Some of the country’s biggest and most prestigious cancer treatment centers are using misleading testimonials that don't disclose their results aren't typical, according to a watchdog report.

Out of 48 cancer centers, 90 percent were “deceptively promoting atypical patient testimonials,” in television and digital marketing material, according to the report, “Deceptive Marketing of Hope,” published last month by Truth In Advertising (TINA.org), a nonprofit consumer group.

The report included high-profile cancer treatment names such as MD Anderson in Houston, Memorial Sloan Kettering in New York, Dana-Farber in Boston, and Moffitt in Tampa, Florida.

It also called out Cancer Treatment Centers of America (CTCA), a for-profit hospital headquartered in Boca Raton, Florida, that is the top-spender on cancer center advertising and marketing, according to Kantar Media.

“Cancer patients and their families [are] facing devastating odds of survival and have a right to know the truth,” said Bonnie Patten, TINA.org's executive director. “To sway this uniquely susceptible population’s decisions as to where they should seek treatment by exploiting false hope is simply not acceptable.”

Americans spend nearly $150 billion annually on cancer care, according to the National Institutes of Health. To attract those dollars, treatment centers across the country spend tens of millions of dollars in advertising.

Testimonials with atypical results

In one video testimonial on the Memorial Sloan Kettering website, patient Carl, last name withheld, shares his gratitude for the medical team who saved his life by successfully treating his pancreatic cancer diagnosed in 2009.

“I never once felt like a number; I always felt like a person,” he said.

The five-year survival rates for someone with pancreatic cancer is only 8.5 percent, a fact not mentioned in the emotional video.

Under FTC's guidelines, for-profit companies must disclose the expected performance numbers if the results shown aren't in advertising aren't typical.

Non-profits, which includes many medical centers, aren't in the federal agency's jurisdiction, and are instead regulated by state deceptive marketing laws.

In one testimonial for CTCA, Chuck G., a patient diagnosed with stage 3 esophageal cancer in early 2001, addressed the issue of numerical results.

“By early October 2001, I was cancer free," he stated. "My recovery defies all statistics. But I agree with my doctors that ‘statistics mean nothing to believers.’”

The testimonial didn't disclose that the five-year survival rate for stage 3 esophageal cancer is 23.6 percent.

In 2018, over 130 instances of CTCA marketing material showcased a cancer patient with life-threatening diagnosis doing well after being treated at one of CTCA's five centers, TINA.org's investigation found. But the materials cited didn't close the majority of cancer patients with the diagnosis shown don't survive past five years. TINA.org has since filed a deceptive marketing complaint with the FTC.

In 1996, CTCA settled an FTC lawsuit against it and other cancer centers by agreeing to not make misleading use of patient testimonials. That agreement ended in 2016.

Advertiser responsibility

NBC contacted the five cancer treatment centers that spent the most money on advertising last year that were cited by TINA.org for using misleading testimonial ads. Dana-Farber declined to comment. The rest defended their advertising practices in statements to NBC News.

In a statement to NBC News, Memorial Sloan Kettering said it stands by the “integrity” of its communications and the importance of enabling patients to share their experiences.

"Our communications address both the success and the complexity of current available and experimental treatments," the company said.

CTCA said in a statement to NBC News, "To ensure clinical accuracy and tell our story in an informative and responsible manner, all of our advertising undergoes meticulous review prior to publication.”

It noted that all of the patients volunteered to share their stories in their own words, without any compensation, in the interest of helping others who receive a similar diagnosis.

MD Anderson said it "takes great care to ensure our messages are accurate, appropriate and responsible" and that it has a "responsibility to educate the general public about prevention, early detection, treatment, research and survivorship."

Moffitt Cancer center said every testimonial is based on actual medical results specific to that patient.

“The patient testimonials used by Moffitt provide an outlet for our patients and their loved ones to share their cancer journey in a transparent and authentic way, regardless of the outcome,” the company said in a statement.

Advertising is designed to persuade people. To do that an advertiser needs to put their best foot forward. No one expects a hospital to talk about the patients that couldn’t be helped.

But an advertiser has a legal obligation to make sure testimonial ads are handled carefully, Georgetown University Law Professor David Vladeck, former Director of the Bureau of Consumer Protection at the FTC said, so they don’t mislead or deceive.

“It is clearly misleading to use a case that is not typical in an ad and not disclose that; viewers have no reason to think that the case isn't typical, and the advertiser knows that, so in these cases the deception is intentional,” Vladeck told NBC News.

TINA.org's executive director Patten said the group didn't seek to prevent consumers from information that could help them distinguish cancer centers from each other.

“That said, I don't think patients should ever make any health care decision based on patient testimonials," said Patten.

"Every person’s health journey is unique and individual, so they can't rely on those [stories] to make their decisions.”