During cancer surgery, a tumor or tumors are removed from your body. Most of the time, the surgeon tries to take out all the cancer and an edge (margin) of normal tissue around it. Surgery is usually done for cancer that can be reached safely and only in one place. For instance, it may be done for a skin growth or a lymph node that the surgeon can feel with their fingers. Surgery may also be done when a growth cannot be felt but is seen only on a picture (medical imaging).

Cancer of unknown primary (CUP) has already spread by the time it's found. So surgery is seldom the only treatment used. Your treatment plan may include cancer fighting medicines (chemotherapy), radiation, or both. But surgery might be considered in some cases. These may include if cancer is found in your lymph nodes or in an organ where your surgeon is able to remove all of it. Surgery may also be done for biopsies to diagnose and help find out the extent of a cancer. Surgery may also be used to help relieve symptoms caused by the tumor, such as pain or other problems (like a blocked intestine or broken bone).

There are many different ways to use surgery to treat CUP. The type of surgery done depends on where the cancer is, the size of the cancer, where it has spread, and what the goal of the surgery is.

If your doctor suggests surgery, be sure you understand how the surgery will be done. You should also understand the goal of the surgery and its benefits and risks.

Like other cancer treatments, surgery can cause side effects. These depend on what kind of surgery you have and where in your body the surgery is done.

Side effects can include:

• Pain at the surgical site (incision).
• Skin irritation and bruising where the surgery was done.
• Infection.
• Bleeding, either inside your body or at the incision.
• Blood clots.
• Damage to nearby organs or tissues.
• Fatigue or feeling tired.
• Reactions to the anesthesia. These are the medicines used to make you sleep during surgery.

Tell your doctor if you have any side effects. There are often ways to treat them. If you have poor health and nutrition, you may have an increased risk for infection. You may also have problems with wound healing.

Your care team will talk with you about your choices for surgery. Bring a family member or close friend with you to checkups to help ask questions and listen to your treatment plan. Write down questions you want to ask about your surgery. Make sure to ask:

• What type of surgery will be done?
• What is the extent of the cancer, and has it spread?
• What's the goal of surgery?
• Will the surgery change the way my body works? (This may happen if an organ is removed.)
• What are the risks and side effects of the surgery?
• When can I return to my normal activities?
• Will the surgery leave scars, and what will they look like?
• Will you have tubes or drains after surgery?
• Will I need to stay in the hospital? If so, how long?

Before surgery, tell your care team if you're taking any medicines. These include over-the-counter medicines, vitamins, herbs, and other supplements. This is to make sure you're not taking medicines that could affect the surgery. After you've talked about all the details with the surgeon and you agree to proceed with surgery, you'll sign a consent form that says that the doctor can do the surgery.

You'll also meet the anesthesiologist. You can ask them questions about the anesthesia and how it will affect you. Just before your surgery, you'll get anesthesia. This is so you fall asleep and don't feel pain.

You may have to stay in the hospital for a few days. This depends on the type of surgery. For the first few days after surgery, you're likely to have pain. It can be controlled with medicine. Talk with your care team about your choices for pain relief. Some people don't want to take pain medicine. But doing so can help your healing. If you don't control pain well, you may not want to cough, turn over often, or get out of bed, for instance. You need to do these things as you heal.

You may have diarrhea. Talk with your doctor, nurse, or a dietitian about what you can eat to help. You may have constipation. This can be caused by pain medicine, from not moving much, or from not eating much. Talk with your care team about getting more fiber or using a stool softener.

You may feel tired or weak for a while. The amount of time it takes to heal from surgery is different for each person.

When you get home, you may get back to light activity. But you may have to stay away from strenuous activity for a while. Your care team will tell you what kinds of activities are safe for you while you heal. They'll also tell you how to care for your incision, when you can shower, and when it's safe for you to drive. You may need help from family and friends until you are able to go back to your normal activities. These include grocery shopping, driving, and activities that involve lifting.

You may need radiation therapy or chemotherapy after surgery. Your doctor will talk with you about this. They will help you make appointments, if needed.

Tell your doctor right away if you have any signs of problems after surgery. Symptoms can include:

• Bleeding.
• Redness, swelling, or fluid leaking from the incision.
• A fever of 100.4°F (38°C) or higher, or as directed by your doctor.
• Chills.
• Chest pain or trouble breathing.

Be sure you know what other problems to watch for. Know how to contact your doctor after office hours and on weekends and holidays.