Radical Resection of Rectal Cancer - Causes, Symptoms, Diagnosis, and Treatment

Introduction

The rectum is the last part of the large intestine. It carries stool or waste from the large intestine to the anus. It is located close to the anus and is a few inches in length. Before passing the stool, it is stored in the rectum temporarily.

There are various rectal abnormalities, such as hemorrhoids, abscesses, and cancer. Rectal cancer is the cancer of rectal cells and tissues. Old-age people who have a family history of rectal cancer have the highest risk of developing this cancer. It is generally characterized by constipation, abdominal pain, and many other symptoms. Rectal cancer is removed through surgical resection and is supported by other medications.

What Is Rectal Cancer?

Rectal cancer is the abnormal growth of cancer cells in the rectum. The rectum is the lowest or last end of the large intestine through which the waste leaves the body and goes out.

What Are the Causes of Rectal Cancer?

The common causes are:

• Hereditary.

• Polyp or growth of cells in the rectum. It is called an adenomatous polyp.

• Tubular adenomas (precancerous polyps in the colon).

• Obesity.

• Tobacco and alcohol consumption.

• High consumption of red meat.

• Cholecystectomy (removal of the gallbladder).

What Is the Epidemiology of Rectal Cancer?

It mainly occurs in young people who are below the age of 50 years.

What Are the Protective Factors of Rectal Cancer?

Various research studies suggest that the following factors protect people from developing rectal cancer:

• Physical activity such as exercise.

• Diet rich in fruits, fiber, vegetables, and fish.

• Vitamins and other nutrients such as calcium and magnesium.

• Garlic consumption is beneficial for preventing this cancer.

• Using Non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of colorectal polyps.

What Are the Symptoms of Rectal Cancer?

• Blood in the stool.

• Anemia.

• Pain in the abdomen.

• Obstruction in the passage of stool.

• Inflammation of the lining of the abdominal wall (peritonitis).

• Constipation.

• Diarrhea.

• Change in the habit of stool passage.

How to Diagnose Rectal Cancer?

1. Patient's History - The patient may give a family history of rectal or colon cancer.

2. Physical Examination - The doctor may examine the abdomen of the patient. The doctor will also examine the liver and various lymph nodes to identify the swelling of the affected organs.

3. Imaging Test - A barium enema test may be performed in which an x-ray is taken after injecting barium into the rectum. The presence of abnormalities shows contrasting images in the x-ray. Computed tomography of the chest, pelvis, and abdomen is also helpful.

4. Sigmoidoscopy - In this, a special endoscope is used to visualize the internal structures of the lower or end part of the large intestine. An endoscope is a thin, flexible tube with a camera and light.

5. Blood Test - Complete blood count, iron levels, liver function, and coagulation test may help manage rectal cancer.

6. Biopsy - To confirm the diagnosis, a biopsy is recommended by taking a small sample of the diseased tissues and studying them under the microscope.

How to Treat Rectal Cancer?

1. Endoscopic Resection - It is done in patients at an early stage of cancer. In this procedure, the diseased tissues are removed without surgery. It is a minimally invasive procedure that is done with the help of an endoscope.

2. Neoadjuvant Therapy - It includes therapeutic agents given to the patient before the primary treatment or surgery.

3. Surgical Resection - It is the surgical approach in which the tumor or diseased tissues are removed completely. This surgery is aimed to:

   1. Remove the margins minimum by five centimeters proximally, two centimeters distally, and more than one millimeter radially.

   2. Restore the continuity of the bowel through anastomosis (surgically reconnecting colons of the large intestine).

The surgical approach includes the following techniques:

Open Transabdominal RCA Surgery:

• Local or general anesthesia is given to the patient.

• In this technique, the rectum or colon, or both are removed.

• A large incision is made on the abdomen of the patient.

• The colon, rectum, and anal sphincter are wholly removed.

• The area where the anus opens is sutured.

• A colostomy creates a new path or passage for the stool.

• A new opening (stoma) is made on the abdomen, where a pouch is attached to collect the waste.

Laparoscopic Transabdominal RCA Surgery:

• This surgery is performed with a laparoscope which is less minimally invasive.

• Local or general anesthesia is given to the patient.

• Four to five incisions are made on the surgery site instead of one large incision.

• A laparoscope (a thin tube with a camera and light) and instruments are inserted through different incisions.

• The rectum, colon, and anal sphincter are removed.

• A colostomy is performed, and a stoma pouch is attached, as mentioned above.

Radical Resection:

• Local or general anesthesia is given to the patient.

• The diseased tissues and the surrounding healthy tissues are removed from the rectum.

• The healthy tissues up to five inches from the tumor's margins are removed.

• This is done to ensure that the diseased cells or tissues are not present in the surrounding area.

• The incision is closed with sutures.

Systemic Therapy or Medications - Generally, the medications are given as a supportive approach. It includes various anticancer drugs. The main aim is to improve the patient's quality of life and treat the associated symptoms. The medications are given for up to 12 months.

What Is the Differential Diagnosis of Rectal Cancer?

The symptoms of rectal cancer may mimic the following conditions:

• Diarrhea.

• Coeliac disease is when the patient's immune system damages its own tissues of the small intestine.

• Intolerance towards food.

• Diverticulosis is when small pouches bulge in the digestive tract.

• Swelling of the veins in the rectum is called hemorrhoids.

• Inflammation of the bowel (inflammatory bowel disease).

• Irritable bowel syndrome is due to a group of symptoms, such as pain in the stomach, diarrhea, and constipation.

• Inflammation of the intestine after radiation therapy (radiation enteritis).

What Are the Complications of Rectal Cancer?

The complications are:

• Obstruction in the large intestine or bowel.

• Recurrence of cancer.

• Cancer of the colon and rectum.

• Spread of cancer to different body parts.

What Is the Success Rate of Rectal Cancer Surgery?

The success rate after the treatment is high, with a survival rate of five years.

Conclusion

The risk of rectal cancer increases with age and those with a family history of rectal cancer. Therefore, patients at high risk should get a screening every ten years. The diagnostic tools for rectal cancer include barium x-ray and computed tomography. Blood tests do not help in diagnosing the condition but help in planning the treatment. The condition is best treated with resection.