食道m3・sm1癌内視鏡切除後の経過

Clinical Course of Esophageal Cancer with Invasion of the m3 and sm1 after EMR

要旨　EMRを施行した食道m₃・sm₁癌46例50病巣を対象として，局所再発や多発癌の頻度，リンパ節転移・再発の診断精度と治療について検討した．局所再発は4病巣（8.0％）に認め，高度なまだら不染の症例や，食道裂孔ヘルニアがない腹部食道の症例に多かった．多発癌は13例（28％）に認められ，全例EMRで治療した．主病巣および多発病巣を含め，局所コントロールが不能な症例はなかった．46例中4例（8.7％）にリンパ節転移，再発が明らかとなっている．これまでのところ原病死はないが，リンパ節転移例を厳密に事前に振り分けることは困難であり，経過観察に重点を置く必要がある．経過観察は6か月ごとに通常内視鏡，EUS，CT，頸部・腹部USをセットにして行うのが効果的で，早期診断を目指すならばEUSは必須である．EMR単独治療例の重点経過観察期間は1年6か月で，CRT追加例では再発時期が遅くなる傾向があるため4年以上の経過観察が必要である．これまでの経験から転移リンパ節は，画像診断で検出可能な大きさになると急速に増大する傾向がある．早期診断のためには，気になるリンパ節が描出されたら経過観察の間隔を3～4か月にせばめ，経時的変化を捉えることが重要である．

　We examined the incidence of local recurrence and multiple cancers, the diagnostic accuracy of lymph-node metastasis and nodal recurrence, and treatment regimens in 46 patients (50 lesions) who underwent endoscopic mucosal resection (EMR) for m₃・sm₁ esophageal cancer. Local recurrence occurred in 4 lesions (8.0％) and was most often associated with multiple spotty iodine-unstained areas in the esophagus or with cancer of the abdominal esophagus without hiatal hernia. Multiple cancers were diagnosed in 13 patients (28％), all of whom were treated by EMR. Local control of primary and multiple lesions was achieved in all patients. Of the 46 patients, 4 (8.7％) were found to have lymph-node metastasis or nodal recurrence. As of this date, no patients have died of their disease, but it is difficult to identify patients with lymph-node metastasis in advance, so close follow-up is mandatory. Effective follow-up programs should include a set of diagnostic studies, i. e., conventional endoscopy, EUS, CT and neck and abdominal ultrasonography, performed at 6-month intervals. EUS is essential for early diagnosis. Patients treated by EMR alone should be followed up intensively for 1 year and 6 months. Patients who additionally receive chemoradiotherapy have a risk of late recurrence and should therefore be followed up for at least 4 years. Our experience indicates that lymph-node metastases tend to grow rapidly once they reach a size detectable in diagnostic imaging studies. If suspicious-looking lymph nodes are detected in diagnostic imaging studies, the interval between follow-up studies should be shortened to 3 to 4 months to facilitate early diagnosis. Changes in lymph nodes should be assessed over time.