The fourth most common form of cancer in the United States, and responsible for as many as 650,000 deaths worldwide each year, colorectal cancers produce growths in the rectum, appendix, and colon that come from benign, mushroom-shaped adenomatous tumors, lymphomas, and squamous cell carcinomas, that may begin in several body organs including the thyroid, colon, pituitary and adrenal glands, and progress to malignant states over time.
Stage One and Stage Two colon cancers that are confined inside the wall of the colon are typically cured with surgeries. Stage Three colon cancers that have matastasized to lymph nodes have seen a cure rate of approximately seventy-five percent with surgeries and chemotherapies, however, Stage Four colon cancers, with distant site spreadings, are not usually curable.
Dividable into constitutional, or whole body, metastatic, or spread to other organs, and localized to the anus, symptoms of colon cancers depend mainly on where the tumors are located in the bowels, how they have metastasized, and may include such things as diarrhea, constipation, rectal tenesmus, small stools, lower gastrointestinal bleeding, bright red bloody stools, melena, black stools, duodenal ulcers, upper gastrointestinal bleeding, bowel obstructions, abdominal pains, abdominal distensions, perforated bowels, peritonitis, blood in the urine, iron deficiency anemia, chronic occult bleeding, pallor, pale skin, fatigue, palpitations, paraneoplastic syndromes, deep vein thrombosis, jaundice, bile duct obstructions, biliary obstructions, pale stools, and liver problems.
Originating from epithelial cells in the rectum, colon, and gastrointestinal tract linings, and resulting in Wnt Signaling Pathway proteins, with some mutations inherited such as adenomatous polyposis coli tumor suppressor genes that help prevent uncontrolled cell growths that may turn into tumors, the TA3 protein that kills Wnt Signaling Pathway defective genes, the transforming growth factor beta protein that controls cell proliferations, the Deleted in Colorectal Carcinoma dependence receptor protein that has long been medically associated with colon cancers, the RAF, RAS, and P13K oncogenes that encourage cell divisions in growth factor responses, the Chromosome 10 tumor suppressor PTEN gene, carcinoembryonic antigen proteins, and KRAS gene mutations.
Risk factors commonly associated with colon cancers may include such things as family and patient histories, alcohol consumption, Vitamin B6, estrogen, diets high in red meats, chronic ulcerative colitis, high selenium levels, Primary Sclerosing Cholangitis, the Human Papilloma Virus, lithocholic acid, smoking, various viruses, and age.
With early detections generally providing a better chance of a cure colon cancers may be diagnosed through such methods as Digital Rectal Examinations for abnormal areas, Fecal Occult Blood Tests for blood in the stools, sigmoidoscopies, colonoscopies, Double Contrast Barium Enemas, blood tests, genetic testings, Positron Emission Tomographies, Stool DNA Tests, high C-Reactive Protein levels, biopsies, and surgeries.
Surgical procedures commonly used for colon tumor removals may include colonoscopies, lymph node removals, mesenteric reconstructed colon surgeries, stoma creations, total mesorectal excisions, abdominoperineal excisions, lower anterior resections, palliative resections, tumor bypasses, proximal fecal diversions, open-and-close surgeries, and laparoscopic-assisted colectomies.
Chemotherapy regimens used for colon cancers may include such medications as Capecitabine, Xeloda, Oxaliplatin, Leucovorin, Tegafur-uracil, Irinotecan, Bevacizumab, Cetuximab, Bortezomib, Panitumumab, Gefitinib, Erlotinib, Oblimersen, and Topotecan.
This Article was compiled from several websites that provide much more information about colon cancer including:
ccalliance.org (colon cancer’s largest national patient advocacy organization)
cancer.org (the American Cancer Society’s website)