Rectal Cancer Symptoms, Causes, Stages, and Treatment Methods

Rectal cancer consists of malignant tumors originating from the inner lining of the rectum, the final part of the large intestine. It is the 3rd most common type of cancer among digestive system cancers. Rectal cancer, along with colon (large intestine) cancer, forms colorectal cancers. The colon is the main part of the large intestine and is approximately 1.5 meters long. Although large intestine and rectal cancers are similar in some respects, rectal cancers can be affected by different genetic and environmental conditions. Colon and rectal cancer commonly arise from adenocarcinomas. More rarely, they consist of lymphomas, carcinoids, and sarcomas. Rectal cancer stages are used to classify the spread of the cancer, the size of the tumor, and the tissues it affects.

In general, aging, lifestyle habits, genetics, and certain diseases can contribute to the development of rectal cancer. Most rectal cancers may not show obvious symptoms and are often diagnosed during routine screenings. Blood and imaging tests, as well as procedures to assist in diagnosis, can be used within the scope of diagnosis. Rectal cancer diagnosed at an early stage shows a high rate of recovery. The risk of cancer formation can be reduced through various lifestyle habits. The majority of rectal cancer cases are seen in people aged 50 and over.

What is Rectal Cancer?

Rectal cancer is a cancer that occurs as a result of uncontrolled cell proliferation in rectal tissues. The rectum is the last 15-20 cm of the large intestine and opens to the anus. It is part of the digestive system and helps in the excretion of waste materials formed from food from the body. Most rectal cancers develop from benign polyps that form on the intestinal wall. Polyps appear as abnormal clusters of cells and are called benign adenomas. Adenomas in the rectum can turn into cancerous cells due to a number of reasons. The transformation of a normal rectal inner lining into abnormal cell growth and subsequently into cancerous cells requires a period of approximately 10-15 years. The exact cause of rectal cancer is unknown, but it may be associated with various risk factors. A combination of acquired or hereditary factors and underlying health problems can trigger carcinogenesis. The stages of rectal cancer, which has the potential to recur after treatment, are as follows:

Carcinoma in situ: Known as Stage 0, it describes abnormal cells present in the mucosa of the rectal wall.

Stage I: Cancer cells formed in the mucosa of the rectal wall spread to the tissues and muscle layers next to the mucosa.

Stage II: The cancer growing in the rectal wall spreads to the surrounding tissues of the rectum.

Stage III: The cancer spreads to tissues outside the rectal wall and to nearby lymph nodes.

Stage IV: The cancer spreads to distant tissues and lymph nodes. It is known as the final stage of rectal cancer.

What Are the Symptoms of Rectal Cancer?

Rectal cancer symptoms may not be seen in the early period and may progress for many years without being noticed. The first symptoms of rectal cancer can usually appear in advanced stages. It can typically manifest itself as changes in bowel and stool characteristics. Symptoms of rectal cancer, which are perceived as warning signs, may include:

Blood in the stool,

Diarrhea or constipation,

Pencil-thin or thread-like stool structure,

A feeling that the bowel has not emptied completely,

Abdominal bloating and fullness,

Cramps and gas pains,

Loss of appetite,

Unexplained weight loss,

Fatigue,

Changes in bowel habits.

Unexplained and involuntary weight loss accompanied by intense abdominal pain can usually be seen in advanced stages. Rectal cancer metastasis symptoms can affect different parts of the body and can be more severe. Colon and rectal cancer symptoms may not be specific and noticeable in the early period. In advanced stages, anal, rectal, and bowel cancer symptoms have similar profiles. For this reason, urgent medical examination may be necessary in the presence of early warning signs and suspicion.

What Causes Rectal Cancer?

The exact cause of most rectal cancer cases is unknown. Changes in the way rectal cells grow, divide, and function form the basis of carcinogenesis. Colorectal cancers have a wide variety of risk factors and do not directly cause cancer. However, these risk factors can increase the likelihood of DNA damage that leads to carcinogenesis. The vital activities of a cell are controlled by DNA. In healthy cells, DNA gives instructions for a specific lifespan, reproduction, and growth. Healthy cells that follow these instructions multiply or die at the right time. However, DNA damage leads to certain changes, resulting in different instructions. According to these instructions, cells can produce more cells very quickly and continue to live longer instead of dying on time. This is the main reason for the formation of cancers. Cancerous cells can spread to healthy tissues and invade other organs. Rectal cancer risk factors may include:

Crohn's disease,

Ulcerative colitis,

Inflammatory bowel diseases,

Familial adenomatous polyposis,

Lynch syndrome,

Juvenile polyposis syndrome,

MUTYH-associated polyposis,

Peutz-Jeghers syndrome,

Obesity,

Diabetes,

Chronic alcoholism,

A diet rich in red meat,

Sedentary lifestyle,

History of radiotherapy,

Use of cigarettes and tobacco products,

History of colon, rectal, ovarian cancer, and adenoma.

Risk factors for rectal cancer may also include non-modifiable factors such as family history, genetics, and aging.

How Is Rectal Cancer Diagnosed?

Diagnosis of rectal cancer requires evaluation of family history and medical history, and a physical examination. Additional different tests can be applied for a definitive diagnosis. Tests that assist in diagnosis are often as follows:

Blood tests: Biochemical markers, hormone levels, and tumor markers in the blood can be measured. In the carcinoembryonic antigen (CEA) test, the levels of CEA released by cancerous cells into the bloodstream are measured.

Digital rectal examination: Involves examination of the rectum with the help of a lubricated glove.

Colonoscopy: Used to detect abnormal lesions, polyps, and cancer in the colon and rectum. A thin, tube-like instrument containing a light and camera is used.

Biopsy: Taking samples from cancerous cells and tissues and examining them in a laboratory environment.

Immunohistochemistry: These are tests where antibodies that bind to dyes or enzymes are left on tissues and their binding to antigens is monitored. The diagnosis and type of cancer can be determined by examining the antigens under a microscope.

MSI: A laboratory test in which tumors are examined for cells that cause defects in DNA repair.

X-ray, MRI, and computed tomography: These are imaging methods used for detailed imaging of tissues and organs.

PET scan: The absorption capacity of radioactive glucose given to the body is investigated. Cancerous cells absorb more glucose than normal cells.

Additionally, endorectal ultrasound allows the rectum and nearby organs to be examined with the help of a sonogram image.

How Is Rectal Cancer Treated?

Rectal cancer treatment consists of various approaches and procedures. One or more treatment methods can be applied simultaneously or sequentially. Rectal cancer surgery is diversified through the use of different devices and techniques. Along with surgery, adjuvant therapies may also be recommended. Frequently used rectal cancer treatment methods are as follows:

Chemotherapy: Drug treatment used to stop the division of cancer cells and destroy them.

Radiotherapy: Rectal cancer radiation therapy uses high-energy X-rays. It is the application of radiation therapy to prevent the growth of cancer cells and destroy them.

Immunotherapy: Treatment that supports the patient's immune system to fight cancer using immunotherapy drugs.

Targeted therapy: Drug treatments that involve targeting and destroying specific cancer cells.

Polypectomy: The process of surgically removing cancerous polyps, usually performed during a colonoscopy.

Local excision: If the cancer in the inner lining of the rectum has not spread to the rectal wall, the cancer and surrounding healthy tissues are removed via local excision.

Resection: The removal of the cancerous rectal region that has spread to the rectal wall and the surrounding healthy tissues. In some cases, tissues located between the rectum and the abdominal wall may also be removed.

Radiofrequency ablation: A probe instrument passed through small incisions made in the abdomen or inserted through the skin contains small electrodes that kill cancer cells.

Cryosurgery: Also known as cryotherapy, it is the process of freezing and killing abnormal tissues.

Pelvic exenteration: A procedure performed in case the cancer has spread to surrounding tissues. In this procedure, the bladder, lymph nodes, rectum, and lower colon may be removed. In men, the prostate, and in women, the cervix, vagina, and ovaries may be removed.

Frequently Asked Questions

Rectal cancer can be understood with the help of tests and procedures such as physical examination, family history, medical history, blood tests, MRI, CT, X-ray and ultrasound images, digital rectal examination, biopsy, colonoscopy, immunohistochemistry, and PET scan. Since the risk of developing colorectal cancers increases with age, it is generally common in people over 50. In addition, there may be a high risk in people who have a family history of colorectal cancer, genetic conditions such as Lynch syndrome and familial adenomatous polyposis, a history of colorectal cancer, use excessive alcohol and tobacco products, and have a diet low in fruits and vegetables and rich in processed meat. Bowel cancer is seen in the 1.5-meter colon part of the intestine. Rectal cancer affects the final part of the intestine that comes after the colon. Therefore, rectal cancer and bowel cancer are not the same. However, the colon and rectum can be affected by cancer at the same time. Symptoms of stage 1 rectal cancer may generally not be noticeable. The reason for this is that it can progress for long periods without showing symptoms. Most of the time, it can be noticed when it starts to show symptoms. However, in some people, rectal cancer can be detected during routine screenings. Small cancerous tumors that have not metastasized in the early stages can be largely cured with surgery. Additional treatments may be needed during the recovery process. However, for advanced stage and metastasized cancers, the chance of complete recovery may be low. While the life expectancy for stage 2 rectal cancer may be longer, the life expectancy for stage 3 rectal cancer may be shorter. Chemotherapy may be required depending on the stage and spread of the rectal cancer. In addition, chemotherapy may be recommended before surgery to shrink the tumor and after surgery to ensure bowel control. Killing cancer cells remaining in the body after surgery can also be achieved with chemotherapy. Rectal cancer can metastasize. With metastasis, cancer can spread to surrounding tissues or organs located further away from the rectum. The risk of metastasis can be reduced with appropriate treatment for rectal cancers diagnosed at an early stage. In general, the five-year survival rate for cancers that do not spread outside the rectum is 91%. The five-year survival rate for stage 2 or stage 3 rectal cancer that has spread outside the rectum and to the inner surface of the abdomen can reach 74%. In the case of stage 4 rectal cancer spreading to the liver, lungs, and distant lymph nodes, this rate is 17%. In this context, life expectancy can be improved in patients who are provided with early diagnosis and treatment. Rectal cancer is a type of cancer that can recur after treatment. Recurrent rectal cancer can also appear in other organs such as the colon, pelvis, lungs, and liver. Treatment for recurrent cancer can be directed at the region where it has spread. Although rectal cancer cannot be completely and definitively prevented, the risk of cancer development can be reduced. Losing excess weight and maintaining an ideal weight, quitting smoking and alcohol, exercising regularly, and a balanced and adequate diet rich in fresh fruits and vegetables, whole grains, and lean products, and limited in processed meats are important in reducing the risk of cancer.

For any questions you may have about rectal cancer and treatment options suitable for your personal health condition, contact the expert Gastroenterology and Hepatology physicians at Hisar Hospital Intercontinental immediately or make an appointment. Early diagnosis greatly increases the chance of success in treatment.