喉頭全剔後に発生したRadiation cancerと思われる頸部食道癌2例

LATE OCCURRENCE OF ESOPHAGEAL CARCINOMA AFTER TOTAL LARYNGECTOMY

　喉頭癌のため喉頭全剔施行後10年以上経過して発生した頸部食道癌2例を最近経験したので報告する。

　Two cases of esophageal carcinoma, occurring 10 or more years after total laryngectomy, are reported.

　The first patient underwent the total laryngectomy, because of laryngeal carcinoma at the age of 53 in 1962, and recieved irradiation (4500rads) postoperatively. He was doing well for 11 years with no evidence of recurrence. In 1973, he developed progressive dysphagia, and the endoscopic examination revealed carcinoma in the cervical esophagus which was then treated with irradiation. He died, however, of cerebral vascular accident in 1974. The second patient developed laryngeal carcinoma, when he was 52 years old in 1959. He was operated on with total laryngectomy and given postoperative irradiation (the dosis was not defined). In 1976, he presented dysphagia due to carcinoma of the cervical esophagus. In 1977, blunt dissection of the esophagus and pharyngogastrostomy were performed. He died of malnutrition without demonstrable tumor at autopsy in 1977.

　The author reviewed the Japanese literature and found 32 cases (male 30, female 2), aged 50-83, with late occurence of the second carcinoma after 5 or more years of treatment of laryngeal carcinoma. The most common site of the second carcinoma was the esophagus, followed, in order of frequency, by the lung and the base of the tongue. The duration between the first and the second tumor ranged from 5 to 32 years, with a mean duration of 12.2 years.

　The reported 2 cases seemed to be radiation-induced carcinoma, but the suppression of immunological surveillance, field carcinogenesis and the multicentricity of carcinoma might also contribute to the occurence of the second carcinoma.