STANFORD, Calif. -- Group therapy has no impact on survival in metastatic breast cancer, according to a randomized trial here that contradicted earlier findings of a significant advantage.
STANFORD, Calif., July 24 -- Group therapy has no impact on survival in metastatic breast cancer, according to a randomized trial here that contradicted earlier findings of a significant advantage.
Patients randomized to weekly group therapy sessions had a median overall survival of 30.7 months, compared with 33.3 months for those taking part in a self-directed education program, David Spiegel, M.D., of Stanford, and colleagues reported in the July issue of Cancer.
However, results varied substantially by the physical location of a treatment program, leaving room for continued examination of the association between psychosocial intervention and advanced breast cancer survival, the investigators said.
"Although the present study failed to replicate earlier findings of psychotherapy treatment effects on survival, it is clear that group psychotherapy is emotionally beneficial for metastatic breast cancer patients," said Dr. Spiegel and colleagues.
It was Dr. Spiegel's own research that first revealed in 1989 an unexpected 18-month survival advantage for psychosocial treatment on emotional outcomes in breast cancer compared with women who received standard supportive care. The work also demonstrated a favorable impact on mood, coping, and pain.
Subsequently, four additional published studies demonstrated improved survival in cancer patients who received psychosocial therapy. However, those results were offset by six other published studies that showed no cancer survival benefit associated with psychosocial intervention. Meta-analyses and systematic reviews yielded similarly disparate results.
Dr. Spiegel and colleagues undertook the current study to replicate the survival advantage demonstrated in their original study. They randomized 122 women with metastatic breast cancer and three with locally advanced disease to weekly 90-minute sessions of supportive-expressive group therapy, plus educational materials, or to the educational materials alone.
According to the investigators, the psychosocial intervention was designed "to build new bonds of social support, encourage expression of emotion, deal with fears of dying and death, help restructure life priorities, improve communication with family members and healthcare professionals, and enhance control of pain and anxiety." The group therapy was offered at three locations: in San Francisco, Stanford, and San Jose, Calif.
Complete follow-up data were available on all 125 patients. Overall survival was 32.8 months and did not differ between treatment groups. A planned site-by-condition interaction analysis revealed significant variation in results by intervention site.
The San Francisco and San Jose results offset each other. In the San Francisco cohort, the control group had a median survival of 18.4 months compared with 51.0 months for the intervention group (P=0.12; 95% CI 6.8-30.0 for control and 2.6-99.3 for intervention). At the San Jose site, the control group had a median survival of 70.6 months versus 29.8 months for the intervention arm (95% CI 13.9-127.2 for control and 26.0-33.5 for intervention). At Stanford the controls had a median survival of 32.8 months compared with 28.4 months for the intervention arm.
Analysis of baseline characteristics revealed significant differences by site and site-by-condition interactions. The three groups differed significantly across sites (but not control versus intervention) with regard to age, education, and hours worked per week. Statistically significant site-by condition interaction existed for disease-free interval and dominant location of recurrence or metastasis.
A post hoc analysis revealed a significant impact of intervention according to estrogen receptor status (P=0.002). Among patients with ER-positive cancer, median survival was 42.5 months in the control group and 30.7 months in the treatment group. In contrast, ER-negative patients randomized to the intervention had a median survival of 29.8 months compared with 9.3 months in control patients, a difference similar to that observed in Dr. Spiegel's original study.
"Although it is possible that psychosocial effects on survival are relevant to a small subsample of women who are more refractory to current hormonal treatments, further research is required to investigate subgroup differences," the authors concluded.