Permalink : http://hdl.handle.net/2115/63412

KEYWORDS : Oral cancer;Squamous cell carcinoma;Multiple primary cancer;口腔癌;多発癌;扁平上皮癌

1984年１月から2011年12月までの27年間に当科で治療を行った口腔扁平上皮癌一次症例373例のうち，口腔内多発癌と診断した22例を対象に臨床的検討を行った．発生時期は同時性3例，異時性10例，同・異時性が９例であった．部位別では頰粘膜，下顎歯肉，舌，上顎歯肉に多く発生していた．第１癌から第２癌までの発生間隔は平均80.6か月，第２癌から第３癌までの発生間隔は平均82.5か月であった．治療法は主に手術を主体とした治療が行われていた．局所再発は50.7％，頸部リンパ節転移は59.1％にみられた．病因特異的累積生存率は５年で81.8％ であったが，10年では50.3％であった．口腔内多発癌は発生間隔が長いだけでなく，局所再発，リンパ節転移が多いため長期にわたる経過観察が必要であり，早期発見だけではなく，より良い口腔内環境を維持しできるだけ発症を抑制させる様な予防策も念頭において治療を行っていく必要がある．
In this study 22 patients with multiple primary oral cancers (out of 373 oral squamous cell carcinoma) were observed. These patients were treated at Oral Surgery of Hokkaido University Hospital from 1984 to 2011. 3 synchronous, 10 metachronous and 9 synchro-metachronous carcinomas were observed. The buccal mucosa, lower gingiva, tongue, upper gingiva were seen frequently. The mean interval between the first and the second carcinomas was 80.6 months, while that between the second and third carcinomas was 82.5 months. 　Surgical treatment was performed for most cases. Local recurrence rate was 50.7% and cervical lymph node metastasis rate was 59.1%. The 5-year and the 10-year disease-specific cumulative survival rate were 81.8% and 50.3%, respectively. The long developmental period, high local recurrence and regional metastasis indicate the necessity of a long term followup and maintenance of good oral environment to inhibit tumor pathogenesis.