Combined associations of a healthy lifestyle and body mass index with colorectal cancer recurrence and survival: a cohort study.

PURPOSE: Colorectal cancer (CRC) risk is associated with modifiable lifestyle factors including smoking, physical inactivity, Western diet, and excess body weight. The impact of lifestyle factors on survival is less known. A cohort study was conducted to investigate the combined effects of a healthy lifestyle and body mass index on prognosis following CRC diagnosis. METHODS: Treatment and follow-up data were collected from the patient files of 1098 participants from the Colorectal cancer low-risk study cohort including stage I-III CRC patients. A healthy lifestyle and BMI (HL) score was computed using self-reported data on smoking status, physical activity, adherence to a Mediterranean diet pattern, and BMI, and divided into four categories ranging from least to most healthy. Survival analyses were performed to assess recurrence-free survival and overall survival across categories of exposure, using the Kaplan-Meier method and Cox proportional hazards models adjusted for age, sex, and educational level. RESULTS: Among 1098 participants with stage I-III CRC, 233 (21.2%) had an HL score of 0-1 (least healthy), 354 (32.2%) HL score of 2, 357 (32.5%) HL score of 3 and 154 (14.0) HL score 4 (most healthy). Patients with the healthiest lifestyle (HL score 4) compared to the least healthy (HL score 0-1) had an improved recurrence-free survival (HL 4 vs HL 0-1, HRadj 0.51 (95% CI 0.31-0.83) and overall survival (HL 4 vs HL 0-1, HRadj 0.52 (95% CI 0.38-0.70). CONCLUSION: Adherence to a healthy lifestyle may increase the recurrence-free and overall survival of patients with stage I-III CRC.

The prognostic significance of microsatellite instability in colorectal cancer: a Swedish multi-center study.

PURPOSE: About 10 to 15% of patients with sporadic colorectal cancer display mutations in DNA mismatch repair (MMR) genes shown as microsatellite instability (MSI). Previous reports of colorectal cancer (CRC) indicate a better prognosis for patients with MSI tumors compared to patients with microsatellite stable (MSS) tumors. In this study, our aim was to investigate whether MSI is an independent prognostic factor in CRC. PATIENTS AND METHODS: Patients with stage I-III colorectal cancer and subject to curative surgery during 2002-2006 in the Swedish low-risk colorectal cancer study group cohort were eligible for inclusion. Deficient MMR (dMMR) status was analyzed by immunohistochemistry (IHC) and/or by MSI testing with polymerase chain reaction (PCR). Prognostic follow-up and treatment data were retrieved from patient records. Statistical analyses to assess MSI-status and prognosis were done using logistic regression and survival analyses using the Kaplan-Meier method and Cox regression hazards models adjusted for age, sex, stage, comorbidity, and tumor location. RESULTS: In total, 463 patients were included, MSI high tumors were present in 66 patients (14%), and the remaining 397 were MSS/MSI low. Within 6 years, distant recurrences were present in 9.1% and 20.2% (P = 0.049), and death occurred in 25.8% and 31.5% in MSI and MSS patients, respectively. There was no statistically significant difference in overall mortality (HR 0.80, 95% CI 0.46-1.38), relapse-free survival (HR 0.82, 95% CI 0.50-1.36), or cancer-specific mortality (HR 1.60, 95% CI 0.73-3.51). CONCLUSION: Despite distant metastases being less common in patients with MSI, there was no association between MSI and overall, relapse-free, or cancer-specific survival.

Colectomy reconstruction for ulcerative colitis in Sweden and England: a multicenter prospective comparison between ileorectal anastomosis and ileal pouch-anal anastomosis after colectomy in patients with ulcerative colitis. (CRUISE-study).

BACKGROUND: There are no prospective trials comparing the two main reconstructive options after colectomy for Ulcerative colitis, ileal pouch anal anastomosis and ileorectal anastomosis. An attempt on a randomized controlled trial has been made but after receiving standardized information patients insisted on choosing operation themselves. METHODS: Adult Ulcerative colitis patients subjected to colectomy eligible for both ileal pouch anastomosis and ileorectal anastomosis are asked to participate and after receiving standardized information the get to choose reconstructive method. Patients declining reconstruction or not considered eligible for both methods will be followed as controls. The CRUISE study is a prospective, non-randomized, multi-center, open-label, controlled trial on satisfaction, QoL, function, and complications between ileal pouch anal anastomosis and ileorectal anastomosis. DISCUSSION: Reconstruction after colectomy is a morbidity-associated as well as a resource-intensive activity with the sole purpose of enhancing function, QoL and patient satisfaction. The aim of this study is to provide the best possible information on the risks and benefits of each reconstructive treatment. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT05628701.

Innate lymphoid cell type 3-derived interleukin-22 boosts lipocalin-2 production in intestinal epithelial cells via synergy between STAT3 and NF-κB.

Escherichia coli and Klebsiella pneumoniae are opportunistic pathogens that are commonly associated with infections at mucosal surfaces, such as the lung or the gut. The host response against these types of infections includes the release of epithelial-derived antimicrobial factors such as lipocalin-2 (LCN-2), a protein that specifically inhibits the iron acquisition of Enterobacteriaceae by binding and neutralizing the bacterial iron-scavenging molecule enterobactin. Regulation of epithelial antimicrobial responses, including the release of LCN-2, has previously been shown to depend on IL-22, a cytokine produced by innate lymphoid cells type 3 (ILC3) during Enterobacteriaceae infections. However, much remains unknown about the extent to which antimicrobial responses are regulated by IL-22 and how IL-22 regulates the expression and production of LCN-2 in intestinal epithelial cells (IECs). Our study demonstrates how IL-22-induced activation of STAT3 synergizes with NF-κB-activating cytokines to enhance LCN-2 expression in human IECs and elucidates how ILC3 are involved in LCN-2-mediated host defense against Enterobacteriaceae. Together, these results provide new insight into the role of ILC3 in regulating LCN-2 expression in human IECs and could prove useful in future studies aimed at understanding the host response against Enterobacteriaceae as well as for the development of antimicrobial therapies against Enterobacteriaceae-related infections.

Vitamin D downregulates the IL-23 receptor pathway in human mucosal group 3 innate lymphoid cells.

BACKGROUND: Vitamin D deficiency is a risk factor for inflammatory bowel disease (IBD). The IL-23-driven tissue-resident group 3 innate lymphoid cells (ILC3s) play essential roles in intestinal immunity, and targeting IL-23/12 is a promising approach in IBD therapy. OBJECTIVE: We set out to define the role of 1α,25-dihydroxy vitamin D3 (1,25D) in regulating functional responses of human mucosal ILC3s to IL-23 plus IL-1ß stimulation. METHODS: Transcriptomes of sorted tonsillar ILC3s were assessed by using microarray analysis. ILC3 cytokine production, proliferation, and differentiation were determined by means of flow cytometry, ELISA, and multiplex immunoassay. Intestinal cell suspensions and ILC3s sorted from gut biopsy specimens of patients with IBD were also analyzed along with plasma 25-hydroxy vitamin D3 (25D) detection. RESULTS: ILC3s stimulated with IL-23 plus IL-1ß upregulated the vitamin D receptor and responded to 1,25D with downregulation of the IL-23 receptor pathway. Consequently, 1,25D suppressed IL-22, IL-17F, and GM-CSF production from tonsillar and gut ILC3s. In parallel, 1,25D upregulated genes linked to the IL-1ß signaling pathway, as well as the IL-1ß-inducible cytokines IL-6, IL-8, and macrophage inflammatory protein 1α/ß. The 1,25D-triggered skewing in ILC3 function was not accompanied or caused by changes in viability, proliferation, or phenotype. Finally, we confirmed low 25D plasma levels in patients with IBD with active inflammation. CONCLUSION: In light of the beneficial targeting of IL-23/12 in patients with IBD, 1,25D appears as an interesting therapeutic agent that inhibits the IL-23 receptor pathway, providing a novel mechanism for how ILC3s could be manipulated to regulate intestinal inflammation.

Composition and functionality of the intrahepatic innate lymphoid cell-compartment in human nonfibrotic and fibrotic livers.

Human innate lymphoid cells have been described to exist in different organs, with functional deregulation of these cells contributing to several disease states. Here, we performed the first detailed characterization of the phenotype, tissue-residency properties, and functionality of ILC1s, ILC2s, and ILC3s in the human adult and fetal liver. In addition, we investigated changes in the ILC compartment in liver fibrosis. A unique composition of tissue-resident ILCs was observed in nonfibrotic livers as compared with that in mucosal tissues, with NKp44- ILC3s accounting for the majority of total intrahepatic ILCs. The frequency of ILC2s, representing a small fraction of ILCs in nonfibrotic livers, increased in liver fibrosis and correlated directly with the severity of the disease. Notably, intrahepatic ILC2s secreted the profibrotic cytokine IL-13 when exposed to IL-33 and thymic stromal lymphopoetin (TSLP); these cytokines were produced by hepatocytes, hepatic stellate cells (HSCs), and Kupffer cells in response to TLR-3 stimulation. In summary, the present results provide the first detailed characterization of intrahepatic ILCs in human adult and fetal liver. The results indicate a role for ILC2s in human liver fibrosis, implying that targeting ILC2s might be a novel therapeutic strategy for its treatment.

Loop-ileostomy reversal-patient-related characteristics influencing time to closure.

PURPOSE: To identify factors associated with timing of stoma reversal after rectal cancer surgery in a large Swedish register-based cohort. METHODS: Three thousand five hundred sixty-four patients with rectal cancer who received a protective stoma during surgery in 2007-2013 were identified in the Swedish colorectal cancer register. Time to stoma reversal was evaluated over a follow-up period of one and a half years. Factors associated with timing of stoma reversal were analysed using Cox regression analysis. Reversal within 9 months (12 months if adjuvant chemotherapy) was considered latest expected time to closure. RESULTS: Stoma reversal was performed in 2954 (82.9%) patients during follow-up. Patients with post-secondary education had an increased chance for early stoma reversal (HR 1.13; 95% CI 1.02-1.25). Postoperative complications (0.67; 0.62-0.73), adjuvant chemotherapy (0.63; 0.57-0.69), more advanced cancer stage (stage III 0.74; 0.66-0.83 and stage IV 0.38; 0.32-0.46) and higher ASA score (0.80; 0.71-0.90 for ASA 3-4) were associated with longer time to reversal. Two thousand four hundred thirty-seven (68.4%) patients had stoma reversal within latest expected time to closure. Factors associated to decreased chance of timely reversal were more advanced cancer stage (stage III 0.64; 0.50-0.81 and stage IV 0.19; 0.13-0.27), postoperative complications (0.50; 0.42-0.59) and higher ASA score (0.77; 0.61-0.96 for ASA 3-4). CONCLUSIONS: Patients with a high level of education had a higher chance of timely reversal but medical factors had a stronger association to time to reversal. Patients with advanced rectal cancer are at high risk for non-reversal and should be considered for permanent stoma.

Tissue-infiltrating neutrophils represent the main source of IL-23 in the colon of patients with IBD.

OBJECTIVE: In IBD, interleukin-23 (IL-23) and its receptor (IL-23R) are implicated in disease initiation and progression. Novel insight into which cells produce IL-23 at the site of inflammation at an early stage of IBD will promote the development of new tools for diagnosis, treatment and patient monitoring. We examined the cellular source of IL-23 in colon tissue of untreated newly diagnosed paediatric patients with IBD. DESIGN: Colon tissues from IBD and non-IBD patients were analysed by quantitative real-time PCR (qPCR), immunofluorescence confocal microscopy and flow cytometry after appropriate sample preparation. Blood samples from IBD and non-IBD patients and healthy controls were analysed using flow cytometry and qPCR. RESULTS: We discovered that tissue-infiltrating neutrophils were the main source of IL-23 in the colon of paediatric patients with IBD, while IL-23(+) human leucocyte antigen-DR(+) or IL-23(+)CD14(+) cells were scarce or non-detectable, respectively. The colonic IL-23(+) neutrophils expressed C-X-C motif (CXC)R1 and CXCR2, receptors for the CXC ligand 8 (CXCL8) chemokine family, and a corresponding CXCR1(+)CXCR2(+)IL-23(+)subpopulation of neutrophils was also identified in the blood of both patients with IBD and healthy individuals. However, CXCL8-family chemokines were only elevated in colon tissue from patients with IBD. CONCLUSIONS: This study provides the first evidence of CXCR1(+)CXCR2(+)IL-23-producing neutrophils that infiltrate and accumulate in inflamed colon tissue of patients with IBD. Thus, this novel source of IL-23 may play a key role in disease progression and will be important to take into consideration in the development of future strategies to monitor, treat and prevent IBD.

Higher frequency of anastomotic leakage with stapled compared to hand-sewn ileocolic anastomosis in a large population-based study.

BACKGROUND: The stapling technique was recommended in a recent Cochrane analysis based on relatively small randomized trials between 1970 and 2009. Data from a large Swedish population-based quality register were analyzed in order to compare the leakage frequency between stapled and hand-sewn ileocolic anastomoses in colon cancer surgery. METHODS: Three-thousand four-hundred and twenty-eight patients with an ileocolic anastomosis were entered in a Swedish regional quality register for colon cancer, including the type of anastomosis used. The patients were analyzed by logistic regression regarding risk for leakage, and Cox proportional hazard regression for survival associated with the technique used for anastomosis. Analyses were made for gender, age, elective or emergency surgery, duration of surgery, bleeding, cancer stage, and local radicality. RESULTS: Most anastomoses were hand sewn (1,908 of 3,428, 55.7 %, p < 0.001), whereas stapling was more common among emergency cases (342 of 618, 55.3 %, p < 0.001). Clinically relevant leakage appeared in 58 patients (1.7 %), of whom 51 (87.9 %) were re-operated. Leakage was found to be more frequent after stapled anastomosis (2.4 vs. 1.2 %, p = 0.006), and in multivariate analysis, stapled anastomosis was the only risk factor (OR = 2.04 95 % CI 1.19-3.50). There was no difference in overall survival related to the technique. CONCLUSION: Hand-sewn anastomosis is not associated with a higher leakage rate when comparing to a stapling procedure and is recommended for routine and emergency right-sided colon cancer surgery. This recommendation is based on what appears to be a lower leakage rate, similar survival and lower material cost.

Rapid functional impairment of natural killer cells following tumor entry limits anti-tumor immunity.

Immune cell dysfunction within the tumor microenvironment (TME) undermines the control of cancer progression. Established tumors contain phenotypically distinct, tumor-specific natural killer (NK) cells; however, the temporal dynamics, mechanistic underpinning and functional significance of the NK cell compartment remains incompletely understood. Here, we use photo-labeling, combined with longitudinal transcriptomic and cellular analyses, to interrogate the fate of intratumoral NK cells. We reveal that NK cells rapidly lose effector functions and adopt a distinct phenotypic state with features associated with tissue residency. NK cell depletion from established tumors did not alter tumor growth, indicating that intratumoral NK cells cease to actively contribute to anti-tumor responses. IL-15 administration prevented loss of function and improved tumor control, generating intratumoral NK cells with both tissue-residency characteristics and enhanced effector function. Collectively, our data reveals the fate of NK cells after recruitment into tumors and provides insight into how their function may be revived.

Intestinal stroma guides monocyte differentiation to macrophages through GM-CSF.

Stromal cells support epithelial cell and immune cell homeostasis and play an important role in inflammatory bowel disease (IBD) pathogenesis. Here, we quantify the stromal response to inflammation in pediatric IBD and reveal subset-specific inflammatory responses across colon segments and intestinal layers. Using data from a murine dynamic gut injury model and human ex vivo transcriptomic, protein and spatial analyses, we report that PDGFRA+CD142-/low fibroblasts and monocytes/macrophages co-localize in the intestine. In primary human fibroblast-monocyte co-cultures, intestinal PDGFRA+CD142-/low fibroblasts foster monocyte transition to CCR2+CD206+ macrophages through granulocyte-macrophage colony-stimulating factor (GM-CSF). Monocyte-derived CCR2+CD206+ cells from co-cultures have a phenotype similar to intestinal CCR2+CD206+ macrophages from newly diagnosed pediatric IBD patients, with high levels of PD-L1 and low levels of GM-CSF receptor. The study describes subset-specific changes in stromal responses to inflammation and suggests that the intestinal stroma guides intestinal macrophage differentiation.

Clinicopathological analysis of colorectal cancer: a comparison between emergency and elective surgical cases.

BACKGROUND: Approximately 15 to 30% of colorectal cancers present as an emergency, most often as obstruction or perforation. Studies report poorer outcome for patients who undergo emergency compared with elective surgery, both for their initial hospital stay and their long-term survival. Advanced tumor pathology and tumors with unfavorable histologic features may provide the basis for the difference in outcome. The aim of this study was to compare the clinical and pathologic profiles of emergency and elective surgical cases for colorectal cancer, and relate these to gender, age group, tumor location, and family history of the disease. The main outcome measure was the difference in morphology between elective and emergency surgical cases. METHODS: In total, 976 tumors from patients treated surgically for colorectal cancer between 2004 and 2006 in Stockholm County, Sweden (8 hospitals) were analyzed in the study. Seventeen morphological features were examined and compared with type of operation (elective or emergency), gender, age, tumor location, and family history of colorectal cancer by re-evaluating the histopathologic features of the tumors. RESULTS: In a univariate analysis, the following characteristics were found more frequently in emergency compared with elective cases: multiple tumors, higher American Joint Committee on Cancer (AJCC), tumor (T) and node (N) stage, peri-tumor lymphocytic reaction, high number of tumor-infiltrating lymphocytes, signet-ring cell mucinous carcinoma, desmoplastic stromal reaction, vascular and perineural invasion, and infiltrative tumor margin (P<0.0001 for AJCC stage III to IV, N stage 1 to 2/3, and vascular invasion). In a multivariate analysis, all these differences, with the exception of peri-tumor lymphocytic reaction, remained significant (P<0.0001 for multiple tumors, perineural invasion, infiltrative tumor margin, AJCC stage III, and N stage 1 to 2/3). CONCLUSIONS: Colorectal cancers that need surgery as an emergency case generally show a more aggressive histopathologic profile and a more advanced stage than do elective cases. Essentially, no difference was seen in location, and therefore it is likely there would be no differences in macro-environment either. Our results could indicate that colorectal cancers needing emergency surgery belong to an inherently specific group with a different etiologic or genetic background.

Costs Related to Diverting Ileostomy After Rectal Cancer Surgery: A Population-Based Healthcare Cost Analysis Based on Nationwide Registers.

Low anterior resection for rectal cancer often includes a diverting loop-ileostomy to avoid the severe consequences of anastomotic leakage. Reversal of the stoma is often delayed, which can incur health-care costs on different levels. The aim is to, on population basis, determine stoma-related costs, and to investigate habitual and socioeconomic factors associated to the level of cost. Multi-register design with data from the Swedish Rectal Cancer Registry, the National Prescribed Drug Register, Statistics Sweden and cost-administrative data from the National Board of Health and Welfare. Data was gathered for 3564 patients with rectal cancer surgery 2007 to 2013, for 3 years following the surgery. Factors influencing the cost of inpatient care and stoma-related consumables were assessed with linear regression analyses. All monthly costs were higher for females (consumables P < .001 and in-patient care P = .031). Post-secondary education (P = .003) and younger age (P = .020) was associated with a higher cost for consumables while suffering a surgical complication was associated with increased cost for inpatient care (P < .001). Patients who had their stoma longer had lower monthly costs (consumables P < .001 and in-patient care P < .001). Female gender, longer duration of stoma, young age, and higher education are associated with higher costs for the care of a diverting stoma after rectal cancer surgery. This study does not allow for analyses of causality but the results together with deepened analyses of underlying reasons form a proper basis for decisions in health care planning and allocation of resources. These findings may have implications on the debate of equal care for all.

The single-cell transcriptional landscape of innate and adaptive lymphocytes in pediatric-onset colitis.

Innate lymphoid cells (ILCs) are considered innate counterparts of adaptive T cells; however, their common and unique transcriptional signatures in pediatric inflammatory bowel disease (pIBD) are largely unknown. Here, we report a dysregulated colonic ILC composition in pIBD colitis that correlates with inflammatory activity, including accumulation of naive-like CD45RA+CD62L- ILCs. Weighted gene co-expression network analysis (WGCNA) reveals modules of genes that are shared or unique across innate and adaptive lymphocytes. Shared modules include genes associated with activation/tissue residency, naivety/quiescence, and antigen presentation. Lastly, nearest-neighbor-based analysis facilitates the identification of "most inflamed" and "least inflamed" lymphocytes in pIBD colon with unique transcriptional signatures. Our study reveals shared and unique transcriptional signatures of colonic ILCs and T cells in pIBD. We also provide insight into the transcriptional regulation of colonic inflammation, deepening our understanding of the potential mechanisms involved in pIBD.

CD45RA+CD62L- ILCs in human tissues represent a quiescent local reservoir for the generation of differentiated ILCs.

Innate lymphoid cells (ILCs) are highly plastic and predominantly mucosal tissue-resident cells that contribute to both homeostasis and inflammation depending on the microenvironment. The discovery of naïve-like ILCs suggests an ILC differentiation process that is akin to naïve T cell differentiation. Delineating the mechanisms that underlie ILC differentiation in tissues is crucial for understanding ILC biology in health and disease. Here, we showed that tonsillar ILCs expressing CD45RA lacked proliferative activity, indicative of cellular quiescence. CD62L distinguished two subsets of CD45RA+ ILCs. CD45RA+CD62L+ ILCs (CD62L+ ILCs) resembled circulating naïve ILCs because they lacked the transcriptional, metabolic, epigenetic, and cytokine production signatures of differentiated ILCs. CD45RA+CD62L- ILCs (CD62L- ILCs) were epigenetically similar to CD62L+ ILCs but showed a transcriptional, metabolic, and cytokine production signature that was more akin to differentiated ILCs. CD62L+ and CD62L- ILCs contained uni- and multipotent precursors of ILC1s/NK cells and ILC3s. Differentiation of CD62L+ and CD62L- ILCs led to metabolic reprogramming including up-regulation of genes associated with glycolysis, which was needed for their effector functions after differentiation. CD62L- ILCs with preferential differentiation capacity toward IL-22-producing ILC3s accumulated in the inflamed mucosa of patients with inflammatory bowel disease. These data suggested distinct differentiation potential of CD62L+ and CD62L- ILCs between tissue microenvironments and identified that manipulation of these cells is a possible approach to restore tissue-immune homeostasis.

Colorectal cancer susceptibility loci in a population-based study: Associations with morphological parameters.

Recent genome-wide association studies have identified multiple genetic loci and single nucleotide polymorphisms (SNPs) associated with either increased or decreased risk of colorectal cancer (CRC). In the present study, our objective was to determine whether 11 of the new susceptibility CRC loci are associated with tumor morphology and to confirm these loci as distinct and etiologically different risk factors in the development of CRC. The following clinical and morphological parameters were analyzed in 1572 samples: tumor size, T-stage, lymph node metastases, degree of differentiation, mucin production, Crohn-like peritumoral lymphocytic infiltration, tumor-infiltrating lymphocytes, desmoplastic reaction, necrosis, invasion of blood or lymph vessels, perineural growth, medullary type, budding, and tumor margin. One SNP from each of the 11 loci (rs6983267 on 8q24.21, rs16892766 on 8q23.3, rs719725 on 9p24.1, rs10795668 on 10p14, rs3802842 on 11q23.1, rs4444235 on 14q22.2, rs4779584 on 15q13.3, rs9929218 on 16q22.1, rs4939827 on 18q21.1, rs10411210 on 19q13.11, and rs961253 on 20p12.3) was genotyped for all cases. Odds ratios, 95% confidence intervals, and the corresponding P values were calculated for the 11 SNPs identified above. A cross tabulation between SNPs and morphology was performed. Several loci showed statistically significant associations with specific phenotypes. The findings are consistent with pathogenic variants in several loci that act in distinct CRC and morphogenetic pathways. Further large-scale studies are required to validate these findings.

Cytokines regulate the antigen-presenting characteristics of human circulating and tissue-resident intestinal ILCs.

ILCs and T helper cells have been shown to exert bi-directional regulation in mice. However, how crosstalk between ILCs and CD4+ T cells influences immune function in humans is unknown. Here we show that human intestinal ILCs co-localize with T cells in healthy and colorectal cancer tissue and display elevated HLA-DR expression in tumor and tumor-adjacent areas. Although mostly lacking co-stimulatory molecules ex vivo, intestinal and peripheral blood (PB) ILCs acquire antigen-presenting characteristics triggered by inflammasome-associated cytokines IL-1ß and IL-18. IL-1ß drives the expression of HLA-DR and co-stimulatory molecules on PB ILCs in an NF-κB-dependent manner, priming them as efficient inducers of cytomegalovirus-specific memory CD4+ T-cell responses. This effect is strongly inhibited by the anti-inflammatory cytokine TGF-ß. Our results suggest that circulating and tissue-resident ILCs have the intrinsic capacity to respond to the immediate cytokine milieu and regulate local CD4+ T-cell responses, with potential implications for anti-tumor immunity and inflammation.

Lack of an association between the TGFBR1*6A variant and colorectal cancer risk.

PURPOSE: Recently a common variant of the TGFBR1 gene, TGFBR1*6A, has been proposed to act as a low-penetrance tumor susceptibility allele for colorectal cancer, but data from published studies with individually low statistical power are conflicting. To further evaluate the relationship between TGFBR1*6A and colorectal cancer risk, we have conducted a large case-control study and a meta-analysis of previously published studies. EXPERIMENTAL DESIGN: A total of 1,042 colorectal cancer cases and 856 population controls were genotyped for the TGFBR1*6A polymorphism. Previously published case-control studies of the relationship between TGFBR1*6A and colorectal cancer were identified, and a meta-analysis was conducted. RESULTS: We found no evidence that homozygosity, heterozygosity or carrier status for the TGFBR1*6A allele confers an increased risk of colorectal cancer; respective odds ratios (OR) were 1.05 [95% confidence interval (95% CI), 0.83-1.32], 0.82 (95% CI, 0.34-1.99), and 0.92 (95% CI, 0.74-1.15), respectively. A meta-analysis of our case-control study and seven other studies that provided data on 2,627 colorectal cancer cases and 3,387 controls also yielded no evidence that possession of the TGFBR1*6A allele is associated with an elevated risk of colorectal cancer; pooled estimate of the OR were 1.20 (95% CI, 0.64-2.24) for homozygosity, 1.11 (95% CI, 0.96-1.29) for heterozygosity, and 1.13 (95% CI, 0.98-1.30) for carriers of TGFBR1*6A. CONCLUSION: Current data provide limited support for the hypothesis that sequence variation in TGFBR1 defined by the TGFBR1*6A allele confers an elevated risk of colorectal cancer.

The CHEK2 1100delC variant in Swedish colorectal cancer.

BACKGROUND: The cell cycle checkpoint kinase 2 (CHEK2) 1100delC variant has recently been identified at high frequency in families with both breast and colorectal cancer, suggesting the possible role of this variant in colorectal cancer predisposition. PATIENTS AND METHODS: To evaluate the role of CHEK2 ll00delC among Swedish colorectal cancer patients, the variant frequency was determined in 174 selected familial cases, 644 unselected cases and 760 controls, as well as in l8 families used in the genome-wide linkage analysis, where weak linkage was seen for the region harboring the CHEK2 gene. RESULTS: CHEK2 l100delC was found in 1.15% of familial and in 0.93% of unselected cases, compared to 0.66% of controls, showing no significant difference between groups. One out of 45 familial cases with a family history of breast cancer was shown to be a carrier. The variant was not identified in the 18 families included in the linkage analysis. CONCLUSION: The CHEK2 1100delC was not significantly increased in Swedish colorectal cancer patients, however, in order to determine the role of the variant in colorectal cancer families with the history of breast cancer a larger sample size is needed.

Persistence of K-ras mutations in plasma after colorectal tumor resection.

Free DNA in the circulation is increased five-to ten-fold in patients with solid tumours compared to healthy controls. A range of tumor-specific mutated DNA has been shown to be readily extractable and possible to analyse from plasma and serum in these patients. K-ras oncogene mutations are an early event in a subset of colorectal tumors and have been found in 30-60% of patients with colorectal carcinoma (CRC). The presence of tumor-derived k-ras gene mutations in the circulation has previously been described before surgery. The aim of this study was to characterize the presence of mutant k-ras in plasma in the short-term postoperative period after radical surgery of CRC patients, and further to characterize this in relation to relapse of the disease. Tumors and corresponding plasma pre- and postoperatively on day three after surgery were collected from 25 patients with CRC (Dukes' stage A-D). Biopsies for DNA extraction from the tumors were collected from the most invasive parts microscopically. After PCR amplification of the k-ras gene (codon 12 and 13), the presence of mutations was analysed by TGGE (temperature gradient gel electrophoresis). Twenty four/25 patients underwent putatively curative resections. Sixteen of the 25 patients (64%) expressed k-ras mutations in their tumor. Of these, 9 patients (56%) also had detectable k-ras mutations in preoperative plasma samples. On day three postoperatively, 8 of these patients persistently were found to have mutant k-ras in the plasma. This was not correlated with tumor stage. None of the 9 tumor mutation-negative cases expressed mutated k-ras in their plasma pre- or postoperatively. The results indicate that plasma mutant k-ras can be detected pre- and early postoperatively in all stages of colorectal neoplasia. No correlation between short-term postoperative persistence of mutant plasma-DNA and disease recurrence at follow-up was found. However, the use of k-ras as a marker during postoperative follow-up and as a possible tool for early detection of recurrent disease must be further characterized.