The NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines) for Distress Management have, since 1997, called for routine screening of distress in patients with cancer. Following the example of pain as the fifth vital sign, the case for using the concept of distress as the sixth vital sign was made by leading psycho-oncologists in 2007. Cancer care organizations in Canada and the International Psycho-Oncology Society have adopted the NCCN Guidelines for Distress Management and have named distress screening as the sixth vital sign, thereby encouraging cancer care clinicians to think of screening for distress when they screen for pain and other vital signs. Using the evidence integration triangle, this article explores the dissemination of the notion of distress as the sixth vital sign in an international context. This exploration shows that NCCN and similar organizations can adopt the evidence integration triangle in its next phase of moving toward full implementation of the NCCN Guidelines for Distress Management.