| 1. |
- Edin, Sofia, et al.
(författare)
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Opposing roles by KRAS and BRAF mutation on immune cell infiltration in colorectal cancer : possible implications for immunotherapy
- 2024
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Ingår i: British Journal of Cancer. - : Springer Nature. - 0007-0920 .- 1532-1827. ; 130
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Tidskriftsartikel (refereegranskat)abstract
- Background: The immune response has important clinical value in colorectal cancer (CRC) in both prognosis and response to immunotherapy. This study aims to explore tumour immune cell infiltration in relation to clinically well-established molecular markers of CRC.Methods: Multiplex immunohistochemistry and multispectral imaging was used to evaluate tumour infiltration of cytotoxic T cells (CD8+), Th1 cells (T-bet+), T regulatory cells (FoxP3+), B cells (CD20+), and macrophages (CD68+) in a cohort of 257 CRC patients.Results: We found the expected association between higher immune-cell infiltration and microsatellite instability. Also, whereas BRAF-mutated tumours displayed increased immune-cell infiltration compared to BRAF wild-type tumours, the opposite was seen for KRAS-mutated tumours, differences that were most prominent for cytotoxic T cells and Th1 cells. The opposing relationships of BRAF and KRAS mutations with tumour infiltration of cytotoxic T cells was validated in an independent cohort of 608 CRC patients. A positive prognostic importance of cytotoxic T cells was found in wild-type as well as KRAS and BRAF-mutated CRCs in both cohorts.Conclusion: A combined evaluation of MSI status, KRAS and BRAF mutational status, and immune infiltration (cytotoxic T cells) may provide important insights to prognosis and response to immunotherapy in CRC.
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| 2. |
- Gkekas, Ioannis, 1981-, et al.
(författare)
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Colon cancer patients with mismatch repair deficiency are more likely to present as acute surgical cases
- 2021
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Ingår i: European Journal of Cancer. - : Elsevier. - 0959-8049 .- 1879-0852. ; 157, s. 1-9
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Tidskriftsartikel (refereegranskat)abstract
- Background: The effect of the genetic imprint on the emergency presentation of colon cancer remains unclear. The disparity between tumours evolving along different carcinogenetic pathways has not been studied systematically. This retrospective multicenter cohort study evaluates the association between mismatch repair status and the risk for acute surgery of colon cancer.Patients and methods: A retrospective multicenter cohort study including in total 870 patients from three different countries. Scandinavian cohort (Finland and Sweden), including a total of 412 patients operated between January 1, 1995 and December 31, 2010, was validated against a cohort from the Czech Republic, including a total of 458 patients, operated between January 1, 2018 and December 31, 2019. The proficiency or deficiency of mismatch repair was determined by immunohistochemistry. Primary outcome was the risk for acute colon cancer surgery given as the Odds Ratio (OR) in the univariable and multivariable analyses. Acute colon cancer surgery was defined as surgery performed during the same hospital admission as when the diagnosis of colon cancer was made.Results: Of the 870 patients (399 females [46%]) included in the analyses, median age at surgery was 69 [interquartile range, 61–76] years, deficient Mismatch Repair (dMMR) status was found in 190 patients (22%), and 179 patients (21%) underwent acute surgery during the same hospital admission as when the diagnosis of colon cancer was made. In the Scandinavian cohort, a significant association between dMMR status and acute surgery was seen in both the univariable (OR 1.82, 95% CI 1.11–3.02, P = 0.017) and the multivariable (OR = 2.21, 95% CI 1.28–3.95, P = 0.005) analyses. This was confirmed in the Czech validation cohort in both the univariable (OR = 1.94, 95% CI 1.09–3.26, P = 0.022) and the multivariable (OR = 1.77, 95% CI 1.15–3.18, P = 0.021) analyses.Conclusion: This multicenter study reveals a strong association between acute colon cancer surgery and dMMR tumour status.
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| 3. |
- Gkekas, Ioannis, 1981-, et al.
(författare)
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Sporadic deficient mismatch repair in colorectal cancer increases the risk for non-colorectal malignancy : a European multicenter cohort study
- 2024
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Ingår i: Journal of Surgical Oncology. - : John Wiley & Sons. - 0022-4790 .- 1096-9098. ; 129:7, s. 1295-1304
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Tidskriftsartikel (refereegranskat)abstract
- Background and Objectives: Disparities between tumors arising via different sporadic carcinogenetic pathways have not been studied systematically. This retrospective multicenter cohort study evaluated the differences in the risk for non-colorectal malignancy between sporadic colorectal cancer (CRC) patients from different DNA mismatch repair status.Methods: A retrospective European multicenter cohort study including in total of 1706 CRC patients treated between 1996 and 2019 in three different countries. The proficiency (pMMR) or deficiency (dMMR) of mismatch repair was determined by immunohistochemistry. Cases were analyzed for tumor BRAFV600E mutation, and BRAF mutated tumors were further analyzed for hypermethylation status in the promoter region of MLH1 to distinguish between sporadic and hereditary cases. Swedish and Finish patients were matched with their respective National Cancer Registries. For the Czech cohort, thorough scrutiny of medical files was performed to identify any non-colorectal malignancy within 20 years before or after the diagnosis of CRC. Poisson regression analysis was performed to identify the incidence rates of non-colorectal malignancies. For validation purposes, standardized incidence ratios were calculated for the Swedish cases adjusted for age, year, and sex.Results: Of the 1706 CRC patients included in the analysis, 819 were female [48%], median age at surgery was 67 years [interquartile range: 60–75], and sporadic dMMR was found in 188 patients (11%). Patients with sporadic dMMR CRC had a higher incidence rate ratio (IRR) for non-colorectal malignancy before and after diagnosis compared to patients with a pMMR tumor, in both uni- (IRR = 2.49, 95% confidence interval [CI] = 1.89–3.31, p = 0.003) and multivariable analysis (IRR = 2.24, 95% CI = 1.67–3.01, p = 0.004). This association applied whether or not the non-colorectal tumor developed before or after the diagnosis of CRC in both uni- (IRR = 1.91, 95% CI = 1.28–2.98, p = 0.004), (IRR = 2.45, 95% CI = 1.72–3.49, p = 0.004) and multivariable analysis (IRR = 1.67,95% CI = 1.05–2.65, p = 0.029), (IRR = 2.35, 95% CI = 1.63–3.42, p = 0.005), respectively.Conclusion: In this retrospective European multicenter cohort study, patients with sporadic dMMR CRC had a higher risk for non-colorectal malignancy than those with pMMR CRC. These findings indicate the need for further studies to establish the need for and design of surveillance strategies for patients with dMMR CRC.
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| 4. |
- Gunnarsson, Ulf, et al.
(författare)
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Association between local immune cell infiltration, mismatch repair status and systemic inflammatory response in colorectal cancer
- 2020
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Ingår i: Journal of Translational Medicine. - : BioMed Central. - 1479-5876. ; 18
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Systemic inflammatory response in colorectal cancer (CRC) has been established as a prognostic factor for impaired cancer-specific survival, predominantly in patients with right-sided tumors. On the other hand, defective mismatch repair (dMMR) tumors, primarily located in the right colon, are known to have favorable survival and dense local immune infiltration. The aim of this study was to see if there is any form of relationship between these seemingly diverse entities.METHODS: Complete clinical and long-term survival data were retrieved for 316 CRC patients operated at Helsinki University Hospital between the years 1998 and 2003. Tissue microarrays were prepared from surgical specimens and further processed and analyzed for local immune cell infiltration using multispectral imaging with a Vectra quantitative pathology imaging system and Inform software. Multiplex immunohistochemistry was applied using antibodies against CD66b, CD8, CD20, FoxP3, CD68 and pan-Cytokeratin. After exclusions, data on immune infiltration were available for 275 patients. Mismatch repair status was determined by immunohistochemistry.RESULTS: CRP was seen to be an independent predictor of cancer-specific survival but not overall survival in uni- and multivariable (HR 1.01 (1.00-1.02); p = 0.028) analyses of non-irradiated patients. There was no significant difference in CRP according to mismatch repair status, but all cases (n = 10) with CRP ≥ 75 mg/l had proficient mismatch repair (pMMR). There was a significant negative correlation between intratumor stromal infiltration by T-regulatory FOXP3+ cells and CRP (p = 0.006). There was significantly lower intratumor stromal infiltration by FOXP3+ cells (p = 0.043) in the right colon compared to the rectum, but no significant difference in CRP (p = 0.44). CRP was not a predictor of overall survival (HR 0.99, 95% CI 0.98-1.01) nor cancer-specific survival in irradiated patients (HR 0.94, 95% CI 0.94-1.02).CONCLUSIONS: There was a significant negative relationship between SIR, defined as an elevated CRP, and intratumor stromal infiltration by T-regulatory FOXP3+ cells. This and the fact that all cases with a CRP > 75 mg/l had pMMR suggests that SIR and dMMR are independent entities in CRC. Indeed, the general lack of difference in CRP between cases with dMMR and pMMR may be evidence of overlap in cases with a less pronounced SIR.
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| 5. |
- Kerdreux, Maïwenn, et al.
(författare)
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Porphyromonas gingivalis in colorectal cancer and its association to patient prognosis
- 2023
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Ingår i: Journal of Cancer. - : Ivyspring International Publisher. - 1837-9664. ; 14:9, s. 1479-1485
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Tidskriftsartikel (refereegranskat)abstract
- Microbiota dysbiosis may affect both the development and progression of colorectal cancer (CRC). Large metagenomic studies have highlighted specific oral bacteria linked to CRC including Porphyromonas gingivalis. Few studies have however analysed the implications of this bacterium in CRC progression and survival. In this study, we investigated the intestinal presence of P. gingivalis by qPCR in both faecal and mucosal samples from two different patient cohorts, including patients with precancerous dysplasia or CRC, as well as controls. P. gingivalis was detected in 2.6-5.3% of CRC patients and significantly different levels of P. gingivalis were found in faeces of CRC patients compared to controls (P = 0.028). Furthermore, an association was found between the presence of P. gingivalis in faeces and tumour tissue (P < 0.001). Our findings further suggested a potential link between mucosal P. gingivalis and tumours of MSI subtype (P = 0.040). Last but not least, patients with faecal P. gingivalis were found to have a significantly decreased cancer-specific survival (P = 0.040). In conclusion, P. gingivalis could be linked to patients with CRC and to a worse patient prognosis. Further studies are needed to elucidate the role of P. gingivalis in CRC pathogenesis.
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| 6. |
- Li, Xingru, et al.
(författare)
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A Detailed Flow Cytometric Analysis of Immune Activity Profiles in Molecular Subtypes of Colorectal Cancer
- 2020
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 12:11
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Tidskriftsartikel (refereegranskat)abstract
- The local anti-tumour immune response has important prognostic value in colorectal cancer (CRC). In the era of immunotherapy, a better understanding of the immune response in molecular subgroups of CRC may lead to significant advances in personalised medicine. On this note, microsatellite instable (MSI) tumours have been characterised by increased immune infiltration, suggesting MSI as a marker for immune inhibitor checkpoint therapy. Here, we used flow cytometry to perform a comprehensive analysis of immune activity profiles in tumour tissues, adjacent non-malignant tissues and blood, from a cohort of 69 CRC patients. We found several signs of immune suppression in tumours compared to adjacent non-malignant tissues, including T cells more often expressing the immune checkpoint molecules programmed cell death protein (PD-1) and cytotoxic T lymphocyte-associated protein 4 (CTLA-4). We further analysed immune cell infiltration in molecular subgroups of CRC. MSI tumours were indeed found to be associated with increased immune infiltration, including increased fractions of PD-1+ T cells. No correlation was, however, found between MSI and the fraction of CTLA-4+ T cells. Interestingly, within the group of patients with microsatellite stable (MSS) tumours, some also presented with increased immune infiltration, including comparably high portions of PD-1+ T cells, but also CTLA-4+ T cells. Furthermore, no correlation was found between PD-1+ and CTLA-4+ T cells, suggesting that different tumours may, to some extent, be regulated by different immune checkpoints. We further evaluated the distribution of immune activity profiles in the consensus molecular subtypes of CRC. In conclusion, our findings suggest that different immune checkpoint inhibitors may be beneficial for selected CRC patients irrespective of MSI status. Improved predictive tools are required to identify these patients.
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| 7. |
- Li, Xingru, et al.
(författare)
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A modified protein marker panel to identify four consensus molecular subtypes in colorectal cancer using immunohistochemistry
- 2021
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Ingår i: Pathology, Research and Practice. - : Elsevier. - 0344-0338 .- 1618-0631. ; 220
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is a heterogeneous disease with different genetic and molecular backgrounds, leading to a diverse patient prognosis and treatment response. Four consensus molecular subtypes (CMS 1–4) have recently been proposed based on transcriptome profiling. A clinically practical immunohistochemistry (IHC) based CMS classifier consisting of the four markers FRMD6, ZEB1, HTR2B, and CDX2 was then demonstrated. However, the IHC-CMS classifier did not distinguish between CMS2 and CMS3 tumours. In this study, we have applied the proposed transcriptome based and IHC-based CMS classifiers in a CRC cohort of 65 patients and found a concordance of 77.5 %. Further, we modified the IHC-CMS classifier by analysing the differentially expressed genes between CMS2 and CMS3 tumours using RNA-sequencing data from the TCGA dataset. The result showed that WNT signalling was among the most upregulated pathways in CMS2 tumours, and the expression level of CTNNB1 (encoding β-catenin), a WNT pathway hallmark, was significantly upregulated (P = 1.15 × 10−6). We therefore introduced nuclear β-catenin staining to the IHC-CMS classifier. Using the modified classifier in our cohort, we found a 71.4 % concordance between the IHC and RNA-sequencing based CMS classifiers. Moreover, β-catenin staining could classify 16 out of the 19 CMS2/3 tumours into CMS2 or CMS3, thereby showing an 84.2 % concordance with the RNA-sequencing-based classifier. In conclusion, we evaluated CMS classifiers based on transcriptome and IHC analysis. We present a modified IHC panel that categorizes CRC tumours into the four CMS groups. To our knowledge, this is the first study using IHC to identify all four CMS groups.
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| 8. |
- Li, Xingru, et al.
(författare)
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Ex Vivo Organoid Cultures Reveal the Importance of the Tumor Microenvironment for Maintenance of Colorectal Cancer Stem Cells
- 2020
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Ingår i: Cancers. - : MDPI. - 2072-6694. ; 12:4
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Tidskriftsartikel (refereegranskat)abstract
- Colorectal cancer (CRC) is a heterogeneous disease, with varying clinical presentations and patient prognosis. Different molecular subgroups of CRC should be treated differently and therefore, must be better characterized. Organoid culture has recently been suggested as a good model to reflect the heterogeneous nature of CRC. However, organoid cultures cannot be established from all CRC tumors. The study examines which CRC tumors are more likely to generate organoids and thus benefit from ex vivo organoid drug testing. Long-term organoid cultures from 22 out of 40 CRC tumor specimens were established. It was found that organoid cultures were more difficult to establish from tumors characterized as microsatellite instable (MSI), BRAF-mutated, poorly differentiated and/or of a mucinous type. This suggests that patients with such tumors are less likely to benefit from ex vivo organoid drug testing, but it may also suggest biological difference in tumor growth. RNA sequencing analysis of tumor sections revealed that the in vivo maintenance of these non-organoid-forming tumors depends on factors related to inflammation and pathogen exposure. Furthermore, using TCGA data we could show a trend towards a worse prognosis for patients with organoid-forming tumors, suggesting also clinical differences. Results suggest that organoids are more difficult to establish from tumors characterized as MSI, BRAF-mutated, poorly differentiated and/or of a mucinous type. We further suggest that the maintenance of cell growth of these tumors in vivo may be promoted by immune-related factors and other stromal components within the tumor microenvironment.
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| 9. |
- Löwenmark, Thyra, 1995-
(författare)
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Gut microbiota in colorectal cancer : The importance of Parvimonas micra
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Colorectal cancer (CRC) is a heterogenous disease consisting of multiple molecular subtypes, each of which has diverse treatment responses and prognoses. The importance of the gut microbiota in CRC development and progression has undergone increasing recognition in recent years, with a structural segregation in terms of microbial composition between CRC patients and healthy controls. However, many questions remain before a full understanding of the impact of the gut microbiota on CRC is reached. The overall aim of this thesis was to explore the role of gut microbes in CRC, including their potential as CRC biomarkers and associations with clinicopathological, immunological, and molecular traits of CRC. A particular focus was the CRC-associated oral pathogen Parvimonas micra.To investigate faecal microbiota as a potential biomarker for CRC, we studied the presence of specific bacteria in faeces from CRC patients and controls using qPCR. We found higher levels of P. micra in faecal samples from CRC patients than from control patients. A test for high levels of P. micra was able to identify CRC with a specificity of 87.3% and a sensitivity of 60.5%. Adding the oral pathogen Fusobacterium nucleatum, colibactin-producing bacteria, and faecal haemoglobin to the test enhanced its sensitivity.We further aimed to explore the associations of P. micra and F. nucleatum with molecular subtypes of CRC and the tumour immune response. The levels of P. micra and F. nucleatum, as analysed by qPCR in both faeces and tumour tissue from CRC patients, were found to be positively correlated. High levels of intratumoural P. micra and F. nucleatum were associated with tumours of the microsatellite instable subtype and BRAF-mutated tumours. For F. nucleatum, an additional association with right-sided tumours was found. Moreover, both P. micra and F. nucleatum in tumour tissue were associated with the immune-activated consensus molecular subtype (CMS) 1 subtype of CRC. In line with this finding, we found novel associations between intratumoural P. micra and specific immune traits, which were evaluated by flow cytometry, indicating an active immune response in CRC. These results were further confirmed using transcriptomics. However, no associations with specific immune traits were found for F. nucleatum.We also investigated associations between faecal and intratumoural levels of P. micra and F. nucleatum and survival in CRC patients. CRC patients with high levels of intratumoural P. micra and F. nucleatum showed reduced five-year cancer-specific survival. This association remained significant for P. micra in multivariable analysis. No associations with cancer-specific survival were found for levels of P. micra and F. nucleatum in faeces.To investigate the faecal microbial landscape of CRC patients on a larger scale, we used 16S rRNA sequencing. Network analysis revealed a cluster of associated bacteria, including P. micra and F. nucleatum, as well as other CRC-related pathogens such as Bacteroides fragilis, Peptostreptococcus stomatitis, and Porphyromonas spp. Furthermore, beta-diversity analysis indicated a significantly different gut microbial composition depending on tumour location and microsatellite instability status. Interestingly, three of the six annotated species most strongly associated with microsatellite instable tumours were also present in the cluster: P. micra, F. nucleatum, and P. stomatis.In conclusion, our results suggest P. micra as a putative candidate for a future non-invasive microbial test panel for detection of CRC. Moreover, our results indicate that intratumoural P. micra and F. nucleatum are associated with immune-active subtypes of CRC, including microsatellite instable tumours and tumours of the CMS1 subtype, as well as decreased patient survival. Furthermore, P. micra and F. nucleatum were found to be associated with a cluster of other CRC-related oral pathogens. An improved understanding of the role of the gut microbiota in tumour progression may lead to the identification of important biomarkers for CRC disease and outcome, as well as potential targets for future therapy.
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| 10. |
- Löwenmark, Thyra, et al.
(författare)
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Parvimonas micra as a putative non-invasive faecal biomarker for colorectal cancer
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- The use of faecal microbial markers as non-invasive biomarkers for colorectal cancer (CRC) has been suggested, but not fully elucidated. Here, we have evaluated the importance of Parvimonas micra as a potential non-invasive faecal biomarker in CRC and its relation to other microbial biomarkers. The levels of P. micra, F. nucleatum and clbA+bacteria were quantified using qPCR in faecal samples from a population-based cohort of patients undergoing colonoscopy due to symptoms from the large bowel. The study included 38 CRC patients, 128 patients with dysplasia and 63 controls. The results were validated in a second consecutive CRC cohort including faecal samples from 238 CRC patients and 94 controls. We found significantly higher levels of P. micra in faecal samples from CRC patients compared to controls. A test for P. micra could detect CRC with a specificity of 87.3% and a sensitivity of 60.5%. In addition, we found that combining P. micra with other microbial markers, could further enhance test sensitivity. Our findings support the potential use of P. micra as a non-invasive biomarker for CRC. Together with other microbial faecal markers, P. micra may identify patients with "high risk" microbial patterns, indicating increased risk and incidence of cancer.
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