Screening for early detection of colorectal cancer (CRC), adenomatous polyps, and precancerous lesions can reduce mortality. This review aimed to illustrate methods, guidelines, and clinical utility of CRC screening programs.
Literature search of PubMed and Scopus electronic databases was independently performed by two authors in September 2021. Articles discussing CRC screening methods and updated guidelines were reviewed.
After reviewing the full text of 55 studies, it was found that the screening tests for CRC are divided into stool-based, endoscopic, and molecular. All CRC screening guidelines recommend screening starting at age 45-50, but vary regarding screening methods, frequency, and timing of screening discontinuation. Controversies include clinical benefits of screening the elderly and discontinuation of screening. Effective screening barriers involve patient- and healthcare-related factors.
Overall, screening should start at age 45-50 for average-risk individuals. Colonoscopy and FIT tests are standard modalities recommended for regular screening. Increasing public awareness of the importance of screening and implementing mass national screening programs can detect early CRC and decrease related mortality.

Colorectal cancer (CRC) is the third most common malignancy worldwide. Most patients with metastatic CRC develop liver or lung metastases, while a minority suffer from brain metastases. There is little information available regarding the presentation, treatment, and overall survival of brain metastases (BM) from CRC. This systematic review and meta-analysis includes data collected from three major databases (PubMed, Cochrane, and Embase) based on the key words \"brain\", \"metastas*\", \"tumor\", \"colorectal\", \"cancer\", and \"malignancy\". In total, 1318 articles were identified in the search and 86 studies matched the inclusion criteria. The incidence of BM varied between 0.1% and 11.5%. Most patients developed metastases at other sites prior to developing BM. Lung metastases and KRAS mutations were described as risk factors for additional BM. Patients with BM suffered from various symptoms, but up to 96.8% of BM patients were asymptomatic at the time of BM diagnosis. Median survival time ranged from 2 to 9.6 months, and overall survival (OS) increased up to 41.1 months in patients on a multimodal therapy regimen. Several factors including age, blood levels of carcinoembryonic antigen (CEA), multiple metastases sites, number of brain lesions, and presence of the KRAS mutation were predictors of OS. For BM diagnosis, MRI was considered to be state of the art. Treatment consisted of a combination of surgery, radiation, or systemic treatment.