Gold specks raise hopes for better cancer treatments

A tiny medical device containing gold specks could boost the effects of cancer medication and reduce its harm, research suggests.

Scientists have completed a study which showed that gold increased the effectiveness of drugs used to treat lung cancer cells.

Experts say that the findings could help researchers use the device to reduce side effects of current chemotherapies by precisely targeting diseased cells without damaging healthy tissue.

Gold is a safe chemical element and has the ability to accelerate – or catalyse – chemical reactions.

Researchers at the University of Edinburgh discovered properties of the precious metal that allow these catalytic abilities to be accessed in living things without any side effects.

Minute fragments, known as gold nanoparticles, were encased in a chemical device by the research team to control these highly-specific reactions in exact locations.

The device was shown to catalyse a directed chemical reaction when implanted in the brain of zebrafish, suggesting it can be used in living animals.

Gold nanoparticles also activated anti-cancer medicines that had been applied to lung cancer cells in a dish, increasing the drugs’ effectiveness.

Some 450 people die from cancer every day in the UK. A cancer diagnosis is made every two minutes. Medications are improving, but often damage healthy cells.

The study was carried out in collaboration with researchers at the University of Zaragoza’s Institute of Nanoscience of Aragon in Spain. It was part-funded by Cancer Research UK (CRUK), and the Engineering and Physical Sciences Research Council and is published in the journal Angewandte Chemie.

Dr Asier Unciti-Broceta from the University of Edinburgh’s CRUK Edinburgh Centre, said: “We have discovered new properties of gold that were previously unknown and our findings suggest that the metal could be used to release drugs inside tumours very safely.

“There is still work to do before we can use this on patients, but this study is a step forward. We hope that a similar device in humans could one day be implanted by surgeons to activate chemotherapy directly in tumours and reduce harmful effects to healthy organs.”

Dr Áine McCarthy, Cancer Research UK’s senior science information officer said: “By developing new, better ways of delivering cancer drugs, studies like this have the potential to improve cancer treatment and reduce side effects. In particular, it could help improve treatment for brain tumours and other hard-to-treat cancers. The next steps will be to see if this method is safe to use in people, what its long- and short-term side effects are, and if it’s a better way to treat some cancers.”

Periodontal disease is associated with higher risk of several cancer types

Periodontal disease was associated with increased risk of several types of cancer in postmenopausal women, even in women who had never smoked.

Journal in Which the Study was Published: Cancer Epidemiology, Biomarkers & Prevention, a journal of the American Association for Cancer Research.

Author: Jean Wactawski-Wende, PhD, a professor in the Department of Epidemiology and Environmental Health and dean of the School of Public Health and Health Professions, State University of New York at Buffalo, was senior author. Ngozi Nwizu, BDS, MMSc, PhD, assistant professor of oral and maxillofacial pathology at The University of Texas School of Dentistry, was lead author.

Background: In recent years, research has shown that periodontal disease is a risk factor for certain cancers, including breast cancer, oral, and esophageal cancers. However, few studies have analyzed the overall risk for all types of cancers.

How the Study Was Conducted and Results: The researchers conducted a prospective cohort study of 65,869 women aged 54 to 86 who were enrolled in the Women’s Health Initiative Observational Study. The women self-reported periodontal disease on questionnaires administered between 1999 and 2003. The researchers monitored cancer outcomes through September 2013. Over an average follow-up time of 8.32 years, the researchers identified 7,149 cases of cancer.

The study showed that a history of periodontal disease was associated with a 14 percent higher risk of developing any cancer. The strongest association was for cancer of the esophagus, which was more than three times more likely in women with periodontal disease than women who did not report periodontal disease. Lung cancer, gallbladder cancer, melanoma, and breast cancer were also associated with significantly higher risk.

The researchers noted that certain cancers, such as breast cancer, lung cancer, and gallbladder cancer, were associated with higher risk in women who smoked and had periodontal disease. Others, such as melanoma, were associated with higher risk in the women who had never smoked but did report periodontal disease.

Author Comment: Wactawski-Wende said the biological mechanisms that connect periodontal disease and cancer are not yet fully understood. She said one possible explanation is that oral pathogens could potentially be carried in saliva and dental plaque, or through diseased periodontal tissues into the blood circulation to reach other body sites and contribute to carcinogenesis; this may possibly explain the strong association in esophageal cancer.

“The esophagus is in close proximity to the oral cavity, and so periodontal pathogens may more easily gain access to and infect the esophageal mucosa and promote cancer risk at that site,” Wactawski-Wende said.

“Our study findings serve to provide further evidence that periodontal disease is linked to cancer, and support the need for further investigation into how periodontal disease contributes to increased cancer risk,” said Nwizu.

The authors said the study’s large size adds to the strength of the findings.

“This study is the first national study focused on women, particularly older women,” Wactawski-Wende said. “Our study was sufficiently large and detailed enough to examine not just overall risk of cancer among older women with periodontal disease, but also to provide useful information on a number of cancer-specific sites.”

Limitations: The authors said that because the study used self-reported data, the prevalence of periodontal disease may have been under-reported. They said further research that uses more precise assessments of periodontal disease could be useful in confirming the link between periodontal disease and cancer, they added.