Cancer Biology or Ineffective Surveillance? A Multicentre Retrospective Analysis of Colitis-Associated Post-Colonoscopy Colorectal Cancers

Preventable Predictive Factors of Post-colonoscopy Colorectal Cancer in Inflammatory Bowel Disease

BACKGROUND AND AIM

Post-colonoscopy colorectal cancer [PCCRC] is a colorectal cancer [CRC] diagnosed after a colonoscopy in which no cancer was detected [index colonoscopy]. Although the overall cumulative rates of PCCRC are low in both the general population and inflammatory bowel disease [IBD] patients, the overall incidence of PCCRC in IBD is greater than that documented in the general population. This study aimed to identify the index colonoscopy-related factors and patients' characteristics influencing IBD-associated PCCRC development.

METHODS

We carried out an observational, retrospective study in which IBD-associated PCCRCs were diagnosed between 2010 and 2023. The PCCRC group was compared with a control cohort of IBD patients without CRC, matched 1:1 by several demographic and clinical features as well as characteristics of index colonoscopy, to minimise selection bias.

RESULTS

Among 61 CRCs identified, 37 [61%] were PCCRC. Twelve of the 37 [32%] PCCRC were diagnosed within 12 months after the previous negative colonoscopy, 15 [41%] within 12-36 months, and 10 [27%] within 36-60 months. In the multivariate analysis, the inadequate bowel preparation of the index colonoscopy (odds ratio [OR]: 5.9; 95% confidence interval [CI]: 11.1-31.4) and the presence of high-risk factors for CRC [OR: 24.03; 95% CI: 3.1-187.8] were independently associated with PCCRC. Conversely, prior exposure to immunosuppressors or biologics [OR: 0.17; 95% CI: 0.03-0.83] and random biopsies sampling at index colonoscopy [OR: 0.19; 95% CI: 0.04-0.85] were inversely associated with PCCRC.

CONCLUSIONS

More than 50% of CRCs in our population were PCCRC. PCCRCs were associated with previous inadequate cleansing and occurred more frequently in high-risk patients.

Undetected Dysplasia at Colectomy in Patients With Inflammatory Bowel Diseases. What Are We Missing?

BACKGROUND AND AIMS

Patients with inflammatory bowel disease (IBD) have a higher risk of developing colorectal dysplasia and colorectal cancer compared to the general population. Although the use of surveillance protocols has improved the ability to detect dysplasia, some lesions are still missed at colonoscopy. This study aims to determine the rate of dysplastic lesions that are undetected at colonoscopies in IBD patients undergoing colectomy and to identify factors associated with missed dysplasia.

METHODS

Patients who had received a total or subtotal colectomy at Mayo Clinic (Rochester, Minnesota), between January 2003 and December 2022, and had a complete colonoscopy within 5 years before surgery were retrospectively enrolled. Data abstracted included demographic information, disease-related data, colonoscopy and pathology reports, and surgery pathology reports. Colonoscopy and surgery findings were compared, and patients were divided into 3 groups: no dysplasia at both, detected dysplasia, and undetected dysplasia.

RESULTS

Among 1320 IBD patients undergoing colectomy, 5.4% had undetected dysplastic lesions identified only at surgery. Factors independently associated with dysplasia detection were endoscopic remission or mild endoscopic disease activity (odds ratio [OR], 2.326; P = .0081; 95% CI, 1.246-4.342), prior dysplasia detection (OR, 1.876; P = .0491; 95% CI, 1.002-3.511), colonoscopy performed for surveillance (OR, 2.380; P = .0048; 95% CI, 1.302-4.350), and longer disease duration at surgery (OR, 1.039; P = .0085; 95% CI, 1.010-1.070).

CONCLUSIONS

Clinicians should be aware of the risk of missing dysplastic lesions, especially when endoscopic disease activity is moderate/severe, and not only for longstanding disease. Efforts should be made to obtain endoscopic remission to make the "invisible" visible.

The Importance of Genetic Screening on the Syndromes of Colorectal Cancer and Gastric Cancer: A 2024 Update

Gastrointestinal cancers (GIC), encompassing colonic, rectal, and gastric malignancies, rank among the most prevalent cancer types globally, contributing significantly to cancer-related mortality. In the scientific literature, various syndromes associated with colorectal and gastric cancers have been elucidated, highlighting the intricate interplay between genetic factors and disease manifestation. The primary objective of this study was to conduct a genetic exploration aimed at elucidating these associations and identifying shared genetic determinants across these cancer types. Notably, considerable research has focused on the KRAS gene mutations, polymorphisms in nucleic acids, the Wnt signaling pathway, and the role of chemokine ligands in tumorigenesis. While investigations into natural plant extracts as potential therapeutic agents are still in their nascent stages, they represent a promising avenue for future research. Ongoing studies are essential to uncover suitable biomarkers that could facilitate the identification and understanding of the genetic links between these GIC. This exploration not only seeks to enhance our comprehension of the underlying genetic architecture but also aims to inform the development of targeted therapies and preventive strategies.

Treat-to-Target and Regular Surveillance of Inflammatory Bowel Disease Are Associated with Low Incidence and Early-Stage Detection of Malignancies: A Retrospective Cohort Study

Inflammatory bowel diseases (IBD), including ulcerative colitis (UC) and Crohn's disease (CD), increase the risk of malignancies, particularly colorectal cancer (CRC). We aimed to assess the incidence of malignancies in IBD patients managed using a treat-to-target approach and recommended surveillance. We retrospectively searched the electronic databases of two tertiary IBD centers in Milan from 2010 to 2019 for new diagnoses of malignancy in patients with pre-existing IBD. A total of 5239 patients with a follow-up of 19,820 years were included. In total, 71 malignancies were diagnosed in 70 patients (38 CD, 32 UC) with a mean age of 52.9 years, of whom 64% were former or active smokers. The annual incidence of all malignancies was 358 per 100,000 patient years (95% CI 275-444), and the standardized incidence rate (SIR) was 0.93 (95% CI 0.73-1.16). Gastrointestinal cancers were the most frequent (n = 17, 23.9%), in particular, CRC (n = 9), with an incidence of 45 per 100,000 (95% CI 15-74) and an SIR of 1.18 (95% CI 0.54-2.09). CRC occurred mainly in UC patients (6/8), while small bowel cancer was seen in CD patients (5/9). Melanoma and breast cancer (n = 8 each) were the most common non-GI cancers. No significant difference in incidence was found between CD or UC. Death occurred in nine patients (11%) and was due to cancer in eight of these cases, two of which were IBD-related. Most malignancies included in the surveillance were diagnosed at early (I-II) stages (20 vs. 4, p < 0.05). In patients with IBD, treat-to-target and strict surveillance were associated with a low incidence of cancer, similar to that of the general population, and the detection of malignancies at an early stage.