Study: Some skin cancer doctors cut more

A new study shows that some surgeons cut away significantly more tissue than their peers when removing skin cancer lesions.

Published in the medical journal JAMA Dermatology, the study, conducted by a consortium of researchers at nine American health systems, found that 140 surgeons among 2,329 who performed Mohs micrographic surgery were statistically more likely to perform additional surgical "stages" per case, extending the size of the wounds and the potential for scarring.

Named for and developed by Dr. Frederic Mohs who pioneered the technique in the late 1930s, Mohs surgery uses exceedingly-thin tumor slices examined under a microscope to determine whether an excised tumor is surrounded on all sides by "clear" tissue with no evidence of cancer. Additional stages are ordered, with the surgeon returning to the waiting patient, until surgeons are satisfied that their margins are clear.

While adding stages is routine and often necessary, it can also be abused. Surgeons often bill Medicare by the state, so more stages can mean more revenue.

Such was the case for Dr. Michael Rosin, a former Florida dermatologist, who was indicted, convicted and imprisoned in 2006 for performing hundreds of unnecessary procedures on Medicare patients. Investigators found that he always billed for a full four stages and, after he was turned in by his office manager who told investigators that, in some cases, tissue samples were sometimes replaced with bubble gum or Styrofoam. The revelations led to a 20-year sentence and an order to reimburse Medicare nearly $3.7 million.

The new study makes no such allegations of chicanery. Researchers simply looked for patterns in Medicare billing, identifying doctors whose average number of stages was a good distance—two standard deviations—from the mean. Doctors were then notified in a private letter of their place on the continuum and many, one year after being notified, had significantly reduced the average number of stages they performed.

Dr. Martin "Marty" Makary, a well known surgeon at Johns Hopkins University Medical School and one of the study's co-authors, said the idea was to explore what would happen when doctors were approached privately in an non-accusatory manner.

"A simple intervention of sharing data with doctors confidentially in a civil, peer-to-peer fashion, resulted in a big impact towards initiating change in physician behavior that affected a lot of patients positively and saved the health care system over $11 million," Makary said.

Across nearly 26,000 procedures, the median number of stages fell from 2.55 to 2.31 from 2017 to 2018 for doctors whose billing practices indicated they were removing more tissue than their peers. While that decrease looks pretty paltry on paper, it hides the fact that, according to the paper, the averages for many individual doctors decreased by a whole stage, skipping a whole round of cutting.

It's hard to say, though, whether those doctors were intentionally adding stages to pad their bill as Rosin did or whether they were simply convinced that their patients could get by with narrower margins.

There is, explained Dr. S. Brian Jiang, director of the Mohs Micrographic Surgery and Dermatologic Oncology Fellowship at UC San Diego, no solid consensus on just how thick those margins should be.

"Some people are OK with a shorter distance, and some are not, they want it further out," Jiang said. "It's what is your level of comfort with calling that margin negative that probably varies from surgeon to surgeon."

Larger tumors, more common among doctors who treat uninsured or underinsured patients, typically need more stages to find the clear margins they seek and the quality of lab preparations available can also affect a surgeon's confidence level, causing them to return to the surgical site for another go while doctors more confidence in their lab teams might be more comfortable standing pat.

The true indication of quality, the surgeon added, is whether a cancer returns after surgery. If a doctor takes more tissue but fewer of his or her patients see their cancers return, then the extra cutting is probably worth it. But, because recurrence rates for individual surgeons are not generally shared in public, it's impossible to know whether the reduction in stages observed in the study will affect the recurrence rate.

"Recurrences don't happen right way. Sometimes they happen five years down the road, so that could be an unintended negative consequence of trying to cut down on the number of stages," Jiang said.

That's not to say, he added, that the study was misguided. It's useful to identify those whose numbers stray quite far from the mean.

"I'd say, for the most part, surgeons are ethical. But I think this study can help us spot out potentially-troublesome practitioners," Jiang said.

Jiang also noted that, in addition to the lack of availability of recurrence data for most surgeons, there is no uniformity in the amount of training received. Some undergo a year-long Mohs fellowship which has participants performing about 1,000 cases under supervision of an expert instructor before working on their own. But much shorter certification programs without long apprenticeship periods also allow dermatologists to practice Mohs. The study only looked at surgeons who were fellowship trained.

Makary, known internationally for his research and advocacy around increasing patient safety and quality, said during a journalism conference in Baltimore Sunday that modern medicine faces a "crisis of appropriateness" that often fails to "measure whether interventions were necessary." He said he and other researchers are in midst of using Medicare billing data that should shed similar light on opioid prescribing, unnecessary cancer care, medical testing and antibiotic prescription.

"We think there are broad implications of this so called 'dear doctor letter' in health care to address avoidable care and avoidable costs," Makary said.

After reviewing the paper Dr. Zia Agha, chief medical officer of San Diego's West Health, a local think tank with broad interest in reducing health care costs, noted in an email that unnecessary services have been estimated to add about $210 billion to nationwide medical bills annually.

"What's really exciting is that this study demonstrates that by simply showing doctors how they stack up against their peers resulted in a significant reduction in unnecessary treatments and associated health care costs," Agha said.