Risks and Side Effects of Cancer Surgery
Any medical procedure has risks. Before you decide to have surgery or any other procedure, it’s important to understand the risks and what will be done to reduce them.
Each procedure has its own risks and side effects. Be sure to ask your surgical team about your risks. The expected benefits of the surgery should outweigh the possible risks.
Your surgical team will take many steps to reduce your risk of side effects and complications. Special leg pumps (pneumatic or compression stockings) and low-dose blood thinners might be used to avoid blood clots, and breathing treatments (respiratory therapy) to help prevent pneumonia. Ask your doctor about the possible complications of your surgery and what will be done to help prevent them.
Safety before and during surgery
There are always risks if you are having surgery. Your surgeon and surgical team will talk to you about these before you give your permission for the surgery.
Hospitals and surgical centers have protocols to reduce some of these risks such as surgical checklists and standard steps for communication. These are for your safety even if they seem repetitive. Some of the steps to prevent common risks include:
Making sure that you are the person who should be getting the surgery. The surgical and operating room staff will ask you to identify yourself by stating your name and birthdate, which is compared to the ID band you got when you checked in or were admitted.
Making sure that you get the right surgery. You will be asked to confirm that you are supposed to be getting the surgery planned. Your surgeon may also mark the site for the surgery on your body with a marker. This is most important if your surgery is on a specific side of your body, such as a mastectomy on your right breast.
Taking steps to lower the risk of infection after your surgery. Your skin will be cleansed with special products to get rid of any pathogens that could cause infection. You might also be given antibiotics before, during, and sometimes after surgery.
Your body temperature will be monitored and kept in a safe range. This can help prevent some side effects of surgery that might make recovery harder.
Performing checks to make sure no surgical equipment is left in your body. Operating room staff do equipment counts before your surgery is finished.
If you have questions or are worried, be sure to ask your surgical team before your operation.
Possible side effects of cancer surgery
Side effects from surgery can be caused by the surgery itself, the medicines used, and your overall health. In general, the more complex the surgery, the greater the risk of side effects.
Minor operations and taking tissue samples (biopsies) usually have less risk than a bigger surgery. Pain at the surgery site is the most common problem. Infections at the site and reactions to the medicines used to numb the area (local anesthesia) are also possible.
Side effects are possible during and after surgery. These side effects usually are not life-threatening and get better with treatment.
You might not feel like eating and drinking as much as you usually do. Poor appetite is common, especially if you had general anesthesia. You may lose weight.
Your appetite almost always returns and you will be back to your normal weight as the effects of surgery wear off. If your appetite does not come back, tell a member of your surgical team.
Bleeding can happen with any surgery and is usually controlled. Bleeding can happen either inside the body (internally) or outside the body (externally). Bleeding can occur if a blood vessel was not sealed off during surgery or if a wound opens up.
You may have some bleeding from your incision after surgery. Your surgical team will tell you how to take care of your incision and when to let them know if you are bleeding. Your wound will likely be covered with a dry bandage.
If you are bleeding a lot, put pressure on your incision site until you can get to your surgeon's office or the emergency room. It may help to put more gauze over your bandage to soak up any extra blood.
Your surgical team will try to limit bleeding when working near blood vessels. They may also check lab tests to see if your blood is less likely to clot normally.
It does not happen often, but if your bleeding is severe, you might need to have another operation to find and stop its source. If you bleed enough, you might need a blood transfusion to replace what you’ve lost.
You can get blood clots in the deep veins of your legs after surgery. This is why it’s important to get out of bed and sit, stand, or walk as soon as possible if permitted by your surgical team.
Blood clots that occur in veins are called a venous thromboembolism (VTE). If the vein is in the leg, thigh, or pelvis, it is called deep venous thrombosis (DVT). A clot like this can become a serious problem if it breaks loose and travels to another part of the body, such as a lung (pulmonary embolism).
You may be given medicines called anticoagulants to help prevent a blood clot after surgery. You may also be asked to wear compression devices or stockings on your lower legs to help prevent blood clots until you can walk around.
If you develop symptoms of a blood clot, it is important to get medical help right away. Let your surgeon know or go to an emergency department if you have:
- Arm or leg swelling on only 1 side of the body
- Pain in the arm or leg where a blood clot is located
- Trouble breathing or chest pain when breathing
- Rapid heartbeat
You may have bruising around the surgery site. After an incision, some blood can leak from small blood vessels under the skin. Let your surgeon know if you have swelling along with the bruising.
You may have some drainage from the incision. Sometimes, the fluid that builds up at the surgery site drains through the surgical wound. These symptoms can be signs of an infection. Tell someone on your surgical team right away if you have any of these symptoms:
- Drainage that smells bad
- Redness around the incision
- Fever
Fatigue is physical and mental tiredness or exhaustion. You might have fatigue because of the anesthesia, the energy needed to heal, loss of appetite, and stress.
Fatigue usually goes away over 2 to 4 weeks after surgery. Ask your surgical team what is typical for the type of surgery you will have and ways to cope with fatigue.
An infection might develop at the site of the incision, but it can also happen in other parts of your body.
You may be asked to help prevent infection by washing with a special soap for a few days before surgery. This soap is good at killing bacteria and can help prepare your skin for surgery. Your surgical team will also try to prevent infection at the site of the incision (cut). You may be given antibiotics, either as a pill or through a vein in your arm (IV), to help prevent infection.
You are also at risk for other infections after surgery. You might get a lung infection (pneumonia), especially if you have a chronic lung illness or if you smoke. Doing deep breathing exercises as soon as possible after surgery helps lessen this risk.
Other infections can develop in your body, especially if your stomach or intestines were opened during the operation. Having a catheter to drain urine can increase the risk of a bladder infection, especially if it’s left in place for a while.
Your surgical team will check for infection and monitor any changes in your temperature, skin, or incision to try to catch and treat any infection early. Signs of infection in a surgical incision include:
- Redness
- Warmth
- More pain
- Drainage from the wound
- Fever
If you have any of these signs, tell someone on your surgical team right away. You may be given antibiotics to take by mouth or antibiotic cream to treat signs of an infection. Antibiotics generally work well to treat most infections.
Occasionally, an infection can become an abscess. An abscess is a closed cavity filled with fluid or pus. A doctor usually has to drain an abscess. Antibiotics alone do not work well for an abscess because the medicine may not be able to reach the infection.
Because nerves in the skin are cut during surgery, you may have some numbness. This doesn’t usually cause any problems, but it can last a long time or sometimes even become permanent. Ask if any nerves will be affected by your surgery and, if so, for how long.
Almost everyone has some pain after surgery. How much pain you have and where it’s located depends on where on your body the surgery was done, the size of the cut or incision, and the amount of tissue removed.
Pain after surgery is normal, but it should not be allowed to slow down your recovery. There are many ways to help control surgical pain. Medicines for pain can range from acetaminophen to anti-inflammatory medicines or stronger medicines, like morphine. See Pain for more information.
After surgery, pain usually goes away gradually as your body heals. Let your health care team know how you are feeling as you recover.
Some people react badly to the anesthesia or other medicines needed during surgery. Although rare, these reactions can be serious because they can cause low blood pressure. Your heart rate, breathing rate, blood pressure, and other signs will be watched closely during surgery to prevent, look for, or correct this.
Some of your body functions, such as bowel activity, can be slow to recover after surgery. If it takes too long for these functions to recover, serious problems might develop. Your energy level can drop, too. Getting out of bed and walking around as soon as possible after surgery can help you recover more quickly.
Surgery on certain parts of the body, such as the abdomen or chest, may cause short-term problems with surrounding organs. These problems are rare but can be serious. They are more likely to happen to people who already have problems with these organs. This is why doctors get a complete medical history and order tests to look for possible risks before surgery.
For example, the intestines may become paralyzed for a short time after surgery in the abdomen (belly). This means that the intestine will not allow food, fluid, and gas to pass through the bowels. It can cause nausea and vomiting, stomach cramps, and bloating until the bowels begin to function again.
These problems usually go away as you heal. Let your surgical team know if you are still having these or other problems. They can help you manage these symptoms.
It is normal to have some swelling around your incision. An incision is a form of injury and the body responds to injury with inflammation. As you heal, swelling usually goes away.
Dealing with changes to your body from cancer surgery
Cancer surgery may change how your body looks, feels, and functions. This can affect your body image, or how you feel about your body. Some people might feel upset or insecure and struggle with the changes to their self-image. If a part of your body does not look like you expected it to after surgery, you might feel sad or self-conscious.
It is as important to treat the emotional side effects of cancer surgery as the physical side effects. Here are some tips to help you prepare for and cope with body changes that affect how you feel about yourself.
Before your surgery
- Gather information about how surgery will affect your body, appearance, and physical abilities. Ask your surgical team for details on what to expect. This can give you time to adjust to the changes.
- Ask about options for reconstructive surgery or prostheses if you need to have a body part removed or altered. A prosthesis is an artificial body part. Ask your surgical team for details on what to expect.
- Ask if there are situations that might come up during your surgery that could cause a different outcome.
- Ask about your options for cancer rehabilitation and other ways to improve your recovery from surgery.
After your cancer surgery:
- Follow your surgical team's instructions for post-surgery care, including wound care, nutrition recommendations, and physical activity.
- Give yourself the time to heal and take part in activities that you enjoy, such as journaling or creating art.
- Let your surgical or cancer care team know how you feel, both physically and emotionally.
- Consider talking with a counselor who can help you cope with changes to your body.
- Join a support group.
The changes to how your body looks and works after surgery will often depend on your type of cancer. Learn more about how your surgery for your type of cancer will affect your body.
Possible long-term side effects of cancer surgery
Ask if there could be any long-term or permanent effects from the surgery. Long-term side effects depend on the type of surgery done. You might want to ask if your surgery will:
- Affect your fertility (your ability to have a baby or father a child)
- Affect your ability to have sex like you’re used to.
- Leave you with any sort of ostomy (opening through which stool or urine drain, or through which you will breathe).
- Cause problems controlling your urine or emptying your bladder.
- Increase your risk for swelling in your arms or legs.
- numbness
Your surgeon should talk to you about the possible long-term effects of surgery before your operation.
Can surgery cause cancer to spread?
The chances that surgery would cause your cancer to spread are very low. Surgeons take special care to decrease this risk. Still, this could happen in some situations. Doctors who have experience in treating cancer with surgery are very careful to avoid these situations.
In the past, larger needles were used to take a piece of the tumor (biopsy) to diagnose cancer. The chance of spread or “seeding” from the biopsy was higher. Now, it’s more likely that a small needle will be used to biopsy your tumor. This, and other improvements to the technique, have greatly lowered the chances of a biopsy causing a cancer to spread.
Sometimes an incisional biopsy is used to get tissue. This is where the surgeon cuts through the skin to remove a small part of the tumor. But this may not be safe for a few types of cancer such as certain tumors in the eyes or in the testicles. Doctors may treat these types of cancer first, without taking a biopsy, or may recommend removing (resecting) the entire tumor if it’s likely to be cancer.
There are a few kinds of tumors that have a bit higher risk of cancer spread when they are cut out. Examples include parathyroid and gallbladder tumors, and some sarcomas. However, this is rare because of advances in equipment and imaging tests.
Exposure to air during surgery
A common myth is that cancer will spread if it’s exposed to air during surgery. This myth may be because people feel worse after surgery than they did before. But it’s normal to feel this way when recovering from any surgery.
People may also believe that air can cause cancer to spread because more cancer may be found during surgery than was seen on scans and x-rays. This isn’t because of the surgery – the cancer was already there; it just didn’t show up on the tests.
Cancer does not spread because it has been exposed to air. If you delay or refuse surgery because of this myth, you could be harming yourself by not getting effective treatment before the cancer spreads on its own.
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- References
Developed by the American Cancer Society medical and editorial content team with medical review and contribution by the American Society of Clinical Oncology (ASCO).
American Society of Clinical Oncology (ASCO). Side effects of cancer surgery. Accessed at cancer.net. Content is no longer available.
Anderson DJ, Sexton DJ. Overview of control measures for prevention of surgical site infection in adults. 2024. UpToDate. Accessed at https://www.uptodate.com/contents/overview-of-control-measures-for-prevention-of-surgical-site-infection-in-adults on March 14, 2025.
National Cancer Institute (NCI). Common Cancer Myths and Misconceptions. Cancer.gov. Accessed at https://www.cancer.gov/about-cancer/causes-prevention/risk/myths on March 14, 2025.
National Cancer Institute (NCI). Surgery to treat cancer. Accessed at https://www.cancer.gov/about-cancer/treatment/types/surgery on March 14, 2025.
Parks LS. Surgical Therapy. In: Maloney-Newton S, Hickey M, Brant JM (eds.), Mosby’s Oncology Nursing Advisor: A Comprehensive Guide to Clinical Practice. 3rd ed. Elsevier; 2024: 304-309.
Last Revised: June 2, 2025
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