Rectal Cancer: Symptoms, Stages, and Treatment Methods

Rectal Cancer: Symptoms, Stages, and Treatment Methods

Rectal cancer is a type of cancer characterized by malignant tumors that develop in the rectum, located in the final section of the digestive system. This disease, which is commonly seen worldwide, is particularly more frequent in individuals over 50 years of age. When detected early, the response rate to treatment is generally higher, while in advanced stages, the disease can pose a vital risk. This article contains comprehensive information about the structure of the rectum, the causes of rectal cancer, its symptoms, stages, diagnosis, and treatment methods.

What is the Rectum and Where is it Located in the Body?

The rectum is the term given to the final section connecting the colon to the anus and is part of the digestive system. The total length of the colon is approximately 1.5-2 meters, with the rectum comprising the final 12-20 cm of this section. It is located in the lower part of the abdominal region, behind the bladder and urinary tract; it extends from the end of the sigmoid colon to the anus. It has a straight tube shape and contains muscles that help expel feces outward.

The rectum is positioned between the sigmoid colon and the anal canal. The sigmoid colon is located at the upper part of the rectum, while the anal canal is the lower section connecting the rectum to the anus. The primary function of the rectum is to retain feces until they are expelled; when the rectum becomes filled, it sends a signal to the brain, signaling the need to use the toilet.

Anatomically, the rectum consists of three sections:

• Mucosa: The layer completely covering the inner surface of the rectum, which secretes mucus to facilitate the expulsion of feces.
• Muscularis propria: Located in the middle section, this muscle layer provides contraction movements.
• Fat layer: Forms the outermost part of the rectum; this region is surrounded by lymph nodes that play a role in the immune system.

Various diseases such as cancer, inflammation (proctitis), and polyps can occur in the rectum. Some rectal polyps may have the potential to become cancerous over time.

What is Rectal Cancer?

Rectal cancer is a type of cancer that develops in the rectum, which constitutes the final 12-15 cm of the colon, and typically begins with malignant tumors called adenocarcinoma. Over time, it can spread to surrounding tissues and organs. Rectal cancer is frequently seen together with colon cancer, and these two diseases together are called "colorectal cancer"; however, each has its own specific characteristics and treatment approaches.

Causes and Risk Factors of Rectal Cancer

Although the exact cause of rectal cancer is not fully known, various risk factors that are thought to contribute to the development of the disease have been identified:

• Age: Risk increases with advancing age; the disease typically occurs in individuals 50 years and older.
• Family history: The presence of colorectal cancer history in the family can elevate risk.
• Genetic factors: Some genetic syndromes and mutations can increase risk.
• Presence of polyps: Non-cancerous tissue growths in the colon and rectum may have the potential to become cancerous over time.
• Dietary habits: A diet rich in fat and red meat, but low in fiber, can increase risk.
• Sedentary lifestyle and obesity: Lack of physical activity and being overweight can elevate risk.
• Tobacco and alcohol use: Both are among the factors that increase risk.
• Racial/ethnic differences: The frequency of occurrence may vary in some population groups.
• Chronic bowel diseases: Chronic inflammatory conditions such as ulcerative colitis, Crohn's disease, and diverticulitis can increase risk.
• Diabetes: It is considered among the health conditions that may increase the risk of rectal cancer.

Preventive Recommendations

• Adopt a healthy dietary pattern rich in vegetables, fruits, and whole grains,
• Engage in regular physical activity,
• Quit smoking and limit alcohol consumption,
• Maintain a healthy body weight,
• Follow recommended screening tests; some healthcare institutions recommend that adults aged 45 and older begin colorectal cancer screening tests at specific intervals.

Symptoms of Rectal Cancer

Rectal cancer typically progresses without symptoms in early stages and is often discovered incidentally during routine screenings. As the disease progresses, the following symptoms may appear:

• Bleeding during bowel movements or blood visible in stool (one of the most common symptoms),
• Mucus (saliva-like substance) visible in stool,
• Changes in bowel habits in the form of constipation or diarrhea,
• Sensation of intestinal motility as if gas is present,
• A feeling that the bowels are not completely emptied,
• Insufficient defecation despite going to the toilet,
• Severe bowel movements,
• Pain and discomfort in the abdominal or rectal region,
• Severe gas and bloating,
• Unexplained weight loss and weakness,
• Signs of anemia (low red blood cell count).

If any of these symptoms are noticed, it is important to consult a specialist as soon as possible, as this is crucial for early diagnosis of the disease and success of treatment.

Diagnostic Methods

In the diagnosis of colorectal cancer, a single test is generally not sufficient; the doctor may request evaluation of symptoms, physical examination, and various tests to be applied together:

• Digital rectal examination: The initial evaluation method where the doctor examines the rectum with a gloved hand.
• Colonoscopy: An examination of the colon and rectum using a thin tube with a camera attached.
• Fecal occult blood test: Used to determine the presence of blood that is not visible to the naked eye in stool.
• Endoscopic biopsy: Taking a tissue sample from the colon and rectum using a thin tube with a camera and tissue sampling apparatus.
• Computed Tomography (CT) / CT colonography: An examination using X-rays to create three-dimensional images of the body.
• Magnetic Resonance Imaging (MRI): An examination using radio waves and magnetic fields to create three-dimensional images of the body.
• Blood tests: May be used in evaluating anemia and certain tumor markers.

After diagnosis, doctors may perform additional tests and evaluations to determine the stage of cancer and plan appropriate treatment options.

Stages of Rectal Cancer

Rectal cancer is generally evaluated in 4 main stages (in some classifications, 5 stages including stage 0) according to the degree of spread:

Stage 0: Cancer is found only in cells on the inner surface of the rectum and has not yet spread to deeper layers. It is typically associated with polyps found incidentally during colonoscopy.

Stage 1: The tumor is located in the rectal wall but has not spread to lymph nodes or other organs. This is known to be a stage with a relatively higher response rate to treatment.

Stage 2: Cancer has spread to the rectal wall and surrounding fat tissue but has not yet reached lymph nodes. In this stage, methods such as surgery and radiotherapy may be considered.

Stage 3: Cancer cells have penetrated the rectal wall and reached nearby lymph nodes. Treatment is usually planned with combined approaches including surgery, radiotherapy, and chemotherapy.

Stage 4: Cancer has spread from the rectum to distant organs, particularly the liver and lungs. In this stage, combined treatment approaches including surgery, radiotherapy, chemotherapy, targeted therapies, and immunotherapy may be considered.

What Does the Severity of a Rectal Tumor Depend On?

Rectal tumors can be either non-cancerous (benign) or cancerous (malignant) in nature. Non-cancerous tumors are not cancer, but may have the potential to become cancerous over time. Cancerous tumors, on the other hand, may have the characteristic ability to spread to other organs in the body, particularly the liver and lungs.

The severity of a rectal tumor varies depending on its size, location, and degree of spread. According to the generally accepted approach, the larger and more widespread the tumor, the more serious the condition is considered.

Treatment Methods

The treatment methods for rectal cancer vary depending on the stage of the disease, the location of the tumor, the patient's general health status, and other individual factors. While surgery alone may be preferred in early stages, in advanced stages it may be necessary to apply multiple treatment methods including surgery, chemotherapy, and radiotherapy together.

Surgical Treatment

Surgery is the most commonly used method in rectal cancer. The goal with surgery is to remove the tumor and surrounding healthy tissue. The main types of surgery are:

• Low anterior resection (LAR): Applied for tumors in the upper part of the rectum. The surgeon removes the tumor and surrounding tissue, connecting the healthy remaining part of the colon to the anus.
• Abdominoperineal resection (APR): Applied for tumors in the lower part of the rectum. The tumor, rectum, and anus are removed; the healthy part of the colon is connected to a stoma opening into the abdominal wall, and a colostomy bag is used for defecation.
• Sphincter-preserving surgery: Aims to preserve the anal muscles and maintain normal defecation function; techniques such as low anterior resection or local excision can be applied depending on the tumor's location.
• Laparoscopic and robotic surgery: These less invasive techniques can be performed with smaller incisions and generally shorter recovery times.

Surgery duration is approximately 2-4 hours; this time varies depending on the patient, the status of the disease, and the conditions encountered during surgery. Anastomotic leak is one of the most common complications after surgery; in addition, infection, bleeding, and changes in bowel function may also occur. The success of surgery varies depending on the surgeon's experience, the patient's general health status, and the stage of cancer.

Non-Surgical Treatment Methods

In some cases in rectal cancer, non-surgical methods may also be considered. The doctor decides which method is appropriate by evaluating factors such as the stage of cancer, the location of the tumor, and the patient's general health status.

• Radiotherapy: Radiation therapy that targets cancer cells. It is typically applied to shrink tumor size before surgery or prevent recurrence after surgery.
• Chemotherapy: Drug therapy aimed at preventing the growth and spread of cancer cells. It can be used before and after surgery.
• Targeted therapy: A treatment method using drugs that target specific molecular weak points in cancer cells; generally evaluated in patients with advanced disease.
• Immunotherapy: A treatment method aimed at strengthening the body's immune system against cancer cells. Checkpoint inhibitors and drugs that directly target cancer cells are included in this group. Possible side effects include weakness, nausea-vomiting, diarrhea, decreased white blood cell count, and infection risk.
• Palliative care: A care approach that focuses particularly on alleviating symptoms and improving quality of life in advanced stages.

Among the factors that affect treatment selection are the stage of cancer, the location of the tumor (non-surgical methods may be considered for tumors close to the anus), and the patient's general health status. It should not be forgotten that a non-surgical treatment approach may not be suitable for every patient; the treatment plan should be determined personally for the patient under medical supervision.

Spread of Rectal Cancer

Rectal and colon cancer can show rapid spread in some cases; the tumor created by abnormal cell growth can spread to other organs in the body, particularly the liver and lungs. The degree of spread varies depending on the size, location, and development stage of the tumor; it is generally known that the larger and more advanced the tumor, the greater the likelihood of spread.

Symptoms that can be associated with spread include pain in the abdominal or chest region, unexplained weight loss, weakness, nausea-vomiting, changes in skin, urine, or stool color, swelling in the legs or ankles, difficulty breathing, and pain during urination or defecation.

Information on Prognosis and Survival

In every disease, early detection is an important factor that increases the likelihood of response to treatment. However, survival duration varies significantly from person to person depending on the stage of the tumor, its size, location, degree of spread, the patient's age, and general health status. For this reason, it is not appropriate to specify a definite life expectancy; each patient experiences a unique process and must always be under medical supervision.

According to general statistical trends shared in the literature, it is known that 5-year survival rates vary as the stage progresses; it is reported that this rate is higher in early stages and may be lower in advanced stages. These figures reflect general trends, and the most accurate information about patient-specific prognosis can be provided by the patient's own doctor.

Factors that may affect the course and progression of treatment include:

• Age: The process may differ in patients in older age groups.
• General health status: The process may differ in patients with additional health problems.
• Degree of cancer spread: The process may differ in patients with spread to other organs.

Healthy eating, regular physical activity, maintaining a healthy weight, staying away from tobacco and alcohol, and following recommended screening tests are among the approaches for supporting general health status.

Approach in Advanced Stage (Stage 4) Rectal Cancer

In the fourth stage of rectal cancer, cancer cells may have spread to distant organs. In this case, the treatment plan is typically shaped with a combined approach including chemotherapy, radiotherapy, targeted therapies, immunotherapy, and palliative care; surgical intervention may not be suitable for every patient.

Symptoms in this stage include pain in the abdominal or chest region, unexplained weight loss, weakness, nausea-vomiting, changes in skin, urine, or stool color, swelling in the legs and ankles, and difficulty breathing. It is important for patients to maintain close communication with their doctors throughout the process and to be informed about treatment options and palliative care options. Approaches to support quality of life include careful adherence to the treatment plan, seeking support from family and friends, participating in support groups, and dedicating time to enjoyable activities.

Conclusion

Rectal cancer is a disease that has a relatively high likelihood of response to treatment when detected in its early stage, but can progress and lead to serious health problems if neglected. When symptoms such as blood in stool, changes in bowel habits, or unexplained weight loss are noticed, it is important to visit a healthcare facility without delay. The diagnosis and treatment process should be conducted by relevant specialist physicians according to a patient-specific treatment plan, supported by colonoscopy, biopsy, and imaging methods, and tailored to the patient's stage and general health status.