特殊組織型の食道癌―治療の立場から

Non-Squamous Cell Carcinoma of the Esophagus

要旨　食道悪性腫瘍2,521例のうち特殊組織型の治療法について述べた．扁平上皮癌2,448例（97.1％）を対象として特殊組織型の治療成績について比較検討した．特殊組織型の内訳は腺癌36例，腺扁平上皮癌2例，腺様嚢胞癌4例，類基底細胞癌4例，未分化癌17例，悪性黒色腫4例である．小細胞癌の予後は悪く，深達度smまででリンパ節転移のないものが切除の対象となりうるが，大部分の症例は予後が悪く化学療法中心の治療が行われている．悪性黒色腫は可能な限り切除を行っているが，症例数が少なく抗癌剤の効果については不明である．その他の癌は病期別の成績では扁平上皮癌とほぼ同等であり，扁平上皮癌と同様な治療をしている．

　In a series of 2,521 patients with esophageal malignant neoplasms treated between 1981 and 2003, specific type cancers presenting with a non-squamous cell carcinoma (non-SCC) were seen in 73 patients (2.9 ％). Treatment results of non-SCCs were compared with those of squamous cell carcinoma (SCC ; n＝2,448 ; 97.1 ％) in this study. Non-SCCs consisted of adenocarcinoma (n＝36 ; arising from Barrett's esophagus in 17 cases, and from ectopic gastric mucosa in 6 cases, and others), adenosquamous carcinoma (n＝2), adenoid cystic carcinoma (n＝4), basaloid carcinoma (n＝4), undifferentiated carcinoma (n＝17), carcinosarcoma (n＝6) and malignant melanoma (n＝4).

　In patients with undifferentiated carcinoma, those with small cell carcinoma had an extremely poor prognosis. Surgical resection was indicated for cases in which the depth of invasion was limited to the submucosa without metastasis to the lymph nodes, but most patients were treated mainly with chemotherapy due to the advanced clinical stage of their carcinomas.

　Regarding malignant melanoma, surgical resection was undertaken for as many patients as possible, because chemo- and/or radiotherapy were thought to be ineffective against malignant melanoma. The true impact of chemotherapy on malignant melanoma is not known with certainty due to the shortage of cases.

　Treatment for other non-SCCs is performed according to therapeutic strategies similar to those of SCC, because treatment results stratified according to clinical stages are almost equivalent to those of SCC.