Rectal Cancer Treatment
Rectal cancer treatement can be complex and involve an number of different specialists including Medical Oncologists, Radiation Oncologists and Surgeons.
If your cancer is a very early stage cancer then surgery is sometimes done up front but for the majority of patients multidisiciplinary input is needed and often surgery is done after some pre treatment with radiation and / or chemotherapy.
The most common approach has been giving radiation and / or chemotherapy followed by a 10 - 12 week break and then surgery. Depending on the final pathology further chemotherapy may be given after you recover from the operation.
A newer approach that is gaining more widespread adoption is called TNT.
Rectal cancer treatement can be complex and involve an number of different specialists including Medical Oncologists, Radiation Oncologists and Surgeons.
If your cancer is a very early stage cancer then surgery is sometimes done up front but for the majority of patients multidisiciplinary input is needed and often surgery is done after some pre treatment with radiation and / or chemotherapy.
The most common approach has been giving radiation and / or chemotherapy followed by a 10 - 12 week break and then surgery. Depending on the final pathology further chemotherapy may be given after you recover from the operation.
A newer approach that is gaining more widespread adoption is called TNT.
What is TNT?
Total neoadjuvant therapy (TNT) means giving all of the chemotherapy and radiation before any surgery. One goal is to shrink the tumor. In some people, the tumor disappears completely — and if that happens, it may be possible to keep the rectum and avoid surgery. This is called "Watch and Wait."
When your response is checked
The timing depends on the order in which your treatments were given:
How the response is checked
Three things are checked:
The three types of response
Complete clinical response (about 41 of every 100 people)
Total neoadjuvant therapy (TNT) means giving all of the chemotherapy and radiation before any surgery. One goal is to shrink the tumor. In some people, the tumor disappears completely — and if that happens, it may be possible to keep the rectum and avoid surgery. This is called "Watch and Wait."
When your response is checked
The timing depends on the order in which your treatments were given:
- If radiation was the last part of your treatment: about 2 months (8 weeks) or more after your final radiation session.
- If chemotherapy came after your radiation: within about a month of your last chemotherapy dose.
How the response is checked
Three things are checked:
- A finger exam of the rectum
- A camera exam (endoscopy or sigmoidoscopy) to look directly at the area
- An MRI scan of the pelvis
The three types of response
Complete clinical response (about 41 of every 100 people)
- Camera exam: a flat, pale, smooth scar where the tumor used to be. There may be tiny red blood vessels (telangiectasias), but no ulcer, no lumps, and no narrowing.
- Finger exam: smooth, flat scar with no lumps.
- MRI: a thin scar, no signs of active tumor, no worrisome lymph nodes.
- All of these must be present. Watch and Wait can be offered.
Near-complete clinical response (about 38 of every 100 people)
- Camera exam: small irregular bumps in the lining, a shallow ulcer, or lingering mild redness in the scar area.
- Finger exam: a smooth firm area or slight surface irregularity.
- MRI: much improved, but a small area of possible residual signal.
- This is a "not quite there yet" result. Often the best step is to wait about 8 more weeks and re-check, because a majority of these turn into a complete response with more time. Watch and Wait may still be an option; surgery is the other choice.
Incomplete clinical response (about 21 of every 100 people)
- Camera exam: visible remaining tumor — a mass, a deep or large ulcer, or clear lumps.
- Finger exam: a tumor can still be felt.
- MRI: tumor still present, sometimes with abnormal lymph nodes.
- Surgery to remove the rectum (total mesorectal excision) is recommended. This is the treatment most likely to cure the cancer in this situation.
A note about biopsies
If the area looks completely healed, a biopsy does not add useful information. If tumor is suspected, a biopsy is also not required — a negative biopsy is often falsely reassuring, so a suspicious appearance alone is enough reason to recommend surgery.
What happens with Watch and Wait
Watch and Wait is not "doing nothing." It is a very close monitoring program:
This is the part patients most often want to understand, so it is worth explaining carefully.
Avoiding rectal surgery avoids a temporary or permanent ostomy bag and the bowel, bladder, and sexual function problems that surgery can cause. The trade-off is committing to frequent testing and accepting the possibility of needing surgery later.
If the area looks completely healed, a biopsy does not add useful information. If tumor is suspected, a biopsy is also not required — a negative biopsy is often falsely reassuring, so a suspicious appearance alone is enough reason to recommend surgery.
What happens with Watch and Wait
Watch and Wait is not "doing nothing." It is a very close monitoring program:
- Finger exam and camera exam every 3–4 months for 2 years, then every 6 months through year 5
- MRI of the rectum every 6 months for up to 3 years
- CT scan of the chest and abdomen every 6–12 months for 5 years
- Colonoscopy 1 year after finishing treatment
- About half of people who start Watch and Wait keep their rectum long term.
- The cancer grows back in the rectum ("regrowth") in a portion of people. When it does, it almost always happens in the first 2 years — 94% within 2 years and 99% within 3 years — which is exactly why the check-ups are so frequent early on.
- If regrowth happens, surgery is done at that point. In the main study of this approach, long-term outcomes after surgery for regrowth were the same as for people who had surgery right away after treatment (64% free of cancer at 5 years in both groups).
This is the part patients most often want to understand, so it is worth explaining carefully.
- Rectal cancer can spread to other organs, most often the lungs and liver. This risk exists for everyone with this cancer, whether they choose Watch and Wait or surgery.
- People whose tumor never comes back in the rectum have the lowest risk of the cancer spreading, although it is still possible and happens in 4/100 people. Their response to treatment was a sign that the cancer was highly treatable.
- People who do have a regrowth have a higher risk — roughly 25 - 30/100 in this group go on to develop spread elsewhere in the body.
- Importantly, in the main study of this approach, that risk was about the same as the risk faced by people who had an incomplete response and went straight to surgery. In other words, the higher risk appears to reflect how the cancer behaved in the first place, not a penalty for having waited.
- This is still an area of active research. Some large studies from other groups have found a somewhat higher spread rate after regrowth than after immediate surgery.
- This is why the CT scans of the chest and abdomen stay in the follow-up plan for 5 years, regardless of which path you take.
Avoiding rectal surgery avoids a temporary or permanent ostomy bag and the bowel, bladder, and sexual function problems that surgery can cause. The trade-off is committing to frequent testing and accepting the possibility of needing surgery later.
If you end up requiring surgery there are two different types of operations that can be done and the choice depends on the location of the tumor and in some cases your personal preference.
What Is Rectal Cancer Surgery?
Rectal cancer surgery removes the part of the rectum that contains the cancer, along with surrounding tissue and lymph nodes. The goal is to completely remove the cancer while preserving as much normal function as possible. Both surgeries described below use a technique called "total mesorectal excision" (TME), which carefully removes the rectum and the fatty tissue around it to give you the best chance of cure.
What Is Rectal Cancer Surgery?
Rectal cancer surgery removes the part of the rectum that contains the cancer, along with surrounding tissue and lymph nodes. The goal is to completely remove the cancer while preserving as much normal function as possible. Both surgeries described below use a technique called "total mesorectal excision" (TME), which carefully removes the rectum and the fatty tissue around it to give you the best chance of cure.
In this operation, the rectum is removed and the colon (large intestine) is reconnected directly to the anal canal. This is called a "coloanal anastomosis." Because this connection needs time to heal, a temporary ileostomy is created at the same time.
An ileostomy is a small opening on your abdomen where a portion of the small intestine is brought to the skin surface. Stool passes into a removable pouch worn on the outside of your body. This diverts stool away from the new connection to protect it while it heals. The ileostomy is typically reversed (closed) after several months, once healing is confirmed and any additional treatments (such as chemotherapy) are completed.
Benefits:
- Preserves your natural anal sphincter muscles, so you can eventually have bowel movements through your bottom
- Avoids a permanent stoma (ostomy bag)
- The temporary ileostomy protects the new connection and reduces the risk of a serious leak
- Generally associated with better body image and quality of life compared to permanent stoma
Risks:
- Anastomotic leak: The new connection may not heal properly (occurs in roughly 10–25% of patients). The temporary ileostomy helps reduce the severity of this complication if it occurs, but if it does sometimes further surgical interventions are required with could involve convertion to a permanent colostomy
- You will need a second, smaller surgery to reverse (close) the ileostomy
- In some cases (approximately 10–20%), the ileostomy may become permanent due to complications, disease progression, or other health issues
- Ileostomy-related complications: dehydration, high stool output, skin irritation around the stoma, small bowel obstruction, or kidney problems
- Bowel dysfunction after ileostomy reversal (see "Low Anterior Resection Syndrome" below)
- Urinary problems and sexual dysfunction
- General surgical risks: bleeding, infection, blood clots, injury to nearby organs, urinary difficulties, and sexual dysfunction
In this operation, the rectum and the anus (including the sphincter muscles) are completely removed. Because the anus is removed, a permanent colostomy is created. A colostomy is an opening on your abdomen where the end of the colon is brought to the skin surface, and stool passes into a pouch worn on the outside of your body for the rest of your life.
This surgery is typically recommended when the cancer is very close to or involves the anal sphincter muscles, making it impossible to safely preserve them.
Benefits:
- Complete removal of the cancer, including the sphincter, when the tumor is too close to preserve it
- No risk of anastomotic leak (since no reconnection is made)
- No risk of low anterior resection syndrome
- A single surgery with no need for a reversal procedure
Risks:
- Permanent colostomy: You will wear an ostomy bag for the rest of your life
- Perineal wound complications: The wound where the anus was closed can have healing problems, especially after radiation therapy (reported in 15–37% of patients)
- Perineal hernia: A bulge can develop in the area where the anus was removed
- Body image concerns and adjustment to living with a permanent stoma
- Urinary problems and sexual dysfunction (may be more common than with sphincter-preserving surgery)
- General surgical risks: bleeding, infection, blood clots, and injury to nearby organs
This surgery is typically recommended when the cancer is very close to or involves the anal sphincter muscles, making it impossible to safely preserve them.
Benefits:
- Complete removal of the cancer, including the sphincter, when the tumor is too close to preserve it
- No risk of anastomotic leak (since no reconnection is made)
- No risk of low anterior resection syndrome
- A single surgery with no need for a reversal procedure
Risks:
- Permanent colostomy: You will wear an ostomy bag for the rest of your life
- Perineal wound complications: The wound where the anus was closed can have healing problems, especially after radiation therapy (reported in 15–37% of patients)
- Perineal hernia: A bulge can develop in the area where the anus was removed
- Body image concerns and adjustment to living with a permanent stoma
- Urinary problems and sexual dysfunction (may be more common than with sphincter-preserving surgery)
- General surgical risks: bleeding, infection, blood clots, and injury to nearby organs
Low Anterior Resection Syndrome (LARS)
If you have the sphincter-preserving surgery (coloanal anastomosis), you should be aware of a condition called Low Anterior Resection Syndrome, or LARS. This is very common — it affects up to 60–80% of patients after sphincter-preserving rectal surgery to some degree.
What is LARS?
LARS is a group of bowel symptoms that can occur after the rectum is removed and the colon is reconnected to the anal canal. Because the rectum normally acts as a storage area for stool, removing it changes how your bowels work. Symptoms may include:
- Frequent bowel movements (sometimes many times per day)
- Urgency — a sudden, strong need to have a bowel movement
- Difficulty holding stool (fecal incontinence or leakage)
- Clustering — having multiple bowel movements within a short period of time
- Feeling of incomplete emptying
- Difficulty telling the difference between gas and stool
- Constipation or difficulty emptying
These symptoms are usually worst in the first few months after ileostomy reversal and often improve over the first 1–2 years, though some patients have long-term symptoms.
What causes LARS?
LARS is caused by a combination of factors:
- Loss of the rectum, which normally stores stool
- Changes in nerve function in the pelvis from surgery
- Effects of radiation therapy on the bowel and pelvic tissues
- Changes in the muscles and sensation of the anal area
How is LARS treated?
Treatment is tailored to your symptoms and their severity. Your care team will work with you using a step-by-step approach:
Step 1 — Lifestyle and dietary changes:
- Eat smaller, more frequent meals
- Identify and avoid foods that worsen symptoms (common triggers include spicy foods, caffeine, alcohol, high-fat foods, and artificial sweeteners)
- Increase fiber gradually to help bulk up stools
- Stay well hydrated
- Keep a food and bowel diary to identify patterns
Step 2 — Medications:
- Anti-diarrheal medications such as loperamide (Imodium) to slow bowel movements and improve stool consistency
- Serotonin receptor blockers (such as ondansetron) have shown promise in reducing LARS symptoms and improving quality of life
- Fiber supplements (such as psyllium) to help regulate stool consistency
- Medications to manage gas or cramping
Step 3 — Pelvic floor rehabilitation:
- Pelvic floor muscle exercises (Kegel exercises) to strengthen the muscles that control bowel movements
- Biofeedback therapy — a specialized technique where a therapist helps you learn to better control your pelvic floor muscles using real-time feedback
- These therapies have been shown to improve symptoms, especially in the first year after surgery
Step 4 — Transanal irrigation (TAI):
- This involves gently flushing water into the bowel through the anus using a special device
- It helps empty the bowel more completely and predictably, reducing accidents and urgency
- Studies have shown that TAI can significantly reduce LARS symptoms, with many patients reporting major improvement
Step 5 — If all else fails:
- In rare cases where symptoms remain severe and significantly affect quality of life despite all treatments, creation of a permanent stoma may be considered
Important to know:
- LARS is not a sign that the cancer has come back
- Many patients see significant improvement over time and it can take up to 18 months after your ileostomy reversal to improve, but after 18 months there is not usually any further improvement in bowel function.
What is LARS?
LARS is a group of bowel symptoms that can occur after the rectum is removed and the colon is reconnected to the anal canal. Because the rectum normally acts as a storage area for stool, removing it changes how your bowels work. Symptoms may include:
- Frequent bowel movements (sometimes many times per day)
- Urgency — a sudden, strong need to have a bowel movement
- Difficulty holding stool (fecal incontinence or leakage)
- Clustering — having multiple bowel movements within a short period of time
- Feeling of incomplete emptying
- Difficulty telling the difference between gas and stool
- Constipation or difficulty emptying
These symptoms are usually worst in the first few months after ileostomy reversal and often improve over the first 1–2 years, though some patients have long-term symptoms.
What causes LARS?
LARS is caused by a combination of factors:
- Loss of the rectum, which normally stores stool
- Changes in nerve function in the pelvis from surgery
- Effects of radiation therapy on the bowel and pelvic tissues
- Changes in the muscles and sensation of the anal area
How is LARS treated?
Treatment is tailored to your symptoms and their severity. Your care team will work with you using a step-by-step approach:
Step 1 — Lifestyle and dietary changes:
- Eat smaller, more frequent meals
- Identify and avoid foods that worsen symptoms (common triggers include spicy foods, caffeine, alcohol, high-fat foods, and artificial sweeteners)
- Increase fiber gradually to help bulk up stools
- Stay well hydrated
- Keep a food and bowel diary to identify patterns
Step 2 — Medications:
- Anti-diarrheal medications such as loperamide (Imodium) to slow bowel movements and improve stool consistency
- Serotonin receptor blockers (such as ondansetron) have shown promise in reducing LARS symptoms and improving quality of life
- Fiber supplements (such as psyllium) to help regulate stool consistency
- Medications to manage gas or cramping
Step 3 — Pelvic floor rehabilitation:
- Pelvic floor muscle exercises (Kegel exercises) to strengthen the muscles that control bowel movements
- Biofeedback therapy — a specialized technique where a therapist helps you learn to better control your pelvic floor muscles using real-time feedback
- These therapies have been shown to improve symptoms, especially in the first year after surgery
Step 4 — Transanal irrigation (TAI):
- This involves gently flushing water into the bowel through the anus using a special device
- It helps empty the bowel more completely and predictably, reducing accidents and urgency
- Studies have shown that TAI can significantly reduce LARS symptoms, with many patients reporting major improvement
Step 5 — If all else fails:
- In rare cases where symptoms remain severe and significantly affect quality of life despite all treatments, creation of a permanent stoma may be considered
Important to know:
- LARS is not a sign that the cancer has come back
- Many patients see significant improvement over time and it can take up to 18 months after your ileostomy reversal to improve, but after 18 months there is not usually any further improvement in bowel function.