Colon and rectal cancer is the third most common cancer in the world of men and the second in women, with approximately 1.4 million cases and 693,900 deaths in 2012.
The main risk factors are male sex, advanced age, certain lifestyles (alcohol, tobacco, overweight), certain diets (red meats, processed meats, low fiber diets ...) and hereditary factors.
Most of these tumors originate in a benign lesion called polyp. The detection and removal of polyps when they have not yet become cancer suppresses the onset of cancer as such, and therefore decrease mortality from this tumor.
More specifically, cancers that are located in the rectum account for almost half of all colorectal cancers , but their treatment is more complex than those found in the rest of the colon. The particular anatomy of the rectum in the narrow area of the pelvis makes its surgical access relatively difficult. In addition, it is important to accurately dissect the correct anatomical planes to completely eradicate the cancerous disease.
What symptoms and signs can rectal cancer detect?
The most common symptom of rectal cancer is bleeding. Unfortunately, this bleeding is attributed in large part to hemorrhoid problems, and the correct diagnosis is delayed until the cancer has reached a more advanced state. It is for this reason that before the slightest perception of bleeding in the feces it is necessary to go to the specialist in Coloproctology .
Rectal cancer produces a number of symptoms that may vary depending on its location within the large intestine. These symptoms are as follows:
- Blood in the stool : is one of the most frequent symptoms of colon cancer. It can be red blood, more frequent in tumors of sigma and descending colon , or of black blood, that mixes with the feces giving rise to black depositions called melenas. Melena appear more frequently when the tumor is located in the ascending colon. When the disease is not detected, anemia usually appears that can cause tiredness, palpitations, dizziness ...
- Change in the rhythm of bowel movements : diarrhea or constipation occurs in people with normal previous bowel rhythm. Diarrhea and constipation are inserted normally.
- Closer stools : This usually occurs because the tumor is narrowing the bowel and does not allow the normal passage of stool.
- Tenesmus or sensation of incomplete evacuation : usually appears in tumors located in the most distal part of the colon .
- Abdominal pain : it is usually a being a frequent symptom. When the tumor partially closes the caliber of the intestinal tube produces a colicky abdominal pain. When the closure is complete is called intestinal obstruction, this being a serious clinical situation requiring urgent medical care. There is prolonged constipation, nausea, vomiting, abdominal pain and malaise.
- Extreme fatigue or weight loss without apparent cause : these are general and nonspecific symptoms that frequently occur in certain diseases, including advanced colon tumors.
Can rectal cancer be prevented? Is it hereditary?
Depending on the presence of risk factors, three groups are distinguished:
- Low risk : a group of people under 50 years of age with no family history of colorectal cancer or polyps. In this context, it is unlikely to develop cancer of this type, so it is not necessary to carry out prevention measures.
- Medium risk : formed by people over 50 years of age, with no history.
- High risk : people who have a family history of colorectal cancer , who have already had cancer or who belong to a family with hereditary cancer. In these cases, the chances of developing colorectal cancer are greater.
How is it detected early?
Often, colorectal cancer can be prevented by regular screening to find polyps before they are cancerous. They are aimed at early detection programs.
Screening for colorectal cancer is the detection of this tumor or pre-malignant polyps when it has not yet had symptoms. Screening allows, on the one hand, the detection of polyps before they degenerate into cancer. On the other hand, it allows the detection of cancer in an early stage when the treatment is less aggressive and more successful.
What is the best screening test for rectal cancer?
- In patients without symptoms
Screening for colorectal cancer using any of the currently available strategies - fecal occult blood screening, sigmoidoscopy, and colonoscopy - has been shown to be the effective cost of performing no screening, which means that population screening programs save money to health systems, given the high price of cancer treatments.
As to what is the best test, there is no comparison between them. In the middle-risk population, there is research comparing colonoscopy performed every ten years with the detection of occult blood in the feces by immunological method every one or two years.
- In patients with symptoms
If the patient has symptoms, usually through a rectal bleed, the most effective diagnostic test is colonoscopy.
How is rectal cancer treated?
Once the tumor has been identified through its relevant tests (colonoscopy, biopsy, endoscopic ultrasound, MRI and CT scan), you will know how to treat it.
- Local excision : it is an excellent operation for small cancers located near the anus and that have not penetrated the muscular layer. However, this technique does not allow removal of the lymph nodes of the rectal mesentery. This operation is indicated for tumors less than 4 centimeters, mobile and in early stages.
- Anterior Resection with colorectal anastomosis : allows the removal of the intestine containing the cancer and the Mesorect where the lymphatic ducts to which the tumor drains. Intestinal continuity is restored by attaching the colon to the rectum.
- Abdominoperineal amputation : occurs when it is necessary to remove the anal sphincters because they are infiltrated for the tumor, which forces to remove the anus, so the patient has a permanent colostomy.
Depending on the preoperative staging, the administration of radiotherapy or preoperative chemotherapy will be indicated.
How is the postoperative of a rectal cancer?
The postoperative evolution will depend on the technique used. Minimally invasive procedures, such as laparoscopic surgery or transanal endoscopic surgery, allow evolution to be more comfortable for the patient, while requiring a shorter hospital stay.