Effects of a psychosocial intervention on survival among patients with stage I breast and prostate cancer: a matched case-control study.

CONTEXT: Psychosocial factors have been linked to the development and progression of cancer and shown to be relevant in cancer care. However, the evidence that psychosocial interventions affect cancer survival is less conclusive. Few methodologically sound studies have addressed this issue.
OBJECTIVE: To investigate the effects of a 6-week psychosocial intervention on survival among patients with stage I breast and prostate cancer.
DESIGN: Matched case-control.
SETTING: 3 rural hospitals or cancer centers in central Pennsylvania. PATIENTS: 21 breast and 29 prostate stage I cancer patients (treatment group) matched with 74 breast and 65 prostate stage I cancer patients from the same hospitals who did not receive the intervention (control group). INTERVENTION: Six 2-hour health psychology classes conducted by a licensed staff psychologist. MAIN OUTCOME MEASURES: Survival time was compared between the 2 groups and with national norms.
RESULTS: The intervention group lived significantly longer than did matched controls. At 4- to 7-year follow-up (median = 4.2 years), none of the breast cancer patients in the intervention group died, whereas 12% of those in the control group died. Twice as many matched-control prostate cancer patients died compared with those in the intervention group (28% vs 14%). Control group survival was similar to national norms.
CONCLUSIONS: These results are consistent with prior clinical trials and suggest that short-term psychosocial interventions that encourage the expression of emotions, provide social support, and teach coping skills can influence survival among cancer patients. However, self-selection bias cannot be ruled out as an alternative explanation for the results. These interventions merit further consideration and research.