ASCO engages in the endorsement and adaptation of clinical practice guidelines to recognize the high-quality work of other guideline-developing organizations, to avoid duplication of effort, and to offer harmonized recommendations across guideline development groups. ASCO develops guidelines in accordance with the principles of the National Academy of Medicine and Council of Medical Specialty Societies. Guidelines developed in a similar manner by other organizations make endorsement by ASCO more likely. If allowed by the partnering organization, ASCO may consider an adaptation of a guideline, building on the original guideline with further inquiry or modifications. Organizations seeking ASCO endorsement consideration are provided with ASCO's endorsement and adaptation procedures at the time of endorsement submission They can request either Endorsement or Endorsement or Adaptation. ASCO endorsement entails a formal review by an independent ASCO Expert Panel, and, if modifications to the recommendations are made, depending upon the original endorsement request, guidelines will be adapted or discontinued, rather than endorsed. The process begins with approval from ASCO's Clinical Practice Guideline Committee (CPGC) leadership to proceed with endorsement development. An ASCO Expert Panel of approximately 10 multidisciplinary content experts, patient representatives, community oncologists, and relevant health providers is formed to develop an ASCO endorsement. ASCO's Conflict of Interest Policy Implementation for Clinical Practice Guidelines and procedures apply to all ASCO expert panels. The CPGC reviews and approves all ASCO guideline products on behalf of ASCO. The endorsement process described in this report is designed to preserve a high-quality and resource-efficient approach for potential ASCO endorsement or adaptation of guidelines developed by other health professional organizations, while maintaining the objectivity, quality, and high standards reflective of ASCO's guiding principles.