The burden of ulcerative colitis (UC) in relation to disease severity is not well documented. This study quantitatively evaluated the relationship between disease activity and quality of life (QoL), as well as health care utilization, cost, and work-related impairment associated with UC in an Australian population. A cross-sectional, noninterventional, observational study was performed in patients with a wide range of disease severity recruited during routine specialist consultations. Evaluations included the Assessment of Quality of Life-8-dimension (AQoL-8D), EuroQol 5-dimension, 5-level (EQ-5D-5L), the disease-specific Inflammatory Bowel Disease Questionnaire (IBDQ), and the Work Productivity and Activity Impairment (WPAI) instrument. The 3-item Partial Mayo Score was used to assess disease severity. Health care resource utilization was assessed by chart review and patient questionnaires. In 175 patients, mean (SD) AQoL-8D and EQ-5D-5L scores were greater for patients in remission (0.80 [0.19] and 0.81 [0.18], respectively) than for patients with active disease (0.70 [0.20] and 0.72 [0.19], respectively, both Ps<0.001). IBDQ correlated with both AQoL-8D (r=0.73; P<0.0001) and EQ-5D-5L (0.69; P<0.0001). Mean 3-month UC-related health care cost per patient was AUD $2914 (SD=$3447 [mean for patients in remission=$1970; mild disease=$3736; moderate/severe disease=$4162]). Patients in remission had the least work and activity impairment. More severe UC disease was associated with poorer QoL. Substantial health care utilization, costs, and work productivity impairments were found in this sample of patients with UC. Moreover, greater disease activity was associated with greater health care costs and impairment in work productivity and daily activities.

Background: This study aimed to investigate clinicopathological and molecular tumour features associated with intratumoral pks⁺Escherichia coli (pks⁺E.coli⁺), pks⁺E.coli^- (non-E.coli bacteria harbouring the pks island), Enterotoxigenic Bacteroides fragilis (ETBF) and Fusobacterium nucleatum (F. nucleatum). Methods: We screened 1697 tumour-derived DNA samples from the Australasian Colorectal Cancer Family Registry, Melbourne Collaborative Cohort Study and the ANGELS study using targeted PCR. Results: Pks⁺E.coli⁺ was associated with male sex (P < 0.01) and APC:c.835-8 A > G somatic mutation (P = 0.03). The association between pks⁺E.coli⁺ and APC:c.835-8 A > G was specific to early-onset CRCs (diagnosed G was not associated with pks⁺E.coli^- (P = 0.36). F. nucleatum was associated with DNA mismatch repair deficiency (MMRd), BRAF:c.1799T>A p.V600E mutation, CpG island methylator phenotype, proximal tumour location, and high levels of tumour infiltrating lymphocytes (Ps < 0.01). In the stratified analysis by MMRd subgroups, F. nucleatum was associated with Lynch syndrome, MLH1 methylated and double MMR somatic mutated MMRd subgroups (Ps < 0.01). Conclusion: Intratumoral pks⁺E.coli⁺ but not pks⁺E.coli^- are associated with CRCs harbouring the APC:c.835-8 A > G somatic mutation, suggesting that this mutation is specifically related to DNA damage from colibactin-producing E.coli exposures. F. nucleatum was associated with both hereditary and sporadic MMRd subtypes, suggesting the MMRd tumour microenvironment is important for F. nucleatum colonisation irrespective of its cause.

The aim of this study was to determine the proportions and predictors of first-degree relatives (FDRs) of colorectal cancer (CRC) patients (i) ever receiving any CRC testing and (ii) receiving CRC screening in accordance with CRC screening guidelines.

Recent epidemiological evidence shows that colorectal cancer (CRC) continues to occur in carriers of pathogenic mismatch repair (path_MMR) variants despite frequent colonoscopy surveillance in expert centres. This observation conflicts with the paradigm that removal of all visible polyps should prevent the vast majority of CRC in path_MMR carriers, provided the screening interval is sufficiently short and colonoscopic practice is optimal. To inform the debate, we examined, in the Prospective Lynch Syndrome Database (PLSD), whether the time since last colonoscopy was associated with the pathological stage at which CRC was diagnosed during prospective surveillance. Path_MMR carriers were recruited for prospective surveillance by colonoscopy. Only variants scored by the InSiGHT Variant Interpretation Committee as class 4 and 5 (clinically actionable) were included. CRCs detected at the first planned colonoscopy, or within one year of this, were excluded as prevalent cancers. Stage at diagnosis and interval between last prospective surveillance colonoscopy and diagnosis were available for 209 patients with 218 CRCs, including 162 path_MLH1, 45 path_MSH2, 10 path_MSH6 and 1 path_PMS2 carriers. The numbers of cancers detected within < 1.5, 1.5–2.5, 2.5–3.5 and at > 3.5 years since last colonoscopy were 36, 93, 56 and 33, respectively. Among these, 16.7, 19.4, 9.9 and 15.1% were stage III–IV, respectively (p = 0.34). The cancers detected more than 2.5 years after the last colonoscopy were not more advanced than those diagnosed earlier (p = 0.14). The CRC stage and interval since last colonoscopy were not correlated, which is in conflict with the accelerated adenoma-carcinoma paradigm. We have previously reported that more frequent colonoscopy is not associated with lower incidence of CRC in path_MMR carriers as was expected. In contrast, point estimates showed a higher incidence with shorter intervals between examinations, a situation that may parallel to over-diagnosis in breast cancer screening. Our findings raise the possibility that some CRCs in path_MMR carriers may spontaneously disappear: the host immune response may not only remove CRC precursor lesions in path_MMR carriers, but may remove infiltrating cancers as well. If confirmed, our suggested interpretation will have a bearing on surveillance policy for path_MMR carriers.

We have previously reported a high incidence of colorectal cancer (CRC) in carriers of pathogenic MLH1 variants (path_MLH1) despite follow-up with colonoscopy including polypectomy. The cohort included Finnish carriers enrolled in 3-yearly colonoscopy (n = 505; 4625 observation years) and carriers from other countries enrolled in colonoscopy 2-yearly or more frequently (n = 439; 3299 observation years). We examined whether the longer interval between colonoscopies in Finland could explain the high incidence of CRC and whether disease expression correlated with differences in population CRC incidence. Cumulative CRC incidences in carriers of path_MLH1 at 70-years of age were 41% for males and 36% for females in the Finnish series and 58% and 55% in the non-Finnish series, respectively (p > 0.05). Mean time from last colonoscopy to CRC was 32.7 months in the Finnish compared to 31.0 months in the non-Finnish (p > 0.05) and was therefore unaffected by the recommended colonoscopy interval. Differences in population incidence of CRC could not explain the lower point estimates for CRC in the Finnish series. Ten-year overall survival after CRC was similar for the Finnish and non-Finnish series (88% and 91%, respectively; p > 0.05). The hypothesis that the high incidence of CRC in path_MLH1 carriers was caused by a higher incidence in the Finnish series was not valid. We discuss whether the results were influenced by methodological shortcomings in our study or whether the assumption that a shorter interval between colonoscopies leads to a lower CRC incidence may be wrong. This second possibility is intriguing, because it suggests the dogma that CRC in path_MLH1 carriers develops from polyps that can be detected at colonoscopy and removed to prevent CRC may be erroneous. In view of the excellent 10-year overall survival in the Finnish and non-Finnish series we remain strong advocates of current surveillance practices for those with LS pending studies that will inform new recommendations on the best surveillance interval.

Microsatellite instability (MSI) is a useful marker for risk assessment, prediction of chemotherapy responsiveness and prognosis in patients with colorectal cancer. Here, we describe a next generation sequencing approach for MSI testing using the MiSeq platform. Different from other MSI capturing strategies that are based on targeted gene capture, we utilize “deep resequencing”, where we focus the sequencing on only the microsatellite regions of interest. We sequenced a series of 44 colorectal tumours with normal controls for five MSI loci (BAT25, BAT26, BAT34c4, D18S55, D5S346) and a second series of six colorectal tumours (no control) with two mononucleotide loci (BAT25, BAT26). In the first series, we were able to determine 17 MSI-High, 1 MSI-Low and 26 microsatellite stable (MSS) tumours. In the second series, there were three MSI-High and three MSS tumours. Although there was some variation within individual markers, this NGS method produced the same overall MSI status for each tumour, as obtained with the traditional multiplex PCR-based method.