Change is complex: rethinking research on psychosocial interventions and cancer.

The widely discussed 1989 study by Spiegel and colleagues, which suggested that a psychosocial group intervention affected survival in metastatic breast cancer, was not replicated by Goodwin and colleagues in 2001. We analyze methodological issues in both studies, including issues of sampling, randomization, interpretation, and the adequacy and validity of psychosocial constructs and measures to assess hypothesized ingredients of change. The notion of psychogenicity is introduced, conceived as the ability of psychosocial interventions to elicit changes hypothesized to be linked to desired medical outcomes. These considerations lead to the conclusion that there is insufficient evidence to be able to generalize from either study for or against the notion that psychosocial interventions can affect survival in breast cancer. The failure to incorporate into research designs a comprehensive understanding of how coping patterns and related factors may interact with psychosocial interventions to influence cancer progression, and to address hypothesized mediating mechanisms is discussed. Finally, strategies are proposed for future biopsychosocial and intervention research in the field of biopsychooncology.