Pitt says broccoli compound holds potential to prevent head and neck cancers

Broccoli continues drawing attention as a natural way to fight cancer, with a University of Pittsburgh study demonstrating its potential to prevent development of a second tobacco-related head and neck squamous cell carcinoma in patients who were curatively treated for their first one. A 2014 Pitt study based in China found that sulforaphane, a natural compound in broccoli with high concentrations in broccoli sprout tea, purged the body of air pollution toxins, including carcinogenic benzene. Now a Pitt study, published 24 June in Cancer Prevention Research, has found that sulforaphane activates genetic detoxification processes with the potential to block carcinogen-induced head and neck cancers located from the lips to the voice box. The study involved mice and laboratory tests but also confirmed activation of this protective genetic mechanism in the mouths of humans who took doses of sulforaphane-rich broccoli sprout tea. Sulforaphane is found in other cruciferous vegetables, as well, including cabbage, cauliflower and kale. Young broccoli and kale plants have particularly high concentrations. While there’s reason to believe that sulforaphane can prevent the cancer outright, researchers say, the best test would involve patients successfully treated for head and neck cancers to see if sulforaphane doses lead to a lower rate of second head and neck cancers, which have a high rate of mortality. For that purpose, study author Julie Bauman, co-director of the UPMC Head and Neck Cancer Centre of Excellence, said Pitt now is recruiting head-and-neck-cancer survivors to participate in a clinical trial to test sulforaphane’s cancer-prevention powers. The trial will use the commercially available sulforaphane-rich dietary supplement Avmacol so doses can be measured precisely, but Dr. Bauman said a cereal-bowl-sized portion of broccoli each day would provide a similar dose. In the study, she and her team, including researchers from Johns Hopkins University and the University of California San Francisco, treated mice prone to oral cancer with sulforaphane versus a control that didn’t receive the compound, and found that sulforaphane markedly reduced the number of cancers that developed. They also studied activation of protective genetic pathways in normal, healthy human cells that line the throat and mouth. Sulforaphane activated genes that detoxify carcinogens found in cigarettes. “Unfortunately, previous efforts to develop a preventative drug to reduce the risk of a second head and neck cancer have been ineffective, intolerable in patients and expensive,” Dr. Bauman said. “That led us to green chemo-prevention. “Identification of a cost-effective, green chemo-preventive agent would have a major global impact on mortality and quality of life in patients at risk, as the burden of such cancers disproportionately affects the developing world,” she said. In the United States, 48,330 new diagnoses are expected this year and 9,570 deaths from head and neck cancers, with males dying at three times the rate per 100,000 population as females; 64 percent survive five years after diagnosis, the National Institutes of Health reports. Most head and neck cancers begin in the squamous cells of the mouth and throat, which the NIH describes as “thin, flat cells that line” the pharynx and inside of the oral cavity. The human papillomavirus, tobacco use and heavy alcohol use are major risk factors for the cancers, it says. Multiple studies of sulforaphane already reveal potential to prevent cancers but few studies have involved human clinical trials. A 6 June study, for example, found sulforaphane to be “a promising molecule against pancreatic cancer” when used in conjunction with other anti-cancer agents. Another recent study described promising natural treatments including sulforaphane to arrest tumour cells in prostate cancer. An April study showed that sulforaphane worked to inhibit various cancer cell lines, including colon cancer. Dong Shin, a professor of medical oncology at Emory University, is studying polyphenol compounds in green tea among other plant-based methods that hold potential to prevent cancer. Others, he said, include sulforaphane, lutein and resveratrol. The Pitt clinical trial, if successful, would provide sufficient evidence to recommend sulforaphane as a preventive treatment, he said. But it would require persistent consumption of broccoli or a proven supplement over time to detoxify the body of cancer-causing agents. “I really congratulate the author and research team and encourage more research,” he said. “A lot of studies are being done but the clinical trials are much tougher to do. This is a good starting point but I think it is premature to recommend it until we see good activity in the clinical trial.”

Pittsburgh Post-Gazette, 12 July 2016 ; http://www.post-gazette.com ;