Richter KK, Fink LM, Hughes BM, Shmaysani HM, Sung CC, Hauer-Jensen M. Differential effect of radiation on endothelial cell function in rectal cancer and normal rectum.
Am J Surg 1998;
176:642-7. [PMID:
9926806 DOI:
10.1016/s0002-9610(98)00280-3]
[Citation(s) in RCA: 39] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND
Chronic radiation injury of the intestine is associated with significant underexpression of a potent physiological anticoagulant, endothelial cell thrombomodulin (TM). This study compared early and late radiation-induced changes in endothelial TM, urokinase plasminogen activator (uPA), and transforming growth factor beta (TGF-beta) in normal rectum and tumors.
METHODS
Rectal resection specimens from 27 patients were analyzed: Nine patients underwent primary resection of rectal cancer, 11 tumors were resected after neo-adjuvant radiotherapy, and 7 because of local recurrence after prior resection and adjuvant radiotherapy. TM, uPA, and extracellular matrix-associated TGF-beta, immunoreactivity were assessed using computerized image analysis.
RESULTS
Multivariate analysis revealed that tumors had more TM-positive vessels (P = 0.003), more uPA-positive cells (P <0.001), and higher TGF-beta immunoreactivity levels (P <0.001) than normal rectum. Preoperative irradiation was associated with decreased proportions of TM-positive vessels in tumors (P = 0.003) and normal rectum (P <0.001). Irradiated tumors had fewer uPA-positive cells (P = 0.003) and less TGF-beta immunoreactivity (P = 0.001) than unirradiated tumors. The proportion of TM-positive vessels in irradiated rectum from patients with recurrence was decreased (P = 0.03), whereas the recurrent (ie, unirradiated) tumors did not differ from primary tumors in terms of TM, TGF-beta, or uPA immunoreactivity.
CONCLUSIONS
The results support a role for endothelial dysfunction in the pathogenesis of radiation proctitis. Maintaining endothelial cell anticoagulant function may be a potential method to optimize the therapeutic ratio of adjuvant radiotherapy of rectal cancer.
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