Be careful! This tumor can easily be mistaken for hemorrhoids in the early stages. These people should have regular checkups.

Author: Ye Yingjiang, Chief Physician, Peking University People's Hospital

Vice President of Anorectal Surgery Branch of Chinese Medical Doctor Association

Reviewer: Fan Xueshun, Chief Physician, China-Japan Friendship Hospital

There is a type of tumor that can easily be mistaken for hemorrhoids in the early stages. In the early stages, the only symptom may be blood in the stool, and hemorrhoids often also present with blood in the stool.

This tumor is low rectal cancer.

Generally speaking, the intestine 15cm away from the anus is called the rectum, which is the last section of the large intestine. The rectum can be divided into three sections, each 5cm long. The top section is called the upper rectum, the section closest to the anus is called the lower rectum, and the middle section is called the mid rectum.

Figure 1 Original copyright image, no permission to reprint

Tumors that occur in the lower rectum are called lower rectal cancer.

Rectal cancer accounts for about 50% of colorectal cancers, and about 70% of rectal cancers are low-position rectal cancers, so the incidence of low-position rectal cancer is still relatively high.

1. What are the symptoms of low rectal cancer?

Low rectal cancer is close to the anus, which is the main outlet for excretion, so the symptoms of rectal cancer are more obvious. However, these obvious symptoms are only seen in the middle and late stages of low rectal cancer. Especially in the early stages of low rectal cancer, the symptoms are sometimes not so obvious.

The main symptoms of low rectal cancer include blood in the stool, tenesmus, a feeling of incomplete defecation, a feeling of falling, mucus, pus and blood in the stool, or an increase in the frequency of bowel movements and changes in stool characteristics.

Under normal circumstances, the stool is relatively formed, without much mucus or bleeding. Low rectal cancer may cause blood in the stool, excessive mucus, frequent bowel movements, and loose stools. The blood in the stool is usually relatively fresh blood.

Low rectal cancer can sometimes grow outward, and a cauliflower-like tumor may grow out of the anus, which you can feel yourself.

If you have blood in your stool, try to get checked as early as possible, and don't simply assume it is hemorrhoids. Even if there is no blood in the stool or other abnormal conditions, it is recommended that high-risk groups undergo regular screening.

2. Who needs regular screening for rectal cancer?

People over 45 years old; people with colon or rectal polyps; people with a family history, that is, direct relatives have had intestinal tumors; people with a history of colon cancer, these people should be screened regularly.

For simple screening of rectal cancer, either sigmoidoscopy or proctoscopy can be performed, but simple screening of rectal cancer is not recommended. It is best to do a full colon endoscopy, which should be performed every 3-5 years.

Figure 2 Original copyright image, no permission to reprint

Can low rectal cancer be detected early through digital anal examination?

The easiest way to detect early stage low rectal cancer is digital rectal examination. If there is blood in the stool or other symptoms, the doctor can feel the area with his fingers to know whether there is a tumor. Generally speaking, the right index finger can reach about 7cm, and the low rectum is within 5cm, which can be completely felt. It can also be felt to tell whether it is a tumor, polyp, or ulcer, because each disease has different characteristics when touched.

Despite this, a colonoscopy is still needed. Digital examination can detect low-positioned rectal tumors, but sometimes the tumors are multiple, not only in the lower rectum, but also in the upper rectum or colon, or other parts of the body. Therefore, if a tumor is felt in the lower rectum, a colonoscopy is still needed to examine the entire colon.

Second, a biopsy is required. Even if you feel something with your hands and suspect it is a tumor, you need to take a biopsy through a colonoscopy to clarify the nature of the lesion. Proctoscopes and sigmoidoscopes can also achieve this purpose, but a full colonoscopy is recommended to examine the entire colon.

3. How to treat low rectal cancer? Can surgery preserve the anus?

There are many ways to treat low rectal cancer, depending on the stage.

In the very early stages, when the cancer has only invaded the first layer of the intestinal wall, local resection may be sufficient.

If the cancer has invaded the second layer of the intestinal wall or above, a radical resection is required. Radical resection includes the removal of the tumor, lymph nodes, surrounding fat that may metastasize, and a certain amount of normal intestinal wall and lymph nodes.

For mid-stage tumors, if there are high-risk factors, such as poor tumor differentiation, invasion of surrounding tissues, or elevated CEA (carcinoembryonic antigen) of the tumor; or if the patient is critically ill, postoperative adjuvant treatment may be required, usually chemotherapy.

In the late stage, surgery alone is not enough. Adjuvant chemoradiotherapy may be needed before surgery, followed by surgery, and then adjuvant chemoradiotherapy after surgery.

For early-stage low rectal cancer, the 5-year survival rate is over 90%, so there is no problem; for mid- to late-stage cancer, the 5-year survival rate is 60 to 70 percent; and for particularly late-stage cancer, the 5-year survival rate is relatively low.

Many patients ask, can the anus be preserved during surgery for low rectal cancer?

Whether the anus can be preserved during surgery for low rectal cancer depends on many factors. Generally speaking, it is easier for female patients to preserve their anus if the tumor is small, the pelvis is wide, and the body is not particularly obese. In addition, whether the anus can be preserved also depends on the doctor's level and philosophy.

I think that preserving the anus is not the first priority. The first priority should be to cure the tumor. Preserving the anus is meaningful only after curing the tumor. In addition, one of the most easily overlooked issues is that the anus sphincter function must be evaluated to preserve the anus. After the evaluation, it is found that the anus has no function before the operation, and the patient always has diarrhea or cannot control the stool or gas. The anus function is not good, so preserving the anus is not very meaningful.

Prevention is the most important thing for colorectal cancer. Eat more fiber-rich foods and avoid long-term constipation; remove polyps or other lesions as soon as possible; have regular checkups, especially if there is a family history; and seek medical attention in time if there are abnormal symptoms such as blood in the stool.