Cancer can start any place in the body. Cancer that starts in the colon or rectum is often called colorectal cancer. It starts when cells in the colon or rectum grow out of control and crowd out normal cells. This makes it hard for the body to work the way it should.
Cancer cells can spread to other parts of the body. Cancer cells in the colon or rectum can sometimes travel to the liver and grow there. When cancer cells do this, it’s called metastasis (pronounced meh-TAS-tuh-sis). To doctors, the cancer cells in the new place look just like the ones from the colon or rectum.
Cancer is always named for the place where it starts. So when colorectal cancer spreads to the liver (or any other place), it’s still called colorectal cancer. It’s not called liver cancer unless it starts from cells in the liver.
In most cases, colon and rectal cancers grow slowly over many years. We now know that most of those cancers start as a growth called a polyp. Taking out the polyp early may keep it from turning into cancer.
Are there different kinds of colon and rectum cancers?
There are a few kinds of colon and rectum cancers. Your doctor can tell you more about the kind you have.
The most common kind is called adenocarcinoma (AD-uh-no-KAR-sin-O-muh). This kind starts in the cells that make mucus to cover the inside surfaces of the colon and rectum.
Questions to ask the doctor
- Why do you think I have cancer?
- Is there a chance I don’t have cancer?
- Would you please write down the kind of cancer you think I might have?
- What will happen next?
How does the doctor know I have colorectal cancer?
Some signs of colorectal cancer are changes in your poop, bleeding, and belly pain. The doctor will ask you questions about your health and do a physical and pelvic exam.
If signs are pointing to cancer, more tests will be done. Here are some of the tests you may need:
Blood tests: Certain blood tests can tell the doctor more about your overall health.
Biopsy (BY-op-see): For this test, the doctor takes out a small piece of tissue where the cancer seems to be. The tissue is checked for cancer cells. This is the best way to know for sure if you have cancer.
CT or CAT scan: Uses x-rays to make detailed pictures of your insides. CT scans can be used to help do a biopsy and can show if the cancer has spread.
Ultrasound: For this test, a small wand is moved around on your skin. It gives off sound waves and picks up the echoes as they bounce off tissues. The echoes are made into a picture on a computer screen. It’s used to help find cancer and see if it has spread.
MRI scan: Uses radio waves and strong magnets instead of x-rays to make detailed pictures. MRI scans are helpful in looking at the liver and the brain and spinal cord.
Chest x-rays: X-rays may be done to see if the cancer has spread to your lungs.
PET scan: PET scans use a kind of sugar that can be seen inside your body with a special camera. If there's cancer, this sugar shows up as “hot spots” where the cancer is found. This test looks at the whole body. It can help if the doctor thinks the cancer has spread, but doesn’t know where.
Questions to ask the doctor
- What tests will I need to have?
- Who will do these tests?
- Where will they be done?
- Who can explain them to me?
- How and when will I get the results?
- Who will explain the results to me?
- What do I need to do next?
How serious is my cancer?
If you have colon or rectal cancer, the doctor will want to find out how far it has spread. This is called staging. You may have heard other people say that their cancer was “stage 1” or “stage 2.” Your doctor will want to find out the stage of your cancer to help decide what type of treatment is best for you.
The stage describes the growth or spread of the cancer through the layers of the wall of the colon or rectum. It also tells if the cancer has spread to nearby organs or to organs farther away.
Grading colorectal cancer
The cancer cells in the biopsy sample will be given a grade. This helps doctors predict how fast the cancer is likely to grow and spread. The grade is based on how much the cancer cells look like normal cells. Grades 1, 2, 3, and 4 are used. Cells that look very different from normal cells are given a higher grade (4) and tend to grow faster. Ask the doctor to explain the grade of your cancer. The grade helps the doctor decide which treatment is best for you.
Questions to ask the doctor
- Do you know the stage and grade of the cancer?
- If not, how and when will you find out the stage and grade of the cancer?
- Would you explain to me what the stage and grade mean in my case?
- Based on the stage and grade of the cancer, how long do you think I’ll live?
- What will happen next?
What kind of treatment will I need?
There are many ways to treat colon and rectal cancers, but the main types of treatment are surgery, radiation, chemotherapy, and targeted therapy.
Two or more types of treatment may be used at the same time, or they may be given one after the other. The treatment plan that’s best for you will depend on:
- The stage and grade of the cancer
- The chance that a type of treatment will cure the cancer or help in some way
- Your age
- Other health problems you have
- Your feelings about the treatment and the side effects that come with it
Surgery for colon cancer
Most people with colon cancer have some type of surgery. The cancer, a small part of normal colon on either side of the cancer, and nearby lymp nodes are often removed. The 2 ends of the colon are then put back together.
For most colon cancers, an opening on the belly to get rid of body waste (poop) is not needed, but sometimes one is used for a short time. This opening is called a colostomy. If you need a colostomy for a short time, your doctor or nurse can tell you more about how to take care of it and when it can come out.
Surgery for rectal cancer
Most people with rectal cancer need surgery. Radiation and chemo might be given before surgery. Sometimes the cancer can be removed through the anus, without cutting through the skin. This might be done to remove some stage 1 cancers that are small and close to the anus.
If the rectal cancer is more advanced and close to the anus, surgery will be done to take out the cancer and make an opening on your belly to get rid of body waste (poop). This is called a colostomy. You will need it for the rest of your life.
If the rectal cancer has spread into nearby organs, more surgery is needed. The doctor may take out the rectum and nearby organs, like the bladder, prostate, or uterus, if the cancer has spread to those organs. You will need a colostomy after that surgery. If the bladder is removed, an opening to collect urine or pee (called a urostomy) is needed, too.
If you have a colostomy or a urostomy, you will need to learn how to take care of it. Nurses with special training will see you before and after surgery to teach you what to do. Ask your doctor what type of surgery you will need. Ask what your body will look like and how it will work after surgery.
Any type of surgery can have risks and side effects. Ask the doctor what you can expect. If you have problems, let your doctors know. Doctors who treat people with colon and rectal cancer should be able to help you with any problems that come up.
Radiation uses high-energy rays (like x-rays) to kill cancer cells. After surgery, radiation can kill small spots of cancer that may not be seen during surgery. If the size or place of the cancer makes surgery hard to do, radiation may be used before the surgery to shrink the tumor so it's easier to take it out. Radiation can also be used to ease some problems caused by the cancer.
For rectal cancer, radiation is given to help keep the cancer from coming back in the place where it started. It’s also used to treat cancer that has come back and is causing problems, like pain. Sometimes the radiation is aimed through the anus to reach the rectum, or small radioactive pellets or seeds might be used. They can be put around or right into the cancer. This is called brachytherapy.
Sometimes, both types of radiation are used.
If your doctor suggests radiation treatment, talk about what side effects might happen. The most common side effects of radiation are:
- Skin changes where the radiation is given
- Feeling sick to your stomach
- Diarrhea, pain when pooping, or blood in the poop
- Having to pee a lot, burning when you pee, or blood in the pee
- Feeling very tired (fatigue)
Most side effects get better after treatment ends. Some might last longer. Talk to your cancer care team about what you can expect during and after treatment.
Chemo is the short word for chemotherapy -- the use of drugs to fight cancer. The drugs may be given through a needle into a vein or taken as pills. The drugs go into the blood and spread through the body.
Chemo is given in cycles or rounds. Each round of treatment is followed by a break. Most of the time, 2 or more chemo drugs are given. Treatment often lasts for many months. Chemo after surgery can help some people live longer. It can also help ease problems caused by the cancer.
Chemo can make you feel very tired, sick to your stomach, and cause your hair to fall out. But these problems go away after treatment ends. There are ways to treat most chemo side effects. If you have side effects, talk to your cancer care team so they can help.
Targeted drugs attack the changes in cells that cause cancer. These drugs affect mainly cancer cells and not normal cells in the body. They may work even if other treatment doesn’t. These drugs have different side effects than chemo, and they are often not as bad.
Side effects of targeted therapy depend on which drug is used. These drugs might cause high blood pressure, low blood counts, heart problems, and liver problems. There are ways to treat most of the side effects caused by targeted drugs. If you have side effects, talk to your cancer care team so they can help.
Clinical trials are research studies that test new drugs or other treatments in people. They compare standard treatments with others that may be better. Clinical trials are one way to get state-of-the art cancer treatment. They are the best way for doctors to find better ways to treat cancer. If your doctor can find one that’s studying the kind of cancer you have, it’s up to you whether to take part. And if you do sign up for a clinical trial, you can always stop at any time.
What about other treatments that I hear about?
When you have cancer you might hear about other ways to treat the cancer or treat your symptoms. These may not always be standard medical treatments. These treatments may be vitamins, herbs, diets, and other things. You may wonder about these treatments.
Some of these treatments are known to help, but many have not been tested. Some have been shown to not help. A few have even been found to be harmful. Talk to your doctor about anything you’re thinking about using, whether it’s a vitamin, a diet, or anything else.
Questions to ask the doctor
- What treatment do you think is best for me?
- What’s the goal of this treatment? Do you think it could cure the cancer?
- Will treatment include surgery? If so, who will do the surgery?
- What will the surgery be like?
- Will I have a colostomy? For how long?
- Will I need other types of treatment, too?
- What's the goal of these treatments?
- What side effects could I have from those treatments?
- What can I do about side effects that I might have?
- Is there a clinical trial that might be right for me?
- What about vitamins or diets that friends tell me about? How will I know if they are safe?
- What should I do to be ready for treatment?
- Is there anything I can do to help the treatment work better?
- What’s the next step?
What will happen after treatment?
You’ll be glad when treatment is over. But it’s hard not to worry about cancer coming back. Even when cancer never comes back, people still worry about it. For years after treatment ends, you will see your cancer doctor. At first, your visits may be every few months. Then, the longer you’re cancer-free, the less often the visits are needed.
Be sure to go to all of those follow-up visits. You will have exams, blood tests, and maybe other tests to see if the cancer has come back.
* Information on this page is from American Cancer Society (www.cancer.org)