It’s as easy as breathing. That expression describes just how much we take our ability to inhale and exhale for granted. Yet breathing is anything but easy for a person who suffers from lymphangioleiomyomatosis (LAM). This progressive and potentially fatal lung disease affects women almost exclusively. It typically develops between the ages of 25 and 50 but can appear later. Though long considered very rare, experts now suspect that LAM is more common than generally believed and is often misdiagnosed as asthma, bronchitis or chronic obstructive pulmonary disease.
I spoke with Francis X. McCormack, MD, a pulmonologist at the University of Cincinnati College of Medicine and scientific director of The LAM Foundation. His good news: The past decade has brought promising advances that offer new hope to patients.
LAM results from an abnormal growth of smooth muscle cells that develop elsewhere in the body and travel to the lungs, destroying normal lung tissue and causing numerous cysts to form. Gradually the lungs become so damaged that oxygen delivery throughout the body is seriously compromised. No one knows what causes LAM, but because it primarily develops in women of childbearing age, estrogen is thought to play a role. Genetics also may influence risk. Though LAM is not traditionally considered a type of cancer, Dr. McCormack said, “Those of us who think about LAM every day have no doubts. It’s the slowest-moving cancer on Earth—but it is cancer.”
Warning signs: The main symptom is shortness of breath. At first, this occurs mainly upon exertion…but as LAM progresses, even normal daily activities leave patients breathless. Although LAM patients often are misdiagnosed with asthma, the patterns of the diseases are different. “With asthma, you have good days and bad days. But with LAM, there isn’t much day-to-day difference—instead, tolerance for physical exertion drops from year to year,” Dr. McCormack explained. Other LAM symptoms include chest pain…frequent coughing…wheezing…and fatigue.
Any unexplained, chronic shortness of breath warrants a visit to the doctor and, quite likely, follow-up with a lung specialist. A high-resolution CT scan (unlike a chest X-ray) is sensitive enough to pick up the lung changes and cysts typical of LAM. To help with the diagnosis, a patient also may get a new blood test called VEGF-D and/or a lung biopsy. In addition, the patient is checked for common LAM complications, such as accumulation of fluid in the chest…collapsed lung…and/or benign kidney tumors.
Treatment: Though LAM has no known cure, there are ways to improve quality of life. A healthy lifestyle—low-fat diet, tobacco avoidance, exercise appropriate to one’s abilities—can help minimize symptoms. Some patients benefit from bronchodilators, medicines that relax muscles around the airways, improving airflow. Given estrogen’s possible involvement, LAM patients generally are advised against birth control pills and estrogen therapy. Since pregnancy hormones might worsen LAM, patients who want to get pregnant should discuss the risks with their doctors.
As LAM progresses, patients may need to use an oxygen tank when exercising or full time. Ultimately, a lung transplant often offers the best hope for improved quality of life and longevity. According to The LAM Foundation, there is no evidence that LAM patients benefit from cancer treatments such as radiation or chemotherapy. However, “targeted” cancer drugs—which act specifically on abnormal biochemical pathways in cancer cells—present a promising area of research.
New breakthrough: The drug rapamycin (Sirolimus), used primarily to prevent rejection after an organ transplant, shows great promise. In a study led by Dr. McCormack, LAM patients who took Sirolimus daily for one year showed significant improvement in lung function, whereas placebo users lost lung function during the study. “The possibility that you could take this drug for life and prevent progression of LAM is intriguing. However, there is concern about cumulative toxicity, so we need more research,” said Dr. McCormack. Possible side effects of Sirolimus include mouth ulcers, acne, increased cholesterol, lung injury and susceptibility to infection. Clinical trials are being planned…meanwhile, the drug can be prescribed off-label for LAM patients.
The vast majority of LAM patients live for more than a decade after symptoms first appear and a number live for more than three decades, The LAM Foundation reports. For more information, visit www.TheLamFoundation.org…for a list of medical centers that have LAM experts, click on “Patients” and “LAM Clinics.”