Dr Eric Winer, an associate professor of medicine at Harvard University and director of the Breast Oncology Center at the Dana-Farber Cancer Institute, told the meeting in Hamburg that it was crucial that more, properly conducted studies should be carried out on complementary and alternative therapies (CAMs).
"Issues of safety with CAMs are critical," he said. "But in many cases, extensive safety evaluation has not been undertaken. Moreover, relatively few CAMs have been tested in conjunction with standard treatments and this is a serious problem. For instance, some CAMs, such as St John's Wort, have been shown to have important and potentially detrimental interactions with standard drugs. Just because a CAM is not known to cause harm does not mean that it is safe, particularly when administered in conjunction with standard treatments. In addition, some studies have shown that the quality and composition of many CAM products varies substantially.
"In the United States and many other countries, there is a rigorous process by which standard medications are evaluated and licensed, but most complementary therapies do not go through this rigorous process. As an increasing number of patients turn to these therapies it is even more important that they should be evaluated properly."
He said that women use CAMs for a number of reasons, "including a desire to improve quality of life, take control over their illness, relieve symptoms and improve overall survival". Some studies had found that women who used CAMs were more likely to have physical and/or psychological symptoms compared to non-users.
"Unfortunately, there are relatively few studies that have demonstrated unequivocal benefits for many of the commonly used CAMs. Many studies suffer from methodological problems, including inadequate sample size, lack of randomisation, failure to 'blind' the study, and poorly defined interventions and measures of outcome.
"It is not necessary that all therapies, particularly CAMs, show a survival benefit. Survival is important, but treatments that improve quality of life clearly have a place, and not all medical therapy prolongs survival. Having said that, a treatment needs to demonstrate that it can either prolong survival or improve quality of life if it is to be considered for use. If any CAM is to be used widely it should be shown to be safe, particularly if it is being used concurrently with another therapy, and that it has some beneficial impact on the patient. Few CAMs have undergone the type of careful scrutiny that I feel is needed."
Dr Winer highlighted studies that demonstrated which CAMs had been adequately evaluated to justify common use and which were in need of further investigation.*
Abstract no: 357 (14.15 hrs Friday 19 March, Hall 8)
Notes
* Dr Winer will give examples of adequately and inadequately evaluated CAMs at the news briefing and in his presentation, but at the time of writing this press release he had not finished reviewing the literature.