Bowel Cancer

Bowel Cancer

Colorectal cancer, often referred to as bowel cancer, arises from uncontrolled cell growth in the colon, rectum, or appendix. Typical symptoms include rectal bleeding and anemia, sometimes accompanied by weight loss and alterations in bowel habits.

The majority of colorectal cancer cases stem from lifestyle factors and advancing age, with only a minority linked to underlying genetic conditions. It typically initiates in the bowel lining and can progress into the underlying muscle layers and beyond the bowel wall if left untreated. Screening, recommended from age 50 to 75, proves effective in reducing colorectal cancer mortality, often utilizing sigmoidoscopy or colonoscopy for localized cancer diagnosis.

Surgical intervention offers curative options for cancers confined within the colon wall, while widespread metastatic cancer is usually incurable, focusing instead on extending life through chemotherapy and enhancing quality of life. Colorectal cancer ranks as the fourth most diagnosed cancer worldwide, with a higher prevalence in developed nations, where approximately 60% of cases are reported.

Signs and symptoms vary based on tumor location within the bowel and the presence of metastasis. Warning indicators include worsening constipation, blood in the stool, weight loss, fever, loss of appetite, and nausea or vomiting, particularly in individuals over 50. Rectal bleeding or anemia is concerning, especially in older adults, while other symptoms like weight loss and bowel habit changes warrant further investigation if accompanied by bleeding.

Risk factors for colon cancer include lifestyle choices such as high-fat, alcohol, or red meat consumption, obesity, smoking, and lack of physical activity. Inflammatory bowel diseases like ulcerative colitis and Crohn's disease elevate cancer risk, with preventive measures including aspirin use and regular colonoscopies. Genetics also play a role, with certain syndromes like Lynch syndrome and familial adenomatous polyposis associated with higher colorectal cancer rates.

Colorectal cancer pathogenesis involves mutations in the Wnt signaling pathway, particularly in the APC gene, leading to abnormal cell growth. Other mutations, including in genes like TP53 and KRAS, contribute to cancer development. Diagnosis typically involves tumor biopsy during sigmoidoscopy or colonoscopy, followed by staging using the TNM system to determine disease extent and metastasis. Imaging tests like CT scans, PET scans, and MRIs aid in staging and treatment planning.