- 期刊
The Clinical Significance of CD117(c-kit) in Gastrointestinal Stromal Tumors
CD117在胃腸道基質瘤的臨床應用和意義
摘要
GIST(gastrointestinal stromal tumor)本指一種源自胃腸道的罕見腫瘤，最近研究顯示在大部份胃腸基質瘤細胞中可見c-kit基因突變，可引起tyrosine kinase活化，即CD117病理免疫組織化學染色呈陽性反應。所以目前對GIST重新分類都以細胞CD117染色陽性爲必要條件。另外目前除手術之外，使用STI571(c-kit的kinase domain抑制劑)更成爲一治療新趨勢。對於過去病理診斷爲GIST的病人，並非都有接受CD117染色。因此我們藉由從西元1992年10月到西元2002年11月在馬偕醫院經外科手術，病理診斷爲胃腸道基質瘤的95個病例，對其病理切片重新作D117，CD34，SMA和S-100特殊免疫組織化學染色。根據染色結果分爲CD117(+)和CD117(-)兩組，分析這兩組病人和腫瘤的臨床特徵之差異，及存活率的比較，並想探究是否CD117染色陽性與否對存活率是否有所影響。並針對影響CD117(+)病人存活率的危險因子加以探討。我們的研究發現，在95個病例中，CD117染色呈現陽性只有81例佔85.2%，CD117染色呈現陰性有14例佔14.8%，與目前定義GIST爲CD117染色陽性腫瘤不同。是否尚有來自與Cajal cell非同源細胞的腫瘤，值得作進一步探討。男性病患，腫瘤發生在胃部，特殊染色CD34陽性病患易傾向CD117染色呈陽性反應。分析兩組的存活時間，CD117(+)爲68.9個月，CD117(-)爲59.3個月，但兩者並無統計上的差異，此結果表示CD117陽性與否和存活率並無關連。此外分析影響CD117(+)病人存活時間的因素，發現腫瘤直徑愈大，腫瘤若無法完全切除，腫瘤若出現轉移或複發，存活時間變短，存活率較差，這些都是統計學上有意義的因子。雖然CD117是目前診斷胃腸道基質瘤一種新的方式，但根據我們研究顯示CD117染色陽性與否並不會對存活率造成影響，此外腫瘤大小和腫瘤是否轉移，則是影響存活率的最重要的預後因子。
並列摘要
The term gastrointestinal stromal tumor (GIST) has been used to refer to the largest group of mesenchymal tumors in the gastrointestinal tract. Recent studies have demonstrated the presence in most GISTs of c-kit gene mutations that cause activation of a c-kit tyrosine kinase. The c-kit proto-oncogene protein is identfied by an immunohistochemical stain positive for CD117. GISTs have now been reclassfled so that cell-surface expression of CD117 is required for diagnosis. STI 571, an inhibitor of the kinase domain of c-kit is a newly developed therapy for GIST. We reviewed 95 cases of GI tract stromal tumors diagnosed by pathology between October 1992 and November 2002 in a single medical center. We performed immunohistochemical staining for CD117, CD34, SMA and S-100 on those specimens. The patients were grouped according to the results of the CD117 immunostaining, and the groups were compared for characteristics and survival. We also analyzed factors associated with prognosis in the CD117 positive group. Of the 95 cases, CD117 immunostaining was positive in 81 cases (85.2%) and negative in 14 (14.8%). Factors associated with a positive CD117 immunostain were male sex, gastric tumors, and a positive CD34. There was no sign (ficant difference in the survival of patients with and without CD117 (68.9 months vs. 59.3 months, F＞0.05). Significant risk factors for a poor prognosis in the group positive for CD117 included tumor size＞5cm, limited resectability, metastasis, or recurrence. In conclusion, immunostaining for CD117 has provided a new definition of GIST, separating these tumors from others of mesenchymal origin. However, in our experience, survival was not influenced by whether the tumor was positive or negative for CD117. Tumor size and tumor metastasis are the most important prognostic factors of survival in our series.