Prognostic analysis of rectal stromal tumors by reference of National Institutes of Health risk categories and immunohistochemical studies.
OBJECTIVE
Prognostic analysis of stromal tumors focusing on the rectal area is rarely performed. This study elucidated prognostic factors by referencing biomarkers of Ki67 and p53.


METHODS
Forty-nine surgically resected rectal stromal tumors were collected from 1986 to 2006. Immunohistochemical studies were performed with antibodies of CD117, CD34, smooth muscle actin, desmin, S100, Ki67, and p53.


RESULTS
The immunoreactivities were: CD34, 83.6 percent; smooth muscle actin, 28.5 percent; S100, 4.1 percent; desmin,16.3 percent;, Ki67, 30.6 percent;, and p53 34.7 percent. Both p53+ and Ki67+ tumors were associated with increased tumor mitosis, increased tumor size, nonspindle cell type, and increased cell pleomorphism (P < 0.05). Increased National Institutes of Health risk was associated with old age, nonspindle cell types, and severe nuclear pleomorphism (P < 0.05). Survival analysis demonstrated that older patients (P = 0.0039), large tumor size (P = 0.003), high mitotic count (P < 0.001), increased risk categories (P < 0.001), high cell pleomorphism (P = 0.003), p53+ (P = 0.007), and Ki67 + (P = 0.002) were prognostic factors for poor disease-free survival. An independent prognostic factor was tumor mitotic count.


CONCLUSIONS
This study demonstrated the prognostic role of Ki67 and p53 in rectal stromal tumors. Notably, tumor mitosis was superior for prognostic prediction compared to National Institutes of Health risk categories.
Tsai
Ming-Chao
MC
Division of Hepato-Gastroenterology, Department of Internal Medicine, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, 123, Ta-Pei Road, Niao-Sung Hsiang, 833, Kaohsiung, Taiwan.
Lin
Jui-Wei
JW
Lin
Shung-Eing
SE
Chen
Hong-Hwa
HH
Lee
Chuan-Mo
CM
Hu
Tsung-Hui
TH
D000199:Actins / Q000378:metabolism; D018952:Antigens, CD34 / Q000378:metabolism; D014408:Biomarkers, Tumor / Q000378:metabolism*; D003893:Desmin / Q000378:metabolism; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism* / Q000473:pathology; D006801:Humans; D007124:Immunoenzyme Techniques; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D011379:Prognosis; D016016:Proportional Hazards Models; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000473:pathology; D009418:S100 Proteins / Q000378:metabolism; D018709:Statistics, Nonparametric; D015996:Survival Rate; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D000199:Actins; D018952:Antigens, CD34; D014408:Biomarkers, Tumor; D003893:Desmin; D019394:Ki-67 Antigen; D009418:S100 Proteins; D016159:Tumor Suppressor Protein p53; D019009:Proto-Oncogene Proteins c-kit