Global oncofertility index-data gap slows progress.

The number of pediatric and young adult cancer survivors is increasing globally due to earlier diagnostics and expansion of targeted chemo- and biological-based therapeutics. As a consequence, cancer-related infertility and reproductive hormone loss is of increasing concern for both male and female survivors. We attempted to estimate the reproductive loss in oncofertility-practicing countries and to develop a global oncofertility index (OFI). This would allow an accounting of the level of urgency of the issue and would provide national comparisons of fertility loss, which differ based on the prevalence and/or diagnosis frequency and treatment variables by countries or region. While the goal is laudable, an index such as this is unachievable due to the lack of the kind of information that would be necessary to calculate such a meaningful index. Without this metric, we will be unable to assess how oncofertility concerns are being addressed and what lessons can be learned from countries that improve such an index over time.