Internal Medicine 2: Colonic Polyps PDF

IM2 INTERNAL MEDICINE 2 Colonic Polyps TRANS 2.2...

IM2 INTERNAL MEDICINE 2 Colonic Polyps TRANS 2.2 MODULE 6 D.R.L. Sebollena, M.D. September 11, 2024 LECTURE OUTLINE C. PATHOPHYSIOLOGY I Colorectal Polyps Adenomatous polyposis coli (APC) gene is inactivated → initiates A. Colorectal Adenomatous Polyps early adenoma development B. Gross Description of Colorectal Polyps KRAS proto-oncogene is then activated leading to loss of DNA and C. Pathophysiology subsequent expansion of adenoma D. Risk Factors Lastly, mutations occur which inactivates TP53 (tumor suppressor E. Predisposing Conditions for Colorectal Polyps gene) leading to invasion and subsequent development of F. Clinical Features carcinoma G. Effects of COVID-19 Pandemic Screening should be done for colorectal cancer to be prevented H. Who Do We Screen? I. Detecting and Screening Colorectal Polyps and Colorectal Cancer J. Cost Utility Analysis of Colorectal Cancer Screening in the Philippines II Summary 🧠 Must Know 📖 Book 📝 Previous Trans I. COLORECTAL POLYPS Grossly visible protrusion from the colorectal mucosa Figure 2. Pathophysiology of colorectal polyps to carcinoma 30% of middle-aged individuals and more than 50% of elderly Batch 2025 Trans individuals will have colorectal polyp/s Histopathologic classification of colorectal polyps: 1 Non-Neoplastic hamartoma (Juvenile polyp) Rarely seen because colonoscopy is rarely done on children 2 Hyperplastic mucosal proliferation (hyperplastic polyps) 3 Adenomatous polyps (pre-malignant) A. COLORECTAL ADENOMATOUS POLYPS Table 1. Histologic Classification Figure 3. Progress of benign adenomatous polyp to a carcinoma and it takes Has the lowest potential to develop about 5-10 years Tubular Adenoma adenocarcinoma and patients are advised to Batch 2025 Trans repeat colonoscopy after 3-5 years Tubulo-villous Intermediate potential to develop D. RISK FACTORS Adenoma adenocarcinoma Table 2. Risk Factors Highest potential to develop adenocarcinoma; Villous Adenoma Polyps are usually detected at age 50 years advise repeat colonoscopy after 1 year old, and has a higher chance of presenting Source: Batch 2025 Trans the older the person gets Most important risk factor Age >50% of elderly have polyps upon autopsy B. GROSS DESCRIPTION OF COLORECTAL POLYPS In other countries, the age for screening has Sessile polyp has a higher risk of developing into invasive been lowered to 45. In the Philippines, this will carcinoma than pedunculated/stalked polyps not be done until we can provide data that there is a need for an earlier screening Males: 2nd most common cause of malignancy Females: 3rd most common cause of Males > Females malignancy In the Philippines: 2nd most common cause of cancer deaths First degree relative with colon carcinoma Excessive consumption: fat, processed meat, alcohol Dietary and Figure 1. Pedunculated/stalked polyp (L) and sessile/serrated polyp (R) Smoking lifestyle factors Batch 2025 Trans Obesity Sedentary physical activity Source: Batch 2025 Trans Acacomm | Colonic Polyps 1 of 4 E. PREDISPOSING CONDITIONS FOR COLORECTAL POLYPS Highest risk: Ureterosigmoidostomy Acromegaly Bacterial and viral infections ○ S. gallolyticus (S.bovis) - in patients with infective endocarditis ○ K. pneumoniae - in patients with pyogenic liver abscess ○ Fusobacterium spp. ○ Clostridium septicum ○ H. pylori ○ HPV F. CLINICAL FEATURES Usually asymptomatic, but can present with overt rectal bleeding Figure 5. A graph from the study showing the increased risk of colorectal cancer Polyps usually occupy only 5% of the lumen which is why it won’t Batch 2025 Trans cause any significant findings. Common in the rectosigmoid area If diagnosed early however, colorectal cancer is preventable and H. WHO DO WE SCREEN? treatable. 1 ALL asymptomatic individuals age 50 years old and above According to WHO: ○ For males: colorectal cancer is the second most common 2 High-risk individuals cause of malignancy (14.3%) Male ○ For females: colorectal cancer is the third most common cause Obesity of malignancy (9%) Smoker Increased consumption of red meat/processed meats Alcohol abuse Physical inactivity Family history 3 Alarm Symptoms Anemia Weight loss Changes in bowel habits Hematochezia/melena Anorexia 1. SCREENING FOR THOSE WITH FIRST DEGREE RELATIVES DIAGNOSED WITH COLORECTAL CANCER Figure 4. Colorectal Cancer Data If a patient has a first degree relative who had colorectal cancer at Batch 2025 Trans age 48 y/o we subtract 10 on the age when the cancer was diagnosed ○ 48y/ominus 10 = 38 G. EFFECTS OF COVID-19 PANDEMIC IN SCREENING ○ First degree relatives are advised to undergo screening COLORECTAL CA colonoscopy at 38 y/o. During the pandemic, there was an estimated 80-90% decrease in This is based on the time of colonic polyp progression to screening malignancy (usually takes 10 years). ○ Non-urgent medical care was interrupted, with colorectal CA Hemorrhoids are the usual misdiagnosis. If symptoms are screening as one of the procedures affected by the pandemic persistent despite adequate treatment, advise colonoscopy ○ During the pandemic, there was a halt in screening for malignancy because resources were diverted to fighting the pandemic. Thus, there has been an increase in colorectal I. DETECTING AND SCREENING COLORECTAL POLYPS cancer. AND COLORECTAL CANCER It is highly recommended for high risk individuals to undergo Stool-based tests for average-risk individuals screening as soon as possible as delays in the procedure prove to ○ FOBT (fecal occult blood test) and FIT (fecal immunochemical be more harmful in the long run. test) ○ Study by Lee et. al (2019): There is a 12-15% increase in ○ Both tests are available in our local setting colorectal cancer mortality if there is a delay of >9 months in CBC screening on high risk populations and for those who tested ○ For males, anemia is uncommon (unlike in females). If anemia positive for stool based blood exams is seen in males, work up for further tests because this is ○ According to the American Gastrointestinal Association (AGA): suspicious for malignancy especially if elderly A delay of beyond 6 months leads to an increase of advancing colorectal cancer cases, while a delay of 12 months would Table 3. Stool-based Tests increase disease mortality ○ Lucie de Jange et al. (2021): Delayed colorectal cancer FOBT FIT screening can impact incidence of its mortality up to 2050. Detects peroxidase activity Uses antibody to detect globin Affected by plant peroxidases (e.g., cauliflower), red meat and No need for dietary modifications vit C intake Detects bleeding from Detects colonic bleeding only the entire GI tract (more specific for colon) Sensitivity of 12.9% - 79.4% Sensitivity of 79% Specificity of 86.7% - 97.7% Specificity of 94% Source: Batch 2025 Trans Acacomm | Colonic Polyps 2 of 4 1. IMAGING BARIUM ENEMA The patient is prepped colon is cleansed with laxatives barium is effused to the rectum until all of the colon has barium Limitation ○ Cumbersome ○ If there is something suspicious, the patient would still need to undergo colonoscopy Figure 8. Large polyp at splenic flexure (L) and surface pattern of large polyp as CT COLONOGRAPHY seen with blue light (R) Batch 2025 Trans Limitation: The patient is still advised to undergo colonoscopy if there is something suspicious to visualize and do polypectomy and biopsy of the polypoid. SNARE POLYPECTOMY Uses a loop of wire with electric current to painlessly remove the COLONOSCOPY polyp The wire cuts through the base of the polyp and cauterizes at the The patient is prepped → bowel is cleansed with laxatives → same time leaving no cut or bleeding. patient is sedated → colonoscope is inserted into the rectum up until the right side of the colon to the terminal ileum Figure 9. Snare polypectomy (L) and normal tissue left at polypectomy site (R) Batch 2025 Trans Figure 6. Barium Enema (L) and CT Colonography (R) J. COST UTILITY ANALYSIS OF COLORECTAL CANCER Batch 2025 Trans SCREENING IN THE PHILIPPINES There is a suspicious polypoid lesion on the right colon (white arrow) Done by epimetrics group The nearer the intervention is to the top left corner, the better value for money it is in terms of saving lives Screening for colorectal cancer is cost-effective. Up until this time, screening colonoscopy is not covered by insurance. Instead, PhilHealth covered advanced cancer treatment, which is not cost-effective because it is better to screen and prevent than only treat when the cancer is already there. Figure 7. Colonoscopy procedure with normal looking colonic mucosa. Batch 2025 Trans This is the transverse colon because of the triangular lumen 2. COLONOSCOPY WITH POLYPECTOMY COLONOSCOPY Medical test that examines the rectum and lower bowel to detect swollen, irritated tissues or polyps NARROW BAND IMAGING Uses a blue light which enables the examiner to see the surface pattern with more details Figure 10. Graph of cost-utility analysis of colorectal cancer screening in the Villiform or stripe type pattern suggests that the polyp is probably Philippines an adenoma, a polyp that may have the risk of turning cancerous. Batch 2025 Trans Removing this polyp prevents it from turning into cancer. This polyp causes no discomfort, and the patient is unaware of it. Acacomm | Colonic Polyps 3 of 4  Table 4. Cost-Utility Analysis of Colorectal Cancer CASE 48 y/o male (+) FOBT 3 A Colonoscopy every 10 years Salient Features (+) FIT Changes in bowel movement B Colonoscopy every 10 years Dyslipidemia on statin (+) FIT Previous smoker C 70 y/o father recently diagnosed with Stage 2 Colon CA Flexible sigmoidoscopy/colonoscopy every 10 years D No screening test Screening Tests to Recommend Source: Batch 2025 Trans Colonoscopy ○ Rationale: Patient already has symptoms or changes in bowel movement and also a previous smoker. This is more of II. SUMMARY age related than a genetic predisposition. COLORECTAL POLYPS For example, 45/M diagnosed with Colon CA, most likely there’s Colorectal adenomatous polyps are pre-malignant lesions. a strong genetic predisposition especially if he is diagnosed less Early detection can prevent colorectal cancer. than 50 y/o. Stool-based tests for average risk individuals ○ If he is diagnosed at 45 y/o, his children should undergo Colonoscopy for high risk individuals and those with positive stool colonoscopy as early as 35 y/o. tests. Screening is cost effective IV. APA REFERENCES We should be more aggressive in screening for colorectal Batch 2025 Trans on Diseases of the Colon and Rectum adenocarcinoma due to the negative effect of COVID-19 pandemic. Figure 11. In colorectal cancer screening, we need to find the picture on the left, to prevent the picture on the right. Batch 2025 Trans III. SYNCHRONOUS SESSION CASE 25 y/o male 1 Salient Features Painless hematochezia No other alarm symptoms Non-smoker, non-alcoholic beverage drinker Primary Impression Hemorrhoids Physical Examination Rectal examination Patient doesn’t need any test Diagnostics Hot sitz baths Laxatives CASE 50 y/o female 2 Salient Features No co-morbids No vices Advice for patient As an average risk patient, stool based tests (FOBT) should be done. ○ If it turns out positive, colonoscopy should be done. Acacomm | Colonic Polyps 4 of 4