"For primary prevention (of melanoma) I think we're putting the nail into the coffin of that theory," said Dr. Robert Dellavalle, chief of dermatology at the Denver VA Medical Center, who was not involved in the new research.

Melanoma is the most lethal of the skin cancers, with 70,000 new cases diagnosed in the U.S. each year and close to 9,000 Americans a year dying from the disease.

About 45 million Americans take statins, which include atorvastatin (Lipitor), lovastatin (Mevacor), pravastatin (Pravachol), rosuvastatin (Crestor), simvastatin (Zocor) and others, to lower their cholesterol.

Evidence from experiments on cells and one trial in people had hinted some of the same properties of statins that protect against heart disease might also prevent melanoma.

But the picture was mixed at best, and several other studies, including work by Dellavalle, found that statins seemed to do nothing to stave off the skin cancer.

To help resolve these discrepancies, Dr. Michael Simon, a researcher at the Karmanos Cancer Institute in Detroit, and his colleagues looked to the massive Women's Health Initiative study, which has tracked about 120,000 women for more than a decade.

The researchers compared roughly 8,800 white women who took a statin medication to 111,000 white women who did not.

They found 89 cases of melanoma among the statin users and 1,111 cases among the non-users during a 12-year period.

That translated to identical rates of melanoma in each group - nine cases a year for every 10,000 women.

No matter what type of statin the women took or how long they took it, the results were the same.

"I don't think there's anything here that suggests statins may be protective for melanoma," Simon said.

It's still possible that statins might protect people against the skin cancer, he added, but "we just have to do the right kind of study."

Because statins have demonstrated benefits on skin cells in the laboratory, it's possible that people taking the drugs achieve insufficient concentrations to make a difference to their melanoma risk, Simon's team writes in the journal Cancer.

Future studies of people at higher risk for melanoma than the broad group of women in the current study could also "provide more conclusive results," they add.

Based on the evidence that statins can help destroy tumor cells in a petri dish, there might be a way to use the drugs in people already diagnosed with melanoma, noted Dellavalle, who is also an associate professor at the University of Colorado School of Medicine.

But as far as prevention goes, Simon believes it would be better to spend resources on things that are known to prevent skin cancer.

Risk factors for melanoma include exposure to UV radiation -- from sunlight or tanning beds, fair skin that tends to burn, moles or other types of pigmented birthmarks, smoking and family history of the cancer.

"I think based on (the study results) we should continue to put our resources into education about sun protection: staying out of the noonday sun, wearing protective sunscreen," Simon told Reuters Health.

SOURCE: bit.ly/HIf2jH Cancer, March 20, 2012.

• A Permanent Economic Emergency