Colorectal cancer is the third most common cancer in men and the second in women worldwide. It is also the fourth main cause of death globally. Nearly 55% of cases occur in more developed regions and risk increases significantly with age. The main risk factors include family history, diet high in fat/meat and low in fiber, smoking, and lack of physical activity. Screening methods include colonoscopy, sigmoidoscopy, and stool tests. Treatment involves surgical resection of the tumor along with lymph nodes, while chemotherapy may be recommended after for more advanced stages to improve survival rates.

1. Gastroenterology
Dalia Cosio Benson
C O L O R E C TA L C A R C I N O M A
U N I V E R S I D A D A U T Ó N O M A D E B A J A C A L I F O R N I A
E S C U E L A D E C I E N C I A S D E L A S A L U D

2. E P I D E M I O L O G Y
 CRC is the 3th most common cancer in men, and the 2nd in women worldwide.
 It is the 4th main cause of death (after stomach, liver and lung)
G L O B O C A N 2 0 1 2
( I A R C )

3. E P I D E M I O L O G Y
M E N W O M E N
3O
2O
G L O B O C A N 2 0 1 2
( I A R C )
4O
4O
Incidence and mortality rates

4. EPIDEMIOLOGY
 Almost 55% of the cases occur in more developed regions.
 Age impacts CRC incidence more than any other demographic factors.
G L O B O C A N 2 0 1 2
( I A R C )

5. E T I O L O G Y
 Familial adenomatous polyposis (FAP)
Inherited
predisposition
Constitutes 1% of all CRC incidence. Hundreds to
thousands of colonic polyps that develop in patients
in their teens to 30s, and if the colon is not
surgically removed, 100% of patients progress to
CRC.
The particular association of brain tumors and
colonic polyposis is called Turcot syndrome
Attenuated APC (AFAP) is a subtype of a condition
known as FAP.
Hereditary nonpolyposis CRC (HNPCC) accounts
for about 3% of all CRCs.
A variant of HNPCC involves skin tumors and is
designated as Muir-Torre syndrome.
Hamartomatous polyposis syndromes are rare
syndromes, mostly affecting the pediatric and
adolescent population, and represent <1% of CRCs
annually.

6. E T I O L O G Y
 It is strongly suggested that the lifestyle and environment plays a very important role for the
development of this disease.
Environmental
factors
High fat and meat
intake
increases bile acid
synthesis and
cholesterol
Higher amounts of
sterols in the colon
convert them into secondary bile
acids, cholesterol metabolites and
other toxic metabolic components
Bacterias

7. E T I O L O G Y
Fiber
 A high-fiber diet was believed to dilute fecal
carcinogens, decrease colon transit time, and
generate a favorable luminal environment
Calcium and
Vitamin D
 Calcium have a protective effect, for its ability
to bind injurious bile acids with reduction of
colonic epithelial proliferation.
 D Vitamine: inhibit cell proliferation and
increase apoptosis.
Nonsteroidal Anti-
Inflammatory Drugs
(NSAIDs)
 Studies Case-Control and cohort studies have
shown a 40-50 % reduction in the mortality of
colorectal Ca in people taking aspirin and other
NSAIDs.

8. E T I O L O G Y
Probable causes Posibles causes Probable
protectors
Posibles
protectors
• High fat and low fiber
intake
• Red meat intake
• Beer intake (specially
for rectal carcinoma)
• Smoking
• Diabetes mellitus
• Enviromental
carcinogens
• Aminas
• Low intake of dietary
selenium
• Aspirins, NSAIDs,
COX-2
• Calcium
• Hormone replacement
(estrógens)
• Low Comporal Mass
Index
• Physical activity
• Foods with higth levels
of carotenes
• Higth fiber diet
• C and E Vitamin
• D Vitamin
• Vegetables (yellow and
green crucíferous)

9. R I S K FA C TO R S

10. PAT H O G E N E S I S
Colorectal tumors resulting from a sequence of accumulations (over several years) of genetic and
molecular alterations, causing normal epithelium becomes a intraepithelial neoplasia ( dysplasia ) and
then a malignant epithelium

11. L O C AT I O N S C R C
Ascending colon
and cecum 25%
Transverse colon
15%
Descending
colon 5%
Sigmoid colon
25%Rectum 20%
Rectosigmoid
junction 10%

12. Abdomial pain
 Colorrectal Ca grows slowly and may present symptoms until 5 years after the start of it.
 Asymptomatic people with cancer often presents fecal occult blood, and bleeding increases by
tumor size and the degree of ulceration.
 Proximal colon cancers usually grow larger than the left and rectum before they clinical
presentation or symptoms.
C L I N I C A L P R E S E N TAT I O N
 Lower GI bleeding
 Change in bowel habits
 Change in appetite
 Weakness
Obstructive
symptoms
Weight loss
Bleeding GI

13. C L I N I C A L P R E S E N TAT I O N
Palpable mass, bright blood per rectum  left-
sided colon cancers or rectal cancer
Melena (right-sided colon cancers)
Lesser degrees of bleeding (hemoccult-positive
stool)
Physical examination
Metastatic disease
 Adenopathy
 Hepatomegaly
 Jaundice
 Pulmonary signs

14. Obstruction is usually…
Sigmoid of left colon
 Abdominal distention and
constipation.
C L I N I C A L P R E S E N TAT I O N
Complications
 Acute GI bledding
 Perforation
 Metastasis
 Impairment of distant organ function

15. DIAGNOSIS LABORATORY
May reflect:
• Iron- deficiency anemia
• Electrolyte derangements
• Liver function anormalities
Carcinoembryonic antigen (CEA)
 Elevated
 Helpful to monitor postoperative patients (if
reduced to normal as a result of surgery)
Evaluation include:
 Complete history
 Family history
 Physical examination
 Laboratory test
 Colonoscopy
 CT scan

16. DIAGNOSIS SCREENING : colonoscopy
The most sensitive method for screening
Adventages
 Direct visualization
 Ability to remove
 Obtain biopsies
Disadventages
 Preparation
 Invasive nature of procedure
 Side affects (perforation <15%)

17. DIAGNOSIS SCREENING FOR CRC
DIGITAL RECTAL
EXAMINATION
 Part of general physical
examination
 Palpable anorectal
masses
FLEXIBLE
SIGNMOIDOSCOPY
 Allow visualization of :
 Rectum,
 Sigmoid colon
 Descending to the
splenic flexure
BARIUM ENEMA
Allow visualization of entire
colon
 Easy preparation
 Lack of conscious
sedation
 Ability to visualize polyps
and masses

18. DIAGNOSIS

19.  New noninvasive technologies:
DIAGNOSIS
Computed tomography (CT)

20. STAGING AND PROGNOSIS
Prognostic factors influencing survival in CRC patients include depth of
tumor invasion into and beyond the bowel wall, the number of
involved regional lymph nodes, and the presence or absence of
distant metastases

21. Average 5-year survival:
- T1, N0: 97%
- T2, N0: 85- 90%
With a single high-risk of extension:
- T3- 4, N0 or involved nodes: 65- 75%
Both higth-risk
- T3, N+: 50%
- T4, N+: 35%
* Adjuvant treatment is recommended.
STAGING AND PROGNOSIS

22. Date of download: 5/2/2016 Copyright © Wolters Kluwer
From: Colon
TNM staging diagram presents a vertical arrangement with color bars encompassing TN combinations showing progression. Colon cancers are
resectable in stage IIIA/B (purple), N1, and become more advanced with nodal progression, N2; stage III (red) is less resectable, and stage IV
(black) is metastatic. Stage 0, yellow; I, green; II, blue; III, purple; IV, red; and IV (metastatic), black. Definitions of TN on left and stage grouping
on right.
Legend:
TNM Staging Atlas with Oncoanatomy, 2e, 2012

23. TREATMENT Surgery
 Primary treatment modality for patients with colonic tumors
Curative is possible in 75% of
patients
Sufficient lengths of bowel must be
resected proximal and distal to the
primary cancer
Resection includes removal of the
major lymphatic drainage system

24. Adjuvant chemotherapy
 Stage I y 0: Not requires
 Stage II: benefits in patients is more controversial.
 Stage III: The benefit of adjuvant chemotherapy has been
clearly demostrated

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Cancer, principles & practice of oncology. 10th edición. Philadelphia: Lippincot Williams;
2012.
 GLOBOCAN 2012 (IARS). Organización Mundial de la Salud.
 Joo Hee, K., et al. (2007). Imcomplete colonoscopy in patinets with occlusive colorectal cancer:
usefulness of CT colonography accorging to tumor location. Yonsei College og Medicine 48(6).
Obtenido de:
http://synapse.koreamed.org/DOIx.php?id=10.3349/ymj.2007.48.6.934&vmode=PUBREADER
 Ignatov, V., Kolev N., Tonev A. (2014).Diagnostic modalities in colorectal cancer- endoscopy, CT and
pet scanning, MRI, endoluminal ultrasound and intraoperative ultrasound. Varna Bulgaria. Obtenido
de: http://www.intechopen.com/books/colorectal-cancer-surgery-diagnostics-and-
treatment/diagnostic-modalities-in-colorectal-cancer-endoscopy-ct-and-pet-scanning-magnetic-
resonance-imaging-
B I B L I O G R A P H Y