Synovial sarcoma: immunohistochemical expression of P-glycoprotein and glutathione S transferase-pi and clinical drug resistance

Pathol Res Pract. 1997;193(1):21-36. doi: 10.1016/s0344-0338(97)80090-8.


Our purpose was to study the role of the expression of P-glycoprotein (Pgp) and glutathione S transferase-pi (GST-pi) in predicting the response to chemotherapy, relapse-free interval, and survival of patients with synovial sarcoma (SS). Thirty-seven cases of primary SS, without regional lymph node or distant metastases, were studied. There were 17 females and 20 males, ranging in age from 7 to 81 years (median, 31 years) with tumors located in the lower extremity (n = 24) upper extremity (n = 5) and trunchus (n = 8). The cases were retrospectively studied without knowledge of clinical course to compare the immunohistochemical expression of Pgp and GST-pi, flow cytometry parameters (ploidy and % of cells in S+G2 phases), and PCNA and Ki-67 labeling of primary tumors before any therapy, with that observed in local recurrences and metastases after chemotherapy. The relationship of the aforementioned parameters with clinicopathological features (gender, age, and histo-blood group of the patients, size, location, histological subtype. TNM stage, and clinical response to chemotherapy of the tumors) was also evaluated. Results revealed that Pgp and GST-pi were expressed in 29.7% and 40.5% of the cases, respectively. In 48.6% of the tumors there was expression of a least one of the drug resistance markers. The markers were coexpressed in 25.0% of the tumors. The prevalence of Pgp expression was lower, but not significantly, in stage I-II (17.6%) than in stage III (40.0%) tumors, and also in cases without clinical progression (16.7%), than in cases with (36.0%). No such differences were observed for GST-pi expression. Pgp and GST-pi expressions were significantly associated with biphasic SS and were particularly noticeable in solid/glandular areas of biphasic SS. The expression of the drug resistance markers was not significantly associated with gender, age, and histo-blood group of the patients, dimension, location, and proliferative activity of the tumors; it was also not significantly related to relapse-free interval and survival of the patients. The expression of Pgp and GST-pi was not significantly associated either to response to chemotherapy or influenced by chemotherapy. We conclude that Pgp and GST-pi expressions are not good predictors response to of the chemotherapy in patients with localized SS. Other drug resistance mechanisms may be active in SS.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP Binding Cassette Transporter, Subfamily B, Member 1 / biosynthesis*
  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Biomarkers, Tumor / biosynthesis
  • Child
  • DNA, Neoplasm / analysis
  • Drug Resistance, Neoplasm*
  • Female
  • Flow Cytometry
  • Glutathione S-Transferase pi
  • Glutathione Transferase / biosynthesis*
  • Humans
  • Immunohistochemistry
  • Isoenzymes / biosynthesis*
  • Joint Diseases / drug therapy
  • Joint Diseases / metabolism*
  • Joint Diseases / pathology
  • Male
  • Middle Aged
  • Retrospective Studies
  • Sarcoma, Synovial / drug therapy
  • Sarcoma, Synovial / metabolism*
  • Sarcoma, Synovial / pathology
  • Soft Tissue Neoplasms / drug therapy
  • Soft Tissue Neoplasms / metabolism*
  • Soft Tissue Neoplasms / pathology
  • Survival Rate


  • ATP Binding Cassette Transporter, Subfamily B, Member 1
  • Biomarkers, Tumor
  • DNA, Neoplasm
  • Isoenzymes
  • GSTP1 protein, human
  • Glutathione S-Transferase pi
  • Glutathione Transferase