COLORECTAL CANCER. Colorectal Cancer arises in Epithelial cells outlining the lumen of Colon & Rectum. Epidemiology: Cancer is the 3rd cause of death ww.(6,3 million D/Y). About 876,000 get CRC/Y. About 525 000 CRC, D/Y. Incidence Rate= 15/ 100 000.
COLORECTAL CANCER Colorectal Cancer arises in Epithelial cells outlining the lumen of Colon & Rectum. Epidemiology: • Cancer is the 3rd cause of death ww.(6,3 million D/Y). • About 876,000 get CRC/Y. • About 525 000 CRC, D/Y. • Incidence Rate=15/ 100 000. • CRC is the 3rd cancer killer after: • 1 Lung Cancer > 2 Stomach.
COLORECTAL CANCER • COLORECTAL POLYPS: • Abnormal growths protruding into the large intestine. • Common condition in 20% of adults. • Most polyps are benign. • They produce no symptoms. • SYMPTOMS OF CRC: • Rectal Bleeding. • Change Of Bowel Habits. • Abdominal Pain, Discomfort. • Decreased Stool Diameter. • Weight Loss.
COLORECTAL CANCER • How Are Polyps Diagnosed? • Colorectal Endoscopy: • 1. Colonoscopy. • 2. Sigmoidoscopy. • Barium enema x-ray techniq. • Fecal Occult Blood Test. (FOBT) • Removal of polyps is advised. • Colostomy is performed for late stages.
COLON CANCER • As a result of accumulation of genetic alterations a polyp (adenoma) is formed which turns into a cancer. • A progression from early to intermediate to late adenoma to a carcinoma.
Staging System Characteristics • 1: Degree of penetration in the bowel wall. • 2: L.N. involvement. • 3: Distant metastases.L.N. Involvement Liver Metastases Kidney Metastases
STAGING SYSTEM OF C.C. • Astler-Coller: • A: Tumor limited to mucosa, • B1: Tumor grows through muscularis mucosae, • B2: Tumor grows beyond muscularis propria, • C1: Stage B1 with regional L.N. metastases, • C2: Stage B2 with regional L.N. metastases, • D: Distant metastases.
GRADING SYSTEM OF C.C. • Grading:- • Normal cells (differentiated) • Cancer (less differentiated). • Less differentiation Faster growth & metastases. • G1: Well differentiated, • G2: Moderately well differentiated, • G3: Poorly differentiated, • G4: Undifferentiated.
COLON CANCER • P53 gene : (TSG) • Located in the S.A. of chromosome 17. • Code for phosphoprotein that functions as T.F. • In respond to DNA damage P53 protein expression is increased, And regulates the transcription of genes that induce cell cycle arrest or apoptotic cell death. • P53 mutation occurs in 80-90% of sporadic C.C.
COLON CANCER • Adenom. Polypopsi Coli (APC) gene: • Located on L.A. of chromosome 5. • APC protein plays a role in:regulation of apoptatic cell death; • Transfection of normal APC gene into cell lines having 2 mutant APC genes induces apoptosis. • Mutations on it occur on 50-80% of sporadic colonic adenoma.
COLON CANCER • H19 Gene: • An imprinted & developmentally regulated gene. • Its product remains untranslated (oncofetal mRNA). • Expressed in tumors arising from tissues, which express it in the fetal life. • Located on chromosome 11p15.5 • To date, itsfunction remains unknown.