Among 598 trials published between 2003 and 2018, only 107 had a female corresponding author, though women made up anywhere from 27% to 39% of academic oncologists during this time period.
Fewer than one in 10 oncologic randomized clinical trials published between 2003 and 2018 had a female corresponding author, according to a study in JAMA Oncology.
Of the 598 trials included in the study, only 107 (17.9%) had a female corresponding author, a rate lower than the percentage of female academic oncologists in this period, which ranged from 27% in 2000 to 39% in 2015.
“Through identification of the factors associated with gender disparities in randomized clinical trial leadership, we hope that the academic oncology community will work to better understand and address the underlying reasons for such imbalances,” wrote study author Ethan B. Ludmir, MD, of the University of Texas MD Anderson Cancer Center in Houston, and colleagues.
Among the factors identified was a lower rate of female corresponding authors among industry-funded trials (14.4% vs 30.1%; P<.001), and trials of gastrointestinal, genitourinary, and hematologic malignancies.
There were higher rates of female corresponding authors found for cooperative group trials (25.9% vs 14.3%; P=.001) and for trials of breast and head and neck cancers.
“The primary modality tested also correlated with female corresponding authorship, with higher rates for radiotherapy and supportive care trials and no female corresponding authors for surgical trials,” the researchers wrote.
Additionally, geographic location was also associated with female corresponding authorship. Higher rates occurred in the United States (22.5%) than for Canada (20%), Europe (12%), and Asia (2.3%).
The researchers did find that the rate of female corresponding authorship was increasing at an estimated 1.2% annually.
One of the limitations of the study was the use of ClinicalTrials.gov as a data source.
“The mandate of ClinicalTrials.gov has shifted somewhat since its debut in 2000,” Ludmir and colleagues wrote. “Older trials, trials that do not use systemic therapy, and trials without enrollment in or affiliation with the United States may be underrepresented. With that in mind, analyses by treatment modality and country/world region should be interpreted with caution.”
Commenting on the study, Julie K. Silver, MD, of Harvard Medical School, Boston, told Cancer Network that the study highlights an important issue regarding the inclusion of women among lead investigators of oncology trials.
“The underrepresentation of women physicians and scientists may affect their own career advancement, but more importantly this may affect scientific discovery and patient care,” Silver said. “Women physicians and scientists provide an enormous brain trust that is key to unlocking the biology of disease.”
Reshma Jagsi, MD, DPhil, of the University of Michigan, Ann Arbor, Michigan, who provided Ludmir and colleagues with insight on the manuscript, echoed the importance of this study, saying research led by women brings different perspectives and consideration to how sex differences might impact study outcomes.
“Understanding whether women are represented in influential positions, such as cancer clinical trial leadership, is important for a number of reasons,” Jagsi said. “Half of the talent pool entering medical school these days is female--these bright young women need role models and adequate opportunities to participate in leadership roles if society is to benefit fully from their potential contributions.
Jagsi and Jens Peter Andersen, senior researcher at the Danish Centre for Studies in Research and Research Policy, Department of Political Science, Aarhus University, Denmark, recently published a similar study, that found that papers with female lead authors were cited between 6.5% –12.6% less than papers with male authors. However, Andersen noted that this difference was driven by a few highly cited studies, and that if one took into consideration the specialty and university prestige, the difference largely disappears.
“The implication of those studies is that there is no merit-based justification for awarding fewer and smaller grants to women,” Andersen said. “We need to build systems for promotions, tenure and grants that give equal opportunity to women (and, might I add, people of color), that take into account that women on average carry the greater share of work at home, with raising families, and also with emotional labor - without taking away from the quality of their research.”