Rectal cancer is commonly classified as colorectal cancer, along with colon cancer. Rectal cancer develops in cells in the rectum, located below the colon and above the anus.
Rectal and colon cancers are often grouped together under the umbrella term colorectal cancer, as the rectum and colon are both parts of the digestive system. Colorectal cancer is the second most common cancer in females and the third most common cancer in males globally.
In the United States, there is a high prevalence of colorectal cancer. The American Cancer Society estimated that in 2020 there were 43,340 new cases of rectal cancer and 104,610 new cases of colon cancer.
There are various types of rectal cancer which we break down below. The majority of rectal cancer diagnoses are adenocarcinoma. There are also rarer types of tumors that require different treatments.
The majority of rectal cancer cases are adenocarcinoma which affects the cells lining the inside surface of the rectum.
Carcinoid tumors occur in hormone-producing cells within the intestines.
Gastrointestinal stromal tumors
Gastrointestinal stromal tumors are rarely found in the rectum, but they can be found anywhere in the gastrointestinal tract. They are thought to arise from the ‘pacemaker cells’ of the gastrointestinal tract.
Lymphoma is classified as a cancer of the immune system. While it commonly starts in the lymph nodes, lymphoma can also start in the rectum.
Hereditary rectal cancer
5-10% of patients develop colorectal cancer due to specific mutations in their inherited genes, referred to as hereditary mutations. For individuals at high risk, genetic testing is advisable to determine whether you have genetic mutations that can increase your cancer risk.
There are five stages of rectal cancer, labeled from 0 to IV. Generally, the lower the number, the less the cancer cells and tumors have spread.
At the lowest stage of rectal cancer, cancer cells are only found in the innermost lining of the rectum wall, called the mucosa.
The tumor has now spread beyond the inner lining but remains within the rectum wall and has not spread to the lymph nodes. Lymph nodes are small filter-like organs that form part of the immune system.
Cancer extends through the outer muscle layer of the rectum but has still not spread to the lymph nodes.
Cancer has now spread to lymph nodes outside the rectum.
Cancer has continued to spread to other organs, tissues, and parts of the body, including the lymph nodes.
While the symptoms of rectal cancer may be minor or even non-existent during the early stages of the disease, there may still be some early warning signs to be aware of. Obvious symptoms usually don’t develop until the disease has progressed into stage II or beyond.
Those over 45, or under 45 but at high risk of developing the disease, are advised to undergo regular screening and a colonoscopy. Talk to your doctor if you are concerned about whether you should start regular rectal cancer screening and how you can manage your risk.
As most colorectal cancer cases develop from polyps, with early screening they can be identified and removed when they first form to help prevent them from growing and spreading.
If early-stage colorectal cancer does cause symptoms, the early warning signs can include:
Changes in bowel habits resulting in bleeding or narrow stools (the most common early warning sign)
Rectal bleeding, resulting in stools red in color
Narrow and ribbon-like stools
A constant feeling of wanting to pass bowel movements
Incomplete emptying of bowels
Anemia and weakness caused by iron deficiency
Persistent abdominal pain
Unexplained or sudden weight loss
Nausea or vomiting
Although these symptoms may also be caused by less serious conditions, such as hemorrhoids, ulcers, and Crohn’s disease, if you are experiencing any of the above, discuss with your doctor as soon as you can.
There are also various other symptoms of rectal cancer which can be local (affecting only the rectum area) or systematic (affecting your entire body). These symptoms include:
Change in frequency of bowel movements
Change in consistency of stools
Constipation or trouble passing bowel movements
Bleeding in the rectum
Blood in stools
Abdominal pain or cramps
You may have risk factors that increase your chance of developing rectal cancer, which include:
Overweight or a high body weight
Low physical activity
A diet high in red and processed meat
A diet low in fruits and vegetables
Regular tobacco smoking
High alcohol use
Personal history of rectal polyps, adenomas, or colorectal cancer, especially if you had it when you were younger
Personal history of inflammatory bowel disease – ulcerative colitis or Crohn’s disease
Immediate family history of colorectal cancer or adenomatous polyps
Having an inherited syndrome, including Lynch syndrome (hereditary non-polyposis colorectal cancer) or familial adenomatous polyposis
Treatment is an essential part of eliminating rectal cancer. The specific treatment recommendations for each patient will depend on their individual case and several factors which include:
The type and stage of cancer
Possible side effects
The patient’s preferences
The patient’s overall health
The costs involved
The patient’s social support network
Other medications that might interfere with the treatment
It’s essential to take time and learn about all of the treatment options available to you, and to ask for clarification when you’re unsure. If you are concerned about which treatments are right for you, talk to your doctor about what you can expect from each type of treatment. The best approach is shared decision-making, where you and your doctors work together to select a treatment plan that works best for you.
The standard treatment options for rectal cancer are explained below.
Surgery can remove the tumor along with some of the surrounding healthy tissue, like part of the healthy colon section and nearby lymph nodes. This surgery is often called surgical resection and is one of the most common treatment options for rectal cancer. The different types of operations include laparoscopic surgery, colostomy for rectal cancer, radiofrequency ablation, or cryoablation.
This type of therapy uses high-energy X-rays, which help to destroy tumors and cancer cells. Radiation therapy is commonly used for treating rectal cancer, as these tumors tend to recur near their original growth site. Radiation oncologists specialize in this type of therapy. A patient usually undergoes a strict radiation schedule consisting of specific treatments over a certain period.
Chemotherapy is one of the most common and widely known treatment options for cancer. It uses drugs that destroy cancer cells to prevent them from growing, dividing and replicating.
Like radiation therapy, a chemotherapy regimen consists of a specific number of treatment cycles over a designated period of time. A rectal cancer patient might receive one drug at a time or a combination of drugs, depending on the severity of their case.
Chemotherapy can also be administered post-operation, meaning it is undergone after surgery to eliminate any remaining cancer cells. For severe cases of rectal cancer, the patient will be prescribed radiation therapy and chemotherapy before surgery to reduce the tumor size and the chance of recurrence after surgery.
Often, a combination of chemotherapy, radiotherapy, and surgery is used to treat rectal cancer that has not spread to other organs.
This treatment option targets specific pathways involved in the development of cancer. It is often used in metastatic cancer.
To find the most effective treatment option, your doctor might run specific tests that identify the proteins, genes, and other factors present in your tumors.
Researchers continue to investigate more about specific molecular targets and new treatments¹ to target tumors and cancer cells. The discovery of new drugs and medications is crucial in the treatment of rectal and colorectal cancer.
This form of therapy is designed to boost the body’s natural defenses to fight rectal cancer. Immunotherapy works by increasing a patient’s immune response to cancer. Outside of clinical trials, only a select group of patients with colorectal cancer (who have defects in their DNA repair system) tend to respond to immunotherapy.
If you or someone you know has colorectal cancer, there are many options for treatment and recovery. Talk to your health professional for a tailored diagnosis and treatment plan that is right for you.
Having a healthy lifestyle¹ can help to lower your risk of developing rectal cancer:
Eat more fruits, vegetables, and fiber, and less red meat and saturated animal fat. It is recommended to eat at least five servings of fruits and vegetables daily.
Exercise regularly. Researchers have shown that even moderate levels of regular physical activity, including walking and incidental exercise like taking the stairs instead of the elevator, can help to reduce the risk of rectal cancer.
Maintain a healthy weight. Being overweight or obese, especially carrying extra fat around your midsection, is a risk factor for developing rectal cancer.
Reduce smoking. Studies show that smokers are 30-40% more likely to die of colorectal cancer than non-smokers.
Reduce your alcohol intake.
While you can control your habits and lifestyle, there are a range of biological factors outside of your control to be aware of:
Age – generally, your risk increases as you get older
Immediate family history of Lynch syndrome or familial adenomatous polyposis
History of cancer
History of inflammatory bowel disease
Family history of cancer
Raising awareness of rectal cancer can encourage people to get regular screenings and educate them on how to prevent or reduce risk factors, as well as provide information for those seeking additional support.
Awareness can increase your chance of survival, especially if you get screened at an earlier stage of rectal cancer which can be treated more effectively.
There are many ways you can increase awareness of rectal cancer in your community:
Share social media posts from cancer organizations
Participate in discussions with your friends, family, and colleagues, and wider network
Attend cancer awareness events
Host cancer awareness events
Write articles or blog posts about colorectal cancer
Volunteer for cancer organizations, like the American Cancer Society
Make donations to relevant organizations
The total annual cost to the healthcare system¹ of colorectal cancer care in the United States is $14.1 billion. In addition, 11% of all cancer treatment costs in the United States are for cases of colorectal cancer.
Depending on the stage of cancer, the average Medicare healthcare spend for newly diagnosed colorectal cancer patients ranges from $40,000 to $80,000. However, total costs can be higher, as some cancer survivors may need to stop work for a certain period, or indefinitely.
Other factors that contribute to costs of colorectal cancer care include:
Treatment plan – The type of treatment and its extent and duration vary from patient to patient, causing total costs to also vary significantly.
Geographic location – Generally, areas that have high costs of living also tend to have higher treatment costs.
Treatment setting – Treatment costs are typically based on various factors which often differ depending on where the care is delivered.
Costs to patients depend on the type and extent of their selected treatment plan.
Generally, there are three main approaches to treating cancer:
Pharmacological therapy – chemotherapy, immunotherapy, and targeted therapy.
Some patients will receive all three types of treatment, while others will receive only one or two.
Colorectal cancer is the third most common cancer diagnosed in men and women in the United States. While this type of cancer is most commonly diagnosed among individuals aged 50 and older, it can also develop in younger patients.
Regular screening is essential, as over 75%¹ of colon and rectal cancers happen to people with no known risk factors.
A personal or family history of rectal cancer or colon polyps can increase the risk of developing rectal cancer. Other risk factors include:
High consumption of red and processed meat
Consuming high quantities of alcohol
The five-year survival rate of rectal cancer will vary depending on the individual and the stage of cancer.
Generally, the five-year survival rate for rectal cancer is 89% at a localized stage, meaning cancer has not spread past the rectum, compared to only 16% when cancer has spread to other parts of the body.
For an individualized assessment, it is essential to discuss it with your health professional.
See more statistics for rectal cancer here.
For most rectal cancer patients, they will have a team of multiple doctors working together to create an extensive individualized treatment plan that pulls together various types of treatments for maximum effectiveness. The medical team will often include a medical oncologist, surgeon, radiation oncologist, and gastroenterologist.
Rectal cancer care teams will also include various healthcare professionals, such as nurses, physician assistants, oncology nurses, pharmacists, counselors, social workers, and dietitians, alongside the patient’s wider support network.