PATHOLOGY & ONCOLOGY RESEARCHVol. 13 No. 3, 2007

 Article

Expression of P-glycoprotein and Metallothionein in Gastrointestinal Stromal Tumor and Leiomyosarcomas. Clinical Implications

Sofia PÉREZ-GUTIÉRREZ1, Ricardo GONZÁLEZ-CÁMPORA2, Joaquín AMÉRIGO-NAVARRO3, Antonio BEATO-MORENO4, María SÁNCHEZ-LEÓN2, Jesús María PAREJA MEGÍA2, Juan Antonio VIRIZUELA-ECHABURU5, Antonio LÓPEZ-BELTRÁN6

1Pathology Service, Juan Ramón Jiménez Hospital, Huelva, Spain
2Department of Pathology, Virgen Macarena University Hospital and University of Seville Medical School, Seville, Spain
3Pathology Service, Hospital Torrecárdenas, Almería, Spain
4Department of Statistic and Operations Research, University of Seville, Seville, Spain
5Oncology Service, Virgen Macarena University Hospital, Seville, Spain
6Department of Pathology, Reina Sofia University Hospital and Córdoba University Medical School, Córdoba, Spain

 

We investigated the expression of P-glycoprotein (P-GP) and metallothionein (MT) in a series of 92 GIST and 14 gastrointestinal leiomyosarcomas (GILMS) with the purpose to expand our knowledge on the biological bases of GIST chemo-resistance and to ascertain their significance in patients’ prognosis. P-GP expression was more frequent in GIST than in GI-LMS (83.7% vs. 21.4%, p<0.001), with no difference between low- and high-risk GIST (p=1.000) or low- and high-grade GI-LMS (p=0.538). P-GP expression was unrelated to anatomic location (gastric vs. intestinal) in GIST (39/45 vs. 35/43, p=0.770) and in GI-LMS (0/2 vs. 2/6, p=1.000). MT expression was non-significantly higher in GI-LMS than in GIST (35.7% vs. 14.1%, p=0.060), with no difference between low- and high-risk GIST (p=1.000) or low- and high-grade GI-LMS (p=1.000). MT expression was unrelated to the anatomic location (gastric vs. intestinal) in GIST (7/45 vs. 6/43) and GI-LMS (0/2 vs. 1/6) (p=1.000 and p=0.1000, respectively). Overall tumor-specific survival (p< 0.001) and disease-free survival (p<0.001) were different in GIST as compared with GI-LMS, and the number of events was higher in GI-LMS. When the survival analysis took into consideration P-GP or MT expression, the overall survival in GIST was influenced by the expression of MT (p=0.021) but not by that of P-GP (p=0.638). However, in GI-LMS, P-GP expression influenced disease-free survival (p=0.050); in addition, it is important to recognize the limited value of these results because of the low number of cases involved in the study. Differential expression of P-GP and MT might explain the known variability in response to systemic chemotherapy in these tumors. Detection of P-GP and MT seems to add certain prognostic value in GIST (MT) or GI-LMS (P-GP). Pathology & Oncology Research, Vol 13, Nr 3, 203-208, 2007

Key words: gastrointestinal stromal tumors; GIST; leiomyosarcomas; P-glycoprotein; metallothionein


Received: Oct 17, 2006; accepted: Jul 10, 2007
Correspondence: Ricardo GONZÁLEZ-CÁMPORA, Department of Pathology, Virgen Macarena University Hospital and University of Seville Medical School, Avda, Dr. Fedriani s/n Seville 41009, Spain; Tel: 34 955008556, Fax: 34 954371284; E-mail: rcampora@us.es

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