Harvard researchers Tuesday issued a sweeping review of alternative medical treatments for cancer patients, separating those that can relieve suffering from those that can cause harm.
Vitamin E, soy, and acupuncture can help, the study reports. Highly restrictive diets, St. John's wort and big doses of injected vitamins can do damage.
The checklist marks the first attempt by a mainstream medical school to provide such a detailed assessment of the expanding roster of alternative therapies, which have grown into a $27 billion-a-year business nationwide. The guidelines are intended to help both doctors and patients navigate the frequently conflicting evidence about which therapies work, and for whom.
"Physicians are getting asked about these things more and more," said Dr. David S. Rosenthal, a cancer specialist at the Dana-Farber Cancer Institute who chairs the American Cancer Society's advisory committee on complementary and alternative medicine. "What this study has done is really to break it down into what we do know so far. It allows a doctor to say, 'There's no evidence this works and in fact it may cause some interactions with what you're taking.' "
Researchers at Harvard's Osher Institute, founded to investigate alternative medicine, compiled the study by reviewing more than 400 published research papers on approaches such as shark cartilage and mind-body therapies. They discovered no magic bullets. Even the most promising alternative approaches, they report in the Annals of Internal Medicine, do not fight cancer directly but instead relieve the symptoms of the disease and the side effects of treatment.
Although largely unregulated by federal agencies and mainstream licensing boards, the dozens of techniques and substances lumped together as "alternative medicine" are being subjected to more scrutiny from scientists and the government.
Studies have shown that up to 91 percent of cancer patients use some form of alternative medicine. But they often never mention it to their doctors.
"The era of don't tell and don't ask is over," said Dr. David Eisenberg, director of the Osher Institute and one of the study's lead authors. "It's not in the patient's interest to withhold this information nor is it in the physician's interest to not ask."
That lack of communication can pose health risks. Dr. Anthony D'Amico, a radiation oncologist at
Brigham and Women's Hospital, described the case of a 55-year-old man with prostate cancer who was scheduled for an operation that involved inserting needles in the prostate. But a blood test showed that the patient was at risk of profuse bleeding because he was taking vitamin supplements that resulted in blood thinning.
As it turned out, the patient was on 60 different alternative medicines.
The Harvard researchers restricted their cancer-therapy study to six categories: diet changes, acupuncture, massage, exercise, mind-body interventions, and nutritional supplements.
In some cases, possible side effects overshadowed any potential benefits. The researchers, for instance, say St. John's wort has been found to dilute the effectiveness of conventional treatments, including chemotherapy.
Acupuncture was among the therapies receiving the most favorable review: It was found both safe and effective in controlling nausea and vomiting and may quiet persistent pain.
For many alternative practitioners, the study provides unprecedented validation from one of the pillars of conventional medicine.
"It will be very helpful if the medical field has this kind of scientific evidence — it makes it more likely that the mainstream medical practitioners will accept this," said acupuncturist Fei Yi, owner of the Weymouth Acupuncture Center. "And if the main medical field accepts this, I hope the insurers will start to cover it."
Health plans do not typically pay for alternative approaches. Instead, companies such as Harvard Pilgrim Health Care might cut deals with providers to offer discounted rates to their members, who still have to pay from their own pocket. For example, Harvard Pilgrim negotiated with a national network of alternative medicine practitioners to give plan members a 25 percent break on treatments by chiropractors and specialists in acupuncture and massage.
A study such as Tuesday's report might result in the plan reviewing what it is willing to cover, a company spokeswoman said.
"We routinely review our benefit levels and packages," Harvard Pilgrim spokeswoman Sharon Torgenson said. "So we would take a look at this."
While the Harvard study is exhaustive, it is not intended to end the discussion. In some cases, treatments landed squarely in a gray zone. For instance, the researchers found that while shark cartilage appears to do no damage to most patients, more evidence is needed that it really works before the scientists would feel confident in enthusiastically recommending it.
"After all of this research, it strikes me how this field is still in its infancy," said Dr. Wendy A. Weiger, an Osher researcher and another lead author of the study. "I guess the biggest thing I've learned is how much more needs to be done."
Stephen Smith can be reached at stsmith@globe.com.