[Study on clinicopathologic parameters of malignant behavior in gastrointestinal stromal tumors].
OBJECTIVE
To determinate the clinicopathologic parameters in predicting the malignant behavior of gastrointestinal stromal tumor (GIST).


METHODS
Eight hundred and forty cases of GIST were retrospectively reviewed. The tumors were classified as malignant if they met any of the following criteria: evidence of gross dissemination (including liver metastasis and/or peritoneal spread), evidence of microscopic dissemination (including lymph node metastasis, infiltration to vessels, fat tissue, nerves and/or mucosal tissue), or disease relapse. The remaining cases were provisionally classified as tumors of uncertain biologic behavior. A number of morphologic parameters were then evaluated under light microscopy and univariate and multivariate analyses were adopted for this study.


RESULTS
Histologic findings correlated with evidences of the following morphologic parameters were considered in accord with the criteria of the malignant behavior: mitotic count>or=10 per 50 high-power fields (P<0.01), muscle infiltration (P<0.01), coagulative necrosis (P<0.01), perivascular growth pattern (P=0.005) and remarkable nuclear atypia (P=0.014). Basing on the above criterion, 485 cases were re-classified as "malignant" and 355 cases "non-malignant". Follow-up data showed that the five-year disease-free survival and overall survival in the "non-malignant" group were 99.3% and 100% respectively, in contrast to 43.9% and 59.7% respectively in the "malignant" group (P<0.01).


CONCLUSIONS
The set of clinicopathologic parameters is useful in predicting the malignant behavior of GIST and prognosis.
Hou
Ying-yong
YY
Department of Pathology, Zhongshan Hospital, Fudan University, Shanghai 200032, China. houyingyong@hotmail.com
Zhu
Xiong-zeng
XZ
Lu
Shao-hua
SH
Zhou
Yang
Y
Hou
Jun
J
Tan
Yun-shan
YS
Shen
Kun-tang
KT
Qin
Jing
J
Sun
Yi-hong
YH
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D046152:Gastrointestinal Stromal Tumors / Q000145:classification* / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000556:secondary; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D010529:Peritoneal Cavity / Q000473:pathology*; D012189:Retrospective Studies; D018570:Risk Assessment; D015996:Survival Rate; D055815:Young Adult