Colorectal Cancer Overview and Risk Factors

Questions and Answers

What is the five-year survival rate associated with Dukes A classification?

90% (correct)

30-60%

75%

Which of the following treatment approaches is aimed primarily at symptom control?

Surgery

Palliative care (correct)

Post-operative chemotherapy

Neoadjuvant chemoradiotherapy

For which cases is post-operative chemotherapy indicated?

Only for Dukes D classification

In all cases after surgery

When positive lymph nodes are present (correct)

For patients experiencing obstruction

What surgery is typically performed for middle and lower third rectal cancers?

Abdomino-perineal resection Signup and view all the answers

Which classification is considered more comprehensive than Dukes classification for staging cancer?

TNM staging Signup and view all the answers

What is the peak incidence age range for colorectal cancer?

55-75 years Signup and view all the answers

Which risk factor has the highest associated risk for developing colorectal cancer?

Chronic ulcerative colitis Signup and view all the answers

What stool characteristics are typical of left-sided lesions in colorectal cancer?

Semi-solid stools Signup and view all the answers

What is the most essential investigation required for diagnosing colorectal cancer?

Endoscopic biopsy Signup and view all the answers

Which of the following is NOT considered a common symptom of colorectal cancer?

Blurry vision Signup and view all the answers

Which imaging technique is essential for staging colorectal cancer?

CT TAP Signup and view all the answers

What percentage of colorectal cancer cases have raised CEA levels useful for monitoring disease?

60% Signup and view all the answers

What type of lesion typically causes blood on the stool surface?

Rectal lesions Signup and view all the answers

What is the peak incidence age range for colorectal cancer?

55-75 years Signup and view all the answers

Which of the following is NOT a risk factor for colorectal cancer?

High-fiber diet Signup and view all the answers

Which of the following genetic conditions is associated with an increased risk of colorectal cancer?

Gardner's syndrome Signup and view all the answers

Which tumor site accounts for 30% of colorectal cancers?

Rectum Signup and view all the answers

What is the most likely presentation of a right-sided colorectal lesion?

Liquid stools and iron deficiency anemia Signup and view all the answers

Which of the following is essential for the diagnosis of colorectal cancer?

Colonoscopy with biopsy Signup and view all the answers

What is the most common emergency presentation of colorectal cancer?

Large bowel obstruction Signup and view all the answers

What is the 5-year survival rate for Dukes' A classification of colorectal cancer?

90% Signup and view all the answers

Which of the following is part of the treatment for unresectable colorectal cancer metastases?

Chemotherapy Signup and view all the answers

What is the primary purpose of the fecal immunochemical test (FIT) in colorectal cancer screening?

To detect blood in the stool Signup and view all the answers

Which of the following statements is true about the incidence of colorectal cancer?

It is the second commonest cause of cancer death in the UK and Ireland. Signup and view all the answers

Which of the following is the MOST significant genetic risk factor for colorectal cancer?

Hereditary Non-Polyposis Colorectal Cancer (HNPCC) Signup and view all the answers

What is the male to female ratio for colorectal cancer incidence?

3:1 Signup and view all the answers

Which of the following is NOT a symptom of a left-sided colorectal lesion?

Tenesmus Signup and view all the answers

Which of the following describes the presentation of rectal colorectal cancer?

Solid stools with blood on the stool surface and tenesmus Signup and view all the answers

What percentage of colorectal cancers present as an emergency (e.g., obstruction or perforation)?

40% Signup and view all the answers

Which of the following is an appropriate imaging technique for staging colorectal cancer?

CT Thorax, Abdomen, Pelvis (TAP) Signup and view all the answers

Which of the following tumor sites has the highest incidence in colorectal cancer?

Descending and Sigmoid colon Signup and view all the answers

What is the Dukes' C classification of colorectal cancer characterized by?

Regional lymph node involvement Signup and view all the answers

What is the purpose of the Carcinoembryonic Antigen (CEA) test in colorectal cancer management?

Monitoring disease progression Signup and view all the answers

Which of the following is a recommended screening method for colorectal cancer in Ireland for people aged 60-69?

Fecal immunochemical test (FIT) Signup and view all the answers

What is the typical surgical procedure for a right-sided colon tumor?

Right hemicolectomy Signup and view all the answers

Which of the following is a treatment option for unresectable tumors or metastases?

Colonic stenting Signup and view all the answers

What is the 5-year survival rate for Dukes' D colorectal cancer with distant metastasis?

5% Signup and view all the answers

Which colorectal cancer treatment involves the removal of the rectum and creation of a permanent colostomy?

Abdomino-perineal resection (APR) Signup and view all the answers

Which of the following conditions is a greater risk factor for colorectal cancer?

Ulcerative colitis Signup and view all the answers

Which imaging technique is used to diagnose caecal carcinoma with circumferential involvement of the caecal wall?

Contrast-enhanced CT Signup and view all the answers

What do contrast-enhanced CT scans often show in advanced colorectal cancer cases with liver metastases?

Low-density metastases involving both lobes of the liver Signup and view all the answers

Which Dukes' stage is characterized by colorectal cancer confined to the bowel wall, with a 90% 5-year survival rate?

Dukes A Signup and view all the answers

Which surgical procedure is appropriate for right-sided colon cancer?

Right hemicolectomy Signup and view all the answers

What is the correct surgical treatment for a tumor located in the sigmoid colon or upper rectum?

Anterior resection Signup and view all the answers

Which surgical procedure is typically performed for low rectal cancers that require removal of the rectum and a permanent colostomy?

Abdomino-perineal resection (APR) Signup and view all the answers

What is the typical presentation of diverticulosis?

Asymptomatic, with diagnosis usually made incidentally Signup and view all the answers

Diverticulitis is the inflammation of which of the following?

Colonic outpouchings Signup and view all the answers

According to the Hinchey classification, what is a paracolic inflammatory mass or mesenteric abscess classified as?

Hinchey 2 Signup and view all the answers

Which stage of the Hinchey classification involves a walled-off abscess?

Hinchey 2 Signup and view all the answers

What is the appropriate management for uncomplicated diverticulitis (Hinchey 1 or 2)?

Medical management with IV antibiotics, IV fluids, and analgesia Signup and view all the answers

In the case of complicated diverticulitis (Hinchey 3 or 4), which of the following is a possible surgical option?

Laparoscopy and washout (Hinchey 3) Signup and view all the answers

What is the surgical procedure called that involves resecting a portion of the colon and creating a colostomy for Hinchey 4 diverticulitis?

Hartmann's operation Signup and view all the answers

Which of the following is a potential complication that may require radiologically guided drainage in diverticulitis?

Mesenteric abscess Signup and view all the answers

Which clinical presentation is associated with Hinchey 3 diverticulitis?

Purulent peritonitis from a perforated abscess cavity Signup and view all the answers

What is the hallmark of Hinchey 4 diverticulitis?

Faeculent peritonitis Signup and view all the answers

Which of the following is a characteristic symptom of left-sided colorectal lesions?

Semi-solid stools Signup and view all the answers

Which symptom is more commonly associated with right-sided colorectal lesions?

Liquid stools Signup and view all the answers

What type of bleeding is commonly seen in left-sided colorectal cancer?

Blood mixed with stool (PR bleeding) Signup and view all the answers

Iron deficiency anemia is more likely to occur with which of the following?

Right-sided colorectal lesions Signup and view all the answers

Which of the following is a common change in bowel habits seen in left-sided colorectal cancer?

Alternating constipation and diarrhea Signup and view all the answers

Which of the following findings is least likely with right-sided colorectal cancer?

PR bleeding with blood mixed in stool Signup and view all the answers

What is the recommended surgical procedure for cancers located in the upper third of the rectum?

High anterior resection Signup and view all the answers

For rectal cancers located in the middle or lower third, which procedure is usually performed if the lesion is less than 5 cm from the anal verge?

Abdomino-perineal resection (APR) Signup and view all the answers

What is the primary goal of Total Mesorectal Excision (TME) in rectal cancer surgery?

To achieve clear margins by excising the entire mesorectal envelope Signup and view all the answers

In which situation might a colonic J pouch be considered?

For rectal cancers requiring low anterior resection Signup and view all the answers

What is a key consideration in the surgical management of rectal cancer regarding pedicle vessels?

High ligation of pedicle vessels is performed to prevent collateral circulation. Signup and view all the answers

Which surgical technique is rarely used in rectal cancer surgery but can be considered in specific cases? A) High anterior resection B) Total mesorectal excision (TME) C) Coloplasty D) Abdomino-perineal resection (APR)

Coloplasty Signup and view all the answers

Study Notes

Colorectal Cancer

Introduction

Second most common cause of cancer death in the UK and Ireland, third in Bahrain.
Highest incidence in the Western world.
Male to Female Ratio: 3:1.
Peak incidence: Ages 55-75 years.
Type of cancer: Adenocarcinoma.

Risk Factors

Genetic: Family history (HNPCC 5%, FAP 1%, Juvenile Polyposis).
- Two first-degree relatives = 1 in 6 lifetime risk.
Colonic Polyps.
Diet: Low fiber, fruits, and vegetables.
Obesity, Male gender, Age (55-75).
Smoking.
Chronic ulcerative colitis or Crohn's disease (UC has higher risk than Crohn's).
Other syndromes: Gardner’s, Peutz-Jeghers Syndrome.

Presentation

Symptoms

Right-sided lesions:
- Liquid stools.
- Iron deficiency anemia symptoms.
Left-sided lesions:
- Semi-solid stools.
- PR bleeding (blood mixed with stool).
- Change in bowel habits.
Rectal lesions:
- Solid stools.
- Blood on stool surface.
- Tenesmus (incomplete evacuation sensation).
Constitutional symptoms:
- Weight loss.
- Lower abdominal pain.
- Emergency presentation in 40% of cases: Large bowel obstruction, perforation/peritonitis, or acute PR bleed.

Signs

Most patients: No specific signs.
Possible findings:
- Anemia.
- Blood per rectum or on stools.
- Abdominal mass.
- Rectal lesion on PR exam.
- Hepatomegaly (indicating metastasis).
- Cachexia (weight loss, muscle wasting).

Tumor Sites

Rectum (30%)
Descending and sigmoid colon (45%)
Right-sided colon (20%)
Transverse colon (5%)

Workup and Investigations

Initial Bedside Investigations

History and examination.
Vital signs: O2 saturation, BP, HR, RR, temperature.
Digital rectal exam and fecal occult blood (FOB) test.
Imaging:
- Erect CXR (perforation).
- Abdominal X-ray (if obstruction suspected).
- CT abdomen/pelvis.
Laboratory:
- Full blood count (FBC), U&E, CRP, LFTs, coagulation profile.
- CEA (carcinoembryonic antigen) – raised in 60% of colorectal cancer cases.
- Urine dipstick +/- beta hCG.
- VBG/ABG (lactate), glucose check.

Endoscopy (Essential for Diagnosis)

Tissue diagnosis through biopsy:
- Rigid/Flexible sigmoidoscopy.
- Colonoscopy (essential to examine entire colon).

Imaging for Staging

CT TAP (Thorax, Abdomen, Pelvis) to assess spread of the disease based on TNM classification (Tumor, Nodes, Metastasis).

Staging

Dukes’ Classification (Older)

Dukes A: Confined to bowel wall (90% 5-year survival).
Dukes B: Through muscularis propria (75% survival).
Dukes C: Regional lymph nodes (30-60% survival).
Dukes D: Distant metastasis (5% survival).

TNM Staging (Current)

More comprehensive, based on tumor size (T), node involvement (N), and metastases (M).

Treatment

Goals:
- Symptom control (initially).
- Urgent intervention for obstruction or bleeding.
- Disease downstaging with chemotherapy or radiotherapy.
- Surgery if necessary.

Surgical Options

Right-sided colon: Right hemicolectomy.
Left-sided colon: Left hemicolectomy.
Sigmoid/Upper rectum: Anterior resection.
Low rectum: Abdomino-perineal (AP) resection + colostomy.

Additional Treatment

Preoperative (Neoadjuvant) chemoradiotherapy: For rectal cancer to reduce local recurrence.
Postoperative (Adjuvant) chemotherapy: If lymph node involvement or vascular invasion is present.
Palliative treatment: For unresectable tumors or metastasis (chemotherapy, stents, surgery for obstruction/bleeding).

Colorectal Screening

Tests: Fecal occult blood (FOB), fecal immunochemical test (FIT).
- Routine screening in the USA.
- In Ireland: FIT offered every two years for those aged 60-69.
CEA Marker:
- Used for monitoring post-resection.
- Not specific to colorectal cancer.

Diverticular Disease

Definition

Acquired sac-like mucosal projections (diverticula) through the colon wall, typically affecting the sigmoid colon.

Epidemiology

Affects 30% of people aged 60+.
More common in westernized countries.
Associated with constipation and increased colonic pressure.

Presentation

Diverticulosis: Usually asymptomatic, found incidentally.
Diverticulitis: Inflammation of diverticula with symptoms such as left lower abdominal pain, diarrhea/constipation, PR bleeding, nausea/vomiting, fever, tachycardia, and tenderness in the left iliac fossa (LIF).

Complications of Diverticular Disease

Inflammation (Diverticulitis).
Bleeding, perforation, or obstruction.
Fistula formation (e.g., colovesical).
Strictures (narrowing of the colon).

Hinchey Classification (Based on CT findings)

Stage I: Paracolic mass/mesenteric abscess.
Stage II: Walled-off abscess.
Stage III: Purulent peritonitis.
Stage IV: Feculent peritonitis.

Treatment

Uncomplicated Diverticulitis (Hinchey I/II)

Medical management: IV antibiotics, fluids, analgesia, and possible radiologically guided drainage.
Surgery considered if medical management fails.

Complicated Diverticulitis (Hinchey III/IV)

Surgical management:
- Laparoscopy and washout (Hinchey III).
- Segmental colectomy or Hartmann’s procedure (Hinchey IV).

Hartmann’s Procedure

Removal of diseased colon segment with colostomy.

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Description

Explore the critical insights into colorectal cancer, including its incidence, risk factors, and age demographics. This quiz delves into hereditary syndromes, lifestyle influences, and the typical presentations of symptoms associated with this prevalent cancer type. Test your knowledge and enhance your understanding of colorectal cancer today.