A recent study found that 29% of breast cancer clinical trials are not comprised of control arms consistent with the current standard of care, published in the Journal of the National Comprehensive Cancer Network (September 2017;15:1131-1139).
In order for clinical trials to be considered scientifically and ethically sound, comparison with the best existing alternative treatment is critical.
Rachel F Dear, MBBS, PhD, Sydney Medical School, University of Sydney (Australia), and colleagues reviewed the care provided to patients in control arms of breast cancer clinical trials in an effort to estimate the consistency with the standard of care in clinical guidelines. Researchers analyzed 210 phase III randomized controlled breast cancer trials that recruited 229,182 women worldwide. The trials compared drug treatment with “standard care” options.
The primary outcome was the proportion of trials in which treatment in the control arm was consistent with current National Comprehensive Cancer Network (NCCN) guidelines. A secondary analysis compared trials outside of the US that provide group therapy not consistent with NCCN guidelines against the German Gynecological Oncology Group (AGO) guidelines.
Results of the analysis showed that 29% of the trials (n = 60) was not comprised of a control treatment group consistent with NCCN guidelines. Similar results were observed in the secondary analysis; twenty-one percent of trials not recruiting in the US were comprised of control treatment arms inconsistent with both AGO and NCCN guidelines.
Among the factors significantly associated with control treatment arms not consistent with guidelines were time period, breast cancer stage and type, recruitment outside of the US, and recruitment in at least four different countries.
Researchers concluded that to provide assurance that clinical trials achieve their goal of obtaining optimal information to guide patient treatment, a closer examination of standard of care for control arms is warranted. “Inconsistency of choice of control arm undermines the quality of evidence generated by clinical trials, which in turn impacts systemic reviews, the development of clinical practice guidelines, planning of future trials, and, ultimately, patient care and outcomes,” Dr Dear said in a press release (September 27, 2017).—Zachary Bessette