Significance of thymidine phosphorylase expression in stromal cells around invasive front of rectal cancer.
OBJECTIVE
Thymidine Phosphorylase (TP) expression in the tumor cells correlates with postoperative recurrence, but the significance of its expression in the stromal cells around the invasive front of the tumor is not clarified.


METHODS
This study was conducted on 95 patients with T2 (n=34) or T3 (n=61) rectal cancer for whom curative surgical resection was performed between 1998 and 2002. As a control, appendix vermiform of twenty patients excised for acute appendicitis during the same period was analyzed. Paraffin-embedded sections of their surgical specimens were immunostained for TP and Vascular Endothelial Growth Factor (VEGF). Relationship between expression level of the binary angiogenic factors and malignant potential were evaluated.


RESULTS
There was a strong relationship between TP expression in the malignant cells at the invasive front of the tumor and depth of tumor invasion. TP expression in the stromal cells was very high regardless of the status of the depth of tumor invasion. TP expressions in the stromal cells in the appendix with inflammation were also very high, which was detectable both in the nucleus as well as in the cytoplasm.


CONCLUSIONS
TP expression in the stromal cells may seem to reflect local immunoreactions, rather than tumor anginogenesis.
Kobayashi
Tetsuya
T
Department of Surgery, Jikei University School of Medicine, Nishi-Shinbashi 3-25-8, Minato-ku, Tokyo 105-8461, Japan.
Kawahara
Hidejiro
H
Koido
Shigeo
S
Kobayashi
Susumu
S
Kashiwagi
Hideyuki
H
Yanaga
Katsuhiko
K
D000230:Adenocarcinoma / Q000201:enzymology* / Q000473:pathology; D000368:Aged; D001064:Appendicitis / Q000201:enzymology / Q000473:pathology; D003593:Cytoplasm / Q000201:enzymology; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000201:enzymology; D012004:Rectal Neoplasms / Q000201:enzymology* / Q000473:pathology; D017154:Stromal Cells / Q000201:enzymology*; D013939:Thymidine Phosphorylase / Q000096:biosynthesis*; D042461:Vascular Endothelial Growth Factor A / Q000096:biosynthesis
D042461:Vascular Endothelial Growth Factor A; D013939:Thymidine Phosphorylase