Synchronicity, multicentricity, and metachronicity of head and neck cancer.

Two hundred patients with squamous carcinoma of the head and neck were evaluated prospectively for synchronous second primary tumors. Complete head and neck examination, chest x-ray, and barium study (when indicated) revealed synchronous tumors of the upper aerodigestive tract in 24 patients (12%). Eleven patients had a second primary in the head and neck area. Nine patients had carcinoma of the lung, while four had carcinoma of the esophagus. Seven patients had a second primary outside the upper aerodigestive tract either in large bowel or prostate. During the period of this study, an additional 13 patients were seen with metachronous tumors 1-12 years after initial treatment of their index tumor. Most of these metachronous tumors were in the lung and esophagus and were noted within 1-3 years of treatment of the primary head and neck cancer. Detection of synchronous second primary is very important for prognosis and management of the index tumor, while early diagnosis of metachronous lesion is crucial in the follow-up of these patients.