Radiotherapy and cisplatin in metastatic squamous cell carcinoma of an unknown primary tumor localized to the neck. A phase II study.

13 male and 8 female patients with metastatic squamous cell carcinoma (SCC) of an unknown primary tumor localized to the neck were treated with radiotherapy (RT) and cisplatin (CDDP). There were 12 (58%) and 9 (42%) patients, while no patient had N1 disease. All patients underwent biopsy. RT was given to all possible sites of the primary tumor (nasopharynx, pyriform sinus, and the base of the tongue). The RT dosage planned for the whole neck or supraclavicular area was 45 Gy, increasing to 60-70 Gy on the metastatic site. CDDP was given at a dose of 30 mg/m2, once weekly during the RT course. We observed 15 (72%) complete responses (CR) and 3 (14%) partial responses, while 3 (14%) patients did not respond to therapy. 12 (58%) patients are with no evidence of disease (NED) currently. The median survival time was 34+ months (range, 18+ to 50+ months). We observed two groups of toxicities: gastrointestinal and kidney toxicity. The majority of patients experienced grade 3 (RTOG) toxicity and no patient experienced grade 4 toxicity. This treatment appears to be effective and suitable for patients with metastatic SCC of an unknown primary tumor localized to the neck.