NEW YORK—When the history of natural medicine in America is written, the University of California, San Francisco's recently completed Tibetan Medicine Breast Cancer Project will no doubt be recognized as a significant step. The question right now is, a step toward what?
The UCSF project is the first-ever attempt at collaboration between allopathic medical oncologists and a traditional Tibetan physician, and it showed that 2 of 9 patients with metastatic breast cancer remained stable and progression-free without any form of allopathic therapy, after a year on Tibetan herbal formulas under the guidance of a Tibetan doctor.
On face value, it suggests Tibetan herbal medicine can be safely practiced in a Western cancer clinic, and may benefit patients with advanced breast cancer. But the study had serious methodological flaws, making it difficult to discern how it advances Tibetan medicine, Western oncology, or breast cancer care.
|Tibetan physician Dr. Yeshi Dhonden, making a pulse diagnosis on a breast cancer patient. Photo by Erika Leemann, Carol Franc Buck Breast Cancer Center, UCSF. |
The year-long collaboration was between Dr. Yeshi Dhonden, a senior Tibetan physician widely respected for his diagnostic skill, and Debu Tripathy, MD, a medical oncologist at UCSF. Dr. Tripathy presented preliminary findings at the first International Conference on Asian Therapies for Cancer, sponsored by Procultura, a non-profit educational organization.
The nine patients had not had any allopathic treatment for at least one month prior to entry, though all had previously been through chemotherapy, surgery or some other Western therapy. They were evaluated by Dr. Tripathy, who used diagnostic imaging and standard oncologic assessment tools, and Dr. Dhonden, who used traditional Tibetan methods including pulse diagnosis, tongue examination and urine study.
Dr. Dhonden then gave dietary advice and prescribed up to 4 of the 7 Tibetan herbal formulas he was permitted by the protocol. These 7 were selected from among 17 different combinations used by Tibetan physicians to treat various types of cancers and their related physiologic states.
Patients were told to follow Dr. Dhonden's instructions as to frequency and duration of herbal therapy. They had monthly visits with Dr. Tripathy for physical exams, blood work, safety monitoring, and symptom assessment. They also had CT scans to assess tumor progression every three months.
At the end of the year, 2 patients showed no further progression. Dr. Tripathy said it is difficult to attribute the delayed progression entirely to the Tibetan herbs since disease stability in the range of 6–12 months is common in this type of cancer. The important point, he said, is there were no toxicities with Dr. Dhonden's formulas, something that cannot be said of chemotherapy.
From the get-go, the study faced daunting logistic and methodologic challenges, not the least of which involved flying the principal treating physician—Dr. Dhonden—from his base in Dharamsala, India, to San Francisco, and convincing the Food and Drug Administration to grant investigational new drug (IND) clearances for seven Tibetan herbal combinations never before seen in the US.
Dr. Dhonden's combinations are comprised of between 8 and 32 different herbs, boiled and taken as teas, usually four times daily. In India, where many Tibetans live in exile, Dr. Dhonden draws from far more than 7 formulas. But Dr. Tripathy said given the difficulty of convincing FDA to give INDs even for single herbs, let alone complex formulas, Dr. Dhonden's treatment options had to be limited. "He felt that seven was the absolute minimum he would need."
Critics of the trial cite this as a major flaw, the equivalent of testing Western oncology by telling an MD to, "practice as he or she usually would," but limiting the therapeutic choices to a handful of available drugs. Dr. Tripathy admitted this was one of several defects in the trial design, but said it was impossible to avoid if the study were to take place at a conventional medical center like UCSF.
Another major problem—a common one in conventional trials of "unconventional" therapies—was the fact that Dr. Dhonden was asked to treat patients with very advanced disease, who are much less likely to respond to any type of treatment. "Dr. Dhonden said very often that earlier disease is easier to treat," recalled Dr. Tripathy.
The trial was so designed because there are no definitive allopathic therapies for metastatic breast cancer. Independent review boards are reluctant to permit trials of "experimental" treatments as monotherapy when there are existing treatments with demonstrated efficacy. For what it is worth, this same logic applies to novel allopathic or biotech cancer treatments.
Dr. Tripathy also added that patients with early-stage breast cancer respond better to almost any form of treatment, meaning the UCSF trial would have required a much larger cohort—on the order of thousands—to have the statistical power to show an effect in less advanced disease.
Admittedly, these considerations have more to do with the intellectual demands of biomedical research than with either good patient care or Tibetan medicine as practiced in its own context. While the project purported to study Tibetan treatment for breast cancer, it seems the real subject was Dr. Dhonden, and his ability to adapt Tibetan practice to academic medical research.
Dr. Tripathy said he admires Dr. Dhonden and other practitioners of traditional medicine who are willing to collaborate with biomedical researchers. "They are putting their practices on the line, and we don't know if our clinical trial designs are even appropriate to evaluate their approaches." Dr. Dhonden was not present at the Procultura conference to share his perspective.
Methodological flaws aside, the trial is the first attempt by an academic medical center to study a comprehensive system of alternative care, rather than a specific treatment modality. Instead of having allopathic doctors test a one-size-fits-all Tibetan formula , the protocol tried to give Dr. Dhonden freedom to make his own diagnoses and prescribe formulas he believed would benefit patients.
Eliot Tokar, one of a very few Americans trained in Tibetan medicine by leading practitioners, including Dr. Dhonden, believes the UCSF trial did not go nearly far enough in this regard.
"The term 'cancer' specifically defines the etiology and treatment of this illness as understood within the constraints of allopathic theory. Tibetan medicine has a wholly different theory and differential diagnosis for illnesses that result in tumor growth. Forcing Tibetan doctors to think in allopathic medical terms … and studying Tibetan medicine as a possible miracle cure for fourth-stage breast cancer does little to increase our understanding," he said.
Dr. Tripathy is beginning to look at the biochemical constituents in some of Dr. Dhonden's herbal formulas. But he also acknowledged that how these plants are traditionally used—in a highly individualized way—is as important as what "active ingredients" they contain.
"Many forms of traditional medicine have recognized the need for individualized treatments. It is only now that we (oncologists) are starting to understand, on a genetic and molecular level, that treatment of cancer must be individualized even if two tumors look the same on the surface. The field of herbal medicine is way ahead in this respect."
Though this intercultural encounter at UCSF was clearly interesting for all parties involved, it remains a question whether any truly useful knowledge emerged, either for the further evolution of Tibetan medicine, the enrichment of American medicine, or the betterment of patient care.