Squamous cell carcinoma metastatic to cervical lymph nodes from unknown primary origin: the impact of chemoradiotherapy

The management of cervical lymph node metastases of squamous cell carcinoma from an unknown primary site is still a therapeutic challenge. We report here our experience in treating these patients with chemoradiotherapy as a curative approach. Data from 40 patients were reviewed. In total, 20 (50%) patients underwent excisional biopsy. All patients underwent radiotherapy, which was delivered to both sides of the neck and pharyngeal mucosa (extensive field), and concurrent chemotherapy consisting of weekly cisplatin at a dose of 40 mg/m(2). The clinical stage of the cervical nodes at presentation was N1 in 25%, N2 in 60%, and N3 in 15%. Most patients (75%) developed at least grade 3 mucositis. Eight patients (20%) had grade 3 xerostomia and 18 patients (45%) required esophageal dilation for stricture. The 5-year overall survival(OS) rate of all patients was 67.5%. The 5-year OS rates of patients with N1, N2, and N3 lesions were 100%, 67%, and 41%, respectively (P = 0.046). The 5-year progression-free survival rate was 62.5%. In multivariate analysis, only N stage significantly affected OS(P = 0.022). Emergence of the occult primary was very limited (1 patient only). Our results suggest that extensive irradiation of both sides of the neck and pharyngeal mucosa with concurrent chemotherapy results in a lower emergence of primary tumor. Because the survival of patients with unknown primary is comparable to that of patients with known primary, an attempt at cure should always be made.