食道癌手術症例にみられる他臓器重複癌―EMR 症例も含めて

Multiple Primary Cancer in the Esophagus and Other Organs

　食道癌と他臓器重複癌は食道癌1,317例の約30％に認められる．90％以上が二重複癌であったが三重複癌以上の多重複癌が約9％に認められた．相手臓器として頭頸部癌が最も多く約40％，次いで胃癌が26％，大腸癌が11％であった．食道癌外科的根治術例335例では63例18.8％に，EMR例348例では110例31.6％に重複癌が認められた．外科的根治術例で重複癌の頻度が低いのは他臓器重複癌が根治可能のときのみ外科手術が施行されるためと思われた．また，外科的根治術例では同時性重複癌が8.3％であるのに比べ，異時性重複癌が10.4％と多く，食道癌術後に発生したものが多かった．食道癌も治る癌の仲間入りをしたようである．頭頸部癌との重複癌では下咽頭癌36.0％と最も多く，次いで舌癌22.7％，喉頭癌14.0％であった．頭頸部癌のスクリーニングで1,320例から食道癌は165例12.5％発見されているが，同様に下咽頭癌が35.8％，舌癌が23.0％を占めた．頭頸部癌で発見された食道癌の85％が表在癌であった．

　Among 1,317 esophageal cancers in our hospital,30％ of them were found to have other primary cancers besides esophageal cancer. 90 ％ of these patients had double cancers and 9 ％ of them had triple or more cancers. The location of the other cancer is most frequently found in the head and neck (40 ％) followed by stomach (26％) then colon (11％).

　These multiple primary cancers were only found in 63 (18.8％) of 335 surgically operated cases, while they were found in 110 (31.6％) of 348 EMR treated cases. The low frequency of multiple primary cancer in the former cases might be attributed to the indication of operation limited to only the curable cases of the other cancer. The esophagectomy cases include synchronous multiple cancers in 8.3 ％ and metachronous multiple cancers in 10.4％, which shows a predominance in postoperative development. Esophageal cancer seemed to be eligible for inclusion in the category of curable diseases.

　Multiple head and neck cancer with esophageal cancer included hypopharyngeal cancer in 36.0 ％, followed by tongue cancer in 22.7％, then laryngeal cancer in 14.0％. By screening 1,320 head and neck cancer patients, esophageal cancer was detected in 165 cases (12.5％), but hypopharyngeal cancer and tongue cancer were detected in 35.8 ％ and 23.0 ％ respectively. 85％ of esophageal cancers detected in head and neck cancer patients were superficial cancers.