Immunotherapy Efficacy in Male and Female Patients With Advanced Cancer

The magnitude of benefit of immune checkpoint inhibitors on overall survival for patients with advanced cancers is sex-dependent, according to a study published in The Lancet Oncology (2018;19[6]:737-746). 

Sex-related dimorphism in immune system response is well knwon, but little is known about the effect of patient sex on the efficacy of immune checkpoint inhibitors as treatment for cancer. 

Fabio Conforti, MD, European Institute of Oncology, Milan, Italy, and colleagues assessed the heterogeneity of immune checkpoint inhibitor efficacy between men and women. 

Using the PubMed, MEDLINE, Embase, and Scopus databases from inception through November 2017, researchers systematically searched for randomized controlled trials of immune checkpoint inhibitors that had available hazard ratios for death according to patient sex. Abstracts and presentations from all major conference proceedings were also included in the study. 

Authors noted the primary end point was to assess the difference in efficacy of immune checkpoint inhibitors between men and women, measured in terms of the difference in overall survival log reported in male and female study participants.

Researchers noted that a total of 7133 studies were identified, 20 of which were eligible randomized controlled trials of immune checkpoint inhibitors that reported overall survival according to patient sex. A total of 11,351 patients with advanced or metastatic cancers were included in the analysis, with the most common cancer types being melanoma and non-small cell lung cancer. 

Additionally, researchers reported the pooled overall survival hazard ratio was 0.72 in male patients treated with immune checkpoint inhibitors, compared with men in control groups. In female patients treated with immune checkpoint inhibitors, the pooled overall survival hazard ratio was 0.86, compared with women in control groups. The efficacy difference between men and women treated with checkpoint inhibitors was significant. 

“Immune checkpoint inhibitors can improve overall survival for patients with advanced cancers such as melanoma and non-small-cell lung cancer, but the magnitude of benefit is sex-dependent,” authors concluded. “Future research should guarantee greater inclusion of women in trials and focus on improving the effectiveness of immunotherapies in women, perhaps exploring different immunotherapeutic approaches in men and women.”—Janelle Bradley