Abstract
Glutathione S‐transferase M (GSTM) family is concerned with oxidative stress, which is associated with breast carcinogenesis and chemotherapy response. The null polymorphism of GSTM1 gene results in a thorough absence of the enzyme function. Our study was to evaluate the association between GSTM1 null/present polymorphism and chemotherapy treatment outcome in breast cancer patients. A total of unrelated 714 patients with a histologically confirmed breast cancer were randomly selected from two independent cancer centers. Polymerase chain reaction was performed to analyze null/present genotypes of GSTM1 in our study. Our study found that the present genotype of GSTM1 was associated with a better relapse‐free survival (RFS) (P = .03) with adjusted hazard ratio (HR) [95% confidence interval (CI)] of 0.63 (95% CI: 0.42‐0.93). The present genotype of GSTM1 was significantly correlated with a better RFS compared with the null genotype in the nonchemotherapy group (HR = 0.17, 95% CI: 0.06‐0.50; P = 0.001), but no effect was observed in the chemotherapy group (HR = 0.81, 95% CI: 0.52‐1.26; P = 0.35). Moreover, the interaction between the GSTM1‐null/present genotype and adjuvant chemotherapy was significant (P = 0.04) in further analysis. Our study suggests that the GSTM1 polymorphism plays a complex role in influencing the chemotherapy response and breast cancer survival. It is suggested that the GSTM1‐present genotype might prevent progression in breast cancer patients. In the meanwhile, it could damage the benefit of adjuvant chemotherapy as well in certain ways.
Highlights
It is well-k nown that internal estrogens and their metabolites have a tight association with carcinogenesis of the breast in human beings
We evaluated the role of GSTM1-null/present polymorphism in the treatment outcome of patients with breast cancer, and we investigated whether this effect would be influenced by adjuvant chemotherapy or not
The present of GSTM1 was significantly correlated with better relapse-free survival (RFS) compared with the null genotype in the nonchemotherapy group (HR = 0.17, 95% confidence interval (CI): 0.06- 0.50, P = .001), but this effect was not preserved in the adjuvant chemotherapy group (HR = 0.81, 95% confidence intervals (95% CIs): 0.52-1 .26, P = .35), with a significant P-value of .04 for interaction between the GSTM1 genotype and adjuvant chemotherapy
Summary
It is well-k nown that internal estrogens and their metabolites have a tight association with carcinogenesis of the breast in human beings. Estrogen-q uinones and their generated oxidative stress play an important role in this process.[1]. We hypothesize that GSTM1-null/ present polymorphism may have an influence on breast cancer progression and chemotherapy treatment response. The underlying relationship between oxidative stress and breast cancer prognosis is sort of complicated in the current understanding. To some extent, the factor whether a patient undergoes chemotherapy or not may cause controversial influences of GSTM1 polymorphism on breast cancer progression and prognosis. We evaluated the role of GSTM1-null/present polymorphism in the treatment outcome of patients with breast cancer, and we investigated whether this effect would be influenced by adjuvant chemotherapy or not
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
