An Evaluation of Sex- and Gender-Based Analyses in Oncology Clinical Trials

Background The objective of this study was to evaluate whether sex- and gender-based analyses and proper sex and gender terminology were used in oncology trials leading to regulatory drug approval. Methods The Food and Drug Administration (FDA) Hematology/Oncology Approvals and Safety Notifications page was used to identify all anticancer therapies that received FDA approval between 2012 and 2019. The trials used to support FDA drug approval were collected along with all available supplemental tables and study protocols. Documents were reviewed to determine if there was a plan to analyze results according to sex and gender and to determine if consistent sex and gender terminology were used. Results We identified 128 randomized, controlled trials corresponding to a cancer medicine, which received FDA approval. No study specified how sex and gender were collected or analyzed. No study reported any information on the gender of participants. Sex and gender terminology were used inconsistently at least once in 76% (97 of 128) of studies. Among the 102 trials for nonsex-specific cancer sites, 89% (91 of 102) presented disaggregated survival outcome data by sex. No study presented disaggregated toxicity data by sex or gender. Conclusion The majority of pivotal clinical trials in oncology fail to account for the important distinction between sex and gender and conflate sex and gender terminology. More rigor in designing clinical trials to include sex- and gender-based analyses and more care in using sex and gender terms in the cancer literature are needed. These efforts are essential to improve the reproducibility, generalizability, and inclusiveness of cancer research.