COLON CANCER PRESENTED BY:

RAHAF HASANEIN

ANATOMY+ BLOOD SUPPLY

COLON ARTERIAL SUPPLY

SMA branches into :

Ileocolic artery (terminal ileum and proximal ascending colon).

Right colic artery (ascending colon).

Middle colic artery (transverse colon).

IMA branches into:

Left colic artery (descending colon).

Several sigmoidal branches (sigmoid colon)

Superior rectal artery (proximal rectum).

The terminal branches of each artery form anastomoses with the terminal branches of the adjacent artery and communicate via the marginal artery of Drummond.

VENOUS DRAINAGE

The veins of the colon parallel their corresponding arteries and bear the same

terminology.

IMV ascends in the retroperitoneal plane over the psoas muscle and

continues posterior to the pancreas to join the splenic vein.

THE LYMPHATIC DRAINAGE

Lymphatic vessels and lymph nodes follow the regional arteries.

COLON NERVE SUPPLY

The Sympathetic nerves arise from T6-T12 and L1-L3.

The parasympathetic innervation to the right and transverse colon is from the vagus nerve; the

parasympathetic nerves to the left colon arise from sacral nerves S2-S4.

POLYPS

Nonspecific clinical term that describes any projection from the surface of the intestinal mucosa

regardless of its histologic nature.

Most colorectal carcinomas evolve from adenomatous polyps.

ADENOMATOUS POLYPS

25% of the population older than 50 years of age.

Increase risk of malignancy?

Classification:

(acc. To histology)

Tubular adenomas (5%).

villous adenomas (40%).

Tubulovillous adenomas (22%).

(Acc. To shape)

Pedunculated -> colonoscopic snare

excision.

Sessile

Complications of polypectomy

include perforation and bleeding.

HYPERPLASTIC POLYPS

Extremely common.

These polyps are usually small (<5 mm) -> hyperplasia without any dysplasia.

Large hyperplastic polyps (>2 cm) -> foci of adenomatous tissue and dysplasia

Hyperplastic polyposis is a rare disorder in which multiple large hyperplastic polyps

occur in young adults. These patients are at slightly increased risk for the development of

colorectal cancer.

SERRATED POLYPS

Some of these polyps will develop into invasive cancers.

A familial serrated polyposis syndrome.

Serrated polyps should be treated like adenomatous polyps.

HAMARTOMATOUS POLYPS (JUVENILE)

Not premalignant.

Associated with mutation in PTEN.

Bleeding is a common symptom, and intussusception and/or obstruction may occur.

Treated by polypectomy.

FAMILIAL JUVENILE POLYPOSIS

AD disorder in which patients develop hundreds of polyps in the colon and rectum.

Annual screening should begin between the ages of 10 and 12 years.

Treatment is surgical and depends on the degree of rectal involvement

If the rectum is relatively spared, a total abdominal colectomy with ileorectal anastomosis.

If the rectum is carpeted with polyps, total proctocolectomy is the more appropriate operation and ileal

pouch–anal reconstruction to avoid a permanent stoma

PEUTZ-JEGHERS SYNDROME

polyposis of the small intestine, the colon and rectum.

Characteristic melanin spots on the buccal mucosa and lips of these patients..

Carcinoma may develop.

Surgery for symptoms.

Screening consists of a baseline colonoscopy and upper endoscopy at age 20 years, followed by annual flexible

sigmoidoscopy thereafter.

CRONKITE-CANADA SYNDROME

GI polyposis in association with alopecia, cutaneous pigmentation, and atrophy of the

fingernails and toenails.

Diarrhea is a prominent symptom, and vomiting, malabsorption, and protein-losing

enteropathy may occur.

Most patients die of this disease.

Surgery for complications.

COWDEN’S SYNDROME

AD.

Hamartomas of all three embryonal cell layers.

Facial trichilemmomas, breast cancer, thyroid disease and gastrointestinal polyps.

Patients should be screened for cancers.

Treatment is otherwise based on symptoms.

INFLAMMATORY POLYPS

Not premalignant.

In inflammatory bowel disease

After amebic colitis, ischemic colitis, and schistosomal colitis.

Microscopic examination shows islands of normal, regenerating mucosa (the polyp) surrounded by areas of mucosal loss.

Polyposis may be extensive, especially in patients with severe colitis, and may mimic FAP.

INHERITED COLORECTAL CARCINOMA

FAMILIAL ADENOMATOUS POLYPOSIS

AD, 1% of all colorectal adenocarcinomas.

Mutation in the APC gene, on chromosome 5q (positive in 75% of cases).

Up to 25% present without other affected family members.

Hundreds to thousands of adenomatous polyps shortly after puberty.

Risk of colorectal cancer 100% by age 50 years.

APC

gene t

est

ing

+

annual flexible sigmoidoscopy beginning at

age 10 to 15 years is done until polyps are identified.

-

Refused or unavailable

annual flexible sigmoidoscopy beginning at

age 10 to 15 years is performed until age 24 years.

every 2 years until age 34 years

every 3 years until age 44 years

then every 3 to 5 years.

Risk for the development of adenomas anywhere in the gastrointestinal tract, particularly in the

duodenum.

Upper endoscopy (every 1 to 3 years beginning at age 25 to 30 years).

Treatment is surgical.

Three operative procedures can be considered:

1. Total proctocolectomy with an end (Brooke) ileostomy

2. Total abdominal colectomy with ileorectal anastomosis

3. Restorative proctocolectomy with ileal pouch–anal anastomosis with or without a temporary ileostomy.

FAP may be associated with extraintestinal manifestations such as congenital hypertrophy of the

retinal pigmented epithelium, desmoid tumors, epidermoid cysts, mandibular osteomas (Gardner’s

syndrome)

central nervous system tumors (Turcot’s syndrome).

Desmoid tumors are often hormone responsive, and growth may be inhibited in some patients with

tamoxifen. COX-2 inhibitors and nonsteroidal, anti-inflammatory drugs may also be beneficial in

this setting.

ATTENUATED FAMILIAL ADENOMATOUS POLYPOSIS

Variant of FAP.

Present later in life with fewer polyps (usually 10–100) predominantly in the right colon.

CRca develops in more than 50% of these patients, but occurs later (average age, 55 years).

Patients are also at risk for duodenal polyposis.

APC gene mutations are present in only about 30% (AD)

Mutations in MYH also result in the(AR).

Genetic testing.

When positive, screen at-risk family members.

If the family mutation is unknown, screening colonoscopy is recommended beginning at age 13 to 15

years, then every 4 years to age 28 years, and then every 3 years.

These patients are often candidates for a total abdominal colectomy with ileorectal anastomosis

because the limited polyposis in the rectum can usually be treated by colonoscopic snare excision.

Prophylaxis with COX-2 inhibitors.

HEREDITARY NONPOLYPOSIS COLON CANCER (LYNCH’S SYNDROME).

HNPCC (Lynch’s syndrome) is more common than FAP.

(1%–3% of all colon cancers).

AD, Errors in mismatch repair.

Development of colorectal carcinoma at an early age (average age, 40–45 years). Approximately 70%

Cancers appear in the proximal colon and have a better prognosis regardless of stage.

The risk of synchronous or metachronous colorectal carcinoma is 40%.

May also be associated with extracolonic malignancies, including endometrial carcinoma, which is

most common, and ovarian, pancreas, stomach, small bowel, biliary, and urinary tract carcinomas.

The diagnosis is made based on family history.

The Amsterdam criteria for clinical diagnosis of HNPCC are:

Three affected relatives with histologically verified adenocarcinoma of the large bowel (one must be

a first-degree relative of one of the others) in two successive generations of a family with one

patient diagnosed before age 50 years.

The presence of other HNPCC-related carcinomas should raise the suspicion of this syndrome.

Screening colonoscopy is recommended annually for at risk patients beginning at either age 20 to 25

years or 10 years younger than the youngest age at diagnosis in the family, whichever comes

first.

Because of the high risk of endometrial carcinoma, transvaginal ultrasound or endometrial aspiration

biopsy is also recommended annually after age 25 to 35 years.

Because there is a 40% risk of developing a second colon cancer, total colectomy with ileorectal

anastomosis is recommended once adenomas or a colon carcinoma is diagnosed.

Annual proctoscopy is necessary because the risk of developing rectal cancer remains high. Similarly,

prophylactic hysterectomy and bilateral salpingo-oophorectomy should be considered in women

who have completed childbearing.

FAMILIAL COLORECTAL CANCER

10% to 15% of patients with colorectal cancer.

Diagnosis before the age of 50 years is associated with a higher incidence in family members.

Screening colonoscopy is recommended every 5 years beginning at age 40 years or beginning 10 years

before the age of the earliest diagnosed patient in the pedigree.

ADENOCARCINOMA AND POLYPS

Most common malignancy of the GIT.

Third most common cancer in women and men.

Third leading cause of cancer-related deaths.

F:M 1:1

RISK FACTORS

Aging

Hereditary Risk Factors

Environmental and Dietary Factors

Inflammatory Bowel Disease

Cigarette smoking

Patients with ureterosigmoidostomy

Acromegaly

Pelvic irradiation

CLINICAL FEATURES

Depend on: Site, Presence of complications and metastases.

SPREAD

Direct extension

Hematogenous

lymphatic

DIAGNOSIS

Hx+ PE

Colonoscopy to obtain biopsy and evaluate for synchronous tumors (5%)

OR flexible sigmoidoscopy and barium enema.

CBC, LFT

Water-soluble contrast enema is performed to assess the degree and level of obstruction and to “clear”

the colon proximal to the obstruction.

A chest/abdominal/pelvic CT.

PET scan (It is routinely performed prior to concurrent colectomy and liver resection for hepatic

metastases)

CEA

STAGING

MANAGEMENT

surgical resection: Remove the primary tumor along with its lymphovascular supply

➢ Surgeries could be curative or palliative

Adjuvant chemotherapy: stage III / VI or locally advanced stage II

combination of 5-fluorouracil/leucovorin with either irinotecan (FOLFIRI) or oxaliplatin (FOLFOX).

STAGE-SPECIFIC THERAPY

Stage 0 (Tis, N0, M0):

Polypectomy

Segmental resection.

Stage I: The Malignant Polyp (T1, N0, M0):

Invasive carcinoma in pedunculated polyp polypectomy or Segmental colectomy.

Invasive carcinoma arising in a sessile polyp extends into the submucosa and is usually

best treated with segmental colectomy

Stages I and II: Localized Colon Carcinoma (T1-3, N0,M0):

Surgical resection.

Adjuvant chemotherapy has been suggested for selected patients with stage II disease

(young patients, tumors with “high-risk” histologic findings).

Stage III: Lymph Node Metastasis (Tany, N1, M0)

Adjuvant chemotherapy has been recommended routinely in these patients.

Stage IV: Distant Metastasis (Tany, Nany, M1).

Highly selected patients with isolated, resectable metastases may benefit from resection

(metastasectomy).

All patients require adjuvant chemotherapy.

colonic stenting for obstructing lesions of the left colon also provide good palliation.

More limited surgical intervention such as a diverting stoma or bypass procedure may be appropriate in

patients with stage IV disease who develop obstruction.

Hemorrhage in an unresectable tumor can sometimes be controlled with angiographic embolization.

External beam radiation also has been used for palliation.

RIGHT HEMICOLECTOMY

Carcinoma of the caecum or ascending colon.

The ileocolic vessels, right colic vessels,

and right branches of the middle colic

vessels are ligated.

Ileal-transverse colon anastomosis

EXTENDED RIGHT COLECTOMY

Lesions located at the hepatic flexure or proximal transverse colon.

Right hemicolectomy + reminder of transverse colon and splenic flexure.

resection of right colic artery, iliocecal artery and middle colic artery.

Anastomosis relies on the marginal artery of Drummond

TRANSVERSE COLECTOMY

Lesions in the mid and distal transverse

colon

Resecting the transverse colon

Ligating the middle colic vessels.

Colocolonic anastomosis.

Extended right may be a safer anastomosis

with an equivalent functional result.

LEFT COLECTOMY

Lesions in distal transverse colon, splenic

flexure, or descending colon.

The left branches of the middle colic

vessels, the left colic vessels, and the first

branches of the sigmoid vessels are ligated.

A colocolonic anastomosis.

EXTENDED LEFT COLECTOMY

Option for removing lesions in the distal transverse colon.

In this operation, the left colectomy is extended proximally to include the right branches of the middle

colic vessels.

SIGMOID COLECTOMY

Lesions in the sigmoid colon

Ligation of the sigmoid branches of the

inferior mesenteric artery.

anastomosis created between the

descending colon and upper rectum.

TOTAL OR SUBTOTAL

COLECTOMY

The superior rectal vessels are preserved.

If the sigmoid is to be resected (total abdominal colectomy with ileorectal anastomosis).

preserve the sigmoid, the distal sigmoid vessels are left intact (subtotal colectomy with ileosigmoid anastomosis).

HARTMANN PROCEDURE.

PROCTOCOLECTOMY

Total Proctocolectomy. In this procedure, the entire colon, rectum, and anus are removed, and the

ileum is brought to the skin as a Brooke ileostomy.

Restorative Proctocolectomy (Ileal Pouch–Anal Anastomosis). The entire colon and rectum are

resected, but the anal sphincter muscles and a variable portion of the distal anal canal are preserved.

Anastomosis of an ileal reservoir to the anal canal

FOLLOW-UP

Stool guaiac test

Annual CT scan of abdomen/pelvis and CXR for up to 5 years

Colonoscopy at 1 year and then every 3 years until negative then every 5 years.

CEA levels are checked periodically (every 3 months in the first year) and then every 6 months the next 4 years.

OTHER TYPES

Carcinoid Tumors.

Lipomas.

Lymphoma.

Leiomyoma and Leiomyosarcoma.

REFERENCES:

Schwartz’s Principles of Surgery.

Bailey and love’s short practice of surgery

Surgical recall.

The washington manual of surgery.

THANK YOU