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Cancer of unknown primary

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Potential side effects of surgery for cancer of unknown primary

Side effects can occur with any type of treatment for cancer of unknown primary (CUP), but not everyone has them or experiences them in the same way. Side effects of surgery will depend mainly on the:

  • type of surgery
  • person's overall health
  • effect of other cancer treatments (for example, radiated tissue may not heal well after surgery)

Side effects can happen any time during surgery. Some may happen during, immediately after, or a few days or weeks after surgery. Most side effects go away after surgery. Late side effects can occur months or years after surgery. Some side effects may last a long time or be permanent.

It is important to report side effects to the healthcare team.

Side effects depend on the type and location of the surgical procedure done to treat cancer of unknown primary (CUP).


Pain often occurs after surgery because of trauma to the tissue during surgery. Pain-relieving medications are used to control pain. It may take time for pain to lessen after surgery. The intensity of the pain will depend on the procedure and how the person heals or tolerates pain. Check with the doctor if pain does not go away or pain medications do not relieve the pain.

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Bleeding or hemorrhage can occur if a blood vessel is not sealed off during surgery, or if the person has a blood clotting disorder. Nursing staff frequently check bandages and drains for heavy bleeding right after surgery. If bleeding occurs and is severe enough, the surgeon may have to take the person back to the operating room to find where bleeding is coming from and stop it.

A small amount of bloody drainage may be expected after surgery. Excessive amounts should be reported to the doctor or the healthcare team.

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Nausea and vomiting

Nausea and vomiting can occur because of the effects of general anesthesiaanesthesiaThe loss of some or all feeling or awareness. used during surgery. Medicines are often given to prevent and control nausea and vomiting. Nausea and vomiting are usually temporary side effects and often go away a few days after surgery.

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Some people develop an infection in the wound after surgery. This is not a common side effect, but can potentially occur after any type of surgery. Sometimes tubes are placed into the wound to drain excess fluid. Antibiotics may be used to help prevent or treat an infection. Wound infections are a temporary side effect of surgery.

Report signs of infection, such as redness, pus or foul-smelling drainage, increased swelling or tenderness of the incision site, and increased temperature (fever) to the doctor or the healthcare team.

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If surgery is done to remove lymph nodes under the arm or in the groin, swelling of limbs (lymphedema) can occur. Lymphedema is due to fluid buildup that can happen when lymph nodes are removed. Lymphedema may appear long after surgery is over and may last a long time.

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Blood clots

A blood clot in the leg is called a deep vein thrombosis (DVT). A DVT can occur right after surgery because the person cannot move around very well, along with other factors. In the most serious cases, a blood clot can break off and travel to the lungs (called a pulmonary embolus or PE). This causes shortness of breath and affects the ability of the blood to get oxygen from the lungs.

Frequent position changes, leg and ankle exercises and early mobility help reduce blood clots. Low doses of a blood thinner, such as heparin, may be given to help reduce the risk of blood clots in people at high risk for developing them. If a person smokes, stopping smoking before surgery helps reduce the risk of blood clots.

Report any redness, swelling, pain or cramps in the calf of the leg to your doctor or healthcare team.

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Nerve damage

If a neck dissection is done to remove cervical lymph nodes, nerves in the neck and shoulder may be injured or damaged. This can cause numbness, shoulder weakness or difficulty moving the arm. These effects may be temporary and usually go away after a few months. If a nerve is removed as part of surgery, the effects can be permanent. There can also be changes in the appearance of the neck. After a neck dissection, the healthcare team may recommend physiotherapy or range of motion exercises to help improve neck and shoulder movement and muscle strength.

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Problems urinating

Sometimes people have trouble urinating after surgery (urinary retention), especially if they have surgery in the abdomen or pelvis. Certain drugs, such as anesthetics or pain medicines, can cause urination problems. These drugs can relax the bladder muscle so it holds more, interfere with bladder contraction and lessen the urge to urinate. The healthcare team will monitor when and how much a person urinates for a short time after surgery. In some cases, the person may need to have a catheter inserted once or twice to drain the bladder after surgery until they can urinate on their own.

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