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Sentinel Node Biopsy for Breast Cancer: Before Your Procedure

What is sentinel node biopsy for breast cancer?

A sentinel node biopsy is done to see if breast cancer has spread to the lymph nodes. Most of the lymph nodes in the breast area are located in the armpit. In this biopsy, your doctor removes certain lymph nodes, called sentinel lymph nodes, and has them tested for cancer. The sentinel nodes are the first lymph nodes that the cancer would travel to from the breast. The results show if the cancer could have moved beyond the breast.

A blue dye or a radioactive material called a tracer—or both—will be injected into your breast. This material then flows through the lymph system. This helps the doctor find the correct lymph nodes. Your doctor will then make a small cut (incision), remove the sentinel nodes, and have them tested for cancer. The incision will leave a scar that usually fades with time. The blue dye leaves a blue mark on your breast that will fade in a few weeks.

If your cancer has spread, you and your doctor will discuss what you can do. Your doctor may remove more lymph nodes, or you may decide to use chemotherapy or radiation.

A sentinel node biopsy takes about an hour, and you will probably go home the same day. Most women can return to work and their usual routine in 2 to 7 days.

If, during the biopsy, your doctor thinks the cancer has spread, he or she may go ahead and remove more lymph nodes.

A sentinel node biopsy often is done at the same time as other breast surgeries. If this is the case, you will get information about the other procedures too.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor or nurse call line if you are having problems. It's also a good idea to know your test results and keep a list of the medicines you take.

What happens before the procedure?

Preparing for the procedure

  • Bring a list of questions to ask your doctors. It is important that you understand exactly what procedure is planned, the risks, benefits, and other options before your procedure.
  • Tell your doctors ALL the medicines and natural health products you take. Some of these can increase the risk of bleeding or interact with anesthesia. Your doctor will tell you which medicines to take or stop before your procedure.
  • If you take blood thinners, such as warfarin (Coumadin), clopidogrel (Plavix), or aspirin, be sure to talk to your doctor. He or she will tell you if you should stop taking these medicines before your procedure. Make sure that you understand exactly what your doctor wants you to do.
  • You may need to stop taking certain medicines a week or more before your procedure, so talk to your doctor as soon as you can.
  • Before your procedure, you will speak with an anesthesia provider to discuss your anesthetic options, including the risks, benefits, and alternatives to each. This may be on the phone or in person.

Taking care of yourself before the procedure

  • Build healthy habits into your life. Changes are best made several weeks before the procedure, since your body may react to sudden changes in your habits.
    • Stay as active as you can.
    • Eat a healthy diet.
    • Cut back or quit alcohol and tobacco.
  • If you have an advance care plan, let your doctor know. If you do not have one, you may want to prepare one so your doctor and loved ones know your health care wishes. Doctors recommend that everyone prepare these papers before a procedure, regardless of the type of procedure or condition.

Procedures can be stressful. This information will help you understand what you can expect. And it will help you safely prepare for your procedure.

What happens on the day of the procedure?

  • If a radioactive tracer is used, you will need to get it injected into your breast late in the day before the procedure or early in the day of the procedure. If blue dye is used, it will be injected into the breast during the procedure.
  • Follow the instructions exactly about when to stop eating and drinking, or your procedure may be cancelled. If your doctor has instructed you to take your medicines on the day of the procedure, please do so using only a sip of water.
  • Take a bath or shower before you come in for your procedure. Do not apply lotions, perfumes, deodorants, or nail polish.
  • Do NOT shave the surgical site yourself.
  • Remove all jewellery, piercings, and contact lenses.
  • Leave your valuables at home.

At the hospital or surgery centre

  • Bring a picture ID.
  • Before surgery you will be asked to repeat your full name, what surgery you are having, and what part of your body is being operated on. The area for surgery may be marked.
  • A small tube (IV) will be placed in a vein, to give you fluids and medicine to help you relax. Because of the combination of medicines given to keep you comfortable, you may not remember much about the operating room.
  • You will be kept comfortable and safe by your anesthesia provider. The anesthesia may range from making you fully asleep, to simply numbing the area being worked on. This will depend on the procedure you are having, as well as a discussion between your doctor, the anesthesia provider, and you.
  • As you wake up in the recovery room, the nurse will check to be sure you are stable and comfortable. It is important for you to tell your doctor and nurse how you feel and ask questions about any concerns you may have.

Going home

  • Be sure you have someone to drive you home.
  • For your safety, you should not drive until you are no longer taking pain medicines and you can move and react easily.
  • Arrange for extra help at home after the procedure, especially if you live alone or provide care for another person.
  • You will be given more specific instructions about recovering from your procedure, including activity and when you may return to work.

When should you call your doctor?

  • You have questions or concerns.
  • You don't understand how to prepare for your procedure.
  • You become ill before the procedure (such as fever, flu, or a cold).
  • You need to reschedule or have changed your mind about having the procedure.

Where can you learn more?

Go to

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Care instructions adapted under license by your healthcare professional. If you have questions about a medical condition or this instruction, always ask your healthcare professional. Healthwise, Incorporated disclaims any warranty or liability for your use of this information.