Chronic ulcerative colitis associated with malignant disease. 1928

Historical Perspectives: Malignancy in Crohn's Disease and Ulcerative Colitis

While both Crohn' disease (CD) and ulcerative colitis (UC) are known to predispose patients to certain intestinal malignancies, the exact mechanism of carcinogenesis remains unknown and optimal screening guidelines have not been established. This article will explore the history of our understanding of intestinal malignancy in inflammatory bowel disease (IBD). To contextualize the medical community's difficulty in linking each condition to cancer, the first section will review the discovery of CD and UC. Next, we discuss early attempts to define IBD's relationship with small bowel adenocarcinoma and colorectal cancer. The article concludes with a review of each disease's surgical history and the ways in which certain procedures produced poor oncologic outcomes.

Combinatorial treatment with polyI:C and anti-IL6 enhances apoptosis and suppresses metastasis of lung cancer cells

Activation of TLR3 stimulates cancer cell apoptosis and triggers secretion of inflammatory cytokines. PolyI:C, a TLR3 agonist, activates immune cells and regresses metastatic lung cancer in vivo. Although polyI:C reportedly kills lung carcinomas, the mechanism remains elusive. Here, we demonstrated that polyI:C suppressed the proliferation and survival of metastatic (NCI-H358 and NCI-H292) and non-metastatic (A549) lung cancer cells. Notably, A549, NCI-H292 and NCI-H358 which are inducible by polyI:C, expressed low-to-medium level of TLR3 protein, and were susceptible to polyI:C treatment. By contrast, NCI-H1299, which endogenously expresses high level of TLR3 protein, was insensitive to polyI:C. We showed that polyI:C stimulated pro-inflammatory cytokines associated with survival and metastasis in a cell type-specific manner. While A549 and NCI-H292 released high levels of IL6, IL8 and GRO, the NCI-H358 cells endogenously secretes abundant levels of these cytokines, and was not further induced by polyI:C. Thus, NCI-H358 was resistant to the inhibition of cytokine-dependent metastasis. NCI-H1299, which was unresponsive to polyI:C, did not produce any of the pro-inflammatory cytokines. Treatment of A549 with a combination of polyI:C and anti-IL6 antibody significantly decreased IL6 production, and enhanced polyI:C-mediated killing and suppression of oncogenicity and metastasis. While polyI:C stimulated the phosphorylation of STAT3 and JAK2, blockade of these proteins enhanced polyI:C-mediated suppression of survival and metastasis. Taken together, polyI:C alone provoked apoptosis of lung cancer cells that express low-to-medium levels of functional TLR3 protein. The combinatorial treatment with polyI:C and anti-IL6 enhanced polyI:C-mediated anticancer activities through IL6/JAK2/STAT3 signalling, and apoptosis via TLR3-mediated caspase 3/8 pathway.

Use and barriers to chromoendoscopy for dysplasia surveillance in inflammatory bowel disease

Traditionally, patients with inflammatory bowel disease (IBD) have been thought to be at increased risk of developing colitis-associated colorectal cancer. Although there are recent data suggesting that rates of colitis-associated cancer in IBD patients is declining, current guidelines still recommend regular dysplasia surveillance for early detection and prevention of neoplasia in patients with IBD. White-light endoscopy with random biopsies has been the traditional approach for dysplasia detection; however, newer technologies and approaches have emerged. One method, dye-based chromoendoscopy, has the potential to detect more dysplasia. However, longitudinal data to showing a benefit in morbidity or mortality from the use of chromoendoscopy are still lacking. Many societies have included recommendation on the use of chromoendoscopy with targeted biopsies as a method of surveillance for colitis - associated colorectal cancer. This narrative review seeks to outline data on dysplasia detection as well as barriers to the implementation of dye-based chromoendoscopy for the prevention and early detection of colitis-associated colorectal cancer.

Association between Toll-like receptor 7 Gln11Leu single-nucleotide polymorphism and basal cell carcinoma

Non-melanoma skin cancers (NMSC) are the most common form of human skin cancer. The majority of NMSC are basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) with a BCC:SCC incidence ratio of 4:1 in immunocompetent patients. Toll-like receptors (TLRs) are transmembrane glycoproteins that recognize pathogen-associated molecular patterns and damage-associated molecular patterns, against which they activate the innate immune response and initiate the adaptive immune response. Genetic variations of these receptors can alter the immune system and are involved in evolution and susceptibility of various diseases, including cancer. Imiquimod, an agonist of TLR7, is applied topically in the treatment of premalignant and malignant skin disorders, in particular BCC. The high efficacy of this TLR7 agonist toward BCC supports a possible role of this receptor in the induction of BCC and, consequently, polymorphisms of this receptor could be responsible for a greater or lesser susceptibility to BCC. The aim of the present study was to evaluate whether the presence of the functional TLR7 rs179008/Gln11Leu promoter polymorphism conferred an increased susceptibility to BCC. A case-control study with 177 BCC cases and 158 controls was performed to highlight the possible association between this polymorphism and the susceptibility to BCC. As the TLR7 gene is localized on chromosome X, the allelic frequency of this polymorphism was analyzed separately in males and females. The analysis of the distribution of frequencies of wild-type TLR7 and variant TLR7 carrying the single-nucleotide polymorphism (SNP) rs179008 in patients with BCC and healthy subjects did not reveal any statistically significant difference between cases and controls. This study does not suggest the involvement of the SNP rs179008 of TLR7 in the susceptibility to BCC, but cannot exclude a role for TLR7 in BCC carcinogenesis considering the high efficacy of the TLR7 agonist, imiquimod, in the treatment of this neoplastic disorder.

Colorectal Cancer in Patients With Inflammatory Bowel Disease: The Need for a Real Surveillance Program

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been widely shown. This association is responsible for 10% to 15% of deaths in patients with IBD, even if according to some studies, the risk of developing CRC seems to be decreased. An adequate surveillance of patients identified as at-risk patients, might improve the management of IBD-CRC risk. In this article we review the literature data related to IBD-CRC, analyze potential risk factors such as severity of inflammation, duration, and extent of IBD, age at diagnosis, sex, family history of sporadic CRC, and coexistent primary sclerosing cholangitis, and update epidemiology on the basis of new studies. Confirmed risk factors for IBD-CRC are severity, extent, and duration of colitis, the presence of coexistent primary sclerosing cholangitis, and a family history of CRC. Current evidence-based guidelines recommend surveillance colonoscopy for patients with colitis 8 to 10 years after diagnosis, further surveillance is decided on the basis of patient risk factors. The classic white light endoscopy, with random biopsies, is now considered unsatisfactory. The evolution of technology has led to the development of new techniques that promise to increase the effectiveness of the monitoring programs. Chromoendoscopy has already proved highly effective and several guidelines suggest its use with a target biopsy. Confocal endomicroscopy and autofluorescence imaging are currently being tested and for this reason they have not yet been considered as useful in surveillance programs.

Has the risk of colorectal cancer in inflammatory bowel disease decreased?

The association between inflammatory bowel disease (IBD) and colorectal cancer (CRC) has been acknowledged for almost a century and is assumedly promoted by a chronic inflammation-driven carcinogenic process in the intestine in combination with a genetic predisposition. The magnitude of the risk of CRC in IBD remains a continuing subject of debate. The early, high risk estimates for CRC in IBD were most likely overestimated due to selected patient populations originating from tertiary referral centers with a disproportional high percentage of patients with severe disease. Later population-based studies calculating risk estimates from a broad spectrum of IBD patients have found the risk to be significantly lower. At present, there is evidence that IBD patients with longstanding and extensive disease with uncontrolled inflammation are those at increased risk. Additional, other recognized risk factors include early age at onset, family history of CRC, and concomitant primary sclerosing cholangitis. A significant amount of effort is put into identifying potential preventive factors of CRC in IBD, including surveillance programs and chemopreventive agents but the individual effect of these remains uncertain. Interestingly, recent studies have reported a decline in risk of CRC over time. Surveillance programs and the new treatment strategies, particular biological treatment might be part of the reason for the observed decline in risk of CRC in IBD over time but future studies will have investigate this assumption.

Risk of colorectal cancer in patients with ulcerative colitis: a meta-analysis of population-based cohort studies

BACKGROUND & AIMS

Patients with ulcerative colitis (UC) have an increased risk of developing colorectal cancer (CRC). Studies examining the magnitude of this association have yielded conflicting results. We performed a meta-analysis of population-based cohort studies to determine the risk of CRC in patients with UC.

METHODS

We used MEDLINE, EMBASE, Cochrane, and CINAHL to perform a systematic literature search. We included 8 studies in the meta-analysis on the basis of strict inclusion and exclusion criteria. We calculated pooled standardized incidence ratios (SIRs) with 95% confidence intervals (CIs) for risk of CRC in patients with UC and performed meta-regression analyses of the effect of cohort size, calendar period, observation time, percentage with proctitis, and rates of colectomy on the risk of CRC.

RESULTS

An average of 1.6% of patients with UC was diagnosed with CRC during 14 years of follow-up. SIRs ranged from 1.05 to 3.1, with a pooled SIR of 2.4 (95% CI, 2.1-2.7). Men with UC had a greater risk of CRC (SIR, 2.6; 95% CI, 2.2-3.0) than women (SIR, 1.9; 95% CI, 1.5-2.3). Young age was a risk factor for CRC (SIR, 8.6; 95% CI, 3.8-19.5; although this might have resulted from small numbers), as was extensive colitis (SIR, 4.8; 95% CI, 3.9-5.9). In meta-regression analyses, only cohort size was associated with risk of CRC.

CONCLUSIONS

In population-based cohorts, UC increases the risk of CRC 2.4-fold. Male sex, young age at diagnosis with UC, and extensive colitis increase the risk.

Salicylate modulates oxidative stress in the rat colon: a proteomic approach

The dietary phenolic compound, salicylic acid, decreases oxidative stress and pro-inflammatory and potentially neo-plastic prostaglandins with a concomitant increase in glutathione peroxidase activity. Salicylic acid, a dietary plant-based phenolic compound and also the main metabolite of aspirin, may contribute to the colon protective effects of plant-based diets. Oxidative stress is a characteristic of pre-cancerous and cancerous colon and inflammatory bowel diseases (IBD) that increase colon cancer risk. The mechanism(s) whereby salicylic acid modulates potentially pro-cancerous activity associated with oxidative stress is further investigated here using a proteomic approach. A rat model of oxidative stress was supplemented with salicylic acid (1 mg/kg diet, mean plasma levels 310+/-32 micromol/l). Soluble colon protein extracts were subjected to 2D PAGE. Salicylic acid modulated proteins, identified using MALDI-TOF and LC/MS/MS, are involved in protein folding, transport, redox, energy metabolism and cytoskeletal regulation. A partial least squares (PLS) analysis approach was used to assist biological interpretation of the altered protein profiles via their associations between previously published biochemical measurements of oxidative stress, prostaglandin levels and increased glutathione peroxidase activity. Early detection of altered homeostasis in colon may assist in identifying pre-pathological features preceding colon tumorigenesis and contribute to an understanding of epidemiological evidence supporting a protective effect of plant-based diets.

Bowel inflammation as measured by fecal calprotectin: a link between lifestyle factors and colorectal cancer risk

The mechanisms by which the lifestyle risk factors obesity, physical inactivity, and low fiber intake predispose to colorectal cancer (CRC) are unclear. Chronic bowel inflammation predisposes to malignancy in cases of inflammatory bowel disease. Many lifestyle risk factors for CRC are associated with evidence of systemic inflammation as indicated by circulating levels of C-reactive protein (CRP), but it is unknown how this relates to inflammation at tissue level. Little is known about the degree of bowel inflammation in general population and the factors that affect it. Therefore, we aimed to assess the relation of levels of bowel inflammation in the general population and lifestyle risk factors for CRC, and to additionally assess whether these associations, if present, were attenuated by controlling for evidence of systemic inflammation. Average CRC risk subjects (320) of either sex aged 50-70 were recruited in South London. A stool sample was provided for calprotectin measurement (a marker of bowel inflammation), serum for CRP, and a detailed dietary and lifestyle questionnaire completed. There was a significant positive relationship between fecal calprotectin and increasing age (P = 0.002), obesity (P = 0.04), physical inactivity (P = 0.01), and an inverse relationship with fiber intake (P = 0.02) and vegetable consumption (P = 0.04). The relationship with obesity was attenuated by controlling for serum CRP. Fecal calprotectin levels are associated with lifestyle risk factors for colorectal cancer. Low-level asymptomatic bowel inflammation may be the link between lifestyle and the pathogenesis of CRC, and circulating proinflammatory cytokines may be part of the mechanism for this link.

Rectal lymphoma in ulcerative colitis treated with azathioprine

Primary malignant lymphoma of the bowel is a rare complication of inflammatory bowel disease. The association of gastrointestinal lymphoma, inflammatory bowel disease and prior immunosuppression remains unclear. We report the first case of azathioprine-treated ulcerative colitis developing rectal lymphoma.