Objectives/hypothesis: To determine if metastatic squamous cell carcinoma with proliferative potential persists in N2 and N3 necks after conventional radiation.
Study design: Retrospective case series.
Materials and methods: We identified 17 patients from our head and neck tumor database who underwent organ-preserving radiotherapy for primary aerodigestive squamous cell cancer and N2-3 regional metastasis. Archival tissue from these 17 neck specimens was evaluated for routine histopathologic evidence of tumor, as well as immunohistochemically for cytokeratin and Ki-67 activity. An assay for apoptosis was also performed on 10 of the specimens.
Results: Routine H&E evaluation suggested metastatic cancer in 11 of 17 irradiated neck specimens. Cytokeratin immunostaining confirmed squamous cell carcinoma in these 11 necks as well as 1 additional specimen that had tested H&E negative. Ki-67 staining demonstrated proliferating tumor in 3 of 17 necks. The apoptosis assay confirmed regions of apoptosis in all of the specimens analyzed.
Conclusions: The discovery of proliferating cancer cells in 3 of 17 irradiated specimens (18%) supports the practice of planned neck dissection after primary radiotherapy for patients with pretherapeutic N2+ metastatic disease.