The expression of insulin receptor substrate 1 and estrogen receptor as prognostic factor on breast cancer patient
Hyun Goo Kim1, Sang Uk Woo1, Hoon Yub Kim1, Gil Soo Son1, Jae Bok Lee1, Jeong Won Bae1, Ok Hee Woo2, Dae Sik Yang3, Jae Hong Seo4, Ae-Ree Kim5
1 Department of Surgery, Korea University, Seoul, South Korea
2 Department of Diagnostic Radiology, Korea University, Seoul, South Korea
3 Department of Radiation Oncology, Korea University, Seoul, South Korea
4 Department of Internal Medicine, Korea University, Seoul, South Korea
5 Department of Pathology, Korea University, Seoul, South Korea
Sang Uk Woo
Department of Surgery, Korea University, Guro Hospital, 97 Gurodong-Gil, Guro-Ku, Seoul
Source of Support: None, Conflict of Interest: None
Background: Insulin receptor substrate 1 (IRS-1) has been known to be an associated factor with breast cancer progression. However, there has been little study with respect to the relationship between the expression of IRS-1 and breast cancer prognosis in clinical practice. In this study, we evaluated the impact of the estrogen receptor (ER) and IRS-1 on the recurrence and survival of breast cancer patients.
Methods: We analyzed the pathologic finding of 376 tissue samples from breast cancer patients who received proper treatment between January 1990 and December 2006 using the tissue microarray. We measured the expression of ER and IRS-1 by immunohistochemistry staining and analyzed the difference of recurrence and survival rate in each subgroup of ER and IRS-1.
Results: Our results show that there is a significant difference of disease-free survival (DFS) according to ER and IRS-1 subgroups with both univariate and multivariate analyses. Specifically, ER-positive and IRS-1-positive breast cancer samples showed improved DFS compared to ER-positive and IRS-1-negative breast cancer (adjusted hazard ratio: 2.17; 95% confidence interval: 1.15–4.09; P = 0.01). There was a difference of overall survival according to ER and IRS-1 subgroups by univariate analysis (P = 0.01), but not by multivariate analysis (P = 0.36).
Conclusion: ER and IRS-1 subgroups appear to be critical factors for the prediction of breast cancer recurrence. In particular, we suggest that the patients who have ER-positive and IRS-1-negative breast cancer undergo more aggressive treatment because they have poorer prognoses.