Collaborative Stage

Note: Site-Specific Factors 3-6 are used to code the presence or absence of lymph node involvement in each of 7 different levels and other groups defined by AJCC. The definitions of the levels are the same for all applicable head and neck sites. One digit is used to represent lymph nodes of a single level, with the three digits of Site-Specific Factor 3 representing lymph nodes of, respectively, Levels I-III; the digits of Site-Specific Factor 4 representing lymph nodes of Levels IV and V and the retropharyngeal nodes; the digits of Site-Specific Factor 5 representing lymph nodes of Levels VI and VII and the facial nodes; and the digits of Site-Specific Factor 6 representing the remaining Other groups as defined by AJCC. In each digit, a code 1 means Yes, the nodes are involved.

Code	Description
000	No involvement of any group: Parapharyngeal lymph nodes Parotid (preauricular, periparotid, and/or intraparotid) lymph nodes Suboccipital/retroauricular lymph nodes
100	Parapharyngeal lymph node(s) involved
010	Parotid (preauricular, periparotid, and/or intraparotid) lymph node(s) involved
001	Suboccipital/retroauricular lymph node(s) involved
110	Involvement of two groups: Parapharyngeal lymph nodes Parotid (preauricular, periparotid, and/or intraparotid) lymph nodes
101	Involvement of two groups: Parapharyngeal lymph nodes Suboccipital/retroauricular lymph nodes
011	Involvement of two groups: Parotid (preauricular, periparotid, and/or intraparotid) lymph nodes Suboccipital lymph nodes
111	Involvement of three groups: Parapharyngeal lymph nodes Parotid (preauricular, periparotid, and/or intraparotid) lymph nodes , Suboccipital/retroauricular lymph nodes
999	Unknown if regional lymph node(s) involved, not stated Regional lymph nodes cannot be assessed Not documented in patient record

CS Site-Specific Factor 6
Parapharyngeal, Parotid, and Suboccipital/Retroauricular Lymph Nodes, Lymph Nodes for Head and Neck