A study has examined the level of research being performed on the intersection between cancer and mental health. Using the sub-field filters 'mental disorder' and 'cancer' to retrieve research papers from the Web of Science between 2002 and 2011, 1,463 papers were identified on this topic, representing 0.26% of cancer research and 0.51% of mental health research. These results highlight a transdisciplinary gap in health-care research that should be addressed.