 1530-0285. ; 24, s. 671-682
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Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to relate the density of tumor infiltrating T cells to cancer-specific survival in colorectal cancer, taking into consideration the CpG island methylator phenotype (CIMP) and microsatellite instability (MSI) screening status. The T-cell marker CD3 was stained by immunohistochemistry in 484 archival tumor tissue samples. T-cell density was semiquantitatively estimated and scored 1-4 in the tumor front and center (T cells in stroma), and intraepithelially (T cells infiltrating tumor cell nests). Total CD3 score was calculated as the sum of the three CD3 scores (range 3-12). MSI screening status was assessed by immunohistochemistry. CIMP status was determined by quantitative real-time PCR (MethyLight) using an eight-gene panel. We found that patients whose tumors were highly infiltrated by T cells (total CD3 score ≥7) had longer survival compared with patients with poorly infiltrated tumors (total CD3 score ≤4). This finding was statistically significant in multivariate analyses (multivariate hazard ratio, 0.57; 95% confidence interval, 0.31-1.00). Importantly, the finding was consistent in rectal cancer patients treated with preoperative radiotherapy. Although microsatellite unstable tumor patients are generally considered to have better prognosis, we found no difference in survival between microsatellite unstable and microsatellite stable (MSS) colorectal cancer patients with similar total CD3 scores. Patients with MSS tumors highly infiltrated by T cells had better prognosis compared with intermediately or poorly infiltrated microsatellite unstable tumors (log rank P=0.013). Regarding CIMP status, CIMP-low was associated with particularly poor prognosis in patients with poorly infiltrated tumors (multivariate hazard ratio for CIMP-low versus CIMP-negative, 3.07; 95% confidence interval, 1.53-6.15). However, some subset analyses suffered from low power and are in need of confirmation by independent studies. In conclusion, patients whose tumors are highly infiltrated by T cells have a beneficial prognosis, regardless of MSI, whereas the role of CIMP status in this context is less clear.
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| 2. |
- Dahlin, Anna M, 1979-, et al.
(författare)
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The role of the CpG island methylator phenotype in colorectal cancer prognosis depends on microsatellite instability screening status
- 2010
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Ingår i: Clinical Cancer Research. - 1078-0432 .- 1557-3265. ; 16:6, s. 1845-1855
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: The aim of this study was to relate the CpG island methylator phenotype (CIMP; characterized by extensive promoter hypermethylation) to cancer-specific survival in colorectal cancer, taking into consideration relevant clinicopathologic factors, such as microsatellite instability (MSI) screening status and the BRAF V600E mutation. EXPERIMENTAL DESIGN: Archival tumor samples from 190 patients from the Northern Sweden Health and Disease Study (NSHDS) and 414 patients from the Colorectal Cancer in Umeå Study (CRUMS), including 574 with cancer-specific survival data, were analyzed for an eight-gene CIMP panel using quantitative real-time PCR (MethyLight). MSI screening status was assessed by immunohistochemistry. RESULTS: CIMP-low patients had a shorter cancer-specific survival compared with CIMP-negative patients (multivariate hazard ratio in NSHDS, 2.01; 95% confidence interval, 1.20-3.37; multivariate hazard ratio in CRUMS, 1.48; 95% confidence interval, 1.00-2.22). This result was similar in subgroups based on MSI screening status and was statistically significant in microsatellite stable (MSS) tumors in NSHDS. For CIMP-high patients, a shorter cancer-specific survival compared with CIMP-negative patients was observed in the MSS subgroup. Statistical significance was lost after adjusting for the BRAF mutation, but the main findings were generally unaffected. CONCLUSIONS: In this study, we found a poor prognosis in CIMP-low patients regardless of MSI screening status, and in CIMP-high patients with MSS. Although not consistently statistically significant, these results were consistent in two separate patient groups and emphasize the potential importance of CIMP and MSI status in colorectal cancer research.
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| 3. |
- Dahlin, Anna, 1979-
(författare)
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The CpG island methylator phenotype in colorectal cancer : studies on risk and prognosis
- 2011
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Background Colorectal cancer (CRC) is the second most common malignancy in developed countries. The mortality is high, with nearly half of patients dying from the disease. The primary treatment of CRC is surgery, and decisions about additional treatment with chemotherapy are based mainly on tumor stage. Novel prognostic markers that identify patients at high risk of recurrence and cancer-related death are needed. The development of CRC has been described in terms of two different pathways; the microsatellite instability (MSI) and chromosomal instability (microsatellite stable, MSS) pathway. More recently, the CpG island methylator phenotype (CIMP), characterized by frequent DNA hypermethylation, has been described as an alternative pathway of tumorigenesis. The event of DNA methylation is dependent on one-carbon metabolism, in which folate and vitamin B12 have essential functions. The purpose of this thesis was to study CIMP in CRC. The specific aims were to investigate the potential role of components of one-carbon metabolism as risk factors for this subgroup of tumors, and the prognostic importance of CIMP status, taking into consideration important confounding factors, such as MSI and tumor-infiltrating T cells. Methods CRC cases and referents included in the Northern Sweden Health and Disease Study (NSHDS, 226 cases and 437 referents) and CRC cases in the Colorectal Cancer in Umeå Study (CRUMS, n=490) were studied. Prediagnostic plasma concentrations of folate and vitamin B12 were analyzed in NSHDS. In both study groups, CIMP status was determined in archival tumor tissue by real-time quantitative PCR using an eight-gene panel (CDKN2A, MLH1, CACNA1G, NEUROG1, RUNX3, SOCS1, IGF2 and CRABP1). MSI screening status and the density of tumor-infiltrating T cells were determined by immunohistochemistry. Results An inverse association was found between plasma concentrations of vitamin B12 and rectal, but not colon, cancer risk. We also found a reduced risk of CIMP-high and CIMP-low CRC in study subjects with the lowest levels of plasma folate. We found that patients with CIMP-low tumors in both NSHDS and CRUMS had a poorer prognosis compared with CIMP-negative, regardless of MSI screening status. We also found that MSS CIMP-high patients had a poorer prognosis compared with MSS CIMP-negative. The density of tumor-infiltrating T cells and CIMP status were both found to be independent predictors of CRC patient prognosis. A particularly poor prognosis was found in patients with CIMP-low tumors poorly infiltrated by T cells. In addition, the density of T cells appeared to be more important than MSI screening status for predicting CRC patient prognosis. Conclusion Rather than being one disease, CRC is a heterogeneous set of diseases with respect to clinico-pathological and molecular characteristics. We found that the association between risk and plasma concentration of vitamin B12 and folate depends on tumor site and CIMP status, respectively. Patient prognosis was found to be different depending on CIMP and MSI screening status, and the density of tumor-infiltrating T cells.
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| 4. |
- Henriksson, Maria L, et al.
(författare)
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Colorectal Cancer Cells Activate Adjacent Fibroblasts Resulting in FGF1/FGFR3 Signaling and Increased Invasion.
- 2011
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Ingår i: American Journal of Pathology. - : Elsevier. - 0002-9440 .- 1525-2191. ; 178:3, s. 1387-1394
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Tidskriftsartikel (refereegranskat)abstract
- Cancer-associated fibroblasts expressing fibroblast activation protein (FAP) have been implicated in the invasive behavior of colorectal cancer. In this study, we use FAP expression as a marker of fibroblast activation and analyze the effect of activated fibroblasts on colorectal cancer migration and invasion in experimental cell studies. We also investigated the expression pattern of FAP in cancer-associated fibroblasts during transformation from benign to malignant colorectal tumors. In immunohistochemical analyses, FAP was expressed in fibroblasts in all colorectal cancer samples examined, whereas all normal colon, hyperplastic polyps, or adenoma samples were negative. In in vitro studies, conditioned medium from colon cancer cells, but not adenoma cells, activated fibroblasts by inducing FAP expression. These activated fibroblasts increased the migration and invasion of colon cancer cells in Boyden chamber experiments and in a three-dimensional cell culture model. We identify fibroblast growth factor 1/fibroblast growth factor receptor 3 (FGF1/FGFR-3) signaling as mediators leading to the increased migration and invasion. Activated fibroblasts increase their expression of FGF1, and by adding a fibroblast growth factor receptor inhibitor, as well as an FGF1-neutralizing antibody, we reduced the migration of colon cancer cells. Our findings provide evidence of a possible molecular mechanism involved in the cross talk between cancer cells and fibroblasts leading to cancer cell invasion.
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| 5. |
- Isaksson-Mettävainio, Martin, et al.
(författare)
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c-Met expression in primary tumors and their corresponding distant metastases
- 2009
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Ingår i: Molecular Medicine Reports. - Umeå : Spandidos Publications. - 1791-2997. ; 1:6, s. 787-790
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Tidskriftsartikel (refereegranskat)abstract
- c-Met is a receptor tyrosine kinase that has beenimplicated in the pathogenesis and growth of a wide variety ofhuman malignancies, including CRC, but its role in metastasisis largely unknown. We compared c-Met expression in primaryhuman colorectal carcinomas and distant metastases from thesame patients. Formalin-fixed paraffin-embedded tissuesamples from 69 colorectal cancer patients were obtained. Theprotein expression of c-Met was evaluated immunohistochemicallyusing a commercial antibody. The difference inexpression between primary tumors and their correspondingdistant metastases was analyzed using the Wilcoxon signedranktest. c-Met expression was statistically significantlylower in the distant metastases compared to their correspondingprimary tumors (p<0.001), whereas no difference was foundbetween lymph node metastases and their correspondingprimary tumors (p=0.957). The degree of c-Met expressionwas not related to clinicopathological characteristics such astumor grade and Dukes' stage at the time of primary tumordiagnosis, or to the location of the distant metastases. Wedemonstrated that c-Met expression is often reduced in distantmetastases compared to their corresponding primary colorectaltumors. Additional studies of c-Met activation and signaltransduction will increase our knowledge about the role ofc-Met in colorectal cancer metastasis.
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| 6. |
- Isaksson-Mettävainio, Martin, et al.
(författare)
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High SMAD4 levels appear in MSI and hypermethylated colon cancers, and indicate a better prognosis
- 2012
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Ingår i: International Journal of Cancer. - Geneve : International union against cancer. - 0020-7136 .- 1097-0215. ; 131, s. 779-788
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is one of the most common causes of cancer related deaths in western countries. CRC are commonly divided in cancers showing microsatellite stability (MSS) or microsatellite instability (MSI). A more novel classification is dependent on promoter hypermethylation of CpG islands (the CpG island methylator phenotype, CIMP), where cancers show high, low or negative methylation status. SMAD4, located on chromosome 18q, has been thoroughly investigated during the last years. Loss of SMAD4 expression has been reported to correlate with poor CRC patient prognosis. In this study we analyze the impact of SMAD4 expression on prognosis in relation to MSI screening status and CIMP status. 479 paraffin-embedded specimens of CRC were examined for nuclear SMAD4 expression using immunohistochemistry. The tumors were scored loss (-), moderate (+) and high (++) expressing tumors. Loss of SMAD4 correlated significantly with decreased survival in all colon cancer patients. High SMAD4 expression, on the other hand, was significantly associated with increased survival, especially in colon cancer patients which has undergone potential curative surgery. In addition, in MSI tumors and CIMP-high tumors, high SMAD4 expression was significantly related to increase in survival, while loss of SMAD4 resulted in a significantly poorer prognosis. SMAD4 expression was not correlated to prognosis in rectal cancer cases. We conclude, loss of SMAD4 indicates a poor prognosis in colon cancer patients. The novel findings that high SMAD4 expression predicts a better prognosis suggests that SMAD4 immunohistochemistry could constitute a prognostic marker in combination with CIMP and MSI screening status.
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| 7. |
- Wikberg, Maria L., et al.
(författare)
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High intratumoral expression of fibroblast activation protein (FAP) in colon cancer is associated with poorer patient prognosis.
- 2013
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Ingår i: Tumor Biology. - : Springer Netherlands. - 1010-4283 .- 1423-0380. ; 34:2, s. 1013-1020
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Tidskriftsartikel (refereegranskat)abstract
- -An active stroma is important for cancer cell invasion and metastasis. We investigated the expression of fibroblast activation protein (FAP) in relation to patient prognosis in colorectal cancer. Colorectal cancer specimens from 449 patients were immunohistochemically stained with a FAP antibody and evaluated in the tumor center and tumor front using a semiquantitative four-level scale. FAP was expressed by fibroblasts in 85-90 % of the tumors examined. High versus no/low expression in the tumor center was associated with poor prognosis (multivariate hazard ratio, HR = 1.72; 95 % CI 1.07-2.77, p = 0.025). FAP expression in the tumor front, though more frequent than in the tumor center, was not associated with prognosis. FAP expression in the tumor center was more common in specimens with positive microsatellite instability (MSI) screening status and in patients with high CpG island methylator phenotype (CIMP) status. However, inclusion of MSI screening status and CIMP status in the multivariate analysis strengthened the risk estimates for high FAP expression in the tumor center (HR = 1.89; 95 % CI 1.13-3.14; p = 0.014), emphasizing the role of FAP as an independent prognostic factor. Stromal FAP expression is common in colorectal cancer, and we conclude that high FAP expression in the tumor center, but not the tumor front, is an independent negative prognostic factor.
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