Study: In myasthenia gravis, surgical removal of the thymus gland proves to be effective and economical

BUFFALO, N.Y. – In patients with myasthenia gravis, the surgical removal of the thymus gland, called thymectomy, added ‘quality adjusted life years’ to patients and was also cost-effective in comparison to pharmacological treatment alone, according to a study published April 13 in JAMA Network Open.

‘Quality adjusted life years’ are a measure used in health economics to represent how much a drug or intervention extends and improves one’s quality of life.

The study of 126 patients was conducted in the context of the National Health Service in the United Kingdom to compare costs and efficacy between thymectomy and presumably lower drug costs versus pharmacological treatment by itself. The study found that for each patient, undergoing thymectomy would result in a gain of .52 in quality adjusted life years and cost savings of £ 13,014 ($17,568).

In 2016, thymectomy was proven to be effective in patients with the most common form of myasthenia gravis in a study led by Gil I. Wolfe, MD, SUNY Distinguished Professor in the Department of Neurology in the Jacobs School of Medicine and Biomedical Sciences at the University at Buffalo. 

The current study, of which Wolfe is a co-author, was undertaken to evaluate the cost-effectiveness of thymectomy. Joseph Lord, a doctoral candidate in public health, economics and decision science at the University of Sheffield, is first author.

“This analysis provided clear proof that the NHS is getting its money’s worth with thymectomy,” says Wolfe. “The surgery is a one-time cost and, in the long run, much less expensive than the very costly medications that have now become available for myasthenia gravis.”

Wolfe notes that those medications can cost at least $300,000 per year and even up to $500,000 a year.

“Even in the U.S., where surgery costs more, it does not approach a $300,000 price tag,” he adds, noting that this would be applicable to other countries as well.

In patients with myasthenia gravis who have a thymic tumor, thymectomy must be performed; the current study was done on patients with non-thymomatous myasthenia gravis, the most common form of the disease, in which thymectomy is a treatment option. Seventy percent of the patients were women with a mean age of 35; the disease is more common among young women.

After surgery, patients will need to continue to take corticosteroids, but at much lower doses than if they hadn’t undergone surgery.

The most important reason for doing the surgery is to reduce reliance on corticosteroids.

“If patients do not undergo thymectomy, corticosteroids like prednisolone have to be used in higher doses,” says Wolfe. “As a result, all of the complications of that class of agents — weight gain, sleep disturbance, hyperglycemia, bone loss, skin changes, mood changes — are more likely.”

Wolfe adds that the success of the study shows that it is possible and valuable to compare different kinds of interventions to discover which are most effective and economical.

“This trial provided a prime example of testing whether a surgical therapy is more effective than medical management alone,” he says. “This type of analysis is possible with a lot of hard work and can be applied to other interventions, such as joint replacement and spinal fusions.

“It is becoming more and more important to really assess the value of what we do,” he adds. “Surgery tends to be expensive, but in certain settings, it not only provides improved quality of life but may also lower long-term health care costs.”   

Funding for the research was provided by the Wellcome Trust.