[Diagnosis and treatment of 39 patients with cervical lymph node metastases of squamous cell carcinoma of unknown primary origin, referred to Netherlands Cancer Institute/Antoni van Leeuwenhoek Hospital, 1979-98].

OBJECTIVE: Evaluation of diagnostic procedures and treatment results in patients with lymph node metastases of squamous cell carcinoma in the head and neck region with an unknown primary.

DESIGN: Retrospective, descriptive.

PATIENTS AND METHODS: In 1979-98, 39 patients (30 male, 9 female; mean age 59 years; range: 39-88) were treated for cervical lymph node metastases of squamous cell carcinoma with an unknown primary. According to protocol, all patients underwent ENT examination, radiodiagnostic procedures and, if possible, examination under general anaesthesia of the upper respiratory and digestive tracts. Most patients were treated by neck dissection followed by bilateral radiotherapy to the neck and to mucosal sites of suspected origin. The data were collected from medical records. The number of patients who had had no local or regional recurrence and were still alive after 5 years were calculated by the Kaplan-Meier method.

RESULTS: There was a median interval of three months (3-100 weeks) between the first symptoms and presentation in our clinic. During this period an extensive search for a primary tumour was performed. Most lymph nodes metastases (37/44; 84%) were found at level II and III. The N-stage was as follows: N1 (6), N2 (14), N3 (19). In two patients a primary tumour was diagnosed 20 and 37 months after treatment, respectively, both at mucosal sites which were not irradiated. A five-year locoregional recurrence-free interval was seen in 66%. The five-year overall survival rate was 52% and was significantly related to the extent of the cervical lymph node metastases.

CONCLUSION: Early treatment of patients with cervical lymph node metastases from an unknown primary tumour improves survival rates. Radiation therapy of the laryngo-pharyngeal axis seems effective in preventing outgrowth of an occult primary.