COLON CANCERDr. Tanuj Paul Bhatia

COLON CANCEREPIDEMIOLOGY

Colon cancer has 4th highest incidence after prostate , breast & lung cancers

Second leading cause for death after lung cancer

Mean age at diagnosis is 5th decade

COLON CANCERETIOLOGY

Sporadic colon ca accounts for 70%> Adenomas> Tobacco> Inflammatory bowel diseases> Dietary factors> Pyrolysis products – benzo (a) pyrene> Micronutrients deficiency

COLON CANCER

Genetics colon ca 23%> Familial adenomatous polyposis – APC > Hereditary nonpolyposis colorectal cancer Lynch 1( colonic syndrome) Lynch 2 (extracolonic syndrome)> Harmartomatous polyposis syndrome> Familial colorectal cancer

COLON CANCER PATHOLOGY

Adenocarcinoma 90-95% - Mucinous ( colloid ) adenocarcinoma

- Signet ring adenocarcinoma Sirrhous tumors Sarcomas Neuroendocrine tumors Melanomas

Ulcerative Ca Colon

COLON CANCERCLINICAL FEATURES

Ascending colon & caecum 24 % - Bleeding , anemia , melena ,abdominal

pain mass , obstruction , diarrhea Transverse colon 13% - Abdominal pain , mass , obstruction

Clinical features

Descending & Sigmoid colon 34% - Changing bowel habits / stool caliber , mucous & blood in stools ,adbominal

pain mass obstruction / perforation Metastatic disease - Cachexia , wt loss , jaundice , mass ,

ascites ,hepatomegaly, bloomer’s shelf , virchow’s nodes

COLON CANCER INVESTIGATIONS

Clinical ExaminationDouble contrast barium enemaColonoscopy & biopsyC T scan abdomen & pelvisChest x-rayLiver function testCarcinoembryonic Antigen

PET & PET-CT - Role is emerging

Barium studies

Colonoscopy

VIRTUAL ENDOSCOPY

CT Colonography Highly sensitive & specific in colon ca

detection Polyps < 5mm sensitivity 11 – 55 %Allows simultaneous staging & imaging for

synchronous lesions

COLON CANCER STAGING

DUKES CLASSIFICATION A – Tumor restricted to but not through bowel wall. B – Penetration through the bowel wall C – Spread to local & regional nodes C1 – Local lymph nodes involved C2 - lymph nodes at point of ligation D – Distant metasatses

TNM STAGING AJCC-UICC

T is – Carcinoma in situT1 - Tumor invades submucosaT2 - Tumor invades into muscularis propriaT3 - Tumor invades thro muscularis propriaT4 – Tumor invades local structures

N0 – No lymph nodesN1 – 1-3 Regional LNs metsN2 – 4 Or more LNs metsN3 – LNs identified along named vascular trunk

M0 – No distant metsM1 – Distant metastases

TNM

STAGE GROUPINGSTAGE 0 – Tis,N0,M0STAGE 1 – T1,N0,MO T2,N0,M0STAGE 2A – T3,N0,M0 2B – T4,N0,M0STAGE 3A – T –T2,N1,M0 3B - T3 –T4,N1,MO 3C - ANY T,N2,M0STAGE 4 - ANY T,ANY N,M1

PROGNOSTIC FACTORS

Advance stage Serosal penetration High tumor grade More than 4 LNs involved Bowel obstn or perforation CEA levels >5ng/ml

MANAGEMENT OF MALIGNANT COLON POLYPS

1. Pedunculated malignant polyps colon - Management by complete excision or snaring2. Sessile malignant polyps < 2cms - Snaring via colonoscopy with 2mm free margins

PROPHYLACTIC SURGERY POLYPS

First consider non surgical management options before surgery

Endoscopic polypectomy reduces the incidence of subsequent cancer 50 – 70 %

HNPCC

Subtotal coloectomy / Total coloectomy with

ileorectal anastomosis

FAP

Total proctocolectomy and IPAA Various designs of ileal pouchs

MANAGEMENTSURGERY

The extent of resection is determined by location of primary ,presence / absence of invasion into adjacent structures & distant mets

RIGHT HEMICOLECTOMY

Extended right Hemicolectomy

LEFT HEMICOLECTOMY

LAPAROSCOPY VS OPEN TECHNIQUES

Recent studies confirmed technically feasible ,safe, yielding an equivalent no

of lymph nodes and lengths of resected bowel when compared with open colectomy.

MANAGEMENT OF LIVER METASTASIS

Appx 15 – 25 % at initial presentation Appx 25 – 50 % will develop liver mets in 3 years

following primary resectionCurative hepatic resection has a survival

advantage 25 – 50 % at 5 yearsIndications . Stage 1 and 2 . Less than 4 hepatic lesions none > 5 cms

without evidence of extrahepatic disease . CEA level < 5ng/ml . Disease free interval atleast 2 years

ALTERNATIVE MODALITIES FOR UNRESECTABLE LESION

RFA -Thermal energyCryo ablation – Rapid freezingMicrowave ablationPercutaneous enthanol infiltration USG

guidedAdjuvant / pallivative hepatic artery

infusionsInterstitial radiotherapy

STAGEWISE TREATMENT

STAGE 0 COLON CANCERTREATMENT OPTIONS

Local excision or simple polypectomy with clear margins

Colon resection for larger lesions not amenable to local excision

STAGE 1 COLON CANCER

Surgical resection and anastomosis

Adjuvant chemotherpy is not indicated other than controlled clinical trials

STAGE 2 COLON CANCER

Wide surgical resection and anastomosis

Adjuvant therapy is not indicated other than controlled clinical trials

STAGE 3 COLON CANCER

Wide surgical resection and anastomosis

Adjuvant chemotherapy with 5-F.U and leucovorin for 6 months

MOSAIC TRIAL – FOLFOX 4Oxaliplatin , leucovorin , 5 FU demonstrated prolonged 3 yrs survival

STAGE 4 & RECURRENT COLON CANCER

Surgical resection of locally recurrent cancer

Surgical resection & anastomosis or Bypass of obstruction or bleeding primary in selected metastatic cases

Resection of liver metastases in selected pt ( 5yr cure rate for solitary/ combination

mets exceeds 20%)Resection of isolated pulmonary / ovarian

mets in selected ptPalliative RadiotherapyPalliative chemotherapy

COLON CANCERPROGNOSIS

STAGESTAGE 0

STAGE 1

STAGE 2

STAGE 3

STAGE 4

5 YRS SURVIVAL 100%

80 -100%

30-70 %

30-60%

3 -30%