"It wasn't perfect, but it was easier," said Lipton, who's healthy today. "I felt normal much more quickly."
If the larger study is successful, Sweden's Dignitana AB plans to seek FDA approval to market the medical device in the U.S. The move could open the way for other brands and insurance coverage.
Clearly there's demand: Despite the lack of FDA approval, a growing number of U.S. patients are renting a similar product, called Penguin Cold Caps, from a British company for $455 a month. Patients haul a collection of caps to chemo sessions on dry ice, or store them in special freezers provided by about 50 hospitals. It's deliberately separate from doctors' and nurses' care — typically, patients bring a friend to help them switch caps every 20 to 30 minutes when one loses its chill.
"I know I'm sick, but I don't want to look it," said Vanessa Thomas, 57, of Baltimore, who is using the Penguin caps at the recommendation of her doctor at MedStar Harbor Hospital. Halfway through her breast cancer treatment, Thomas says her hair feels only a little thinner.
The FDA declined comment on the Penguin caps.
Beyond breast cancer, advocates say the caps may be useful with other solid tumors as well.
What's the evidence behind scalp cooling? A recent review by oncologists in the Netherlands found numerous overseas studies conclude scalp cooling can work — but it's far from clear which patients are most likely to benefit, even how cold the scalp should be. That's because most of the research so far has been from observational studies that can't provide proof. But it seems harder to save hair with higher doses and certain types of chemo.
Researchers at New York's Weill Cornell Breast Center reported at a recent meeting of the American Society for Clinical Oncology that among just over a dozen Penguin cap users tracked so far, one lost enough hair to use a wig.
As for safety, UCSF's Rugo said a recurring tumor in the scalp is incredibly rare.
Hair-preserving approaches need good testing, adds Dr. Laura Esserman, a UCSF breast cancer specialist.
"If it matters to our patients, it should matter to us," she said. "It's really not more complicated than that."