We thank Lau et al1 for presenting their experience with observation after a clinical complete response (CR) to radical chemoradiotherapy in regionally advanced head and neck cancer. The issue of neck dissection after a clinical CR has been a matter of contention. Several reports have presented data for and against planned neck dissection.
The need of the hour is to identify those patients who have the highest risk of subclinical residual disease despite a clinicoradiologic CR. Nodal diameter would be one of the most important predictive factors.2 It would also be a surrogate marker for tissue hypoxia, predicting a relative resistance to radiation therapy. Signs of extracapsular extension (ECE) on clinical or radiologic examination would be another important factor that may benefit from the removal of neck nodes and their surrounding soft tissue.3 The probability of ECE would also be dependent on nodal diameter. Both diameter and ECE have a known relevance to outcomes after radiotherapy, especially in extensive nodal disease with an unknown primary site. These factors could have been better addressed in Lau and colleagues' article. Although nodal diameter was analyzed in their article as one of the possible predictors of recurrence, the categorization was not clearly mentioned. The exclusion of N3 nodes from analysis further hampers the solution to this issue, as it is an indirect measure of nodal diameter. In a study by Argiris et al,4 the outcomes after neck dissection were improved for N3 disease, but not for N2 disease, after a clinicoradiologic CR.
Agarwal JP, Mallick I, Ghosh-Laskar S, Gupta T, Budrukkar A, Murthy V. Selecting Patients for Planned Neck Dissection After Chemoradiotherapy in Regionally Advanced Head and Neck Cancer. Arch Otolaryngol Head Neck Surg. 2008;134(10):1121-1122. doi:10.1001/archotol.134.10.1121