Unproven treatments for breast and lung cancers are especially dangerous, researchers say. So, why do people opt for these alternatives?

Alternative cancer treatments that seem too good to be true may actually be dangerous.

In fact, these treatments can more than double the risk of death for some people with cancer, according to a recently published study.

Some alternative treatments promise a cure or a way to fight cancer without the harsh side effects of chemotherapy or radiation.

In order to find out how people with cancer fare on these treatments vs. traditional medications, researchers from Yale University turned to the National Cancer Database.

Dr. Skyler Johnson, a physician at the Radiation Oncology at Yale-New Haven Hospital and lead author of the study published in Journal of the National Cancer Institute, said he wanted to look into survival rates for alternative medicine after he saw an increase in people wanting to pursue these methods.

“We had started to see lots of patients who were coming in with advanced cancers who had been diagnosed earlier but who had tried an alternative therapy,” Johnson told Healthline. “It clearly impacted their survival.”

This issue was debated after Apple co-founder Steve Jobs died of cancer in 2011 after trying alternative treatments.

In their study, Johnson and his co-authors used the data from the National Cancer Database to see how people with cancer fared on alternative treatments compared with traditional therapies.

They found data on 281 people with breast, prostate, lung, or colorectal cancer that had not metastasized. These people had chosen alternative therapies not proven by science to be helpful in treating cancer.

Researchers then compared how these people fared compared with 560 people who had undergone conventional cancer treatment such as radiotherapy, chemotherapy, or surgery.

“It was needed for us to be able to have informed discussions with patients,” said Johnson. “To tell them this is the risk and benefit from this decision.”

Overall, they looked at how people fared from 2004 to 2013, with the median follow-up of slightly more than five years.

They found that people who chose alternative medicine were two and half times more at risk of dying.

For breast and colorectal cancers, the risk was even higher.

People with breast cancer were more than five times as likely to die if they pursued solely alternative treatment.

People with colorectal cancer were more than four times as likely to die as their counterparts who underwent conventional treatments.

Johnson said the study will help doctors relay concrete information to people considering alternative medicine.

This is especially true for people who have cancer that has not yet metastasized and has a high survivability rate.

“Cancer cures is one of those things that need to be done in a timely fashion,” he said.

There was one cancer outlier in the study.

Prostate cancer didn’t have as much of a difference in life expectancy between people treated conventionally and those treated with alternative medicine, but Johnson pointed out prostate cancer is extremely slow growing and many people can live more than a decade without significant health impacts.

Johnson said anecdotally he’s heard from people that they believe the alternative therapy they are pursuing has no downside.

“In conversations, it seems that there’s a belief that the alternative therapies are as effective, and that they’re also nontoxic,” said Johnson.

Dr. Jordan Berlin, a medical oncologist at the Vanderbilt University Medical Center, said the study is not surprising but could still help people with cancer.

“Data like this is helpful,” he told Healthline. “Knowing we can say to our patients the track record for these things in general has not been better.”

Berlin said these alternative treatments tend to come in and out of fashion. Right now, he’s seen people pursue using medical marijuana, salves, and unproven supplements for cancer treatment.

Berlin said he understands why some would be more willing to look into alternative medicine after a cancer diagnosis.

“I tell people that cancer is the scariest word in the English language,” Berlin said. “They’re looking for anything that might help.”

Berlin said that for many people the promise of these treatments can become especially appealing when facing an initial diagnosis.

“When you hear 100 percent of people [cured] with no side effects, and we tell people every side effect we could possibly cause, it’s very appealing,” Berlin said.

Berlin said when people pursue alternative medicine, he does his best to insist they come back for scans so he can monitor their progress.

If they get worse and want to pursue traditional treatment he can start them on conventional therapies, hopefully before the cancer metastasizes.

However, some people may still put their faith in their original, unproven treatment when they make a recovery.

“I’ve had this where one of my patients says how well they did on alternative therapy,” Berlin said. “In truth, they got chemo too, or radiation. No one gave any credit to those therapies.”

Berlin said he’s willing to talk to people who want to pursue supplemental treatment in addition to conventional treatments.

He does warn them there are risks that supplements or other ingested items could negatively affect cancer medication.

He also said more should be done to understand which, if any, alternative treatments could be a help either by alleviating symptoms or actually combatting tumor cells.

“It is worthwhile to study something of these things… we want to know as much as anybody” he said.

Both Berlin and Johnson said the study will only do so much to convince some people who are skeptical of conventional medical treatment.

Johnson said he keeps a list of people who ignored medical advice in favor of alternative treatments, and reaches out to them periodically.

While Johnson hopes the study will help people get better care, he acknowledged a lot of work remains for doctors trying to gain the trust of their patients and attempting to understand why those patients want to pursue alternative treatments.

“Facts don’t often change people’s beliefs,” Johnson said. “Developing trust with people is really the bottom line.”