Two decades of advances in clinical oncology - lessons learned and future directions.

Since the publication of the first issue of Nature Reviews Clinical Oncology, we have witnessed advances in multiple research areas that have culminated in improved outcomes for many cancer types, although substantial unmet needs remain for a majority of patients worldwide. Here, we have asked experts in several key specialities to reflect on the progress from the past 20 years and propose the next steps to enable further advances. Although we are aware that this Viewpoint cannot provide full coverage of the vast field that is clinical oncology, we hope that these messages inspire a diverse range of readers.