Axillary lymph node dissection: removing armpit lymph nodes in breast cancer

Lymph nodes are small bean-shaped structures found all over the body, including near the breast. They filter lymph fluid as it passes through them. Cancer Research UK explains that the lymph nodes in the armpit, the axilla, drain lymphatic fluid from the breast and arm, and they are divided into three groups, levels 1 to 3, according to where they sit around the pectoralis minor muscle.

Axillary lymph node dissection (ALND), or axillary clearance, is an operation to remove most or all of these nodes. The nodes are sent to the laboratory so that the pathologist can count how many contain cancer cells. That information helps the team stage the cancer and decide on further treatment such as radiotherapy, chemotherapy or hormone therapy. The NHS notes that removing lymph nodes in the armpit is one of the types of breast cancer surgery, alongside breast-conserving surgery and mastectomy.

Checking the armpit usually starts before surgery. Cancer Research UK says you have an ultrasound scan of the lymph nodes under your arm at the same time as your other diagnostic tests, and a biopsy of any node that looks abnormal. If the biopsy shows that cancer has spread to the armpit nodes, you will usually have surgery to remove all or most of them, at the same time as your breast surgery.

If the nodes look normal on ultrasound, or a biopsy shows no cancer cells, a sentinel lymph node biopsy is done instead. A sentinel biopsy may therefore be followed by a further operation. Cancer Research UK says that if cancer cells are found in the sentinel nodes you usually need more treatment, which may be a further operation to remove most or all of the remaining nodes, generally about 2 weeks after the results, or radiotherapy to the armpit instead of surgery.

The sentinel node is the first lymph node that fluid from the breast drains into, and therefore the first node the cancer could spread to. Cancer Research UK says surgeons usually remove about 1 to 3 nodes in a sentinel node biopsy, found using either a mildly radioactive tracer with blue dye or a magnetic tracer called Magtrace used with a probe called Sentimag. The blue dye can stain the breast slightly blue and turns the urine green for a few days.

Some hospitals can test the sentinel nodes during the operation using one-step nucleic acid amplification (OSNA), so the rest of the nodes can be removed in the same operation if needed, avoiding a second operation. The surgeon will explain which approach applies to you before surgery.

You have a general anaesthetic, so you are asleep throughout. The surgeon makes a small cut in the armpit and removes the lymph nodes, which are sent to the laboratory. You get the results at your follow-up appointment, and Cancer Research UK says results of laboratory tests can take a few weeks.

After the operation you usually wake up in the recovery room before moving back to the ward or day unit. You usually see your surgeon one to two weeks later so they can check the wound, explain the results and talk about further treatment. You will be given the contact details of your breast care nurse or the ward if you need to ask something before then.

Not everyone has problems, but Cancer Research UK says the risk is bigger after axillary dissection than after removing only a few nodes. The main problems are summarised below.

• Lymphoedema: long-term swelling in the arm or hand caused by lymph fluid that cannot drain away. It can happen any time after surgery or radiotherapy to the armpit, cannot be cured once it develops, but early treatment can help control it. Speak to your specialist nurse or surgeon if your arm or hand seems swollen.

• Shoulder stiffness: the shoulder can become stiff and painful, and a nurse or physiotherapist will show you exercises to improve movement.

• Seroma: fluid can collect near the wound and around the armpit, causing swelling, pain and a higher risk of infection. It normally goes away on its own within a few weeks, and can be drained with a needle if painful.

• Wound infection: redness, swelling, warmth, pain or discharge, possibly with feeling unwell or a temperature. Antibiotics may be needed.

• Nerve pain: numbness, tingling or shooting pain in the armpit, upper arm, shoulder or chest wall, which usually settles over weeks or months.

• Cording (axillary web syndrome): a tight band of scar tissue in the armpit, often within the first weeks or months, which is harmless but can be painful and limit arm movement.

The NHS describes lymphoedema as a long-term condition that causes swelling in the body's tissues, usually in an arm or leg, which develops when the lymphatic system does not work properly. Secondary lymphoedema is much more common than primary lymphoedema and often affects people who have had treatment to the lymph nodes, such as for breast cancer. Symptoms can include a heavy or aching feeling, difficulty moving the limb, tightness of jewellery or watches and repeated skin infections.

There is no cure, but the NHS says it is usually possible to control the main symptoms using compression garments, good skin care, regular movement and exercise, a healthy lifestyle and specialised massage techniques. Cellulitis is the most common complication, with symptoms including redness and heat in the skin, pain, increased swelling and a high temperature, and it needs prompt treatment. See a GP if you develop typical symptoms, as the NHS advises.

Your care team will explain exercises for the arm and shoulder, which Cancer Research UK links to better movement. Report concerns early: swelling of the hand or arm, redness or warmth at the wound, or increasing pain. You will have regular check-ups during and after breast cancer treatment, and the NHS encourages people to contact their specialists with any symptoms or side effects rather than waiting for the next appointment.

Emotionally, a breast cancer diagnosis and surgery can be demanding. Specialist breast care nurses are usually the main point of contact, and charities and the NHS provide further support.

In the UK, breast cancer surgery, including axillary surgery, is delivered through NHS breast units after a multidisciplinary team has reviewed the tests. Private breast surgeons carry out the same operations, and some people use private care for faster appointments or a second opinion. In both cases ask who will coordinate follow-up, who to contact about swelling or wound problems and how lymphoedema services can be reached if needed.