Cancer immunotherapy using checkpoint inhibitors may achieve greater mortality reductions in men than they do in women, new research has suggested.
In a meta-analysis and systematic review published in Lancet Oncology, researchers analyzed 20 randomized, controlled trials of immune checkpoint inhibitors that included detail on overall survival and patients’ sex; altogether, these studies involved 11,351 patients with advanced or metastatic cancers.
They found that while men treated with checkpoint inhibitors had a significant 28% reduced risk of death, compared with male controls, the survival benefit in women was smaller (14% reduced risk of death, compared with female controls).
Fabio Conforti, MD, from the European Institute of Oncology, Milan, and coauthors commented that the magnitude of the difference between the effect seen men and that in women was clinically significant.
“The pooled reduction of risk of death was double the size for male patients than for female patients – a difference that is similar to the size of the difference in survival benefit observed between patients with non–small cell lung cancer with PD-L1 positive (greater than 1%) tumors versus negative tumors, who were treated with anti-PD-1,” they wrote.
This difference between the benefit seen men and that in women was evident across all the subgroups in the study, which included subgroups based on cancer histotype, line of treatment, drugs used, and type of control.
However there was greater heterogeneity in the magnitude of the effect of checkpoint inhibitors on mortality in men than there was in women. The authors suggested this could be explained by the fact that the drugs have lower efficacy in women and this may therefore reduce the variability of results when compared with those in men.