There are many different potential side effects of breast cancer treatment. Lymphedema is one of them. It occurs when something disrupts the lymphatic system’s job of moving excess fluids around the body. The fluids build up and cause swelling of soft tissues, or lymphedema.

Primary lymphedema is due to inherited or genetic factors. Secondary lymphedema is the result of injury or obstruction. In higher income countries, most cases of secondary lymphedema are due to cancer or cancer treatment, the most common being breast cancer.

Research from 2018 suggests that lymphedema affects about 1 in 5 people treated for breast cancer. Mild cases can be overlooked or misdiagnosed.

In this article, we’ll address some of the factors that can raise the risk of getting lymphedema after breast cancer.

Breast cancer-related lymphedema tends to occur in the breast, chest, or arm. It can happen within days of treatment or years later.

The most obvious symptom is abnormal swelling, which may start out as a feeling of fullness or heaviness. Other symptoms may include:

  • pain
  • tightness
  • numbness, tingling
  • weakness, difficulty using your arm
  • skin that feels thicker or leathery
  • skin sores, infection
  • slow-to-heal wounds

Research suggests that with progression, lymphedema may cause elevated rates of depression and anxiety. Lymphedema can have a negative impact on quality of life.

Many risk factors go into your chances of developing lymphedema after breast cancer. Some risk factors have to do with treatment, and others are unrelated. Some risk factors are modifiable, while others are not.

In general, the chances of developing lymphedema after breast cancer range from 5 to 50 percent.

The following are some treatments that may raise the risk of developing lymphedema.

Removal of lymph nodes

Removal of axillary (armpit) lymph nodes is one of the main treatment-related risks of lymphedema.

This may be particularly true of a full axillary lymph node dissection, which would include lymph nodes above, below, and under the minor pectoral muscle. Axillary lymph nodes are located under the arm.

Some studies indicate that the rate of lymphedema in people who have axillary lymph node dissection is four times higher than for those who have sentinel lymph node dissection. Sentinel lymph nodes are the ones closest to the tumor.

The American Cancer Society estimates the risk of lymphedema at about 5 to 17 percent after sentinel lymph node removal and 20 to 30 percent after axillary lymph node removal.

Radiation of lymph nodes

Radiation treatments to underarm lymph nodes can cause scarring and blockage of the lymphatic system. Research shows that about 10 to 15 percent of people who receive radiation therapy to regional lymph nodes develop lymphedema.

Mastectomy and other breast surgery

Lymphedema happens when there’s an interruption in the flow of lymph fluid. This can happen when lymph nodes are removed during surgery for breast cancer. This can include mastectomy or breast-conserving surgery, also known as lumpectomy.

Cancer in the lymph nodes

A cancerous tumor in the lymph nodes may block the flow of lymph fluid.

Scar tissue

Scar tissue that forms near lymph nodes can interfere with the lymphatic system. Scar tissue may develop due to surgery or radiation therapy.

Breast density

A 2020 study indicates that low breast density may be a risk factor for severe lymphedema. Study authors suggest that, along with other risk factors, breast density may help predict the development of lymphedema and estimate its severity.

With or without cancer treatment, the main biological factor is a high body mass index (BMI). Other than having obesity, risk factors for lymphedema include:

  • heavy smoking
  • having diabetes
  • previous surgery in the armpit area

There’s no cure for lymphedema. But treatment can help reduce swelling, ease symptoms, and keep it from worsening. Lymphedema treatment may include:

  • Compression sleeve. This is a special sleeve that fits tightly on your arm to help with the flow of lymph fluids.
  • Exercise. Moving the affected arm can reduce swelling by improving the flow of lymph fluids.
  • Physical therapy. Physical therapists who work with breast cancer patients can perform a type of massage called manual lymph drainage. This can improve the flow of lymph fluids and reduce swelling.
  • Pneumatic pump. A pumping mechanism inflates a sleeve worn on the arm to help move fluid.
  • Weight loss. Losing extra weight may be helpful if possible.

Surgical options may include:

  • Lymphovenous anastomosis/bypass. In this procedure, other lymphatic vessels are connected to nearby veins, rerouting the extra lymph fluid.
  • Vascularized lymph node transfer. Any scar tissue is removed. Then, healthy lymph nodes are taken from another part of the body and implanted in the affected area.
  • Liposuction. Excess skin and subcutaneous tissue from the arm are removed.

If lymphedema is caused by a cancerous tumor, the cancer should be treated.

Avoid using the affected arm for blood pressure readings, blood draws, or needlesticks. To help prevent infection, try to keep your skin clean and tend to even minor cuts right away. When your arm is swollen, elevate it above your heart when possible.

Despite known risk factors, there’s no way to accurately predict who will develop breast cancer-related lymphedema. You can’t totally prevent it, but there are things you can do to lower your chances. Some of these are:

  • Keep up with your breast cancer follow-ups.
  • Report all new symptoms or changes to your doctor or healthcare team right away.
  • Engage in regular physical activities and be sure to exercise the affected arm or arms.
  • Don’t use the affected arm for injections, blood draws, or blood pressure readings.
  • Get immediate treatment for burns, skin infections, or injuries to the affected arm.
  • Try not to wear clothing that’s too tight or restrictive around the affected area.

Research published in 2010 suggests that early physical therapy may reduce the risk of lymphedema after axillary lymph node dissection. In the small study, participants were treated by a physical therapist using:

In addition, moderate, dynamic, and high frequency exercise can reduce the incidence of lymphedema.

If you’ve recently had breast cancer surgery, ask your doctor if physical therapy is a good choice for you.

Lymphedema is a chronic condition. Without treatment, it’s likely to progress, so the earlier you speak with a doctor, the better. Here are some signs that you should make that call now:

  • You have a feeling of fullness in your arm.
  • There’s noticeable swelling.
  • You have trouble moving your arm normally.
  • Skin on the affected side is red, warm, or cracking.
  • You have frequent infections in your arm.
  • You have pain in your arm with no known cause.

Lymphedema is a chronic condition. But it can be managed enough to ease symptoms, prevent additional complications, and slow or stop progression.

Ask your doctor about your individual risk factors and what steps you can take to lower your chances of developing lymphedema after breast cancer.