Lack of iodine makes goiters— enlargement of the thyroid gland in the neck—common in some parts of the world. In the United States, salt is enriched with iodine, so the condition is far less common. When goiters do occur, it is typically due to other factors, such as Graves’ disease (overactive thyroid) or Hashimoto’s disease (underactive thyroid), as well as an individual’s anatomy or family history. And when goiters go untreated, they can grow down into the chest, spreading behind the breastbone and collarbone; in some cases, they grow all the way down to the arch of the aorta. These substernal goiters tend to grow slowly and steadily—sometimes with symptoms, sometimes without.
Because of how and where they grow, substernal goiters can be very difficult to remove, with increased risk of complications. In his practice, Alliric I. Willis, MD, Associate Professor of Surgery, observed that substernal goiters seemed to occur more frequently among minority patients, older patients and patients who perhaps lacked access to care because of their insurance.
“The condition also appeared to be relatively more common with men, even though women make up the majority of thyroid surgery patients whether for goiter or malignancy,” he says. “I became interested in trying to find out: Does this condition have particular demographic risk factors or disparities?”
To explore that question, Dr. Willis collaborated with Dylan P. Thibault, MS, and Allison W. Willis, MD, MSCI, (also his wife) from the Center for Clinical Epidemiology and Biostatistics at the University of Pennsylvania. He was also assisted by Ambria S. Moten, MD, a surgical resident (PGY 1 and 2) that he mentored at Temple University. The team used data from the National Inpatient Sample—a federally funded dataset that provides insights into about 20 percent of the population and thus can form the basis of a national sample. The data showed that 110,889 patients underwent thyroidectomy for goiter from 2000 to 2010. Of those, 5,525 (5%) were substernal goiters.
Their analysis confirmed that Dr. Willis’ clinical observations were, in fact, accurate. Patients with substernal goiters were indeed older, more likely to be Black or Hispanic and to have Medicare insurance. In addition, they had a higher comorbidity index (meaning they had other conditions, such as high blood pressure, diabetes and/or obesity) and were more likely to be admitted on an emergency basis.
“We also found that these patients were more likely to have postoperative complications, and most alarmingly, we found that substernal thyroidectomy patients had 73 percent increased odds of death during admission compared to those patients undergoing a nonsubsternal thyroidectomy,” Dr. Willis explains. He also notes that insurance seems to play an especially significant role, with privately insured patients far less likely to have a substernal goiter. These findings emphasize the importance of early referral of goiter patients for surgical evaluation and an increased appreciation of the challenges associated with substernal goiter operations.
With Dr. Willis as principal author, the findings were published in The American Journal of Surgery. This study builds on similar research Dr. Willis has conducted around the role of demographics in the diagnosis and treatment of cancers of the breast, rectum and stomach.
“It’s an interesting field that is becoming increasingly appreciated as we talk about quality and outcomes,” he says. “We can’t just look at the big picture. We have to focus at the individual patient level, including those who may not be achieving great outcomes. As clinicians, we can ask the right questions, team up with good epidemiologists and biostatisticians, and do analyses to figure out what’s significant—and what we can do to make outcomes better for everyone.”
"Alliric Willis Leads Study Exploring Demographics, Disparities and Outcomes in Substernal Goiters,"
Jefferson Surgical Solutions: Vol. 11
, Article 6.
Available at: http://jdc.jefferson.edu/jss/vol11/iss2/6