特殊組織型の食道癌―治療の立場から

Non-Squamous Cell Carcinomas of the Esophagus : The National Cancer Center Hospital, Tokyo, Experience

要旨　1988年から2003年までに診断・治療された食道悪性腫瘍2,370例の中で特殊組織型の治療法および治療成績について述べた．特殊組織型とはいえ，基本的には扁平上皮癌と同様に考えてTNM分類に基づき，治療方針が決定されていた．平滑筋肉腫の治療の第一選択は手術であるが，リンパ節郭清の意義は少なく，術後では遠隔転移再発に注意すべきであろう．小細胞癌では，多くの症例で治療開始時に頸部リンパ節転移または遠隔臓器転移を伴う進行した病期であり，化学療法あるいは化学放射線療法を選択するのが一般的であろう．また，切除例の中でも転移リンパ節個数の少ない症例では，長期生存例が存在していることから，症例によっては手術も選択肢の1つとなりうるものであろう．悪性黒色腫に関しては切除が第一と考えられていたが，理想的治療法は確立されていないと言える．しかし，これまでの経験より，臨床病期が比較的早期あるいは切除可能と診断されても，早期に遠隔臓器転移を来す傾向があり，現在では切除の対象ではないと考えられる．それ以外の特殊組織型食道癌の治療方針では，当面，通常の扁平上皮癌と同様に考えて対応すべきと思われる．

　Among the 2,370 patients with malignant tumors of the esophagus treated from January 1988 to December 2003 at the National Cancer Center Hospital in Tokyo, there were 28 (1.2 ％) with Barrett adenocarcinoma, 8 (0.3 ％) with adenocarcinoma of the esophagogastric junction, 17 (0.7 ％) with adenosquamous carcinoma, 1 (0.04 ％) with adenoid cystic carcinoma, 22 (0.9 ％) with basaloid-squamous carcinoma, 32 (1.4 ％) with undifferentiated carcinoma, 1 (0.04 ％) with leiomyosarcoma, 21 (0.9 ％) with carcinosarcoma, and 10 (0.4 ％) with malignant melanoma.

　The present report documents the results of our experience with those specific groups of malignant tumors.

　Surgical resection is the first choice of treatment for patients with leiomyosarcoma.

　Among patients with small cell type of undifferentiated carcinoma, many were treated with chemo or chemoradiation therapy because they were classified in the advanced stage with clinically verified cervical lymph node metastasis positive or distant organ metastasis. Surgical resections achieved long-term survival for patients with a few metastatic lymph nodes.

　Optimal treatment for patients with primary malignant melanoma of the esophagus has not been established. Surgical resection is thought to be the main approach to treatment. However, patients with malignant melanoma tended to have distant organ metastasis within a few months after surgery even though they had exhibited early stage signs of the disease. Based on the results of this study, we consider patients with malignant melanoma should be treated using a non-surgical approach.

　Treatment for patients with other specific types of malignant tumors should be performed according to the treatment strategy for those with squamous cell carcinoma.