What is rectal cancer?
Rectal cancer is cancer that starts in the rectum. The rectum is the last few creeps of the internal organ. It begins at the end of the last part of the colon and ends when it reaches the short, narrow passageway to the anus. Cancer disease inside the rectum (rectal cancer) and cancer inside the (colon cancer) are regularly alluded to together as “colorectal cancer”.
While colon and rectal cancers are similar in many ways, their treatments are completely different. This is mainly because the rectum is located in a narrow space, and it barely separates from other organs and structures. The narrow space can be surgically removed from the rectal cancer complex.
Previously, long haul endurance was remarkable for individuals with rectal cancer, even after broad treatment. Thanks to advances in treatment over the past few decades, rectal cancer survival rates have improved dramatically.
What are the types of rectal cancer?
By far most rectal cancer is a sort called adenocarcinoma. This is a cancer of the cells that line the inner surface of the rectum. Includes rare tumor types:
- Carcinoid tumors: That starts in the hormone-producing cells in the intestine
- Gastrointestinal stromal tumors: (a type of soft tissue sarcoma that can be found anywhere in the digestive system but is rare in the rectum) or other types of sarcoma that begins in the blood vessels or connective tissue of the rectum
- Lymphoma: It is a cancer of the immune system that most commonly begins in the lymph nodes but can start in the rectum
What are the stages of rectal cancer?
The stages describe how far cancer has spread in the rectum and whether it has spread (metastasized) to other organs. This is important information for MSK doctors when designing a care plan for you.
There are five stages of rectal cancer.
- Stage 0: This very early cancer is only found in the inner lining of the rectal wall.
- Stage 1: The tumor has spread outside the inner lining but remains inside the rectal wall and has not spread to the lymph nodes (small organs that are part of the immune system).
- Stage II: Cancer has spread through the thick outer muscle layer of the rectum but has not spread to the lymph nodes.
- Stage III: Cancer has spread outside the rectum to one or more lymph nodes.
- Stage IV: Cancer has spread to other parts of the body, such as the liver or lungs. Cancer may be in the lymph nodes.
What are the symptoms of rectal cancer?
Some symptoms of rectal cancer may be caused by other conditions. For example:
- Weakness and fatigue
- Appetite changes
- Weight loss
- Frequent abdominal discomfort, gas, cramps, and pain
Other signs and symptoms include rectal cancer:
- It changes how often your bowels move
- The feeling that your bowels are not emptying completely
- Pain when moving your bowels
- Diarrhea or constipation
- Blood or mucus in the stool
- Narrow stools
- Iron deficiency anemia
Causes and risk factors for rectal cancer
The cause of rectal cancer is unknown, but the risk of developing the disease increases with age. People with a family history of colorectal cancer or some hereditary cancer syndromes have a higher risk. Other known risk factors include rectal cancer:
- Alcohol use
- Sedentary lifestyle
Rectal cancer treatment
Rectal cancer treatment often includes a combination of treatments. When possible, surgery is used to cut out the cancer cells. Other treatments, such as chemotherapy and radiation therapy, may be used after surgery to kill any cancer cells that remain and reduce the risk of the cancer returning.
If surgeons are concerned that cancer cannot be removed completely without damaging nearby organs and structures, your doctor may recommend a combination of chemotherapy and radiation therapy as initial treatment. These combination treatments may shrink cancer and make it easier to remove during the operation.
Rectal cancer is regularly treated with medical procedures to eliminate cancer cells. Which process is best for you depends on your specific situation, such as the site and stage of cancer, the aggressiveness of the cancer cells, your general health, and your preferences.
Includes operations used to treat rectal cancer:
- Removing very small cancers from the inside of the rectum: Very small rectal cancers can be removed using a colonoscopy or another specialized type of endoscope inserted through the anus (trans-anal resection). Surgical tools can be passed through the laparoscope to remove cancer and some healthy tissue around it.
This procedure may be an option if the cancer is small and unlikely to spread to nearby lymph nodes. If a lab analysis finds that your cancer cells are aggressive or more likely to spread to lymph nodes, your doctor may recommend additional surgery.
- Removing all or part of the rectum: Larger rectal cancers that are far enough from the anal canal can be removed in a procedure (low anterior resection) that removes all or part of the rectum. Nearby tissues and lymph nodes are also removed. This procedure preserves the anus so that waste can leave the body naturally.
How the procedure is performed depends on the location of cancer. On the off chance that the malignancy influences the upper aspect of the rectum, that aspect of the rectum is taken out, and afterward, the colon is connected to the rest of the rectum (colonic and rectal anastomosis). The rectum may be removed completely if the cancer is located in the lower part of the rectum. Then the colon forms into a sac and is attached to the anus (colonic anastomosis).
- Removing the rectum and anus: For rectal cancers that are located near the anus, it may not be possible to remove cancer completely without harming the muscles that control bowel movement. In these cases, surgeons may recommend a procedure called a perineal abdominectomy (APR) to remove the rectum, anus, and some colon, as well as nearby tissues and lymph nodes.
The surgeon makes an opening in the abdomen and connects the remaining colon (colostomy). Waste leaves your body through the opening and collects in a bag attached to your abdomen.
- Chemotherapy uses drugs to destroy cancer cells. For rectal cancer, chemotherapy may be recommended after surgery to kill any cancer cells that might remain.
- Chemotherapy may also be used with radiation therapy before an operation to shrink large cancer so that it can be easily removed with surgery.
- Chemotherapy may also be used to relieve symptoms of rectal cancer that cannot be removed with surgery or that has spread to other areas of the body.
Radiation treatment utilizes incredible fuel sources, for example, X-beams and protons, to murder cancer cells. In people with rectal cancer, radiotherapy is often combined with chemotherapy that makes the cancer cells more vulnerable to radiation damage. It might be utilized after medical procedures to execute any cancer cells that may remain. Or it can be used before surgery to shrink cancer and make it easier to remove.
When surgery is not an option, radiation therapy may be used to relieve symptoms, such as pain.
Combined chemotherapy and radiation therapy
The combination of chemotherapy and radiation therapy (radiotherapy chemotherapy) makes cancer cells more vulnerable to radiation. This combination is often used for large rectal cancers and those that are more likely to return after surgery.
Radiation chemotherapy may be recommended:
- Before surgery: Chemoradiotherapy may help shrink cancer enough to make the surgery less invasive. Combined treatment may increase the chance that your surgery will leave the anal area intact so that waste can leave the body naturally after surgery.
- After surgery: If surgery is your first treatment, your doctor may recommend radiation chemotherapy afterwards if there is an increased risk that cancer will return.
- As the primary treatment: Your doctor may recommend chemotherapy to control the growth of cancer if rectal cancer is advanced or if surgery is not an option.
Targeted drug therapy
Targeted drug therapies focus on specific abnormalities present within cancer cells. By preventing these abnormalities, targeted drug treatments can cause cancer cells to die.
Targeted drugs are usually combined with chemotherapy. Medicines aimed at people with advanced rectal cancer are usually reserved.
Immunotherapy is a medication therapy that utilizes your invulnerable framework to battle disease. Your immune system, which is fighting disease, may not attack your cancer because cancer cells produce proteins that help them hide from immune system cells. Immunotherapy works by interfering with this process. Immunotherapy is usually limited to advanced rectal cancer.
Supportive (palliative) care
Palliative care focuses on providing relief from pain and other symptoms of acute illness. Palliative care specialists work with you, your family, and other doctors to provide an additional layer of support that complements your ongoing care.
Palliative care is provided by a team of specially trained doctors, nurses, and other professionals. Palliative consideration groups plan to improve the personal satisfaction of individuals with cancer and their families. This type of care is offered alongside curative treatments or other treatments you may be receiving.
Follow-up care and survivorship of rectal cancer
Once the patient has finished treatment, they will be closely monitored for repeat treatment. Follow-up recommendations after rectal cancer treatment include:
- A physical examination (including a digital rectal exam) every 3 months for 2 years, then every 6 months for 3 years;
- The CEA level is checked (if it is raised at diagnosis) every 3 months for 2 years, then every 6 months for 3 years;
- Colonoscopy is one year, with a repeat in one year if it is abnormal, or every 2-3 years if no polyps are found.
- A pelvic CT scan every 6-12 months is recommended in patients with more localized disease.
- Annually a CT scan of the chest, abdomen, and pelvis is recommended for patients who have a high risk of colon cancer recurrence.
- For patients who have completed treatment for stage 4 disease, a pelvic tomography scan is recommended every 3-6 months for the first 2 years.
Fear of repetition, the financial impact of cancer treatment, employment issues, and coping strategies are common emotional and practical issues that plague rectal cancer survivors. Your health care team can identify the resources needed to support and manage these practical and emotional challenges faced during and after cancer.
Cancer survival is a relatively new area of focus for oncology care. With more than 15 million cancer survivors in the United States alone, there is a need to help patients make the transition from effective treatment to survival. What will happen next, how do you get back to normal, what should you know and do to live healthy in the future? A survivor care plan can be a first step in educating yourself about navigating life after cancer and helping you to communicate informally with health care providers. Create a survivor care plan today.
Diagnosis of rectal cancer
Once rectal cancer is detected by screening tests, further tests are needed to determine the extent of the tumor. Tests used to determine tumor spread are CT scans, magnetic resonance imaging, and endoscopic ultrasound (EUS). A EUS machine is a type of ultrasound that uses sound waves to determine the depth of a tumor and whether surrounding lymph nodes are involved.
The biopsy is usually performed during an endoscopic ultrasound, colonoscopy, or proctoscopy (a test that looks only at the area of the rectum), allowing your caregiver to determine the type of tumor. CEA level is a marker of colorectal cancer present in the blood and is elevated in 95% of cases. Women with advanced tumors should also have a pelvic exam to assess whether the lump has invaded the vagina or the cervix.
In addition to the tests listed above, a tumor sample may be sent to a pathology laboratory. This can be done using a biopsy sample or a larger sample, which is removed during surgery. A pathologist will prepare a pathology report, which is a written report that gives you more details about the type of tumor, its size, and any changes to it. Often pathology reveals adenocarcinoma.
Tissue taken from the biopsy should be examined for mutations of four mismatched repair genes (MMR) and microsatellite instability (MSI). This should be done in all stages of colorectal cancer. The MMR genes include MSH2, MLH1, MSH6, and PSM2. Disruptions to the MMR test may indicate that the tumor was caused by an inherited cancer syndrome.
Microsatellite changes occur in the DNA sequence of cancer cells or in the inability to repair errors that occur when DNA is copied into the cell. When this occurs it is called small satellite instability (MSI). MSI can be classified as high MSI (MSI-H), fixed microsatellites (MSS), or low MSI (MSI-L). This information can help guide your treatment. Patients with metastatic colorectal cancer should have tumor genetic tissue for RAS mutations, which include the KRAS, NRAS, and BRAF mutations. These results can help determine your treatment options.
Prevention of rectal cancer
Rectal cancer is preventable. Almost all types of rectal cancer develop from rectal polyps, which are benign tumors on the rectal wall. The detection and removal of these polyps by colonoscopy reduce the risk of developing rectal cancer. Your doctor can make accurate rectal cancer screening recommendations based on your medical and family history. Screening usually begins at age 45 * in medium-risk patients, or at younger ages in patients at high risk of rectal cancer.
Although this has not been proven with certainty, there is some evidence that diet may play an important role in preventing colorectal cancer. To the best of our knowledge, a diet rich in fibre (whole grains, fruits, vegetables, and nuts) and low in fat is the only nutritional measure that may help prevent colorectal cancer.