Risk factors for high-grade dysplasia or carcinoma in colorectal adenoma cases treated with endoscopic polypectomy

Analysis of Patients Undergoing Colonoscopies and the Importance of Exam Quality for Colorectal Cancer Screening

Objective To determine the impact of the quality of colonoscopy examination for colorectal cancer screening.

Methods Retrospective observational study of medical records from patients treated at the endoscopy and colonoscopy service of Hospital Universitário Evangélico Mackenzie (Curitiba, PR, Brazil) from January 2019 to January 2020.

Results The analysis was based on 337 medical records from patients with adenomas identified during colonoscopy, and 1,385 medical records from patients without adenomas. The estimated occurrence rate of diagnosis of adenoma during colonoscopy in the target population of the study was of 19.6%, with a 95% confidence interval ranging from 17.7 to 21.5%. Of the 337 patients with adenoma, 136 (40.4%) presented the advanced form. Statistical analysis indicated a significant association between the quality of colonoscopy preparation and test completion.

Conclusion The quality of colonoscopy images is a critical factor for colorectal cancer screening, as it leads to higher rates of adenoma detection and test completion.

Reappraisal of the characteristics, management, and prognosis of intramucosal colorectal cancers and their comparison with T1 carcinomas

BACKGROUND AND AIMS

The recent description of "invasive" forms of intramucosal carcinoma (IMC) has rekindled interest in studying the characteristics, management, and prognosis of IMCs and comparing them with T1 colorectal cancers (CRCs).

METHODS

This population-based study included 282 cases of IMC and 207 cases of T1 CRC diagnosed by colonoscopy after a positive fecal blood test through a screening program.

RESULTS

IMC presented mainly in the form of pedunculated polyps (68.4%) located in the distal colon (69.9%) ≥20 mm in size (60.6%). IMCs were resected endoscopically in 227 (80.5%) patients and surgically resected in 55 (19.5%) patients. Surgical patients had more right-sided, more sessile, and larger lesions. There was no sign of lymphovascular invasion. Compared with T1 CRCs, IMCs demonstrated lower rates of sessile polyps (31.6% vs 49.8%, P < .0001), primary and ultimate surgical treatment (19.5% vs 39.1% and 19.9% vs 78.7%, P < .0001, respectively), lymph node metastasis in surgical patients (0% vs 9.5%, P = .041), cancer recurrence and cancer-related mortality (0% vs 5.6% and 0% vs 2.5%, respectively), and bleeding after endoscopic resection (1.8% vs 8.7%, P = .001). By multivariate analysis of the pooled cohort (IMC + T1 CRC, n = 489), the factors significantly associated with first-line surgery were shown to be polyp characteristics and the gastroenterologist who performed the colonoscopy.

CONCLUSIONS

IMCs account for a quarter of all screening-detected CRCs. They have an excellent prognosis regardless of whether endoscopic or surgical treatment is performed. IMCs differ significantly from T1 carcinomas in terms of management and prognosis.

Risk factors associated with the detection and missed diagnosis of colorectal flat adenoma: a Chinese multicenter observational study

OBJECTIVES

Flat colorectal adenomas have a high risk of malignancy; however, their detection is often difficult due to their flat morphology. In this retrospective, large-scale study, we investigated the prevalence and characteristics of flat adenomas in a population in China.

METHODS

We analyzed the data collected for 16951 consecutive patients who underwent colonoscopy at four participating hospitals between September 2013 and September 2015. All colonoscopies were performed without magnification.

RESULTS

Among the 1,6951 patients, 2938 (17.3%) had adenoma and 796 (4.7%) had flat adenomas. The detection of flat adenoma showed a weak correlation with the detection of adenoma (r = 0.666). Multivariable logistic regression analysis revealed the following independent factors influencing the detection of flat adenomas: patient-related factors of age, presence of warning symptoms, history of adenomas and bowel preparation as well as endoscopist-related factors of endoscopist's level of proficiency, number of colonoscopy operators and withdrawal time.

CONCLUSIONS

The prevalence of flat adenomas in our study on Chinese patients was consistent with that reported from other countries. Factors conducive to the detection of flat adenomas were patient age of > 60 years, warning symptoms, history of adenoma, good bowel preparation, experienced endoscopist, single-operator colonoscopy and colonoscopy withdrawal time of >6 min.

Multiple Gastrointestinal Polyps in Patients Treated with BRAF Inhibitors

PURPOSE

BRAF inhibitors (BRAFi) extend survival in BRAF-mutant melanoma but can promote the growth of Ras-mutant neoplasms. This study determined if gastrointestinal polyps found in BRAFi-treated patients harbored Ras mutations.

EXPERIMENTAL DESIGN

Colonic and gastric polyps were identified and resected from BRAFi-treated melanoma patients. Next-generation sequencing (NGS) was performed on polyps. The ability of BRAFi to promote polyp formation was functionally characterized in Apc Min(+/-) mice. MAPK and β-catenin pathway activity was assessed by immunohistochemistry in mouse and human polyps.

RESULTS

Fourteen patients treated with BRAFi underwent endoscopy to assess for polyps. Seven out of 7 patients >40 years of age and treated for >2 years were found to have colonic tubular adenomas with 4 out of the 7 patients having 5 or more polyps. One patient presented with bleeding from hyperplastic gastric polyps that recurred 6 months after BRAFi rechallenge. NGS performed on polyps found no mutations in MAPK pathway genes, but found APC mutations in all tubular adenomas. A significant increase in the number of polyps was observed in BRAFi-treated compared with control-treated Apc Min(+/-) mice (20.8 ± 9.2 vs 12.8 ± 0.1; P = 0.016). No polyps were observed in BRAFi-treated wild-type mice.

CONCLUSIONS

BRAFi may increase the risk of developing hyperplastic gastric polyps and colonic adenomatous polyps. Due to the risk of gastrointestinal bleeding and the possibility of malignant transformation, further studies are needed to determine whether or not endoscopic surveillance should be recommended for patients treated with BRAFi.

Risk factors associated with colorectal flat adenoma detection

OBJECTIVES

Colorectal flat adenomas have been associated with a higher risk of colorectal malignancy. We describe demographic characteristics and endoscopic findings in patients with colorectal flat adenomas.

METHODS

In total, 1934 consecutive patients undergoing colonoscopy were prospectively included. Polyp shape was classified according to the Japanese classification. Chromoendoscopy was applied whenever a flat lesion was suspected. Indications for colonoscopy, demographic data, and characteristics of neoplastic lesions were recorded. Patients were classified as follows: group 1, no adenomas (n=1250); group 2, only protruding adenomas (n=427); group 3, protruding and flat adenomas (n=118); and group 4, only flat adenomas (n=139).

RESULTS

Approximately one in every 10 patients (13.2%) had flat adenomas. Among them, concomitant protruding adenomas were identified in approximately half of the cases. In multivariate analysis, age older than 50 years [odds ratio (OR)=1.62; 95% confidence interval (CI)=1.08-2.43, P=0.02], protruding adenomas (OR=2.17; 95% CI=1.65-2.87, P<0.001), follow-up colonoscopy for polyps or cancer (OR=2.22; 95% CI=1.59-3.10, P<0.001), screening colonoscopy (OR=1.60, 95% CI=1.15-2.22, P=0.005), and specifically trained endoscopist (OR=2.02, 95% CI=1.53-2.68, P<0.001) were associated independently with flat adenoma detection.

CONCLUSION

Flat adenomas have specific demographic factors that might help to improve detection. Particularly, age older than 50 years, colorectal neoplasia surveillance, and the presence of protruding adenomas should alert endoscopists to the possible presence of these lesions. Trained endoscopists may offer a greater chance of detecting these lesions.

Colectomy for endoscopically unresectable polyps: how often is it cancer?

BACKGROUND

Colonoscopy has an established role in reducing the burden of colorectal cancer through early detection and removal of polyps. For endoscopically unresectable polyps, colectomy is generally indicated to prevent malignant transformation or to remove cancer already present.

OBJECTIVE

This study aimed to determine the incidence of malignancy and the factors predictive of malignancy in surgically resected benign polyps. DESIGN/PATIENTS/SETTING: This study was a retrospective chart review of patients undergoing a colectomy for a colonic polyp (no preoperative diagnosis of cancer) in 4 hospitals within the Mayo Clinic Health System.

MAIN OUTCOME MEASURES

Patient characteristics, endoscopic location and size, and preoperative and operative polyp pathology were tabulated. Correlations between these features and the finding of invasive carcinoma on surgical pathology were assessed.

RESULTS

A total of 750 patients met our inclusion criteria. Patients were predominantly male (55.2%) with an average age of 69.4 ± 9.8 years. A majority of polyps were located in the right colon (70.9%). Invasive cancer was identified in 133 patients (17.7%). Multivariate analysis revealed polyps in the left colon (adjusted OR 2.13, 95% CI (1.22-3.72)), and those with high-grade dysplasia (adjusted OR 4.60, 95% CI (2.91-7.27)) were more likely to harbor carcinoma. Age, sex, polyp dimension, and villous features were not predictive of malignancy. Of the patients with cancer, 31 (23.3%) had nodal disease.

LIMITATIONS

This study is limited by its retrospective nature, the change in terminology and technique over time, and the partially subjective nature of an endoscopically unresectable polyp.

CONCLUSIONS

The finding that polyp size and villous features do not strongly predict malignancy differs from previous endoscopic studies. This study confirms that polyps located in the left colon or with high-grade dysplasia are more likely to harbor cancer. The results of this study suggest that endoscopically unresectable polyps are best treated by radical oncologic resection.

Câncer ano-reto-cólico: aspectos atuais IV - câncer de cólon - fatores clínicos, epidemiológicos e preventivos

O câncer colorretal tem alta incidência populacional e alto índice de mortalidade, com diferenças pouco relevantes entre os povos de diversas nações, como atestam os estudos epidemiológicos dessa doença. Embora a abordagem médico-cirúrgica do câncer colorretal tenha sido favorecida pelos novos conhecimentos adquiridos com a engenharia genética, pelos progressos que aprimoraram o tratamento, principalmente na área de neo-adjuvância, com as inovações nos aparelhos de radioterapia e com a constante introdução de novas e potentes substâncias quimioterápicas, o prognóstico da doença continua sombrio. Todavia, dados colhidos em estudos sobre a biologia do tumor - sua origem, crescimento e desenvolvimento e comportamento biológico - têm acenado para a possibilidade de cura quando os métodos preventivos, em prática, facilitam a abordagem precoce da lesão. Nesse contexto, o câncer colorretal é passível de cura, podendo, inclusive dispensar, para tanto, o tratamento adjuvante ou aliviar o paciente da abordagem cirúrgica mutilante. Assim, o maior esforço posto em ação no início desse século está sendo representado pelos movimentos de educação popular em massa para a prevenção do câncer de reto e dos cólons com incentivo para o teste de sangue oculto nas fezes.