© 2004 Foundation for Promotion of Cancer Research
Prognostic Implications of the Expression of erbB2, Topoisomerase II
and Thymidylate Synthase in Metastatic Gastric Cancer After Fluorouracil-based Therapy
1 Division of Cancer Research, National Health Research Institutes, 2 Pathology Department and 3 Surgery Department, Veterans General Hospital-Taipei, 4 National Yang Ming University Medical School and 5 Department of Internal Medicine, Kaohsiung Medical University Hospital, Taipei, Taiwan
For reprints and all correspondence: Jacqueline M. Liu, Division of Cancer Research, National Health Research Institutes, c/o A191 Taipei-Veterans General Hospital, Shipai Rd, Sect 2, no. 201, Taipei, Taiwan. E-mail: jmliu{at}nhri.org.tw
Received July 1, 2004; accepted October 9, 2004
Objective: This retrospective study aimed to ascertain the expression of erbB2 in relation to topoisomerase II
(T2
) and thymidylate synthase (TS) markers in 30 consecutive metastatic gastric cancer patients with a specimen available for study.
Methods: All patients had been entered on consecutive chemotherapeutic clinical trials that were all 5-fluorouracil based. The specimens were evaluated by fluorescence in situ hybridization to ascertain erbB2 and T2
gene amplification, and by immunohistochemical staining for T2
and TS protein expression.
Results: erbB2 amplification was detected in 16.7% of specimens, with co-amplification of the T2
gene in 40%, and 44% had undetectable TS protein expression. KaplanMeier survival curves showed significantly prolonged overall survival in patients with erbB2 and T2
gene amplification, T2
protein overexpression and absence of TS protein expression (P = 0.0011, P = 0.0048, P = 0.0061 and P = 0.0267, respectively, by log rank test). There was a positive correlation between erbB2 amplification and T2
amplification, T2
protein overexpression, and a trend towards absence of TS expression (P = 0.0001, P = 0.003 and P = 0.066 by Fisher's exact test).
Conclusion: High dose fluorouracil/leucovorin-based chemotherapy may have the potential to reverse the adverse effects resulting from erbB2 gene amplification in gastric cancer.
Key Words: gastric cancer erbB2 topoisomerase II
survival thymidylate synthase