Maybe you’ve heard that drinking too much coffee causes cancer but a daily cup of green tea lowers your risk. Or perhaps you’ve read that surgery can make an early-stage cancer more severe. There’s no shortage of myths, though it is worth noting that each form of cancer has its nuances.

Related: Having just one soft drink a day could increase your cancer risk

Misinformation runs rampant, and here’s what two experts hear the most often and said should be debunked.

Caffeine Causes Cancer

Reports that coffee could come with warning labels in California has reignited this rumor. The chemical acrylamide is produced in some foods when heated at very high temperatures. In coffee, this potential carcinogen forms during the roasting process.

Surgeon Dr. Syed Ahmad, who specializes in pancreatic diseases at the University of Cincinnati Cancer Institute, told Newsweek patients are often worried that any caffeinated beverage can cause cancer. But is there any validity to the rumor?

“We don’t think so,” Ahmad said. “There’s been lots of studies that have been done that do not demonstrate a definite link between caffeine and cancer.”

In fact, some studies have shown that caffeine could prevent DNA damage, which would offer protective benefits against the disease. But as with most things, caffeine is best consumed in moderation. Too much caffeine could lead to troubled sleep and heightened osteoporosis risk.

Air Exposure Makes Tumors Spread

Determining whether surgery is the best treatment option is reliant on many factors, including whether the disease has advanced from its initial stage. But some worry that an operation could end their life rather than save it.

“You let air in, and the cancer spreads like wildfire” is one myth Dr. Julian Guitron, thoracic and lung surgeon at the University of Cincinnati, has often heard.

He explained that this thinking stems from a time before CT scans were available to depict clear images of cancerous tumors. Previously, doctors would attempt to remove a mass but discover cancer had already spread throughout the body.  

When patients still aren’t convinced with this reasoning, Guitron explains that our bodies need oxygen for survival.

“Your cells are always getting oxygen, or else they wouldn’t live,” he told Newsweek.

Lung Cancer Is Always Caused by Smoking

To be clear, smoking is the leading cause of lung cancer. However, Guitron said many think it’s the only way to develop the disease.

Roughly one-fifth of Americans who die from lung cancer have never smoked or used tobacco, but that hasn’t prevented the man-made stigma accompanying a diagnosis. Because of this attitude, Guitron said research and treatment options remain underfunded.

“The myth of 'If I don’t smoke, I won’t get lung cancer' has been very damaging,” Guitron said.

Other risk factors include excessive exposure to asbestos, arsenic, diesel exhaust and radon, a natural gas from rocks and dirt that can get trapped inside buildings.

In a sense, cancer can’t be prevented because aging is a major risk factor. However, studies have shown that eating plenty of fruits and vegetables, limiting alcohol and exercising can lower your chances of developing many types of cancers.