Node counts in neck dissection: are they useful in outcomes research?

OBJECTIVES: We studied the unilateral nodal yields for procedures reported as standard or modified radical neck dissection (RND) to determine their applicability in outcomes research.
METHODS: We analyzed the unilateral nodal yields for all procedures reported as RND for carcinoma of the oral cavity, pharynx, and larynx at our institution from 1985 to 1997 (n = 64, no prior treatment). These included both standard and modified techniques, encompassing levels I through V of the neck. Each side of a bilateral RND was treated as a separate case. This sample was compared with a similar population from the National Cancer Institute's Surveillance, Epidemiology, and End-Results (SEER) registry. Nodal yield was obtained for RND alone and for unspecified neck dissection with primary excision for the same diseases and time period (n = 1499).
RESULTS: The mean nodal yield from 64 RND was 30 vs 27 in the SEER data. The standard deviation was 14.7 compared with 17.2 in the SEER data. Values ranged from 7 to 66 nodes whereas the SEER range was from 1 to 97 nodes. Although the SEER data contain nodal yields from regional or selective neck dissection, we corroborate our findings of large variance in nodal yield from our RND sample.
CONCLUSIONS: Large variance in nodal yields from RND may have undefined effects on quality of life, cure rate, and survival. Until correlation of nodal yields with outcomes is examined, we cannot know how to relate RND to outcomes.