Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection.
OBJECTIVE
The pathogenic role of alteration of cell-cycle proteins in rectal stromal tumors (GISTs) remains unclear. This study aimed to elucidate the prognostic role of p21 to compare with p53, PCNA, and Ki-67 in rectal GISTs.


METHODS
Forty-nine surgically resected CD117 (+) rectal GISTs were enrolled from 1986 to 2006. Immunohistochemical studies were performed with antibodies of p21, p53, PCNA, and Ki-67.


RESULTS
The labeling index (LI) of immunoreactivities range from 0% to 65% for p53, 0% to 60% for p21, 0% to 67% for Ki-67, and 30% to 93% for PCNA. LI of four markers were positively correlated (P < 0.05). LI of four markers were also positively correlated with tumor mitosis and tumor size (P < 0.05). Tumors with high p53, p21, or Ki-67 LI were associated with increased NIH risk, non-spindle cell type, and high cell pleomorphism (P < 0.05). Survival analyses demonstrated that large tumor size (P = 0.012), high tumor mitosis (P < 0.001), increased NIH risk (P = 0.003), high cell pleomorphism (P = 0.004), high p53 LI (P = 0.005), high p21 LI (P = 0.009), high PCNA LI (P = 0.001), and high Ki-67 LI (P = 0.042) were poor prognostic factors for disease-specific survival.


CONCLUSIONS
Elevated p21 expression is associated with poor prognosis of rectal stromal tumors after resection.
Hu
Tsung-Hui
TH
Division of Hepato-Gastroenterology, Department of Internal Medicine, Chang Gung Memorial Hospital, Kaohsiung Medical Center, Chang Gung University College of Medicine, Taiwan. hutsh@ms32.hinet.net
Tai
Ming-Hong
MH
Chuah
Seng-Kee
SK
Chen
Hong-Hwa
HH
Lin
Jui-Wei
JW
Huang
Hsuan-Ying
HY
Chou
Yeh-Pin
YP
Yi
Li-Na
LN
Kuo
Chung-Mou
CM
Changchien
Chi-Sin
CS
D000328:Adult; D000367:Age Factors; D000368:Aged; D014408:Biomarkers, Tumor / Q000378:metabolism; D002467:Cell Nucleus / Q000473:pathology; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000378:metabolism* / Q000401:mortality* / Q000473:pathology; D006801:Humans; D007150:Immunohistochemistry; D019394:Ki-67 Antigen / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008940:Mitotic Index; D009364:Neoplasm Recurrence, Local / Q000401:mortality; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism; D019009:Proto-Oncogene Proteins c-kit / Q000378:metabolism*; D012004:Rectal Neoplasms / Q000378:metabolism* / Q000401:mortality* / Q000473:pathology; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D014408:Biomarkers, Tumor; D050759:Cyclin-Dependent Kinase Inhibitor p21; D019394:Ki-67 Antigen; D018809:Proliferating Cell Nuclear Antigen; D016159:Tumor Suppressor Protein p53; D019009:Proto-Oncogene Proteins c-kit