Lower Extremity Edema
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: May 8, 2013
My mother was diagnosed three months ago with stage IV lung cancer with metastasis to the brain. She received radiation therapy for about 5 weeks and as of her last MRI, the tumors in both areas of the brain have shrunk. Her next MRI is coming up soon. She is on one liter of oxygen and can get around a little bit. Her biggest problem now is that her left leg has been swollen from her knee down to her ankle. This has been ongoing for at least one month and has gotten worse. If it were not for her leg, she would be able to get out of the house and do things. Her leg has been scanned several times and no clots were found. Her oncologist says there is nothing he can do about it, and that the swelling is due to fluid retention from the cancer. I have a hard time believing that there is nothing that can help her with her leg. Do you have any suggestions?
Barbara Campling, MD, Medical Oncologist, responds:
It certainly sounds like your mother is in a difficult situation. In a patient with lung cancer that has spread to the brain, the first thing to do is exactly what her doctors have done, namely to give radiotherapy to the brain. This is usually helpful in shrinking the brain metastases, and at least for some time, and in relieving the symptoms caused by the metastases.
From what you say, her major complaint at the moment is swelling of one leg. The most important problem to rule out in this situation is a blood clot in the leg, a problem that is common in patients with widespread cancer. It sounds like her doctors have looked for a blood clot, and they have not found any evidence of this. It is important that this problem has been ruled out, because if she had a clot she would require anticoagulant therapy to prevent the clot from dislodging and going to the lung (a pulmonary embolus), which could be very serious. What other types of problems can cause swelling of one leg in a patient with lung cancer that has spread to the brain? There are many possibilities, and it is hard to be specific without actually examining her. Your mother has probably been on a steroid medication, such as decadron, to reduce swelling from the brain metastases. This medication can predispose patients to edema. Many patients with advanced cancer have a low level of protein in the blood, and this could also predispose them to edema. If your mother has any underlying problems with the circulation in one leg, the swelling could be predominantly on one side. If the problem is due to fluid retention, a diuretic medication might be helpful. Is there any evidence that your mother's cancer has spread to the abdomen? If there is a tumor deposit in the pelvis, this could cause obstruction to blood flow from the leg, leading to swelling. If this is the case, it is possible that some specific treatment for the cancer, either chemotherapy or radiotherapy might help.
If the swelling in the leg is painful, there are a couple of other possibilities that would be worth considering. Does she have spread of cancer to the bones? If this is the case, the pain can usually be alleviated with some local radiotherapy. Does the leg appear hot and swollen? If this is the case, I would wonder about an infection in the soft tissues of the leg, which could be treated with antibiotics. Here is another thought. Sometimes patients with non-small cell lung cancer can develop pain in their lower legs, especially over their shins. This can be due to a peculiar syndrome called "hypertrophic pulmonary osteoarthropathy" that is associated with some lung cancers and caused by a substance secreted by the lung cancer cells. This can be quite painful, and it is sometimes associated with swelling. I suppose it is possible that it might be more prominent on one side than the other. This particular problem usually responds quite nicely to non-steroidal anti-inflammatory drugs.
Even if your mother's doctors never do find out what is causing the leg swelling (which is quite possible), it should still be possible to help her feel more comfortable. Symptomatic treatment with special stockings that apply pressure to the leg should help to reduce the swelling. She should try to keep her leg elevated whenever possible. If the leg is painful, there are a variety of pain medicines that could help. Her doctors should be able to relieve your mother's distress at least to some extent.