Colorectal cancer: A narrative review

Abstract

Colorectal cancer is the second most common cancer in women and a third in men globally. Its mortality is rising with a major contribution from a low- and middle-income countries. We highlight the current trends in the demographics, histopathological patterns and management of colorectal cancer to improve care and prognosis of the disease. A search of PubMed, Hinari, Google Scholar, Directory of Open Access Journals and African Journal Online was made.  Only full articles were reviewed. Most colorectal tumours develop via a multistep process involving a series of histological, morphological and genetic changes that accumulate over time. Clinical features are varied, non-specific and dependent on the site of the tumour and the extent of luminal narrowing caused by the tumour. Colonoscopy is vital in establishing the diagnosis of colorectal cancer as it allows visualization of the colon and permits tumour biopsy. Treatment is both multimodal and multidisciplinary involving surgery, radiation therapy and cytotoxic therapy. The incidence and mortality may be significantly reduced by screening which can either be invasive or non-invasive. The non-invasive uses tumour markers such as guaiac faecal occult blood test or immunohistochemical faecal occult blood test while the invasive tests include the flexible sigmoidoscopy and colonoscopy. The burden of colorectal cancer may likely increase due to its current trend and ageing population; deficiency in cancer prevention efforts as a result of lack of government policies, low level of awareness and inadequacy of cancer registries. We advocate collaborative efforts to combat the scourge of the disease.