SEATTLE--The two studies most often cited as proof that psychological support can improve survival in cancer patients came under challenge at the annual meeting of the American Association for the Advancement of Science.
Wallace L. Sampson, MD, associate chief of hematology and oncology, Santa Clara Valley Medical Center, San Jose, Calif, and clinical professor of medicine, Stanford, argued that flaws in their methodology account for the studies' positive outcomes.
The two studies were conducted by psychiatrists. One at Stanford University, led by David Spiegel, MD, involved a group of women with disseminated breast cancer. The second, carried out by Fawzy Fawzy, MD, and his colleagues at UCLA, looked at a group of patients with stage I melanoma.
Both trials randomized patients to groups that provided psychological support in addition to their medical treatment, or to control groups that received only medical therapy.
One problem in the Stanford study, in addition to having small numbers, is that the researchers randomized significantly more patients to the treatment group than to the control group, in order to have enough patients for therapy groups, Dr. Sampson said. Equal numbers or an excess of controls is more usual.
He noted that the paper did not specify how randomization was accomplished or when assignments took place after acceptance into the study, although therapy and control groups seemed to be similar in retrospect.
"If one violates the initial randomization, one cannot rely on the results, especially if the randomization is broken for a specific reason," he said.
Dr. Sampson noted a more disquieting problem when he compared the survival findings of the Stanford study with survival statistics in national and regional data bases, particularly the National Cancer Institute's SEER data, and in studies of the natural history of breast cancer.
"The therapy group in the Spiegel/Stanford study lived as long as expected from national, regional, and other data," he said. "The control group was aberrant, in that all patients were dead by four years, whereas every other study shows that in patients at this disease stage (after metastasis has been diagnosed), about 10% are still alive at 10 years."
He cited another methodological problem: The study was originally designed to look at quality of life issues--survival was not an endpoint--and the outcome data were obtained retrospectively. "In my mind," Dr. Sampson said, "that study is simply not interpretable and should never have received the amount of publicity it got." Other studies have shown no effect of support groups on survival, he added.
The UCLA melanoma study by Dr. Fawzy and his team was prospective and did find a statistically significant difference in the survival of the therapy group compared to the control group. However, here again Dr. Sampson faulted the study because its survival data for the control group deviated widely from other data available on such patients. "When you compare their data to national data, you find that their patients who received the intervention did no better and no worse than these patients in general," he said.
SEER data show that at five years, about 90% to 95% of stage I melanoma patients are still alive and well, "and that is what their therapy group did," he said. While the therapy group followed the norm, the control group did not. Only 74% of controls were alive at six years, and this created the same validity problem for the UCLA study as this dichotomy did in the Stanford trial.
"In neither of the two studies does one find consistency with all other data reported," Dr. Sampson said. "I simply suspect these are aberrant results."