Expression of PRL proteins at invasive margin of rectal cancers in relation to preoperative radiotherapy.
OBJECTIVE
PRL-3 (phosphatase of regenerating liver) is involved in metastasis of colorectal cancer; however, its therapeutic implication in cancer patients has not been studied. We investigated the relationships of PRL expression to radiotherapy (RT) in rectal cancer patients.


METHODS
Phosphatase of regenerating liver expression was immunohistochemically examined in distant (n = 36) and adjacent (n = 82) normal mucosa, primary tumor (n = 125), biopsy specimens (n = 96), and lymph node metastasis (n = 30) from rectal cancer patients participating in a clinical trial of preoperative RT.


RESULTS
Phosphatase of regenerating liver expression was increased from the distant to adjacent mucosa and to the primary tumor (p < 0.05). PRL was highly expressed at the invasive margin in 28% of the primary tumors and 26% of the metastases. In the RT group, strong PRL expression at the invasive margin was related to distant recurrence (p = 0.006) and poor survival (p = 0.01), but not in the non-RT group. The survival significance remained even after adjusting for Dukes' stage and differentiation (p = 0.02). Additional multivariate analyses showed that the correlation with prognostic significance of PRL differed between the RT and non-RT groups (p = 0.01).


CONCLUSIONS
Phosphatase of regenerating liver expression (rather than PRL-3 alone) at the invasive margin predicted resistance to RT and unfavorable survival in rectal cancer patients with preoperative RT.
Wallin
Asa R
AR
Department of Oncology, Institute of Biomedicine and Surgery, University of Linköping, Linköping, Sweden.
Svanvik
Joar
J
Adell
Gunnar
G
Sun
Xiao-Feng
XF
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016009:Chi-Square Distribution; D005260:Female; D006801:Humans; D007413:Intestinal Mucosa / Q000201:enzymology* / Q000528:radiation effects; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009362:Neoplasm Metastasis; D009363:Neoplasm Proteins / Q000032:analysis*; D009367:Neoplasm Staging; D011379:Prognosis; D016016:Proportional Hazards Models; D017027:Protein Tyrosine Phosphatases / Q000032:analysis*; D012004:Rectal Neoplasms / Q000201:enzymology* / Q000473:pathology / Q000532:radiotherapy*; D012007:Rectum / Q000201:enzymology
D009363:Neoplasm Proteins; D017027:Protein Tyrosine Phosphatases