(J Pat Carter/Associated Press file)

Skin cancer treatment costs skyrocketed in the past decade, rising five times faster than treatment costs for all other cancers, according to a new Centers for Disease Control and Prevention study.

Between 2002 and 2006, $3.6 billion a year was being spent on skin cancer treatment in the United States; during the following five years, that figure rose to $8.1 billion annually. That's an increase of 126 percent, while treatment costs rose by just 25 percent for all other cancers during the same time period.

The study, published Monday in the American Journal of Preventive Medicine, underscores just how big of an economic burden skin cancer is to the U.S. health-care system, even though it is considered a mostly preventable disease.

One of the major reasons for this dramatic rise in dollars spent on treating skin cancer: The sheer number of skin cancer patients has also been on the rise, from 3.4 million annually during the first half of the study to almost 5 million from 2007 to 2011.

"It's clear that not enough has been done in terms of skin cancer prevention behaviors," said Gery Guy of the CDC's Cancer Prevention and Control division and the study's lead author. Researchers looked at both nonmelanoma and the less-common melanoma types of skin cancer. "In a lot of these cases, skin cancer, for the most part, is preventable," Guy said. "We know sun safety and avoiding indoor tanning go a long way."

But it's not just that more people are receiving treatment; the cost per patient has also gone up, as more treatments are taking place in pricier hospital settings. From 2002 to 2006, it cost roughly $1,000 to treat the average skin cancer patient; treatment costs increased to $1,600 per patient during the following five years, according to the CDC study.

Patients may not be feeling the pinch in their own bills, as out-of-pocket costs have decreased slightly, while private health insurance and Medicare are both paying significantly more for skin cancer treatments, according to the study.

While it's been known that certain skin cancer rates have increased, that $8.1 billion figure for annual treatment costs surprised researchers. Measuring those costs "really gives us a sense through prevention efforts, how many cases could be prevented and how many health-care savings to our system could be incurred," Guy said.