Objective: To perform a number to treat analysis for planned neck dissection after organ preservation protocols (OPPs) in N2-3 neck disease for head and neck cancer.
Methods: We performed a literature review from 1993 to the present and collected aggregate data to produce the following four variables: (1) percentage of N2-3 necks still harbouring cancer after radiotherapy in OPPs (C); (2) percentage of regional recurrence after planned neck dissection (P); (3) unsuccessful salvage rate in patients in whom a watch and wait strategy for neck disease was employed (S); and (4) the mortality rate of planned neck dissection (M). The number to treat can be estimated as 1/((C x S + C x M) - (P + M)) RESULTS: The number to treat in this analysis was 4.4.
Summary: In organ preservation therapy with N2-3 disease, one needs to perform 4.4 neck dissections to prevent one fatal regional recurrence. Although this calculation does have some inherent biases and errors, it may form the basis for an informed discussion with patients faced with the option of planned neck dissection.