Association between pharmaceutical involvement and outcomes in breast cancer clinical trials.

BACKGROUND

Since 1992, pharmaceutical industry support has surpassed National Institutes of Health funding for clinical research in the United States. In this study, the authors sought to evaluate the impact of this shift in funding from public to private sponsors on the nature of published breast cancer clinical research.

METHODS

All published breast cancer clinical trials from 2003, 1998, and 1993 were reviewed from 10 select English-language medical journals to evaluate pharmaceutical involvement over time and the association between sponsorship, trial design, and results. Clinical studies that reported disease-specific outcomes from medical therapy for breast cancer were eligible for analysis. Pharmaceutical involvement was defined as reported pharmaceutical industry funding, provision of drug, and/or authorship for each publication.

RESULTS

In total, 140 eligible studies were identified, including 45 studies that were published in 1993, 39 studies that were published in 1998, and 56 studies that were published in 2003. Among those, 67 publications (48%) reported pharmaceutical industry involvement, 36 publications (26%) had at least >/=1 pharmaceutical industry author, And 100 publications (71%) were considered positive. Pharmaceutical involvement was identified in 44% of the studies published in 1993, in 38% of the studies published in 1998, and in 58% of the studies published in 2003. Pharmaceutical authorship was reported in 22% of the 1993 studies, in 21% of the 1998 studies, and in 34% of the 2003 studies. For studies that were published in 2003, those that reported pharmaceutical involvement were more likely to be positive (84% vs 54%; P = .02; Fisher exact test), to be single-arm studies (66% vs 33%; P = .03), and to evaluate metastatic disease (72% vs 46%; P = .06).

CONCLUSIONS

Pharmaceutical involvement in published clinical breast cancer research may affect study design, focus, and results. Further research is warranted, including analysis of unpublished studies, to evaluate the impact of increasing pharmaceutical industry involvement on clinical research.