Cyclooxygenase-2 expression in colorectal carcinoma, adenomatous polyps and non-tumour bearing margins of resection tissues in a cohort of black Africans

Background Emerging data suggest a negative role of cyclooxygenase-2 (COX-2) in colorectal carcinomas (CRC). Investigating this in developing communities such as ours helps to contribute to existing understanding of these lesions. Methods and findings Formalin-fixed paraffin-embedded CRC colectomy tissues and their corresponding non-tumour margins of resected tissues were sectioned and stained with COX-2 antibody. Adenomatous polyp tissues from non-cancer bearing individuals were similarly processed for comparison. COX-2 expression was scored for percentage (< 5% = 0; 6%-25% = 1; 26%-50% = 2; 51%-75% = 3; 76%-100% = 4) and intensity (no staining = 0; yellow = 2; yellowish-brown = 3, brown = 4). Total immunoscore (percentage + intensity score) ≥ 2 was regarded as positive COX-2 expression. Outcome was statistically evaluated with clinicopathological data to determine COX-2 expression-associated and predictor variables. Ninety-five CRC cases and 27 matched non-tumour tissues as well as 31 adenomatous polyps met the inclusion criteria. Individuals with CRC had a mean age of 56.1 ± 12.6 years while those with adenomatous polyps had a median age of 65 years (range 43–88). COX-2 was differentially overexpressed in CRCs (69/95; 72.6%) and in adenomatous polyps (17/31; 54.8%) than in non-tumour tissues 5/27 (18.5%); p < 0.001). The difference in COX-2 expression between CRC and polyps was non-significant (p > 0.065). Tumour grade, advanced pT-stage, tumour-infiltrating lymphocytes, and dirty necrosis were also significantly associated with COX-2 expression (p < 0.035; 0.043, 0.035 and 0.004, respectively). Only dirty necrosis and Crohns-like lymphocytic aggregates predicted COX-2 expression (p < 0.05). Conclusion This study showed a progressive increase in COX-2 expression from normal to adenomatous polyp and CRC tissues, this being associated with poorer prognostic indicators. Although COX-2 appears early in CRC, it may play a secondary role in promoting tumour growth and invasiveness.

The Clinical Significance of Colon Polyp Pathology in Nonalcoholic Fatty Liver Disease (NAFLD) and Its Impact on Screening Colonoscopy in Daily Practice

Aim. Nonalcoholic fatty liver disease (NAFLD) has been known as a risk for the presence of colon polyp and CRC development. This study was aimed to find out the clinical significance of colon polyps’ pathology among NAFLD patients. Method. A retrospective database study was done in patients who underwent elective colonoscopy within one-year period in a referral private hospital, Jakarta. Subjects were adult patients who also had documented abdominal ultrasound (US). The association between NAFLD and colonic polyp was analyzed using Chi-square test with odds ratio (OR) and its corresponding 95% confidence interval (CI). Results. A total of 138 adult patients were enrolled; 68 (51.1%) were men. Patients’ mean age was 56.8 ± 15.3 years old. Colon polyps were found in 49 (35.5%) cases; the most common histopathology was adenoma (42.9%). NAFLD was found in 68 (49.3%) of patients. Colon polyps were found to be more among patients with NAFLD than in those without NAFLD (44.1% vs. 27.1%; OR: 2.119; 95% CI: 1.040–4.318). Colon polyps were found in 30 (44.1%) NAFLD patients, where 18 (26.5%) patients had adenomatous polyp, and from this subset of patients with adenomatous polyp, 6 (8.8%) patients had mild dysplasia, 8 (11.8%) had moderate dysplasia, 1 (1.5%) had severe dysplasia, and 3 (4.4%) had adenocarcinoma. Conclusions. NAFLD is associated with increased risk of any colon polyp, regardless of the histopathological type, compared with patients without NAFLD. This finding implies the necessity to perform screening colonoscopy in patients with NAFLD in the future.

Training a computer-aided polyp detection system to detect sessile serrated adenomas using public domain colonoscopy videos

Background Colorectal cancer (CRC) is a major public health burden worldwide, and colonoscopy is the most commonly used CRC screening tool. Still, there is variability in adenoma detection rate (ADR) among endoscopists. Recent studies have reported improved ADR using deep learning models trained on videos curated largely from private in-house datasets. Few have focused on the detection of sessile serrated adenomas (SSAs), which are the most challenging target clinically. Methods We identified 23 colonoscopy videos available in the public domain and for which pathology data were provided, totaling 390 minutes of footage. Expert endoscopists annotated segments of video with adenomatous polyps, from which we captured 509 polyp-positive and 6,875 polyp-free frames. Via data augmentation, we generated 15,270 adenomatous polyp-positive images, of which 2,310 were SSAs, and 20,625 polyp-negative images. We used the CNN AlexNet and fine-tuned its parameters using 90 % of the images, before testing its performance on the remaining 10 % of images unseen by the model. Results We trained the model on 32,305 images and tested performance on 3,590 images with the same proportion of SSA, non-SSA polyp-positive, and polyp-negative images. The overall accuracy of the model was 0.86, with a sensitivity of 0.73 and a specificity of 0.96. Positive predictive value was 0.93 and negative predictive value was 0.96. The area under the curve was 0.94. SSAs were detected in 93 % of SSA-positive images. Conclusions Using a relatively small set of publicly-available colonoscopy data, we obtained sizable training and validation sets of endoscopic images using data augmentation, and achieved an excellent performance in adenomatous polyp detection.

Uterine adenoma

Before talking about uterine adenoma in general, the author is trying to bring some clarity to the confusing nomenclature of endometrial diseases. Mucous polyps, endometritis fungosa, true adenoma, adenomatous polyp, benign adenoma and adeno-carcinoma, all described by various authors as variations of true adenoma.