While thyroid cancer remains relatively rare, the number of cases has risen about 6.5 percent, according to National Cancer Institute statistics.

This percentage makes the thyroid disease the fastest growing cancer, reports The Indianapolis Star. The condition affects 11 out of 100,000 people annually.

“Ten years ago, if I saw four new thyroid cancer patients a year, it would have been a lot,” G. Irene Minor, a radiation oncologist at the Indiana University Health Central Indiana Cancer Center, told the news provider. “Now sometimes I see that many in a month, and I have seen three in a week.”

The rise in thyroid cancer instances have medical professionals quite puzzled, with some attributing the increase to better screening technology, while others remain skeptical about it only being improved detection practices.

Tod Huntley, an otolaryngologist at the Center for Ear, Nose, Throat and Allergy in Indianapolis, told the news provider that he thinks it is a combination of “increased surveillance” as well as “an actual biological change in disease prevalence.”

Patients  do not typically exhibit any thyroid cancer symptoms other than a lump in their neck, although some experience throat problems like difficulty swallowing. The disease, which affects heart rate, blood pressure, body weight and more, most often occurs in females under the age of 45.