Combined surgery and postoperative radiotherapy for cervical lymph node metastases from an unknown primary tumour

During the 20-year period under study, 125 squamous cell carcinoma cases were detected among 234 patients with cervical lymph node metastases from an unknown primary tumour diagnosed in Slovenia. Fifty-eight patients were treated by surgery and postoperative radiotherapy, 56 of whom were eligible for follow-up and treatment evaluation.

There were six females and 50 males ranging in age from 33 to 81 years (median 56 years). Neck dissection was performed in 48 patients, while eight patients underwent extirpation of a single lymph node metastasis. On histopathological examination, disease was assessed as pN1 in six patients, pN2 in 37 patients and pN3 in 13 patients. The degree of tumour differentiation was G1 in one patient, G2 in 26 patients, G3 in 22 patients and GX in seven patients. Extracapsular tumour spread was found in 37 out of 48 examined specimens. Postoperatively, the irradiation field covered different sites of possible occult primary in 48 patients and in eight patients it was limited to the involved side of the neck. The median tumour doses were 59 and 55 Gy, respectively.

After a median follow-up of 8.6 years, a total of five (9%) primary tumours were subsequently discovered, all in the head and neck region. Twenty-three (41%) patients were alive without evidence of disease and 14 (25%) patients died due to cancer-unrelated causes. Disease-related deaths occurred in 19 (34%) patients, the cause of death being primary tumour in three patients, advanced nodal disease in 10 patients and distant metastases with no evidence of persistent tumour in the head and neck region in six patients. The 5- and 10-year disease-specific survival rates were 66% and 52%, respectively, and the overall survival rates were 52% and 22%, respectively. The patients' survival significantly correlated (P < 0.05) with extracapsular tumour spread and the extent of the irradiation field.

With acceptable toxicity, a superior control rate of neck disease and survival results favourably comparable to those reported elsewhere and obtained by a single modality approach, our study supports the use of combined therapy. In patients with a poor clinical and histopathological profile a more aggressive treatment approach exploiting chemotherapy seems to be justified.