colonrectum-cancer.ppt

Colorectal CancerLi JinpingDepartment of surgical oncology Affiliated Hospital of Ningxia UniversityWorldwide incidence for CRC Incidence varies in different region of the world,increased in North American,West Europe,Australia,New Zealand.Higher incidence in industrialized areas,8.5%of all new cancer cases diagnosed worldwide.Groups that move to high risk areas assume the risk of that geographical region.Geographical distributionHigh risk areas include North America,Europe and Australia.Low risk areas include central and South America,Asia and Africa.Secular trendsThe numbers of new cases of colorectal cancer worldwide has increased rapidly since 1975.2003 Estimated US Cancer Cases*Men675,300Women658,800210,816Breast79,056 Lung/bronchus72,468 Colon&rectum39,528 Uterine corpus26,352 Ovary26,352 Non-Hodgkin lymphoma19,764 Melanoma of skin19,764 Thyroid13,176 Pancreas13,176 Urinary bladder62,238 All other sitesProstate 222,849Lung/bronchus 94,542Colon/rectum 74,283Urinary bladder 40,518Melanoma of 27,012skinNon-Hodgkin 27,012lymphoma Kidney20,259Oral cavity 20,259Leukemia 20,259Pancreas13,506All other sites114,801Men675,300Women658,8002003 Estimated US Cancer Deaths*Men285,900Women270,60067,650 Lung/bronchus40,590 Breast29,766 Colon&rectum16,236 Pancreas13,530 Ovary10,824 Non-Hodgkin lymphoma10,824 Leukemia8,118Uterine corpus5,412Brain/ONS5,412Multiple myeloma62,238 All other sitesLung/bronchus 88,629Prostate 28,590Colon&rectum 28,590Pancreas 14,295Non-Hodgkin 11,436lymphomaLeukemia11,436Esophagus11,436Liver/intrahepatic 8,577bile ductUrinary bladder8,577Kidney8,577All other sites62,898The number of colorectal cancer in China?1980年79,8001985年91,200+14.2%2002年151,000+65.6%2005年172,000+13.9%*Annual increase of 4.2%（Shanghai，1973-1993）the incidence of colorectal cancer has also increased in Chinayearyear200020002002200220052005IncidenceIncidence（1/100,0001/100,000）manman14.014.013.313.315.015.0womanwoman9.59.510.010.09.79.7totaltotal23.523.523.323.324.724.7Incidence and mortality of colorectal cancer in China200020002002200220052005IncidenceIncidence（万）（万）14.514.515.115.117.217.2MortalityMortality（万）（万）8.38.38.68.69.99.914.514.515.115.117.217.28.38.38.68.69.99.90 05 5101015152020200020002002200220052005发病发病死亡死亡万万yearyearThe Accident of Cancer in Beijing(during 1993 to 1997)The Accident of Cancer in Beijing(during 1993 to 1997)Colorectal Cancer Including colon and rectal cancer.malignant tumor from ileocecal junction to the dentate line of anus。Colon cancer refers to the carcinoma between ileocecal junction and sigmoid colon.Rectal Cancer refers to the carcinoma between the junction of the sigmoid colon and the dentate line.Distribution of colorectal cancer in colonRectum 45Sigmoid colon 25%Descending colon 5Transverse colon 9Ascending colon 18%Risk factorsvAge.The risk of developing colorectal cancer increases with age.Most cases occur in the 60s and 70s.Overall age-standardized incidence rates were 65.1 per 100,000 for men and 47.6 per 100,000 for womenMale-female ratio=1.37Mortality rates were also higher in men than women25.4 versus 18.0 per 100,000GenderRace and EthnicityHigher rates and mortalities among blacks than whitesGenetic factorsStreptococcuspneumoniae32%Sporadic Colon Cancer92%Familial Adenomatous polyposis and rare syndromes1%Hereditary nonpolyposis colon cancer5-6%Chronic IBD 1%familial adenomatous polyposis Hereditary non-polyposis CRC History of CRC in first degree relatives Inflammatory bowel disease(clone and specially,ulcerative colitis)Polypsulcerative colitisAdenoma to Carcinoma PathwayAPClossNormalEpitheliumEarlyAdenomaCancerHyper-proliferationIntermediateAdenomaLateAdenomaK-rasmutationChrom 18lossp53lossAdenomaNormalCancerLifestyle factors-NutritionFruit,Vegetables,and FiberMajority of case-control studies have shown an association between higher intake of vegetables and lower cancer riskRecent large cohort studies have shown weak or non-existent association between fiber and colon cancer riskFolateHigher intake of folate has been relatively consistently associated with lower colon cancer riskLifestyle factors-NutritionCalciumAvoidance of low intakes of calcium may minimize risk of colon cancerFat,Carbohydrates,and ProteinsExcess energy intake leading to obesity increases the risk of colon cancerPossible association of red meat with increased riskLifestyle factors-BMIHigher BMI(body mass index)is associated with an increased risk of colon cancerApproximately twofold higher risk in individuals who are overweight or obeseLifestyle factors-physical activityIndividuals who are more physically active have a decreased risk of colon cancerSome benefits appear to be independent of BMIStudies have shown dose-response relationship between physical activity and colorectal cancerHighest risk observed in persons who are both physically inactive and have high BMIsLifestyle factors-othersAlcoholSomewhat controversial,but appears that high alcohol intake increases riskTobaccoMost studies indicate excess risk in smokers Environmental Factors.Industrialized countries are at a relatively increased risk compared to less developed countries or countries that traditionally had high-fiber/low-fat diets.DietStudies show that a diet high in red meat and low in fresh fruit,vegetables,poultry and fish increases the risk of colorectal cancer.Aspirin and NsaidA substantial body of evidence supports a protective effect of aspirin and other nonsteroidal anti-inflammatory drugs on the development of colon cancer.pathyologyThe pathology of the tumor is usually reported from the analysis of tissue taken from a biopsy or surgery.A pathology report will usually contain a description of cell type and grade.The most common colon cancer cell type is adenocarcinoma which accounts for 95%of cases.Other,rarer types include lymphoma and squamous cell carcinoma.Cancers on the right side(ascending colon and cecum)tend to be exophytic,that is,the tumour grows outwards from one location in the bowel wall.This very rarely causes obstruction of feces,and presents with symptoms such as anemia.Left-sided tumours tend to be circumferential,and can obstruct the bowel much like a napkin ring.Staging of Colorectal CancerColon cancer staging is an estimate of the amount of penetration of a particular cancer.It is performed for diagnostic and research purposes,and to determine the best method of treatment.The systems for staging colorectal cancers largely depend on the extent of local invasion,the degree of lymph node involvement and whether there is distant metastasis.Definitive staging can only be done after surgery has been performed and pathology reports reviewed.An exception to this principle would be after a colonoscopic polypectomy of a malignant pedunculated polyp with minimal invasion.Preoperative staging of rectal cancers may be done with endoscopic ultrasound.Adjuncts to staging of metastasis include Abdominal Ultrasound,CT,PET Scanning,and other imaging studies.Dukes system Dukes classification,first proposed by Dr Cuthbert E.Dukes in 1932,identifies the stages as:A-Tumour confined to the intestinal wall B-Tumour invading through the intestinal wall C-With lymph node(s)involvement D-With distant metastasis Frequency of Colorectal Cancer by Dukes StageSurvival by Dukes StageTNM system The most common current staging system is the TNM system,though many doctors still use the older Dukes system.The TNM system assigns a number:T-The degree of invasion of the intestinal wall T0-no evidence of tumor Tis-cancer in situ(tumor present,but no invasion)T1-invasion through submucosa into lamina propria(basement membrane invaded)T2-invasion into the muscularis propria(i.e.proper muscle of the bowel wall)T3-invasion through the subserosa T4-invasion of surrounding structures(e.g.bladder)or with tumour cells on the free external surface of the bowel N-the degree of lymphatic node involvement N0-no lymph nodes involved N1-one to three nodes involved N2-four or more nodes involved M-the degree of metastasis M0-no metastasis M1-metastasis presentTNM system The stage of a cancer is usually quoted as a number I,II,III,IV derived from the TNM value grouped by prognosis;a higher number indicates a more advanced cancer and likely a worse outcome.Stage 0:Very early cancer on the innermost layer of the intestine Stage I:Cancer is in the inner layers of the colon Stage II:Cancer has spread through the muscle wall of the colon Stage III:Cancer has spread to the lymph nodes Stage IV:Cancer that has spread to other organs AJCC stage groupingsSymptoms of Colorectal CancerTime CourseSymptomsFindingsEarlyNoneNoneOccult blood in stoolMidRectal bleedingChange in bowel habitsRectal massBlood in stoolLateFatigueAnemiaAbdominal painWeight lossAbdominal massBowel obstructionDiagnosis Digital rectal exam(DRE)Fecal occult blood test(FOBT)Endoscopy Sigmoidoscopy ColonoscopyDouble contrast barium enema(DCBE):Virtual colonoscopyBlood testsgenetic testing Positron emission tomography(PET)Digital rectal exam(DRE):The doctor inserts a lubricated,gloved finger into the rectum to feel for abnormal areas.It only detects tumors large enough to be felt in the distal part of the rectum but is useful as an initial screening test.A digital rectal exam is an examination of the lower rectum to check for hemorrhoids,anal fissures,and stool abnormalities such as frank(evident)or occult (hidden)blood.The tumor within 8cm from the anus can be found by digital rectal exam Fecal occult blood test(FOBT)Examination of stool for occult(“hidden”)bloodCan detect one teaspoon or less of blood in a bowel movementUses chemical reaction between blood and reagentEndoscopySigmoidoscopy/ColonoscopySigmoidoscopy Sigmoidoscopy is the minimally invasive medical examination of the large intestine from the rectum through the last part of the colon.There are two types of sigmoidoscopy,flexible sigmoidoscopy,which uses a flexible endoscope,and rigid sigmoidoscopy,which uses a rigid device.Flexible sigmoidoscopy is generally the preferred procedure.A sigmoidoscopy is an effective screening tool.A sigmoidoscopy is similar but not the same as a colonoscopy.A Sigmoidoscopy only examines up to the sigmoid,while colonoscopy examines the whole large bowel.ColonoscopyColonoscopy is the endoscopic examination of the colon and the distal part of the small bowel with a CCD camera or a fiber optic camera on a flexible tube passed through the anus.It may provide a visual diagnosis(e.g.ulceration,polyps)and grants the opportunity for biopsy or removal of suspected lesions.Double contrast barium enema A double-contrast barium enema is a procedure in which x-rays of the colon and rectum are taken after a liquid containing barium is put into the rectum.Barium is a silver-white metallic compound that outlines the colon and rectum on an x-ray and helps show abnormalities.Air is put into the rectum and colon to further enhance the x-rayHEPATIC FLEXURESPLENIC FLEXURETRANSVERSE COLONCECUMASCENDING COLONDESENDING COLONTERMINAL ILEUM NORMAL COLON Normal air contrast barium enema(double contrast-air and barium per rectum)shows filling of colon with air and barium retrograde to the cecum with reflux into the terminal ileumPEDUNCULATED COLON POLYP(DESCENDING COLON)stalk on polyp-pedunculatedCOLON POLYP Polyp on wall without stalk is coated and outlined by barium COLONOBSTRUCTIONDistension extends to distil descending colon.COLON CANCERBarium enema showing apple-core type constricting lesion with proximal dilation of colon”APPLE-CORE”constricting lesion Blood testsMeasurement of the patients blood for elevated levels of certain proteins can give an indication of tumor load.In particular,high levels of carcinoembryonic antigen(CEA)in the blood can indicate metastasis of adenocarcinoma.These tests are frequently false positive or false negative,and are not recommended for screening,it can be useful to assess disease recurrence.genetic testing Gene tests(also called DNA-based tests),the newest and most sophisticated of the techniques used to test for genetic disorders,involve direct examination of the DNA molecule itself.Other genetic tests include biochemical tests for such gene products as enzymes and other proteins and for microscopic examination of stained or fluorescent chromosomes.Positron emission tomographyPositron emission tomography(PET)is a nuclear medicine imaging technique which produces a three-dimensional image or picture of functional processes in the body.The system detects pairs of gamma rays emitted indirectly by a positron-emitting radionuclide(tracer),which is introduced into the body on a biologically active molecule.Images of tracer concentration in 3-dimensional or 4-dimensional space(the 4th dimension being time)within the body are then reconstructed by computer analysis.In modern scanners,this reconstruction is often accomplished with the aid of a CT X-ray scan performed on the patient during the same session,in the same machine.Computed tomographyComputed tomography(CT)is a medical imaging method employing tomography created by computer processing.Digital geometry processing is used to generate a three-dimensional image of the inside of an object from a large series of two-dimensional X-ray images taken around a single axis of rotation CT ColographyColon PolypCT ColographyColon PolypCT ColographyColon CancerTreatment of colorectal cancerOnce colorectal cancer is diagnosed,the best chance of a cure is through surgery.Radiation therapy and chemotherapy may be needed afterwards to help prevent the cancer from spreading or coming back.surgerySurgeries can be categorised into curative,palliative,bypass,fecal diversion,or open-and-close.Curative Surgical treatment can be offered if the tumor is localized.Very early cancer that develops within a polyp can often be cured by removing the polyp(polypectomy)at the time of colonoscopy.In colon cancer,a more advanced tumor typically requires surgical removal of the section of colon containing the tumor with sufficient margins,and radical en-bloc resection of mesentery and lymph nodes to reduce local recurrence(colectomy).If possible,the remaining parts of colon are anastomosed together to create a functioning colon.In cases when anastomosis is not possible,a stoma(artificial orifice)is created.Curative surgery on rectal cancer includes total mesorectal excision(lower anterior resection)or abdominoperineal excision.In case of multiple metastases,palliative(non curative)resection of the primary tumor is still offered in order to reduce further morbidity caused by tumor bleeding,invasion,and its catabolic effect.If the tumor invaded into adjacent vital structures which makes excision technically difficult,the surgeons may prefer to bypass the tumor(ileotransverse bypass)or to do a proximal fecal diversion through a stoma.The worst case would be an open-and-close surgery,when surgeons find the tumor unresectable and the small bowel involved;any more procedures would do more harm than g