Existential and meaning-based interventions aimed at enhancing quality of life and spiritual well-being of patients with advanced cancer are among the most pressing needs for optimal supportive and palliative care.4,5
Our group has developed, refined, and pilot-tested IMCP to address this need.7
We initially focused on a group format for this intervention. However, it became clear that high rates of attrition and missed sessions necessitated a more flexible, individual format. This study represents our initial attempt to evaluate the effectiveness of an individual-format, meaning-based intervention in improving quality of life and spiritual well-being.
These results provide evidence that IMCP is effective in improving spiritual well-being, a sense of meaning, overall quality of life, and physical symptom distress in patients with advanced cancer. For many of the outcome variables (spiritual well-being, quality of life, and physical symptom distress), the improvements observed for IMCP patients at the post-treatment assessment were significantly stronger than those observed in our control condition (TM). Although no significant differences in treatment effects were observed at the 2-month follow-up assessment, most of the significant post-treatment findings were echoed in the mixed models analyses that included all three time points. Attrition was also substantially less in this study of IMCP, because 66% of participants completed all seven treatment sessions compared with only 29% of participants in our MCGP trial.7
These results replicate and extend the findings of our randomized, controlled trial of a group format of MCGP in patients with advanced cancer but with markedly lower attrition rates.7
The consistency of these findings across the two studies provides evidence that Meaning-Centered Psychotherapy, whether in an individual or group format, is an effective intervention for existential distress in patients with advanced cancer, despite having less impact on symptoms of anxiety or depression.
We compared IMCP with TM to control for time and attention. Past studies have suggested that TM enhances psychological well-being and reduces symptom distress, but little improvement was evident for TM participants in this study. This null finding for TM may reflect the timing of our post-treatment assessments, because studies of TM have typically assessed patients 24 to 48 hours after treatment rather than 7 weeks later.20
However, it is also possible that TM was helpful in that patients did not worsen. Without treatment, the trajectory of psychological distress and quality of life in patients with advanced cancer may decline. Future research should include a no-treatment condition to analyze the trajectory of distress in patients with cancer who have not been treated.
The possibility that psychological well-being deteriorates over time without intervention might also explain the somewhat weaker treatment effects observed at the 2-month follow-up assessment, because IMCP participants showed some attenuation in the improvements made during treatment (ie, smaller within-group effect sizes). However, the mixed models analysis suggests that the attenuation in treatment effects was modest. Nevertheless, the lack of significant improvements at the follow-up assessment in this study differs from our findings with MCGP,7
in which improvements were stronger 2 months post-treatment. The differences between our IMCP and MCGP studies may reflect unique benefits of a group-based intervention in this population.
This study has several limitations. As is true of many intervention studies focusing on patients with advanced cancer, we encountered difficulties in recruitment and attrition, resulting in a modest sample of well-educated patients who were willing to participate in a randomized clinical trial (limiting generalizability). Sample size limitations also hindered our statistical power, because our sample was roughly half as large as recommended by our a priori power analyses. Thus, despite observing substantial within-group effect sizes for many variables in the IMCP arm that indicated clinically significant improvement for IMCP participants, some between-group differences were not statistically significant. Likewise, sample size limitations and the unequal allocation of patients to therapists (one therapist treated 43 participants, and the remaining 21 IMCP participants were divided among three different therapists) hindered analysis of whether some IMCP therapists were more effective than others or whether particular patient characteristics predicted treatment response. Therapists were also confounded with treatment arm because trained massage therapists conducted TM and psychologists conducted IMCP. Treatment adherence was methodically assessed; however, the inter-rater reliability of adherence ratings was not evaluated. Finally, because study participation was not contingent on having a requisite level of distress, participants with relatively little distress had less opportunity to improve following intervention than those with more distress.
Despite these limitations, this pilot randomized controlled trial provides preliminary support for the efficacy of IMCP in enhancing spiritual well-being, a sense of meaning, and overall quality of life and reducing physical symptom distress in patients with advanced cancer. The need for empirically supported interventions for patients struggling with existential distress and end-of-life despair has been widely acknowledged, and this study provides support for IMCP as a means to accomplish this important goal.