When VJ Sleight's breast cancer returned last year, she wondered if the unusual recurrence – 23 years after her original diagnosis -- had anything to do with the controversial hCG diet that she had repeatedly followed.
The near-starvation diet, which I detailed in the Chicago Tribune story "Long-discredited hCG diet makes a comeback, allows followers just 500 calories a day for six weeks. Hoping to quell hunger pangs, dieters also regularly take human chorionic gonadotropin, or hCG, a hormone taken from pregnant women's urine.
Sleight's doctors told her there wasn't any research to support the link between hCG and breast cancer.
And some research has shown hCG can have a preventive effect. Dr. Irma Russo, who has studied the effects of hCG for over 30 years, said she and other colleagues have found that in breast cancer patients with metastatic lesions, "hCG treatment can reduce tumor size."
HCG also "prevents mammary cancer in rats and reduces tumor size in rats that already have developed mammary tumors," said Russo, Chief of the Molecular Endocrinology Section of the Breast Cancer Research Laboratory at Fox Chase Cancer Center. "Our studies indicate that hCG treatment does not stimulate the growth of preexisting tumors, whereas other hormonal stimuli, such as hormone replacement therapy (HRT) or even pregnancy can increase breast cancer risk."
In addition, Russo's research has shown that high levels of hCG during the first trimester of pregnancy are associated with reduced incidence of postmenopausal breast cancer.
Still, that's not to say hCG is safe, even at the low doses used in the diet. "To my knowledge, there are no studies of hCG safety in women with functioning ovaries and breast cancer in remission," said Dr. Rasa Kazlauskaite, an endocrinologist and preventive medicine expert at Rush University Medical Center.
In fact, it's possible that hCG could stimulate breast cancer recurrence by stimulating estrogen/progesterone production in the ovaries, if a woman is still pre-menopausal," said Kazlauskaite. "In women with functional ovaries, hCG stimulates ovary to produce estradiol, which is known to stimulate existing breast cancer growth, she said.
Since Russo's laboratory work has shown that hCG reduces estrogen receptors, "the net effect potentially may be prevention, rather than stimulation," said Kazlauskaite. "The ongoing and future studies in humans should show whether it is true."