咽頭表在癌に対する局所切除と治療成績—ESDの立場から

Treatment Results of Superficial Pharyngeal Cancer Treated by ESD

要旨●当院で2006年4月〜2020年4月の期間にESDを施行した咽頭癌75例102病変を対象とした．病理結果は，上皮内癌（EP）：上皮下層癌（SEP）は60：42であった．一括切除率は100%，一括完全切除率91%（93/102），深達度別ではEP群で97%（58/60），SEP群で83%（35/42）であった．偶発症については，輸血を要する術中出血は0%，内視鏡的止血術を要する後出血は1%（1/102）であった．EP群に局所再発を来した病変はなく，SEP群で2.4%（1/42）に認めた．転移再発はEP群ではなく（0/40），SEP群で35例中8例（23%）に認めた．8例中，リンパ節転移のみ5例，遠隔転移のみ2例，リンパ節転移と遠隔転移1例であった．転移部位は甲状軟骨，骨，肝，肺であった．SEP群での原病死率は全体で8.6%（3/35），ly0，v0では3%（1/30），ly1 and/or v1では40%（2/5）であった．EP群40例中20例（50%）で異時多発癌を認め，その部位は多岐にわたっていた．5年疾患特異的生存率はEP群100%，SEP群86%であった（log-rank検定，p＝0.0269）．5年全生存率はEP群100%，SEP群51%であった（log-rank検定，p<0.001）．EP・SEP咽頭癌に対するESDの短期成績は良好であり，ESDは第一選択手技と考えられた．一方EPであっても半数に異時多発癌を認めるため，全身のサーベイランスが必要である．またSEPでly1 and/or v1の場合は転移率，原病死率が高く，adjuvant chemotherapyなどの追加治療を検討すべきと考えられた．

　One hundred and two lesions in 75 pharyngeal cancer cases, treated by ESD from April 2006 to April 2020 were enrolled in this retrospective study.The invasion depth of EP（epithelial carcinoma）and SEP（subepithelial carcinoma）were 60 and 42, respectively. The en bloc and R0 resection rates were 100% and 91%（93 and 102）, respectively. R0 resection rates were 58/60（97%）and 34/42（81%）, in the EP group and SEP group, respectively. There were no incidences of intraoperative bleeding requiring blood transfusion（0%）, and 1 case（1/102, 1%）of postoperative bleeding requiring endoscopic hemostasis.There was 0% incidence of recurrent lesions in the EP group, and 2.4%（1/42）in the SEP group. Metastatic recurrence was observed in eight patients（23%, 8/35）in the SEP group, but none in the EP group（0/40）. Among the eight patients, five had only lymph node metastases, two had only distant metastasis, and one patient had both lymph node and distant metastases. Thyroid cartilage, bone, liver, and lung were the sites of metastases. The primary disease mortality in the SEP group was observed to be 8.6%（3/35）overall, 3%（1/30）in ly0v0 group, and 40%（2/5）in ly1 and/or v1 group. Multiple metachronous carcinomas were reported in 20 of the 40 patients in the EP group（50%）at various sites.The 5-year disease-specific survival rate in the EP group was 100%, and in the SEP group, it was 86%（log-rank test p＝0.0269）. The 5-year overall survival rates in the EP group and SEP group were 100% and 51%, respectively（Log-rank test p<0.001）.The short-term results of ESD for EP/SEP pharyngeal cancer were excellent, and ESD was considered the first-line procedure. Conversely, since half of the patients with EP have metachronous carcinomas, systemic surveillance is necessary. In addition, the metastasis rate and the mortality rate from the original disease are high in the case of ly1 and/or v1 in SEP, necessitating the consideration of additional treatment such as adjuvant chemotherapy.