BRUSSELS - Cancer patients buying shark cartilage capsules as a treatment for the disease are wasting their money, a cancer expert says.
Dr Lene Adrian, of Copenhagen University Hospital in Denmark, said that the health supplement had no effect when it was tested on Danish breast cancer patients.
"There was no evidencethat the therapy had any benefit.
"I would not advise patients to use it," she told the European Breast Cancer conference.
Shark cartilage has been sold as an alternative treatment for cancer since the publication in the early 1990s of Sharks Don't Get Cancer, a book by William Lance.
It suggested that a protein in shark cartilage prevented the fish from getting cancer by blocking the development of small blood vessels that cancer cells need to survive and grow.
The idea spawned a market for shark cartilage supplements estimated to be worth $NZ122.45 million a year.
Researchers have since discovered that sharks do get cancer, but they have a lower rate of the disease than other fish and humans.
Danish researchers tested the treatment on 17 women with advanced breast cancer that had not responded to other treatments.
The patients took 24 shark cartilage capsules a day for three months, but the disease still progressed in 15 of the women, and one developed cancer of the brain.
The cancer did stabilise in one woman, but Dr Adrian said that was not unusual in patients with metastatic breast cancer that had spread to another part of the body.
"The evidence that shark cartilage has no place in cancer treatment is growing stronger.
"I would not recommend it, since it has no convincing effect, it produces gastrointestinal side-effects and it is expensive," she said.
The Danish results support research that found powdered shark cartilage did not prevent tumour growth in 60 patients with an advanced cancer.
