Colorectal Cancer

Colorectal Cancer

    * Introduction
    * Causes
    * Signs and symptoms
    * Diagnosis
    * Treatment
Defines colorectal cancer malignant tumors that originate in the colon mucosa, colon cancer is found in more than 15 cm from the anal edge rectosigmoidoscopie or above three sacral vertebrae, rectal cancer is below this level. This cancer is most frequently diagnosed, both males and females how he represents the fourth location of cancer in the world. Most of these cancers start from adenomas or polyps that develop in the lining of the colon. Approximately 80% of cases are sporadic, the remaining 20% are inherited. Predisposing factors include chronic ulcerative colitis and granulomatous colitis, cancer risk increases with duration of these diseases. Time to malignizarii precancerous lesions is 10-20 years. Screening tests performed in the population can identify and remove polyps before they become cancerous. Once diagnosed, the prognosis of colorectal cancer depends on its dissemination. Unfortunately most people with cancer do not experience any symptoms, inh early stages of the disease, so screening tests such as colonoscopy are very important. Signs and symptoms occurring in advanced stages include: changes in bowel habits, blood in the stool, weakness, dizziness, anemia, abdominal discomfort, unexplained weight loss, intestinal pain, feeling of incomplete defecation. Colorectal cancer is preventable, even cured if discovered in its early stages. Repeated screening detects polyps before they become cancerous. People over 50 who have risk factors for this disease should perform a colonoscopy every 10 years, a Barium test every five years and annual hemocult. Surgery excision is the first therapeutic option. Depending on the clinical stage of the disease is surgery followed by chemotherapy or not, and if the tumor is very large, surgery is necessary before radiotherapy. Complications include recurrence of cancer, liver or lung metastasis, cachexia and death. Prognosis depends on the degree of tumor invasion in prfunzimea intestinal wall, and the lymph nodes disemninarea or extra-regional.
Pathogenesis Carcinogenesis colony, a process known to be sequential, is due to the accumulation of mutations in the genome that regulates cell growth in the colon. Not every mutation appeared to be useful for carcinogenesis, a large proportion of mutations are lethal, nesupravietuind cells. 4-5 cells must accumulate mutations, including activation of oncogenes and inactivation of tumor suppressor genes to initiate the malignant process. In normal mucosa, epithelial surface is regenerated every 6 days. Cryptic cells migrate from the crypts to the surface, where ESS differentiate, mature and lose their ability to divide. In adenomas. Certain genetic mutations alter this process, beginning with the inactivation of APC gene, allowing further uncontrolled division of cells migrated to the surface. The growth rate of cell division, there are other mutations that activate K-RAS gene, and p53. These cumulative defects in apoptosis and cell division control-d cells have eternal life. Cancer disseminates through the intestinal wall, marrow metastasis, regional lymph perineural and intraluminal.
Pathology Microscopic describe three types: -Ulcerative Vegetable exofitica table, sessile, friable, ulcerated -Infiltrative: rare tumors, hard, and infiltrative stenosis producing wall retraction was -Ulcerated. Location: The vast majority is located at the front of sigmoidiene nivelulo junction in recent years it seems like the right colon tumors have increased in incidence. In the rectum, sigmoid, right colon and caecum, where the lumen is larger and has space for tumor growth, tumors are vegetable polypoid and ulcerated. The left colon, the lumen is smaller tumors are canceling, infiltrative radiological spine aspestul producing apple